CN1229373A - Permanent-magnetic hydrodynamic methods and apparatus for stabilizing continuous casting belt - Google Patents

Abstract

Permanent-magnetic hydrodynamic methods and apparatus stabilize a moving, flexible, thin-gauge, heat-conducting, magnetically soft ferromagnetic casting belt (50) against thermal distortion while moving along a mold cavity (C) being heated at its front surface by heat coming from molten metal being cast while being cooled at its reversed surfaces by flowing pumped liquid coolant. Hydro-magnetic devices (38) are arranged in an array (51) wherein flows of pumped coolant (93) pass through fixedly throttling passageways (90) feeding pressure pockets facing the belt's reverse surface. These pockets are shown rimmed by magnetic pole faces (34). Coolant issues from the pressure pockets as fast-moving films to cool the belt's reverse surface and levitate the belt spaced from the pole faces while the belt is stabilized in even condition by powerful reach-out magnetic attraction forces.

Description

Permanent magnetohydrodynamic method and apparatus for stabilizing continuous casting strip

The present invention relates to the field of continuous casting of molten metal poured into a continuous belt caster employing one or more endless, flexible, moving, heat-conducting casting belts, e.g. metal casting belts, defining A moving mold cavity or mold space along which the one or more casting belts move and, at the same time, zone by zone of each casting zone enters the mold cavity along which the crystallization The mold cavity moves and then leaves the moving crystallizer cavity. Such continuously cast products are usually continuous slabs, plates, sheets or strips or generally rectangular continuous rods.

More specifically, the present invention relates to a permanent magnetohydrodynamic method and apparatus for stabilizing movement of a flexible, thin, thermally conductive soft magnetic casting strip against thermal deformation, such casting strip moving along a mold cavity, which The front surface is heated by the heat from the molten metal, while the reverse side is cooled by pumped flowing liquid coolant.

In continuous casting of molten metal in a caster employing at least one moving flexible thin heat-conducting belt, such as a metal casting belt, it is extremely important that despite the presence of hot metal and due to the hot metal entering the front of the belt The high temperature caused by the surface, and the thermal stress of the casting belt caused by the cooling of the opposite side by an appropriate coolant, the moving casting belt can still keep traveling along a predetermined required path, and the casting belt itself is required to be uniform and straight of. Continuous casting of molten metal in a caster employing at least one such casting belt is often affected by thermally induced buckling, twisting, buckling, or wrinkling (referred to as "distortion") of the casting belt. Heat-induced transverse twisting and buckling in such cast strips are illustrated in Figure 8 of each of Hazelett et al. U.S. Patent 3,937,271; 4,002,197; 4,062,235; and 4,082,101 and in Figure 5 of Allyn et al. U.S. Patent 4,749,027. This also causes overheating warpage and buckling in the cast strip. The occurrence of these strip deformations can be very sudden, like the popping sound of a vacuum vessel when air suddenly enters the vessel when the cover is just opened. Moreover, this deformation is often irregular, unpredictable in the degree and location of deformation in the cast strip, which should be smooth and free of deformation as it moves along the mold cavity of.

This thermally induced deformation is most likely to occur near the input region of the mold cavity, where the moving belt is first subjected to the intense heating of the molten metal entering the moving mold cavity or just entering the mold cavity. Initial solidification of the molten metal occurs or begins near the input region, during which deformation of the cast strip may result in a cast product containing cracks, pits or segregation of alloy components. These defects in cast products can lead to problems in their strength, formability, and appearance.

In US Patent 2,640,235 (column 7), C.W. Hazelett discloses an upper and lower cooling assembly for upper and lower cooling belts. These cooling assemblies operate in the same manner, while each cooling assembly consists of a plate of some suitable easily magnetizable material which forms the soft magnetic core of an electromagnet. When a plate is magnetized due to an electric current, its effect is to pull a strip towards itself. To prevent this movement of the strip to the plate, copper or brass spacers are used which make a cavity between the strip and the plate. Cooling water is introduced into this chamber to cool the belt. Although the cooling water is introduced with considerable pressure and is usually sufficient to deform the belt, it is stated in the patent specification that this deformation does not occur because the magnetic plates supporting the belt rest firmly against the rigid spacers . The specification states that with this method it is possible to cool the strip while simultaneously guiding and supporting it against deformation so that the exact dimensions of the product can be guaranteed.

U.S. Patent 3,933,193 by William Baker et al discloses an apparatus for continuous casting of metal strip between moving casting belts. The casting strip is held tightly against the support surface by means of an attractive force caused by a negative pressure on the opposite side of the casting strip or by means of a magnetic force for the same purpose.

Olivio Sivilotti et al. in U.S. Patent 4,190,103 (at column 2, lines 38-44) state: "Therefore, in one embodiment of the apparatus described above, the casting belt is opposed to the The surface of the adjacent support is pulled. Another arrangement is to provide a magnetic member acting on a ferromagnetic casting belt through the ferromagnetic support to keep the casting belt on the desired path."

The assignee of the present invention, Hazelett Strip-Casting Corporation, has conducted experiments with fixed electromagnetically supported finned sliders in sliding contact with the opposite side of the moving casting strip, but they were not feasible from the standpoint of excessive wear and friction. Does not have sufficient performance to justify its persistence. Furthermore, these electromagnetic fin sliders have not been successful in reliably maintaining or stabilizing the moving casting belt in a straight condition.

We have found that the magnetic devices described by C.W. Hazelett, Sivilotti et al., or Baker et al. in the aforementioned patents have not found practical application in the continuous casting industry of molten metals, because as cast strips or strips with magnetic devices Magnetic attraction as a function of the gap (gap) between, i.e., too fast and/or too sharp a weakening of the tension on the cast strip or strip that would otherwise attempt to displace the thermally induced deformation of the moving cast strip or strip The part is pulled back to the predetermined desired straightness. The magnetic attraction (pull force) of these prior devices cannot extend across large gaps and is therefore not suitable for pulling back to a flat condition cast or strip portions that have deviated significantly from the desired flat state due to thermally induced deformation. There is a lack or deficiency here of what we call reach-out attraction, a lack or deficiency of reach-out pull.

Baker et al. neither disclose nor suggest the importance of what we have found to be termed "stick out attraction" (ie, "stick out pull").

In our invention, the device extension force is provided by means of the unique permanent magnetic material described herein placed in the magnetic circuit, as previously described, to extend and span the pole surface of the magnetic circuit with a soft magnet The space (gap) between moving, flexible thin plate-shaped heat-conducting cast strips made of magnetic material, so as to pull the thermally deformed part of the cast strip towards the surface of the magnetic pole to maintain the cast strip in the specified required stable flat state Within limits, as will be explained below, in this state the strip is hydrodynamically supported by the injected coolant flow, whereby the stabilized strip is cooled by the injected coolant and rapidly advancing cooling The repulsive force exerted by the liquid floats and moves along its predetermined path while being suspended in a stable and straight state, and the casting belt neither slides relative to the fixed object nor is it worn by the fixed object, but along the moving along a water film that is essentially frictionless.

In some preferred embodiments of the present invention, comprising a plurality of hydro-magnetic devices arranged in an array, wherein the injected coolant flow is directed through fixed throttle channels as throttle nozzles facing the opposite side of the casting strip pressure tank. These coolant streams are sprayed from throttle nozzles close to or surrounded by the pole surface, using the coolant escaping (spraying) from the pressure groove to exert a repulsive force on the opposite side of the casting belt, and the sprayed coolant Have the shape of a fast moving coolant film radiating from the pressure slots and moving forward between the opposite side of the moving cast belt and the pole face. These fast-moving films cool the strip and exert a hydrodynamic force that pushes against the opposite side of the moving strip to support and hold the strip a certain distance (float) from the coolant-jet pole surface, while at the same time, through The strong magnetic attraction (pull) extending from these poles and across the gap to the moving casting belt stabilizes the casting belt in a straight state. Thus, the pumped liquid coolant is throttled twice. When it is injected into the pressure groove facing the casting belt through the fixed throttle channel, it is throttled once. It is throttled again as it flows out of these slots and across the pole faces surrounding the slots. In fact, the coolant is sprayed in the form of a fast-moving coolant film across the gap between the cast strip and the pole surfaces, which surround the pressure slots and act like coolant injection surfaces.

The hydromagnetic devices in these arrays include powerful permanent magnets constructed of unique permanent magnetic materials. These magnets located in the magnetic circuit in each array provide projecting magnetic attractions with exceptional properties which we believe are critical to the successful performance of the disclosed embodiments of the invention. The extremely strong magnetic potential provided by this permanent magnet (which has an extremely high maximum energy product in MegaGauss-Oersteds) is not, in our opinion, in these arrays or "pads" of hydromagnetic devices The sole reason for the successful operation in the magnetic circuit in . Another feature that we consider extremely critical to their successful operation is their extremely low demagnetization permeability, so low that it is about the same size as air and water or a vacuum order of magnitude. This very low demagnetization permeability, as disclosed, causes the pole surfaces and the poles of the magnetic circuit to exert an extremely strong magnetic attraction force (pull force) on a moving flexible thin thermally conductive cast strip containing soft magnetic magnetic material, Instead, these attractive forces extend (protrude) relatively far from the pole surface and extend through the gap (gap) between the pole surface filled with air and/or water and the moving casting belt. The magnets in the magnetic circuit provide an array of coplanar pole surfaces with alternating north and south poles facing the opposite side of a moving flexible thin thermally conductive cast strip containing soft ferromagnetic material.

In the preferred embodiment of the invention we take advantage of the variable repulsive force (thrust) inherent in the pumped coolant which is ejected from the throttled nozzle of the hydromagnetic device and which provides the force of motion applied across the pole surface. Cast with a fast-traveling coolant film on the reverse side. These repulsive forces fall off faster as a function of the increased gap (increased gap) between the backside of the cast strip and the pole surface over which the fast-moving coolant film flows. These repulsive forces are balanced by a projecting attractive (pull) force acting on the moving cast belt at the same location by the pole surfaces, which decreases relatively slowly as a function of the increasing gap. The balanced beneficial interplay between the faster-falling repulsive effect and the slower-falling pull-out magnetic pull levitates the moving cast belt, which is reliably stabilized within defined limits thanks to the pull/push balance . Thus the cast strip is forced to levitate and stabilized in a flat state, supporting (floating) the throttled pressurized coolant in the pressure tank and the fast moving coolant overflow film traveling in the space between the pole surfaces on the opposite side of the cast strip superior.

In these hydromagnetic devices, a specially designed sweep nozzle (sweep nozzle) is used to spray auxiliary coolant at an acute angle to the casting belt to form a unidirectional flow along the opposite side of the casting belt. The gap aids cooling while deflecting, redirecting and eventually clearing the fast-traveling coolant film that has crossed the pole surface.

Thus, by balancing this reach out pull against the hydrodynamic force of the injected liquid coolant ejected from the throttling nozzle in the hydromagnetic device, the opposite side of the moving casting belt is simultaneously in close proximity Pushing forces are applied at the location of the pole surfaces to stabilize the cast strip in suspension (floating) away from the pole surfaces without contact therewith, stabilizing the moving cast strip with the specified desired uniformity and flatness.

This strong stick-out force acting on a thin cast strip of magnetically soft ferromagnetic material behaves differently with conventional materials, even with magnets made of Alnico 5, when a significant gap is created in said magnetic circuit, At gaps such as 1.5mm (0.060 inches), these traditional materials lose most of their appeal.

It is contemplated that any permanent magnetic material can successfully implement embodiments of the present invention, provided that these materials are installed as permanent magnets in a magnetic circuit comprising a soft magnetic ferromagnetic material of opposite polarity An array of magnetic poles whose pole surfaces may face the opposite side of a moving casting belt, while such pole surfaces are in close proximity to throttle nozzles (for example, these pole surfaces surround or are on the edge of the throttle nozzle), and these nozzles may face the casting The opposite side of the band, where the pole surfaces and pole members apply projecting magnetic attraction forces (pull forces) to a moving, flexible, thin, thermally conductive cast band comprising soft magnetic ferromagnetic material, where the projecting The initial value of the magnetic attraction force on the pole surface is strong enough, and at the same time, the projecting magnetic attraction force acts on the cast strip close to the array, as the distance between the cast strip part and the pole surface increases up to 1.5mm (0.060 inch ) as a function of the gap from its initial value falls rather slowly so that the cast strip is forced to be stably supported within an appropriate range of flatness and gap spacing, while the cast strip is hydrodynamically suspended away from the pole surface in On the pressurized coolant flow, which is ejected by the throttle nozzle and as a fast running film from the pressure groove in the throttle nozzle, the film is between the pole surface and the opposite side of the casting belt. flow through the gaps in between.

Rotary means for rotating the permanent magnets can be provided in order to reduce their strong protruding pull on the casting strip when required, by significantly reducing the pulling force it is possible to install and dismount very wide flexible thin casting strips without damaging them. Alternatively, the magnetic flux emanating from the magnets may be shunted by means of a suitable shunt so as to substantially reduce its pull on the strip for proper handling of the strip.

The present invention successfully addresses or substantially overcomes and eliminates long-standing problems in continuous casting machines caused by thermally induced deformation of a moving, endless, flexible, thin, heat-conducting casting belt.

The term "thin" as used herein for thermally conductive cast strips made primarily of steel refers to strips having a thickness of less than one tenth of an inch (about 2.5 mm), and typically less than 0.070 inches (about 2.0 mm).

The magnetic permeability of soft magnetic materials is defined as B/H, where "B" is the magnetic flux density of the material in Gauss, and "H" is the magnetic coercive force of the material in Oersted. As used herein, the term "soft magnetic material" refers to a material having a maximum magnetic permeability at least 500 times that of air, water or vacuum, which has a permeability of about 1. For example, the maximum magnetic permeability of ordinary transformer steel is about 5,450 when the magnetic flux density B is 6000 Gauss and its magnetic coercive force H is about 1.1 Oersted. See CRC Handbook of Chemistry and Physics , 66th Edition, 1985 -1986, page E-155. The phrase "soft magnetic" as used in the term "soft magnetic material" means that the material is relatively easy to be magnetized or demagnetized. Therefore, the adjective "soft" here is opposite to the adjective "hard", which is used for materials that require a large magnetic coercive force for magnetization and demagnetization, so that such materials are difficult to magnetize and demagnetize. Generally, common transformer steels used to make up thin cast strips in twin-belt casters, as well as quarter-hard rolled low-carbon strip steels, fall within the scope of "soft magnetic materials".

In the nomenclature of the American Society for Testing and Materials: A 340-39, Standard Terminology on Symbols and Definitions for Magnetic Testing (ASTM: A 340-39, standard Terminology of Symbols and Dekinitions Relating to Magnetic Testing ), "Residual magnetic susceptibility , Br" is defined as "the magnetic induction value corresponding to zero magnetizing field when the magnetic material is subjected to symmetrical cyclic magnetization conditions".

The permeability of a hard magnetic material is ΔB/ΔH when measured at the relevant useful part of the demagnetization curve, which itself is defined in the B-H hysteresis loop in the second (fourth) quadrant of the normal hysteresis loop line, that is, the B-H loop or part of the B-H curve. "Normal hysteresis loop" is defined in the above-mentioned American Society for Testing and Materials (ASTM) nomenclature.

Other objects, situations, characteristics and advantages of the present invention will be understood through the following detailed description of the preferred embodiments provided with reference to the accompanying drawings, which are only for the purpose of illustration rather than limitation of the present invention, while The drawings are not necessarily to scale but serve to more clearly illustrate the principles of the invention. In particular, it will be described below with regard to twin-belt casters and generally with the bottom carriage of such casters. Corresponding symbols are used throughout the drawings to indicate similar components and parts. The large outline arrows point in the "downstream" direction with respect to the longitudinal direction (upstream-downstream orientation) of the moving mold chamber or mold space, thus, these arrows indicate solidified metal and entry into the moving mold chamber from the inlet The crystallizer space of the body movement flows in the direction of the outlet product flow. The direction of flow of the liquid coolant is usually in the same direction as the solidified metal. Local flow of liquid coolant is indicated by simple single line arrows.

Fig. 1 is a perspective view of a twin-belt casting machine as viewed from the upper outside on the upstream side. This caster is an illustrative example of a relatively wide, medium thin strip type continuous caster in which the invention can be used to great advantage.

Fig. 2 is an enlarged partial perspective view of the hydromagnetic device located on the bottom carriage in an embodiment of the present invention, viewed from the upper downstream side. For greater clarity, in Figure 2 the moving flexible casting belt is shown partially broken. Fig. 2 is a view taken along II-II direction in Fig. 3 and Figs. 4 and 4A.

FIG. 3 is a top view of a hydromagnetic device, three of which are shown in FIG. 2 . In Figure 3, the casting belts and their pulley drums have been omitted for clarity of illustration.

FIG. 3A is a close-up view of a portion of FIG. 3 schematically showing the flow of liquid coolant relative to the lower opposing face of the lower casting belt shown.

Figure 4 is a longitudinal sectional view, viewed from the side of the casting machine, showing a typical hydromagnetic device or a hydromagnetic assembly as it is surrounded by other parts of the lower frame of the belt casting machine shown in Figure 1 or an array. The moving edge baffles of the casting machine are shown in Figure 1 and in Figure 4 they are not shown for clarity.

Fig. 4A is similar to Fig. 4 but shows a hydromagnetic device for interacting with an upstream side nip pulley pulley, also referred to as nip pulley roller.

FIG. 4B shows an enlarged view of a portion of FIG. 4A showing a modified embodiment of the present invention which includes a flat downstream directed "afterburner" coolant purge nozzle.

FIG. 4C is an enlarged view of a portion of FIG. 2 showing the "afterburner" coolant purge nozzle of FIG. 4B.

Figure 5 is a partial vertical view combined with partial sectional views of the equipment in the skid frame of a casting machine embodying the invention as seen from upstream to downstream. In FIG. 5, the three regions marked VA, VB and VC respectively are the regions identified by the viewing lines VA-VA, VB-VB and VC-VC respectively in FIG. 4B.

FIG. 6 is an enlarged view of a portion of FIG. 5 showing a typical magnetic circuit having a thin, fast-traveling coolant film passing between the pole faces and a moving cast belt counterface gap. Here, for a clearer illustration, the relative thickness of the cooling film gap is exaggerated.

Figure 7 is a graph illustrating the equilibrium or stabilization of the moving casting strip as a function of the distance of the gap between the moving casting strip and the magnet-nozzle pole surface (edge of the coolant pressure pocket). In other words, Figure 7 represents the pull/push balance between (i) a slower-falling protruding magnetic attraction, which may be referred to as an inward pull, and (ii) a faster-falling The repulsive force of the pumped coolant and the high velocity thin coolant film can be called the outward thrust. Also, for comparison and to illustrate more clearly, a relatively rapid and undesired drop in the attractive force provided by the AlNiCo 5 magnet is shown.

FIG. 7A is similar to the left portion of FIG. 7 with a 6:1 horizontal scale. Figures 7'A and 7A" are also included for illustration.

Figure 8 is a longitudinal vertical sectional view viewed from the side of the moving mold chamber region of the carriage, showing an array of hydromagnetic devices, ie hydromagnetic devices located at various positions along the length of the moving mold chamber. One of these hydromagnetic devices is represented in a flexible mount.

Fig. 9 is a view similar to Fig. 8, but it shows another preferred embodiment of the present invention, wherein the hydromagnetic array shown in Fig. 8 is positioned downstream by the support shown in Fig. 9 Roller replaced.

Fig. 10 is a view similar to Fig. 8, but has represented another preferred embodiment, wherein, shown in Fig. replaced by the downstream back-up roll shown. The two arrays opposite the backup rollers in the downstream lower frame shown in Figure 10 are non-magnetic coolant pads.

Figure 11 is an enlarged vertical sectional view looking downstream from the vantage point on the upstream side of Figure 5, showing a permanent magnet arrangement rotatable by a fluid-driven magnet rotation mechanism. The permanent magnet arrangement is shown in an open circuit or "off" position.

Figure 12 is a vertical cross-sectional view of the apparatus shown in Figure 11, viewed from a vantage point outside of Figure 4 . FIG. 12 is a cross section taken along line XII-XII of FIG. 11 .

FIG. 13 shows another embodiment of the present invention in which a movable soft magnet magnetic bypass is used instead of the rotatable permanent magnet arrangement shown in FIGS. 11 and 12 . Figure 13 is an oblique view, viewed substantially from the vantage point of Figure 5, diagrammatically showing an array of hydromagnetic devices positioned beneath a moving casting belt, with a toothed bar of soft magnetic ferromagnetic material , it acts as a bypass, which means it is in the "off" position (the pole surface is demagnetized)

Figure 14 is a view similar to Figure 13 but showing the bypass in the "on" position (pole surfaces are magnetized).

Figure 15 shows the hysteresis loops of two different permanent magnet materials: Alnico 5 and the most preferred permanent magnet material described in detail later, we use this permanent magnet in most of the preferred embodiments of the present invention .

Fig. 16 is a longitudinal vertical sectional view viewed from the side of the casting machine, showing another hydromagnetic device or assembly in the hydromagnetic pad array. The hydromagnetic device shown is surrounded by other parts of the upper carriage of the belt casting machine as shown in FIG. 1 . Fig. 16 is similar to Fig. 4A showing the lower casting belt and the lower bite pulley; while Fig. 16 shows the upper casting belt and the upper part in a cooperative combination with an existing other structure of an embodiment of the present invention Bite into the pulley.

Fig. 17 is an enlarged partial cross-sectional view showing multiple magnetic circuits according to another prior art construction having a thin fast-traveling coolant film passing between the pole faces and the opposite side of the moving cast belt the gap between. The left portion of this view is the portion indicated by A-A in FIGS. 16 and 19 . The right part of Fig. 17 is taken along A'-A'. For a clearer representation, the relative thickness of the coolant film is exaggerated here.

Fig. 18 is an enlarged partial cross-sectional view similar to Fig. 17, however, Fig. 18 is a view away from the part further downstream of the biting belt wheel, the left and right parts of Fig. 18 are located along the lines B-B and Fig. 19, respectively. B'-B'.

Fig. 19 is a partially enlarged view of Fig. 16, showing in detail the style of the rotatable body assembly.

This instruction manual will be described for a twin belt casting machine which features upper and lower carriages for rotating the upper and lower casting belts. For ease of explanation, the description will be made with respect to the lower shelf. In a twin-belt caster, the line of passage along which the solidifying metal advances is usually straight. In a single belt caster (not illustrated here), the channel wires may follow a slightly curved path. Also, in a twin-belt caster, the channel lines may run substantially straight in the longitudinal direction of the caster, while the belts may be slightly curved in a transverse direction of the caster at one point of the mold cavity. For all these cases, the array of channel wires, or their guides, formed by the position of the pole surfaces may be referred to as a "coplanar array" or a "planar array".

Although a "flat" belt may travel along a channel line following a slightly curved path, it is considered to be in a straight line when it traverses the entire channel line along the channel line with the desired straightness. condition. Also, a flat belt that is slightly transversely bent at a certain portion of the channel line can also be considered to be in a straight state. An array of pole surfaces for guiding the cast strip moving along the passage line with the desired straightness may be referred to as a "coplanar array" of pole surfaces or may be referred to as a "planar array".

Figure 1 is a view of a wider twin-belt caster 36 from upstream, above and from the outside. The lower carriage is marked L and the upper carriage is marked U. The molten metal is introduced into the moving mold cavity or mold space C by means of a molten metal feeding device (not shown) known in continuous casting machine technology (Figs. 4, 4A, 5, 6, 8, 9 and 10) the entry end 49. The introduction of molten metal is marked schematically by a large hollow arrow 37 on the left in FIG. 1 . The continuously cast product shown on the right in FIG. 1 exits the outlet end of the moving mold cavity (arrow 57 ).

硬度的轧制低碳钢制成。可以对铸带的前表面进行本领域已知的适当的处理，例如喷砂和/或涂覆。如本领域所公知的，运动的结晶器腔体C的两侧被两个已知的旋转的整体环链边部挡板54所约束。下铸带50和块环链54，如运动箭头55所示，绕着一个与运动结晶器腔体的入口(上游)端49相对的下(咬入)带轮56和一个与运动结晶器腔体的出口端相对的下带轮58旋转。上铸带52绕着一个上部上游(咬入)带轮60和一个上部下游带轮62旋转。这种双带铸机的结构和操作在带型铸机技术领域中是已知的。如果读者需要关于这种铸机的更多的信息，可以参考Hazelett等人的专利。The lower and upper sides of the moving crystallizer cavity C are bounded by rotating lower and upper annular, flexible, thin thermally conductive casting belts 50 and 52, respectively. In the preferred embodiment of the invention, the cast strips 50, 52 are made of a soft magnetic material. For example, from metallic materials such as

Hard rolled mild steel. The front surface of the cast strip may be subjected to suitable treatments known in the art, such as sandblasting and/or coating. The sides of the moving crystallizer chamber C are bounded by two known rotating integral chain side baffles 54, as is known in the art. The lower casting belt 50 and block chain 54, as indicated by the motion arrow 55, revolve around a lower (bite) pulley 56 opposite the inlet (upstream) end 49 of the moving mold chamber and a The lower pulley 58 relative to the outlet end of the body rotates. The upper casting belt 52 rotates about an upper upstream (bite) pulley 60 and an upper downstream pulley 62 . The construction and operation of such twin belt casting machines is known in the field of belt casting technology. If the reader desires more information on such casting machines, reference is made to the Hazelett et al. patent.

The view point of FIG. 2 is marked in FIGS. 3 and 8 by the dotted line II-II. The lower casting belt 50 is shown guided by an array of hydromagnetic devices 38 generally indicated at 51 . Array 51 may be referred to as a hydromagnetic pad. Each hydromagnetic device comprises a magnetic pole member 39 extending longitudinally with respect to the upstream-downstream direction (arrow 61 ) of the moving crystallizer cavity C. In the array 51, the elongated pole members 39 are arranged parallel to each other and spaced apart. Their top surfaces provide a coplanar array of pole surfaces 34 . Between the elongated pole members 39 an elongated space 66 is defined which extends longitudinally with respect to the mold cavity as shown.

The elongated pole members 39 are constructed of soft magnetic material, such as soft magnetic steel, such as Type 430 chrome stainless steel. The cast strip 50 is supported in motion against the pole surface 34 by the hydrodynamic force provided by the liquid coolant sprayed from the throttle nozzle. The throttle nozzle will be explained later.

In an array 51 of hydromagnetic devices 38 we have installed a number of relatively compact permanent magnets 32 having north and south magnetic poles, labeled N' and S' respectively in FIG. 2 . These magnets are inserted in the elongated spaces 66 between successively spaced parallel elongated pole members 39 in the array 51 . Preferably, there is at least one permanent magnet 32 in each space 66, so that throughout the array 51, as will be understood from FIGS. The two outermost pole members in the array) have a pair of permanent magnet poles of the same polarity facing opposite sides thereof. These same polarity permanent magnet pole pairs have alternating north (N′) and south (S′) poles across the array 51 . Therefore, as shown in FIG. 2, the pole member 39 on the left has a pair of north permanent magnet poles N' facing its opposite side. The next successive pole member 39 in the middle of FIG. 2 has a pair of south permanent magnet poles S' facing its opposite side. Next, the next successive pole member 39 on the right in FIG. 2 has a pair of north permanent magnet poles N' facing its opposite side, and so on, thereby spanning the array 51 .

As a result of this arrangement of permanent magnets 32, in successive hydromagnetic devices 38 spaced across array 51, pole surfaces 34 of pole members 39 alternately have north (N) and south (S) poles, moving toward A strong protruding attractive force (pull force) is exerted on the casting belt 50 (FIGS. 2, 5 and 6).

As shown in FIG. 3, there are a plurality of permanent magnets 32 in the array 51, for example, five are shown in FIG. 4. As shown most clearly in FIG. In each elongated space 66 at longitudinally spaced, longitudinally aligned positions along the length of the long pole members 39, the first magnet 32 in each space 66 in the array 51 is positioned adjacent to the polarity of two adjacent pole members 39. The upstream end 118 of the surface 34 . The last of the plurality of magnets in each space is located near the downstream end 120 of the pole surfaces 34 of two adjacent pole members 39 . In FIG. 4A , which shows a nose array 51 n , five magnets in each space 66 abut one another near a downstream end of the nose array to avoid interference with the wheeled wing 128 .

In Fig. 6, dashed line 30 indicates a complete magnetic circuit at the center of Fig. 6, and parts of two other magnetic circuits at the left and right. The relative thicknesses of the cast strip 50 and the size of the gap 75 (spacing) between the pole surface 34 and the cast strip are exaggerated for clarity of illustration. A complete magnetic circuit 30 starts from the north pole N' of a permanent magnet 32 in the center of FIG. 6 . For example, with five magnets in each space 66 , with respect to each space 66 and two adjacent pole members 39 , this magnetic circuit 30 represents any one of five such magnetic circuits. The magnetic circuit extends from the pole N' into the first pole member 39 of the hydromagnetic device 38, and from there in the first member to the first pole surface 34, where the strong magnetomotive force of the magnet causes The strong first pole N magnetization of the surface. The magnetic circuit extends from this first pole surface 34 across the first gap 75 and into the soft magnetic tape 50, and then in the strip towards the second gap 75. The magnetic circuit extends across the second gap 75 and into the pole surface 34 on adjacent pole members of adjacent hydromagnetic devices 38 in the array 51 at the strong south pole S magnetized by the strong magnetomotive force of the magnet 32 . The magnetic circuit extends in the second pole member 39 towards and into pole S'. This magnetic circuit ends in the magnet from its S' pole to its N' pole.

As an example of a suitable arrangement, the pole members 39 in the array 51 are evenly spaced about their midpoints as shown. The midpoint-to-midpoint spacing of pole members 39 may, for example, range from about 3/4 inch to about 2 inches. These elongated pole members may be, for example, about 1/2 inch thick, defining an elongated space 66 between adjacent pole members extending longitudinally relative to the mold cavity. In FIG. 6 these spaces appear to be slightly wider near the cast strip 50 due to the slight narrowing of the pole member 39 facing its pole surface 34 . The permanent magnet 32 in the embodiment extends from S' pole to N' pole as shown.

Each permanent magnet 32 may comprise a number of individual permanent magnets suitably stacked in a north-to-south fashion, arranged end-to-end in series; and/or a number of individual permanent magnets, the individual permanent magnets Side by side side by side, so as to provide a very powerful magnet 32, the magnet 32 has a general north (N') pole and south (S') pole at its opposite end or surface 33 (FIGS. 3A and 6). ) poles, and the magnetic field lines pass through the end or surface 33. If the magnets are made of a material which is prone to corrosion, these are preferably interspace plated in order to resist corrosion, for example nickel plating. As shown in Figures 2, 3, 5 and 6, these permanent magnets 32 are designed as cuboids, about 1.5 inches long to 1 inch long in the S' to N' direction of its internal magnetic field lines, and its cross section is at least about 1 square inches.

The end surface 33 of the magnet 32 having N′ poles and S′ does not have to be in actual precise contact with the side surface of the pole member 39 . These magnet end surfaces 33 need only abut the side surfaces of adjacent pole members. The term "adjacent" herein may include actual contact. If there is any space between the end surface 33 and the side surface of the pole member 39, the space gap formed between the end surface 33 and the pole member 39 should be small enough in the direction of the magnetic field line loop 30, so that in each complete magnetic There are only two effective gaps 75 in the road 30 . With little or no air gap on the pole surfaces 33, each total complete magnetic circuit 30, magnetized by the strong magnetomotive force provided by the unique characteristics of the permanent magnets 32, will have incredible The ability, "reaching out" through the gap 75, is used to apply a strong pulling force to the moving casting belt 50 in a way that cannot be achieved with conventional magnets or full-sized electromagnets. This attractive force decreases relatively slowly as the gap 75 increases, as will be further explained in conjunction with FIGS. 7 and 7A.

Referring again to Figure 6, it can be seen that the two gaps 75 in each complete magnetic circuit 30 are filled with a relatively thin film 114 of relatively fast moving liquid coolant, which will now be explained. Using the coolant supply system shown in FIGS. 4 and 4A , liquid coolant 93 is pumped into a duct passage 92 extending longitudinally in each pole member 39 . The liquid coolant 93, typically water containing a rust inhibitor, is suitably filtered to remove particulates and then pumped into a water header 100 extending laterally in the lower carriage L. The end of this header 100 is shown in FIG. 1 . The coolant 93 pumped in the header 100 can be pressurized above, for example, about 30 pounds per square inch (p.s.i.), but in a particular machine, the pressurization should not be so high that the belt is suspended from the gap 75 Together, the protruding magnetic attraction force obtained at gap 75 acts against thermal deformation, forcibly stabilizing the cast strip. Supply pipes 98 (only one shown) extend from header pipe 100 . Each such supply pipe is connected to a channel 96 drilled diagonally in the pole member 39 which is connected to a conduit passage 92 within the pole member.

The shape of the elongated pole member 39 shown in FIG. 4A is changed from the shape shown in FIG. 4 so that an elongated pole having the structure of FIG. 39n can be inserted into slots 127 between wings 128 on the lower nip pulley roller 56 (FIG. 4A). This biting region 110 of the inlet 49 is represented in FIG. 4A by an axis 111 which passes through the inlet and the lower biting pulley 56 and also passes through the shaft (not shown) of the upper biting pulley 60 ( FIG. 1 ). The dotted line is indicated.

To accommodate such congested conditions, a plurality of supply pipes 98 may be oval in cross-section to provide adequate flow capacity, evenly spaced side by side on one to two half inch centers along the header 100. The duct passage 92 extending longitudinally in the elongated pole member 39 can be considered a boost tube as it supplies pumped coolant 93 to a plurality of specially designed throttling nozzles comprising fixed The channel 90 for the flow and the pressure groove 102 facing the cast strip and surrounded by the pole surface 34 as an edge. The upstream and downstream ends of each conduit passage 92 are plugged at 94 as shown in FIGS. 4 and 4A .

The coolant 93 pumped from the pipe passage 92 enters the fixed throttle passage 90, directing the throttled pumped coolant flow 97 into the pressure groove 102 facing the opposite side of the casting belt. A number of such pressure tanks are shown in Figures 2, 3, 3A, 4 and 5. They are shown as ovals and are elongated in the longitudinal direction of the pole surface 34 . For example, pressure groove 102 has a pole surface length of 3/8 inch longitudinally and is approximately 3/16 inch deep and 3/16 inch wide. These elliptical pressure grooves 102 are closely spaced along the length of the pole face 34, for example about one-eighth of an inch apart between their respective downstream and upstream ends of the ellipse; The 34 has two pressure grooves per inch longitudinally (ie, about an inch and a half center to center). For example, as shown, each pressure groove 102 has an area of about 0.06 square inches facing the surface of the casting belt.

The throttled coolant flow 97 in the pressure tank 102 exerts a thrust (repulsion) against the moving casting belt 50 . The throttled coolant exits each pressure groove, radiating outward from the pressure groove in the form of a fast-moving liquid film 114 into the gap 75 and across the pole surface 34 forming the edge of the pressure groove. In addition to the thrust applied by the throttled pressurized coolant flow 97 to the opposite side of the moving belt 50, each fast-traveling liquid film 114 also exerts a dynamic thrust (repulsion) to the opposite side of the belt. These fluid dynamics that arise in and around each pressure groove 102 follow any increase in the adjacent gap 75 due to any deformation displacement of a localized region of the cast strip 50 away from the associated pole surface 4. The push (repulsion) force is immediately reduced (almost instantaneously).

One of the purposes of each throttling passage 90 is to isolate (isolate, separate) the associated pressure tank 102 from which the pressurized liquid coolant 93 is fed into the pressure tank from the associated conduit passage 92 . By virtue of this isolation, any changes in the pressure of the coolant stream 97 entering a particular slot 102 (due to transient deformation displacements in localized areas near the moving belt 50) will not affect the flow of coolant 93 in the vicinity of the conduit passage 92. pressure. Consequently, no forced backflow effect occurs due to the localized pressure changes that would occur instantaneously in the coolant flow 97 entering any of the pressure tanks. Thus, each pressure slot 102 with its coolant flow 97 and its radiant flow film 114 functions independently of the adjacent slots. The behavior of any fluid 97 and any liquid film 14 does not significantly affect the pressure of the pressurized coolant 93 in the conduit passage 92, nor does it significantly affect the action of any cavity pressure pockets or any other coolant film.

In order to achieve this isolation, the inside diameter (I.D.) of the throttling passage 90 (which can be viewed as a very long fixed orifice) is preferably no greater than, for example, about 1/16 inch (about 0.063"), and due to possible Openings that are accidentally blocked have an I.D. of less than about 0.04", so preferably no less than about 0.04". As shown in FIG. 6, passageway 90 is approximately three quarters of an inch long with an I.D. of approximately 0.045 inches.

As an example of suitable operating parameters, the pressure of the liquid 93 in the header 100 (FIGS. 4 and 4A) may be above about 30 p.s.i, but as noted above, not excessive. In the following example for explanation, the header pressure is set in the range of about 100 p.s.i. to 110 p.i.s. (range of about 7 bar). Since a relatively insignificant pressure drop is assumed to occur in the supply pipe 98 and the connecting passage 96, the pressure of the coolant 93 in each conduit passage 92 is in the range of approximately 100 p.s.i. to 110 p.s.i.

For ease of illustration, it is initially assumed in Figure 6 that the moving casting belt 50 is stabilized in position by a pull/push balance. The moving belt is supported by a throttled liquid flow 97 and a relatively thin film 114 of fast-moving coolant overflowing from the pressure tank 102 through the gap 75 . With such a stable initial condition of the cast strip, only the proper liquid flow 97 enters the groove 102 . "Liquid flow" here refers to the value (ie, amount) of coolant volume per unit of time. Thus, for example, under these initial conditions, it is assumed that a pressure drop of approximately 30 to 40 p.s.i. occurs in the throttle passage 90 . Thus, for example, the pressure of the stream 97 entering the pressure tank 102 is about 100 to 110 p.s.i. of the header pressure minus about 30 to 40 p.s.i. , the pressure of liquid stream 97 should be in the range of about 60 to 80 p.s.i.

Now, for ease of explanation, assume that thermal deformation begins to take place, moving the local region of the moving cast belt 50 in FIG. The overflow of these liquid films 114 radiated increases rapidly, and the liquid flow 97 into the pressure tank increases, causing the pressure drop in the throttling passage 90 to generate a pressure drop to increase rapidly, for example about 40 to 50 p.s.i. Thus, the pressure of the liquid flow 97 entering the pressure tank 102 immediately becomes assumed to be about 50 to 70 p.s.i., and the stretching force of a relatively constant magnetic attraction force in the magnetic circuit 30 immediately deforms the cast strip 50. The region pulls back to its original stable position, again being hydrodynamically supported by the immediately restored, steady throttling fluid flow 97 and the steady, relatively thin, fast-traveling fluid film 114 .

In the overall effect in the hydromagnetic device 38 there is a fixed throttling channel (fixed elongated hole) 90 immediately upstream of the pressure tank 102 in the direction of coolant flow from 93 to 97 . Also, there is a variable orifice provided by the variable space of the gap 75 immediately downstream of the pressure tank 102 in the direction of coolant flow in the rapidly advancing liquid film 114 . Thus, advantageously, the pressure of the coolant flow 97 entering the pressure slot 102 immediately (almost instantaneously) responds to changes in the spacing of the gap 75, and thereby immediately allows the strong protruding magnetic pull to balance the weakened hydrodynamic thrust, making the movement The state of the cast strip 50 reaches equilibrium.

It can be noted from FIGS. 3A and 6 that the throttling coolant flow 97 and the fast-traveling coolant film 114 (FIG. 6) radiate from the pressure slot 102 directly adjoining the pole surface 34, the flux lines in the magnetic circuit 30 at The pole surface 34 is very strong. In this localized manner, the pull/push relationship of the protruding magnetically attractive pull and hydrodynamic push is balanced in close proximity to themselves, i.e., only a small lateral distance along the thin cast strip 50 Opposite thrust and pull balances occur within. Thereby only an insignificant moment arm is involved for the effective action of these opposing pulling and pushing forces on the casting belt. Thus, advantageously insignificant mechanical deformations (as opposed to thermal deformations) are introduced into the thin cast strip by means of opposing pulling and pushing forces acting in a localized manner.

The direction and shape of the rapidly advancing coolant film flowing over the pole surface 34, indicated by the flow lines 114, is shown in FIG. 3A. The throttling coolant flow 97 (FIG. 6) and these rapidly overflowing coolant films 114 float the cast strip 50, keeping it at a distance from the pole surface 34, thus effectively mitigating the impact caused by the moving cast strip and the sliding supports or Friction and wear problems arising from the contact of cast belt supports.

At the same time, these fast-moving liquid films 114 effectively remove heat from the opposite side of the belt (not shown in FIG. 3A ) that cuts or brushes over any slower moving coolant to effectively cool the belt. If the unidirectional sweeping flow 115 (sweeping flow) (to be described later) is not used, the fast-moving coolant film 114 will flow over the pole surface 34 at the same time as the adjacent pole member after flowing over the corresponding pole surface 34. The fast-traveling coolant films impinge upon each other and may create an intermediate turbulent impact zone 113 near the centerline of each elongate space 66, wherein the coolant has substantially zero net unidirectional momentum, so that, except for gravitational fall or Apart from the spiu-off, there will be no effect on removing coolant from the pole members 39 .

In order for any turbulent flow of coolant 113 to be diverted, redirected, fused, recovered, and removed from each elongated space 66 along with the fast-traveling coolant film 114 to make room for the continuous flow of coolant flowing out of the pressure slots 102 And to provide proper cooling of the cast strip, a fast moving, high volume, unidirectional stream of scavenging coolant 115 ( FIGS. 3A , 4 and 4A ) is introduced into the upstream end of each space 66 . This unidirectional purge flow 115 prevents any coolant flow near the opposite side of the strip from being too slow to properly remove heat from the opposite side (i.e., for proper cooling of the strip to prevent thermal damage to the strip too slow). This purge flow 115 allows all coolant to eventually flow in one direction while maintaining a relatively constant velocity between the coolant and the strip at all points on the opposite side of the strip to prevent thermal damage to the strip. These unidirectional purge streams 115 of coolant, shown more clearly in FIGS. Pressurized coolant stream 93 enters these scavenging nozzles.

Each cleaning nozzle 112 (FIGS. 4 and 4A) is aimed at a sharp angle to the downstream side, forming a less acute angle as it reaches the opposite side of the moving casting belt. Each scavenger nozzle 112 has a cap-shaped fingernail deflector 116 mounted near the downstream discharge end of the scavenger nozzle for discharging a high velocity, powerful scavenger coolant stream 115 laterally from the scavenger nozzle. Nail-shaped baffles 116 point at a slightly smaller acute angle (ie, a smaller angle) than their associated cleaning nozzles 112 to the opposite side of the moving casting belt.

Each fingernail-shaped deflector 116 directs the powerful liquid stream 115 (FIG. 3A) ejected from the cleaning nozzle to an upstream, boat-shaped tip 118 on the casting belt near each elongated pole member 39 (best seen in FIGS. 3 and 3A). Visible) in a relatively uniform, precisely defined region near the liquid stream 115 flows from its removal nozzle at an acute angle of impact to the opposite side of the casting belt. The downstream end of the pole member 39 is also generally shaped into a pointed bow 120 ( FIGS. 2 and 3 ) like its upstream boat tip 118 . The bore of the scavenging nozzle 112 has a cross-sectional area larger than the orifice 90 but smaller than the conduit passage 92 . The relative ratio of the cross-sectional area of the scavenging nozzle 112 to the cross-sectional area of the duct passage 92 is sized such that the cooling fluid entering the pressure tank 102 enters the pressure tank 102 under the pressurized pressure of the coolant in the header 100 ( FIGS. 4 and 4A ). The agent stream 97 (FIG. 6) is not starved, and at the same time, the purge stream 115 is not starved. Therefore, the velocity, flow, and momentum of the scavenging coolant 115 are sufficient to merge, deflect, and scavenge in a downstream direction carrying away all coolant turbulence 113 and all fast-traveling liquid film 114 after escaping from gap 75 Fast and large enough, while maintaining a substantial relative velocity at all points on the opposite side of the cast strip, which is sufficient to ensure protection against thermal damage to the cast strip.

Shortly after the purge coolant 115 (plus any other coolant carried downstream therewith) exits the downstream end of the elongated space 66, a deflector 122 extending transversely with respect to the moving belt diverts the coolant from the moving Scoop away on casting tape. An associated coolant flow tank (not shown) is used to return scooped coolant to a supply reservoir (not shown). Such a coolant guide bucket 122 and its coolant flow channels may be compared, for example, to the Hazelett et al. US Pat. No. 3,036,348 is similar to the diverter funnel in FIGS. 6 and 7.

As shown in FIG. 4A, the pole members 39 (only one shown) have a narrow upstream-side protruding nose portion 39n that protrudes beyond a nip region 110 so that the nose 39n is inserted into the Bites into the groove 127 between the two wings 128 on the pulley roller. Thus, referring to FIG. 4A , both the cleaning nozzle 112 and its nail-shaped deflector 116 are located slightly upstream relative to the biting area 110 . As indicated by 51n in Figures 8, 9 and 10, an array of hydromagnetic devices 38 having a narrow nose portion 39n is referred to as a nose array.

The bite pulleys 56, 60 and their wings 128 shown schematically integral with the pulley body are made of a non-magnetic material, such as a diamagnetic or paramagnetic material, such as type 304 austenitic stainless steel , so that the wings and biting pulleys do not allow leakage of magnetic flux away from the pole members 39, 39n and into the wings and pulleys that would cause the pole surface 34 from the nose 39n of the pole member 39 A reduction in the projected magnetic flux of the cast strip is obtained for stable motion. As an option, the wings may be made of the non-magnetic stainless steel described above, while the body of the pulley is made of soft ferromagnetic material for forming a complete magnetic circuit with the pole member nose 39n. Alternatively, the wings 128 may be made of soft magnetic magnets while the pulley body is made of a non-magnetic material. Extending permanent magnets are then arranged to magnetize the wings with alternating north and south poles to attract and stabilize the casting belt during operation of the caster. For example, as shown in Figures 11 and 12, these magnets may be movably mounted with the operating mechanism to move the magnets to reduce the magnetic attraction force between the wings and the pulleys to remove the casting belt and the belt from the casting machine. Install other casting belts. As an option, moveable shunts such as those shown in Figures 13 and 14 may be used to reduce the magnetic attraction between the wings and the casting belt for removal and installation as described above.

The permanent magnet material in each permanent magnet strongly magnetizes the magnetic circuit 30 (FIG. 6), and also strongly magnetizes the entire pole member 39 to provide a strong force to the moving cast belt 50 containing the soft magnetic material. Extending the attractive force (pull force), the permanent magnet material has some very important magnetic circuit characteristics: (1) a sample of this permanent magnet material has a normal hysteresis loop intersecting the B-axis at one point ( B-H loop), wherein the sample has a remanence Br with a magnetic flux density equal to or greater than about 8,000 Gauss. (2) A sample of this permanent magnet material has a normal hysteresis loop (B-H loop), wherein a straight line tangent to the midpoint of that portion of the loop in the second or fourth quadrant has a representation The slope of the point differential demagnetization permeability, if the air permeability is 1, the differential demagnetization permeability ΔGauss/ΔOersted is approximately equal to or less than 4. And, the permanent magnet material needs to have very strong stability, that is, roughly speaking, it needs to be difficult to demagnetize, that is, from the magnetic sense, relatively "hard", requires a large demagnetization coercive force to make The permanent magnet is demagnetized. These beneficial features of magnet 32 are discussed further in connection with FIGS. 7 and 15 .

The term "Midpoint Differential Demagnetization Permeability" of a sample of permanent magnet material as used herein means the slope expressed as ΔGauss/ΔOersted of a straight line where the loop lies in the second or fourth quadrant The midpoint of the part is tangent to the B-H loop of the sample. It should be understood that the B/H loop of the sample is plotted in a graph where the B and H values are scaled along the vertical and horizontal axes, respectively, such that the B/H or ΔB/ΔH of the vacuum, i.e., The slope of the magnetic flux density B resulting from the application of the coercive force H to the vacuum is always 1 when it is on the same graph; in other words, the coercivity applied to the vacuum The force changes ΔH, and the rate of change of the magnetic flux density ΔB is always one. In the table below we list preferred parameters for these important key properties.

Table I

A sample of permanent magnet material in magnet 32 has a BH loop intersecting the B axis at a point where the residual induction _Br has a flux density value in Gauss :

General Equal to or greater than 8,000

Preferably equal to or greater than approximately 9,000

More preferably equal to or greater than about 10,000

Most preferred About 11,000 or more

Table II

A sample of permanent magnet material in magnet 32 with a midpoint differential demagnetization permeability expressed in ΔGauss/ΔOersted :

Preferably equal to or less than about 4

More preferably equal to or less than 2.5

Most preferred Equal to or less than 1.2

We mentioned in the previous introduction that, in our opinion, the strong magnetomotive force shown in Table I provided by the above-mentioned permanent magnet 32 is not the only prerequisite for smooth operation. As shown in Table II, their very low midpoint differential demagnetization permeability is also critical. For example, alnico 5 has a midpoint differential demagnetization permeability of about 30. The ratio of this amount of AlNiCo5 of about 30 compared to the most preferred value of 1.2 in Table II is about 30/1.2, equal to 25. Thus, for a given length of the N' pole to the S' pole of the magnet, generally speaking, the incremental increase in the pitch of the gap 75 (FIG. 6) causes a disruptive effect on the magnetic attraction force provided by the AlNiCo magnet of approximately 25 times the disruptive effect on the magnetic attraction force provided by the magnet 32 in the present application. This is not just a quantitative difference, but a qualitative difference! Thus, the Alnico 5 magnet loses control over the thermal deformation of the cast strip 50 or 52; while the magnet 32 of the present invention, configured in an array 51 or 51n and operating as described for the preferred embodiment, does not lose control over all control of thermal deformation.

Another way to consider the unusual role that magnet 32 plays in its own magnetic circuit 30 (FIG. 6) is to realize that the flux lines in magnetic circuit 30 must pass through magnet 30 from S' to N', the The exceptional performance is provided by an extremely low midpoint demagnetization permeability of, for example, about 1.2. Assume that magnet 32 has a physical length of one inch (25.4 mm) from end 33 to end 33 . A magnitude of 1.2 compared to a value of 1 for air means that the flux lines in the magnet 32 itself must span an "internal apparent air gap" of length 1 physical inch divided by 1.2, i.e. 0.83 inches (21 mm) of the interior Apparent air gap. The 1.5mm gap 75 at the pole surface 34 is equal to 7.1% compared to the 21mm "internal apparent air gap" of the magnet itself. In contrast, an AlNiCo 5 magnet with a length of 1 physical inch divided by its assumed midpoint differential demagnetization permeability of magnitude 30 has an "internal apparent air gap" of only 0.033 inches (0.84 mm). A gap 75 of 1.5 mm equals 178% compared to the "internal air gap" of 0.84 mm for the AlNiCo 5 magnet itself. See again that 178% is 25 times more damaging to magnetic attraction than 7.1%. In Permanent Magnet Design and Application Handbook written by Lester R. Moskowitz, a professional engineer and published in 1976 and 1985 by Krieger Publishing Company of Malabar, Florida 32950, in his title "Analysis of a magnetic hysteresis loop. (The hysteresis curve shown is typical for Alnico 5)", by drawing a straight line tangent to the midpoint of the second quadrant, the midpoint differential demagnetization permeability of Alnico 5 is calculated to be about 30.

As shown in Figures 4 and 4A, the elongated pole members 39 are secured and supported by a transverse beam 104 made of a nonmagnetic material (either paramagnetic or diamagnetic), such as Type 303 nonmagnetic austenitic stainless steel . The pole members 39 are placed in the slots 106 in the beam 140 . At the upstream end of the pole member 39 is a retaining aperture 95 for alignment and auxiliary support of the pole member. The transverse beam 108 located below the beam 104 is contained in a chassis frame 141 of the lower carriage L. As shown in FIG. The beam 108 is made of a suitable structural material, such as structural steel.

In our current understanding of the invention, we believe that when the invention is applied in the furthest upstream position of the twin-belt caster 36, i.e. in approximately the first third of the entire length of the mold cavity C It is most valuable when it is at or around one, because the thermal stress on the casting belt is the strongest here. The first third is measured from inlet 49, as shown in Figures 8, 9 and 10, where a feed nozzle 138 introduces molten metal. This furthest upstream zone is the region where the brittle, solidifying metal initially transitions from liquid to solid state.

The arrays 51 and 51n in Figures 4, 4A and 5 are rigidly mounted by transverse beams 104, 108 to a cast belt carriage chassis frame. For continuous casting of certain metals it may be desirable to employ hydromagnetic arrays or pads 51n and 51 rigidly mounted along the entire length of the mold cavity C.

Practice in continuous casting has shown that in the casting belt support equipment connected to the downstream part of the mold cavity C, a moderate degree of elasticity is usually required, especially in the aluminum alloy casting process, in which case the metal is running through the The cast product P is not completely solidified through its thickness, but enough solid metal has formed that it deforms significantly during cooling. This resiliency keeps the front surface of the moving belt in tight contact with the cooled metal.

In continuous casters for metal casting operations where resiliency is required in the belt support apparatus, one or more downstream arrays 51 may be mounted on coil springs, or on compliant, resilient lateral supports on file. The location and alignment of the downstream array 51 facing or away from the casting cavity C may be adjusted by means not shown in operation. Such a belt support adjustment mechanism for adjusting the compliant, resilient support may be similar to the Hazelett and the mechanisms shown and described in US Patents 4,552,201; 4,671,341; 4,658,883 and 4,674,558 to Wood.

One way to adjust the elasticity and compliance of the stabilizing water magnetocast belt pad array 51 is to use throttling passages 90 of different diameters (best seen in FIG. 6 ). A given boost pressure can be selected in the range above about 30 psi, and can be selected as required for the use of one or more specific moving, endless, flexible, thin thermally conductive casting belts for casting specific metals or metal alloys.

As shown in FIG. 8, in an embodiment of the present invention, there is a cast belt stabilizing array 51 of four hydromagnetic devices 38. As shown in FIG. Additionally, there are two belt stabilizing nose arrays 51n operatively connected to the lower and upper nip pulley rolls 56 and 60. In these nose arrays 51n, upstream elongated nose portions 39n (FIG. 4A) of pole members 39 are inserted into slots 127 between lower and upper nip circumferential wings 128 on pulley rollers 56 and 60, respectively. Downstream of the nose-shaped array 51n (in the direction indicated by the direction arrow 61), there is a coolant guide funnel 122, and such guides are also provided downstream of the lower and upper arrays 51 near the middle part of the crystallizer cavity C. Liudou. Coolant flowing from the downstream ends of the lower and upper downstream arrays 51 may drop down the backside of the lower casting belt and overflow the edge of the upper casting belt.

In Figure 8, an upper downstream water pad array 53 is flexibly mounted to the chassis frame 142 of the upper cast belt carriage by means of flexible mounts 140 such as coil springs. Magnets are generally omitted from the water cushion array 53 .

With respect to the embodiment of the invention shown in FIGS. 9 and 10, it can be seen from FIG. 4A that any deflector (and applicator) bucket 123 preceding the winged belt support roll 126 is fitted with an edge pan The water collecting pipe 101 extending laterally of the rack. The pressurized coolant flow 93 is supplied into the header 101, and on the diversion and coolant applicator 123, includes a plurality of coolant jets 105 aimed at the coolant applicator surface 107 directed downstream. agent discharge nozzle 103 (only one can be seen in FIG. 4A ). Such a deflector and applicator bucket 123 with a water collection pipe 101 , discharge nozzle 103 and applicator surface 107 is known in the art. As shown in Figure 4A, immediately downstream of the coolant application surface 107 is a winged belt support roll 126 known in the art.

In the embodiment of the invention shown in FIG. 9 , there is a winged belt support roll 126 located downstream from the first deflector and spreader 123 in the lower and upper belt carriages L and U. The first sequence, which is immediately downstream of the nose array 51n. There is then a second deflector and spreader hopper 123 following the second sequence of winged casting belt support rolls 126 in both carriages. As shown in U.S. Patent Nos. 4,552,201 to Hazelett and Wood; Bendable and adjustable.

In the embodiment of the invention shown in FIG. 10, the upper carriage of the twin-belt caster 36 is assembled similarly to the upper carriage of the twin-belt caster 36 shown in FIG. Belt support roller sequence, each of these two sequences is located after the diversion and distribution bucket 123. In Fig. 10, the lower carriage has two non-magnetic arrays 53 of hydrodynamic devices 38 which are identical to Figs. , 4A, 5 and 6 are similar to the array 51 of hydromagnetic devices 38 shown. These arrays 53 are located behind a diverter funnel 122 that is similar in structure to the diverter funnel 122 shown in FIG. 4 .

Depending on the amount of scavenging coolant 115 used, it may be necessary to employ an integral, flat liquid coolant nozzle or "afterburner" (type acting) nozzle 130 (Fig. The downstream end points downstream and is part of its whole. The afterburner (action) nozzle 130 covers the belt 50 or 52 between the last pressure tank 102' and the coolant-belt-impact zone of the coolant 132 from the spreader after leaving the deflector 107 area in between. As shown, the impingement zone 134 of the coolant 132 (see also FIG. 4A ) is close to where the first support roll wing portion 126 is shown in contact with the casting belt 50 . Afterburner nozzle 130 is shown in Fig. 4B-Fig. 4C, Fig. 4B is an enlarged portion of Fig. 4A, and Fig. 4C is an enlarged portion of Fig. 2, in Fig. Cast belt 50. The afterburning nozzle 130 replaces the region of the downstream pointed bow 120 ( FIGS. 2 , 3 ). A final pressure tank at the farthest right in Fig. 4B is designated 102' because it differs from the other pressure tanks in that the nozzle 130 is connected to the nozzle 102' and is supplied with liquid therefrom coolant. Restricted passage 90' inserted into pressure groove 102' differs from the other restricted feed passages 90 in that it has a significantly larger diameter, eg, approximately 3/16 inch in diameter. A flat straight side of each afterburner nozzle 130 is defined by the back of the cast strip 50 or 52 . The other flat straight side is defined by a reduced platform-like edge surface 133 formed at the afterburner end of the pole member 39 . The nozzle 130 is shown longitudinally in cross-section in FIG. 4B and from an oblique view from above in FIG. 4C. The downstream branch scavenging flow of coolant from nozzle 130 is indicated by arrow 130 (FIGS. 4B and 4C). Instead of nozzles 130, any of several means may be used to inject liquid coolant downstream, for example using internal passages which may be provided in the pole members, which passages are empty on the sides of the pole members and generally point towards downstream. Alternatively, ducts or orifices and/or deflectors may be provided in space 66 between the pole members for downstream distribution of liquid coolant.

As shown in Figure 11, a magnet rotating member 145 may be provided to reduce the strong sticking attraction of the magnetic circuit 30 on the cast strip 50 so that the thin flexible cast strip can be installed or removed without damaging it. The device 145 has an elongated cylindrical rotor 147 mounted on bearings 148 (FIG. 12) and extending longitudinally of the strip carriage, oriented parallel to and located between the pole members 39. Cylindrical rotor 147 has an axially open housing 146 made of two halves of magnetically soft ferromagnetic stainless steel, such as Type 430 stainless steel. The rotor contains a plurality of magnets 32 ( FIG. 12 ) whose internal flux paths S'-N' are oriented parallel to a diametrical surface 149 passing through the rotor 147 axis of rotation 151 . The rotor housing 146 has flattened sides 155 parallel to the diametrical face 149 to effectively form a north pole N' and a south pole S' on the rotor housing. Adjacent to the rotor 147 is mounted an intermediate bridge 154 of soft magnetic material, such as Type 430 stainless steel. These bridges 154 have cylindrical concave surfaces 153 facing the cylindrical rotor 147 and adjoining therewith at a distance.

In FIGS. 11 and 12, the rotor 147 is shown in its "off" position, in which the magnetic circuit is effectively disconnected, generally similar to 30 shown in FIG. The magnetic flux coming out of the magnet 32 is deflected away from the pole surface 34 . The deflected magnetic flux substantially bypasses the path from N' to S' by passing through the magnetic bridge 154 generally parallel to the direction of the rotor diameter face 149 . In this “off” position, the diameter face 149 and the flattened side 155 of the rotor are oriented parallel to the side surfaces of the pole members 39 . Therefore, the magnetic flux reaching the pole surface 34 is greatly reduced. Thereby, the attractive force on the casting belt 50 is greatly reduced, so that it can be installed and removed without causing damage to it. Upper and lower supports 156 and 158 are non-magnetic, for example, made of type 303 austenitic stainless steel.

To "turn on" the magnet rotation device 145 , its rotor 147 is rotated 90° about the axis 151 so that its diametrical face 149 is directly aligned with the central area of the concave surface 153 of the bridge 154 . Thus, the north poles N' and south poles S' of the magnets are closely magnetically connected by corresponding N' poles and S' poles located on their housings to closely connect these bridge members 154 so that in the array shown in FIG. Form a complete magnetic circuit. The "through" magnetic circuit in FIG. 11 can be thought of as passing from the magnet north pole N' through an N' pole of the rotor housing 34, 146, a first bridge member 154, a first pole member 39 to a first Pole surface 34, and enter cast band 50 through a first gap 75, extend in cast band to and pass through a second gap 75 and enter a second pole face 34, pass a second pole member 39 to reach second The bridge piece 154 passes through an S' pole of the rotor housing 146 to reach a magnet south pole S', together with the magnetic circuit from the S' pole to the N' pole inside each magnet, a complete magnetic circuit is formed.

In order to rotate the rotor 147 by 90° to its "on" position, its housing 146 is provided with a pivot 152 (Fig. 12) which is journalled in bearings 148 mounted on supports 156, 158. The housing 146 also has a clevis arm 162 fixed to the pivot and pivotally connected at 161 to a piston rod 163 connected to a piston in a hydraulic cylinder 160 165 on. A return spring 166 biases the piston to the "off" position of the magnet rotating device 145. The "on" position of rotor hanger arm 162 in FIG. 11 is indicated by dashed outline 162'. The hydraulic cylinder 160 has a piston chamber 167 which is connected to the coolant supply line 98 via a hose 164 . Thus, whenever pressurized coolant is supplied through header 100, the coolant enters piston chamber 167 and lifts piston 165 against the biasing force of spring 166 to turn rotor 147 to its "on" position. Once the coolant pressure is turned off, the spring 166 returns to the "off" position of the magnet rotation device 145 .

Instead of using separate hydraulic cylinders 160, to operate each rotor 147, all magnet rotation devices 145 in the array 51 hanger arms 162 may be pivotally connected to a common actuating rod that extends out of the array 51 and Manual or hydraulic operation for turning all rotors 147 to their "on" or "off" positions simultaneously.

Figures 13 and 14 show an alternative mechanism for turning the magnetic circuit to the "ON" or "OFF" position using a longitudinally moveable shunt bar of soft magnetic magnet material, such as Type 430 stainless steel. )170. The bypass lever 170 is slidably adjacent the pole member 39 and is slidable from its "OFF" position in FIG. 13 to its "ON" position in FIG. 14 . The bypass rod is toothed so as to provide a plurality of mesa-like projections 172 with spaced grooves 174 . The plateaus are spaced longitudinally along the rod 170 with a midpoint-to-midpoint spacing equal to twice the midpoint-to-midpoint spacing “d” of the pole members 39 . These plateaus 172 and their spaced slots 174 extend about the same distance "d" along the bypass rod. Thus, as shown in FIG. 13, in the "OFF" position, each plateau 172 directly adjoins, ie directly engages, two oppositely magnetic pole members 39, thus, directly from the N pole The center of member 39 bridges to the center of the adjacent S pole member so as to shunt the field lines away from pole surface 34 . Conversely, in the "on" position, all of the platforms 172 directly abut (engage) the pole members 39 of the same polarity (e.g., N), while the spacing slots 174 all face and engage with the pole members of the same polarity (e.g., S). The pole members are spaced apart and of a polarity opposite that of the pole members connected to the plateau. Thus, only minimal shunting occurs and the entire magnetic circuit 30 (FIG. 6) is completed as previously described.

In the illustrated embodiment of the invention, the elongated pole members 39 are mounted in an upstream to downstream orientation, as this longitudinal upstream to downstream orientation is well suited for twin belt casters. It appears to us that there may be moving belt caster configurations in which the transverse mounting of elongated pole members including a number of specially designed nozzles 90, 102 and their cleaning nozzles 112, 116 It is convenient to propel the coolant stream 115 laterally across the opposite side of the moving casting belt.

At the same time, we note that the elongated pole members 39 are longitudinally shaped such that the pole surfaces 34 are longitudinally curved to suit the special case, for example, in a single-strip caster where the path of a single cast strip generally follows A gently curved arc with a large radius. In such a casting machine with a longitudinally curved casting cavity, the pole surfaces 34 would be longitudinally curved in a gently curved arc corresponding to the gentle arc of the moving belt, so that the moving belt would be magnetohydrodynamically stabilized on its desired precise path. Such longitudinally curved pole surfaces can be considered as coplanar arrays because they stabilize the moving cast strip in a straight state.

Alternatively, in a continuous caster in which one or a pair of casting belts moves along a straight path, the pole surface 34 is straight in the longitudinal direction along the casting path, but the pole surface array may be gently curved in the transverse direction of the path. , so that it gently bends the casting strip laterally as it moves along the casting path. This array of laterally curved pole surfaces can be considered coplanar because they stabilize the moving cast strip in a flat state.

The effect of these embodiments of the present invention is that the moving casting belt is forced to remain straight and is limited within a narrow range of straightness (flatness) while also being limited within a distance from the magnetic The clearance (gap 75 ) of the pole surface 34 of the hydrodynamic support array 51 or 51 n of the device 38 is within a narrow range.

It is contemplated that any permanent magnet 32 made of a permanent magnet material having the very important key properties described above will successfully implement these embodiments of the disclosed invention. We prefer to employ magnets 32 comprising permanent magnetic materials commercially known as rare earth magnetic materials, such as magnets composed of magnetic materials comprising at least one "rare earth" chemical element (lanthanide chemical elements numbered 57 to 71), For example magnets of permanent magnetic material preferably containing the rare earth chemical elements neodymium or samarium. For example, a magnet composed of a permanent magnet material containing a compound of cobalt and samarium (Co ₅ Sm) with a maximum energy product of about 20 MGOe (Megagauss-Oersted) can be used because its BH hysteresis loop has a A remanent induction B _r of 9,000 Gauss, a magnet containing a Co ₁₇ Sm ₂ material with a maximum energy product of about 22 to 28 MGOe can also be used because its BH loop has a remanent induction in the range of about 9,000 to 11,000 Gauss B _r .

The Co ₅ Sm permanent magnet material with a maximum energy product of about 20MGOe has a mid-point differential demagnetization permeability of about 1.08. Co ₁₇ Sm ₂ permanent magnet materials with maximum energy products in the range of 22 to 28 MGOe have midpoint differential demagnetization permeability in the range from about 1.15 to 1.0.

Our most preferred permanent magnet 32 contains a three-element (ternary) compound of iron, neodymium and boron, commonly known as NdFeB, Nd-Fe-B or NdFeB based permanent magnet material, the maximum magnetic energy product range of NdFeB About from 25 to 35 MGOe. Such magnets may be referred to as "neodymium (neo) magnets", with neodymium (neo) magnets having from about 32 to 35 MGOe being most preferred at present. NdFeB permanent magnet materials with a maximum energy product of about 25 to 35 MGOe have a B-H loop with a remanent induction Br in the range of about 10,700 Gauss to about 12,300 Gauss and a midpoint differential demagnetization permeability of about 1.15. Neodymium (Neo) magnets have very low corrosion resistance, so they are nickel-plated.

We expect that in the future, other permanent magnet materials, such as iron-samarium-nitride and other unknown three-component compound permanent magnet materials and unknown four-element (quaternary) permanent magnet materials, may become commercially available products. It is possible to have a B-H loop with a sufficiently high residual magnetic induction Br as shown in Table I, and also have a sufficiently low midpoint differential demagnetization permeability as shown in Table II, which is suitable for the embodiments of the present invention.

Figure 15 shows an approximate generalized B-H loop 200 for a NdFeB permanent magnet material with a maximum energy product of about 35 MGOe. The B-axis and the H-axis intersect at the origin 216 . Such "neodymium neo magnet" materials typically exhibit a saturation magnetization at 202 of the order of from 20,000 to 25,000 Gauss as shown. The B-H curve 200 intersects the positive B-axis at point 204 with a remanence Br from about 12,000 to 12,300 Gauss. The portion of the loop 200 in the second quadrant ii (the demagnetization quadrant) is advantageously substantially a straight line 206 which slopes down to a point 208 on the horizontal H-axis with a value of about -11,000 Oersted. The negative sign for Oersted to the left of the B-axis indicates that the coercive force H acts in the opposite direction of the original coercive force that produced the initial magnetic saturation at 202 . Circle 210 represents the characteristic of portion 206 of loop 200 in the second quadrant ii of demagnetization which is the region of our present interest. The product of the indicated magnetic flux density value of about 7,000 Gauss times the indicated coercivity value of about 5,000 Oersted at the midpoint 212 of the substantially straight demagnetized portion 206 of the curve 200 gives the maximum The magnetic energy product is approximately 35,000,000 Gauss Oersteds, ie, approximately 35 megagauss Oersteds (approximately 35 MGOe).

The midpoint differential demagnetization permeability is determined at the midpoint 212, which is the slope of the line at the midpoint 212 to the tangent to the portion of the BH loop 206, approximately 1.15. In general, this permanent magnetic "neo-magnet" material has (1) a residual magnetic induction B _r of about 12,000 to about 12,300 Gauss, and (2) an average differential demagnetization permeability of about 1.15, allowing Provides a powerful and helpful sticking out attraction as stated.

Also shown in FIG. 15 is an approximate general BH loop 220 for Alnico 5 with a saturation magnetization. This hysteresis loop of AlNiCo 5 intersects the B axis at a residual magnetic induction Br of about 12,800 Gauss, as shown in Figure 6-3 of the above-mentioned Lester R. Moskowitz handbook for AlNiCo 5 As measured by the hysteresis residual magnetic induction B _r line. However, the Alnico 5 curve 220 has a saturation magnetization not greater than about 15,000 Gauss. The demagnetization curve 222 for Alnico 5 in the second quadrant ii falls almost vertically, intersecting the H-axis at 226, where it is less than 1,000 Oersted. Therefore, the maximum energy product of AlNiCo 5 is not greater than about 7MGOe. In addition to the small energy product ratio, the steep drop off of the demagnetization curve 22 for AlNiCo 5 indicates a midpoint differential demagnetization permeability of about 30 at the midpoint 224, which, as explained above, means that AlNiCo 5 is not suitable for the magnet used in the embodiment of the present invention.

A straight line 230 is shown in FIGS. 7 and 7A, which basically represents the increased gap distance 75 when using a magnet made of permanent magnet material "neo magnet" with optimum properties such as a maximum energy product of 35 MGOe. The pole surface 34 is plotted as a function of the gradual decrease in the protruding attractive force (pull force) of a moving cast strip such as cast strip 50. Increasing the gap distance 75 results in an equivalent increase in the demagnetization coercive force experienced by the permanent magnet 32, so that the attractive force drops along a generally straight line 230 having a straight portion similar to the B-H loop 200 in FIG. 15 206 features.

The gap distance 75 in inches and millimeters is shown on the horizontal axis, and the average pulling force (negative for magnet attraction) and average pushing force (positive for coolant repulsion) acting on the belt is shown on the vertical axis. The average pulling and pushing forces acting on the moving cast belt in psi (pounds per inch ² ) are difficult to measure, so these values along the vertical axis are only approximate; but their relative values are generally approximately proportional , and the most meaningful is their relative value.

Also shown in Figures 7 and 7A is a steeply falling curve 240 drawn as a function of gap distance 75, which essentially represents the flow of coolant 97 (Fig. The rapidly falling hydrodynamic repulsion (thrust against the belt) of the fast-traveling coolant film from the pressure pockets radiating out through the gap 75 . Assuming a properly pumped coolant is provided to the header 100, then increasing the diameter of the orifice 90 serves to increase the liquid flow 97 (FIG. 6) and increase the thickness of the membrane 114, thereby increasing the gap distance 75 and The effect of shifting curve 240 slightly to the right while also making curve 240 less steep can be thought of as making the action of the repelling coolant pad slightly more "elastic".

Under the conditions indicated generally at 242 of Figures 7 and 7A, a state is produced which stabilizes the moving belt equilibrium, at 242 the two curves 230 and 240 intersect. The curve intersection 242 is a state where there is no randomly varying thermally expanding strip deformation force (which will be treated below as if it were an "intrinsic strip pressure"), e.g. The opposite side of is cooled while under the influence of the hot metal in the mold cavity C, the heat generated in the casting strip causes expansion forces.

Although the term "force" appears more natural than the term "pressure" in describing the dynamics of the cast strip with reference to Figures 7, 7A, 7A' and 7A", we find that the thermodynamics produce a similar The effect of pressure. This pressure-like effect of internal thermal deformation force has the meaning of the word "pressure" in the following discussion, but is not added to the casting belt by the pressure groove 102 when the casting belt is in a stable state of equilibrium The greater pressure of the coolant. In the process of continuous casting of metal, there is always a rapid drift instability and also an indeterminate internal casting strip pressure. It is convenient to imagine that the random continuous Rapid vertical drift horizontal lines 260' and 26" are represented. Fig. 7A' shows the internal pressure of the medium-sized (about 3 p.s.i. pressure) casting belt represented by the reference line drawn by a horizontal line 260' Transient Condition. Figure 7A" shows the transient condition of the higher intrinsic belt pressure (pressure equal to approximately 5.5 p.s.i.) depicted by horizontal line 260".

In order to determine whether a given combination of conditions will lift the strip for stable and precise suspension, it is necessary to map all the forces, actual coolant pressures applied to the strip and the inner strip involved. pressure. In Figures 7 and 7A only the coolant pressure is given without plotting the random intrinsic belt pressure. However, during operation, there are generally two repulsive forces as shown in Figure 7A': not only (i) that produced by the coolant flow and coolant film 114 (each curve 240 in Figures 7 and 7A) pressure, but also (ii) the additional pressure generated by the transient stochastic intrinsic belt pressure depicted at 260', which is about 3 p.s.i. in Fig. 7A'. In FIG. 7A' these two curves 240 and 260' are added to form a new curve 240' which is the total repulsive pressure (thrust) against the magnetic (attractive pressure) curve 230. We can think of this composite curve 240' as continuously, randomly, and randomly changing up and down, as indicated by arrow 241 . The new intersection point 242' created between the protruding magnetic attraction curve 230 and the resultant thrust curve 240' in FIG. The magnetotraction pressure of the protruding magnets 32 is reduced by only a small percentage, so that the protruding magnetic attraction force remains firmly enforcing a stabilized cast strip.

In contrast, when considering the Alnico 5 magnetic curve 250, it can be seen that the instantaneous equilibrium intersection point between this curve 250 and the resultant thrust curve 240' is shifted farther to the right from position 252 in Figure 7A , move to intersection 252'. The magnetic stress, represented by curve 250 for Alnico 5, therefore drops by about 33%. Random abrupt changes in internal cast strip pressures 260' (FIG. 7A') and 260" (FIG. 7A") constantly move the equilibrium intersection point to a new location.

When the assumed transient random intrinsic cast strip pressure increases, equal to 5.5 p.s.i. as depicted by the horizontal line 260" of Fig. . The stick out magnetic balance intersection 242″ plotted on curve 230 represents only a small extra movement to the right, where the stick out pull is slightly further reduced by an additional small percentage. But for Alnico 5 The magnet, at an indeterminate intersection point 252" on the AlNiCo 5 curve 250, shows that the magneto-induced traction drops by less than half of what occurred before the cast strip pressure 260" within the transient stochastic. The gap 75 is substantially increased It is about 0.10 to 0.12mm larger. Furthermore, the equilibrium position 252" is no longer a definite intersection point but an area of uncertainty because the two curves 250 and 240" are not as guaranteed by the overhanging magnetic curve 230 The meeting at a defined large angle rather than at a very sharp acute angle (between the nearly parallel curves 250 and 240") makes the equilibrium position relatively uncertain. In this particular case, for a considerable distance, the curves 240" and 250 converge in an almost parallel relationship, making it almost impossible to reliably enforce a stable positioning of the cast strip. If an attempt is made to use AlNi In the case of a Cobalt 5 magnet, any stochastically unstable intrinsic strip pressure significantly higher than that plotted on curve 260" will unconditionally overcome the magnetic force represented by Alnico 5's curve 250 and dislodge the strip from pole member 39 control.

This very different behavior between the stick out magnetic attraction force curve 230 and the alnico 5 pull force curve 250 shown in FIGS. The intersection of (thrust) curves 240 is closer to vertical than parallel. On the other hand, the intersection of the Alnico 5 attraction curve 250 and the hydrodynamic coolant (thrust) curve is more parallel than perpendicular. Thus, thermal deformation displacement of a portion of the moving belt with a gap distance as small as 0.2 mm is likely to cause loss of stability control of the moving belt when dealing with random unstable forces with Alnico 5 magnets. Conversely, even when the gap distance is as large as 1.5 mm (about 0.06 inches) in Fig. 7, the attractive force (traction force) of the most preferred protruding represented by curve 230 drops by less than 50%, so the Stretch out traction most likely without losing the obligatory stability control.

In one embodiment of the present invention, another configuration of the hydromagnetic device 38A allows the rotatable permanent magnet 32 to be placed in the slot 127 between the wings 128 of each bite pulley 60 and 56 . The protruding magnets 32 together with their associated modified elongated pole members 39A are thus always located upstream of the bite zone line 110 . Thus, the upstream positioning of such magnets 32 together with their modified pole members 39A provides a coplanar array 51 of pole surfaces 34 spaced parallel to each other along the nip line 110 extending throughout upstream. Thereby, a sufficiently protruding magnetic attraction force emanating from a coplanar array of mutually spaced parallel pole surfaces 34 is available for stabilizing near upstream of the inlet 49 (FIG. 1) of the molten metal 37 into the moving mold cavity C Ferrous cast strips 50 and 52 in the zone. This upstream zone of the moving mold cavity near the nip zone line 110 includes the initial solidification zone adjacent to the solidified metal skin of the two rotating casting belts 52 and 50, which zone is extremely critical in the continuous casting of high quality metal products of (Figure 1).

Referring primarily to FIG. 16 , the protruding magnet 32 is shown interposed between the wings 128 of the upstream biting pulley 60 . The upstream end 118 of the pole surface 34 of the modified elongated pole member 39A at the bite region line 110 is shown. The line 110 is the tangential position of the casting strip 52 as it exits the nip into the belt vanes 128 and becomes travel in the downstream plane (straight) of the moving cavity C.

In the embodiment shown in Figures 11 and 12, the rotatable magnet 32 is located downstream in alignment with the wheeled wings 128 and extends upstream to be interposed between these wings. In the constructions shown in FIGS. 16 to 19, all parts of each modified pole member 39A, including their magnets, are made within the width of one pulley groove 127 (FIG. 17). In this embodiment shown in Figures 16 to 19, the center-to-center uniform spacing of the wings 128 is about one inch (about 25 millimeters), the thickness of the wings is about 1/8 inch (about 3.2 mm), and the width of the slot is about 1/8 inch (about 3.2 mm). About 7/8 inches (about 22mm). Accordingly, all parts of the modified pole member 39A are made narrow enough to be confined within a width of less than 7/8 inch (less than about 22mm). Thus, these modified elongated pole members 39A are disposed at a center-to-center parallel spacing of about 1 inch (25 mm) across the array of hydromagnetic pads 51 .

The illustrated bite pulley 60 has a solid core with wings machined integrally from the core, as best shown in FIGS. 16, 17 and 19 . The bite pulley 60, with its wings 128, is made of non-magnetic stainless steel, such as Type 316 wrought stainless steel, which is a non-magnetic material that has virtually no effect on a magnetic environment.

Referring now also to FIG. 17 , and looking downstream, it can be seen that the rotatable magnet 32 is located between the wheeled wings 128 . In Figure 17 (and also Figures 16, 18 and 19), the magnets 32 are shown rotated to the position where they magnetize the cast strip (extend to attract the cast strip). The rows of magnets 32 extending alternately from upstream to downstream in the array 51 are assembled within their respective pole members 39A in their magnet rotation means 145A such that they have the same polar orientation, for example their north poles N (N′) at the top; while the staggered rows of rotatable magnets 32 are assembled within their respective pole members 39A in their magnet rotators 145A such that they have opposite pole orientations with their south pole (S') at the top. The magnetic poles of the elongated pole members 39A in successive hydromagnetic devices 38A spaced apart from each other across the array of hydromagnetic pads 51 are drawn to the rotating cast belt 52 by these poles at the positions shown. The surface 34 has interleaved north (N) and south (S) poles facing the rotating casting belt 52 .

The magnetic force "line" 30 spans the air gap 129 near the wheeled wing 128 and across (through) the wheeled wing 128 itself, which is non-magnetic. A moderate amount of leakage flux 30' is unavoidable. However, the large amount of projecting flux 30 required passes through the pole surface 34 and extends through the cast strip 52 so that the cast strip is strongly projected and attracted towards the magnetically coplanar pad array 51 of the pole 34 .

The pumped coolant 93 at the previously described pressure is provided by a header (not shown), such as the header 100 shown in Figures 4 and 4A. This pressurized coolant 93 is fed through a supply pipe 98 and via a diagonal channel 96, into an upstream-pointing intermediate conduit passage 92A (FIGS. 16, 17 and 19) and from there into a downstream-pointing conduit passage 92 (FIG. 16 -19). These passages may be viewed as pressurized passages feeding pressurized coolant into the fixed-restriction passage 90 . The throttled and decompressed coolant 97 ejected from the channel 90 enters the pressure groove 102, and the fast moving coolant film 114 (Figs. Narrow gap 75. A balance is thereby achieved between the magnetic force and this hydrodynamic force, resulting in the stable levitation of the moving ferrous cast strip 52 against the coplanar array (flat array) 51 of the pole surfaces 34, as previously described for other embodiments of the invention like that.

It should be noted that the fixed passage 92 of FIGS. 4 and 4A has a portion in the upstream direction and a portion in the downstream direction, but their longer portions are on the upstream side. Instead, as shown in FIG. 16 , it is the intermediate conduit passage 92A that directs the coolant 93 upstream until a sufficiently large distance behind the nip line 110 . These intermediate conduit passages 92A then communicate with conduit passage 92 at a location far enough upstream from line 110 that coolant 93 flows downstream along this effective length of conduit passage 92 . The ends of passages 92A and 92 are closed by plugs 94 .

The cleaning nozzle 112 (seeing one in Fig. 16) near the front end 118 of the magnetic pole surface 34 and the tail end cleaning nozzle 120 (only seeing one in Fig. 16) located at the downstream 120 of the water magnetic pad array 51 ("reburner Nozzles") provide scavenging coolants 115 and 135, respectively, which are directed at an acute angle to the opposite side of the cast strip 52 for advantageous cooling which is ejected from the pressure slot 102 and which has passed through the gap 75 between the pole surface 34 and the cast strip reverse side. The agent film 114 (Figs. 17 and 18) is deflected downstream and propels it downstream.

It can be seen that in the embodiment of the invention shown in FIGS. 2 to 6 and 11 to 14 there is a magnet 32 located between elongated pole members 39 . In addition, in order to apply a reach-out attractive force to the casting belt, the internal North (N')-South (S') field lines of the magnets in each fixed position in FIGS. 2 to 6 and FIGS. 13 and 14 The paths of the pole members 39 are oriented parallel to the plane of the cast strip and perpendicular to the side surfaces of the pole members 39 . Magnetic rotation means 145 in FIGS. 11 and 12 are also located between pole members 39 . The magnetic rotating device 145 is shown in FIG. 11 in the "OFF" position, wherein the paths of the internal North (N')-South (S') flux lines of its magnets 32 and rotor 147 are oriented perpendicular to the plane of the cast strip and Parallel to the side surface of the pole member 39 . When the control arm 162 of the rotatable device 145 is turned to the "on" position 162' (FIG. 11), the internal North (N')-South (S') flux path of the magnet 32 and its rotor 147 becomes the same as The cast strip planes are oriented parallel and perpendicular to the pole members 39 .

In FIG. 11, there is a bridge 154 made of soft magnetic demagnetizing material with elongated cylindrical concave surfaces 153 facing and adjacent to the elongated cylindrical rotor 147 of the magnetic rotary device 145 for The rotor in the "on" position transmits flux between two adjacent pole members 39 .

In the embodiment shown in Figures 16 to 19, modified magnetic rotation means 145A (only one shown) are located within their respective modified elongated pole members 39A. For emphasis, it is repeated here that each modified magnetic rotary device 145A (Figs. 16-19) is located within each modified magnetic pole member and is distinct from the magnetic rotary device 145 (Figs. 11 and 12), which between two adjacent pole members 39 .

In order to incorporate the magnetic rotary device 145A into each of the modified elongated pole members 39A, each such pole member is made into first and second parts 39A-1 and 39A-2, each of which has a An elongated cylindrical concave surface 153 (FIGS. 17 and 18) faces and abuts the elongated cylindrical rotor 147 of the magnetic rotary device 145A.

The first pole member portion 39A-1 is adjacent to the casting belt 52 or 50 and is configured to include a conduit passage 92, a throttle passage 90, a pressure groove 102, a pole surface 34, cleaning nozzles 112 and 120, and includes as shown in FIG. 16- Other parts mentioned in 19.

Second pole member portion 39A-2 is remote from cast band 52 or 50 and includes diagonal passage 96, intermediate passage 92A and includes other features as shown in FIGS. 16-19. The second portion 39A-2 also includes a frame portion 176 of the array 51 (FIG. 18). The frame 176 shown in FIG. 18 transversely spans and rigidly connects the plurality of second pole members 39A- 2 . The illustrated frame 176 includes a plurality of elongated cylindrically curved surfaces 153 that abut but are spaced from each rotor 147 in each modified pole member 39A. The frame 176 can be machined to span and connect to as many distant pole member portions 39A-2 as desired. It can span the full width of the belt if desired, depending on the manufacturing process. Alternatively, a plurality of narrower frames 176 may be formed and arranged side by side so as to span laterally the entire width of the belt.

To assemble and support the entire array 51 in the casting machine, a beam 180 (Figs. 16 and 19) is secured to the frame 176 (or to multiple narrower frames 176 arranged side by side).

As indicated by the diagonal dashed line 178 in FIGS. 16 and 19, the frame 176 is slotted to provide clearance for biting into the pulley wing 128 represented by the gap 129 in FIG. The slot cut at 178 provides a plurality of slots, each having a width equal to two air gaps 129 (FIG. 17) plus the width of one wing 128, and thereby forming a plurality of upstream extending away from the pole member portions. 39A-2 (Figures 16, 17 and 19). To provide clearance for the core biting into the pulley 60, one surface of each remote pole member portion 39A-2 is machined diagonally at 180.

To secure adjacent pole member portions 39A-1 to frame 176, longitudinally extending shoulders 182 are provided on both sides of their members 39A-1. Clamping rods 184, e.g. made of non-magnetic stainless steel, are non-magnetic, e.g. Magnetic mechanical bolts 186 are mounted to frame 176 . The width of the fastening bar 184 is suitable for positioning the adjacent pole portions 39A- 1 spaced apart from each other and parallel. Simultaneously, the length dimension of mechanical bolt 186 is such that when the cylindrical curved surface 153 close to magnetic pole portion 39A-1 suitably bands a certain distance against the rotor of each magnetic rotating device 15A, the end of mechanical bolt will be close to the socket 187. Ends.

Referring again to FIG. 16, it can be seen that the nose 39n-1 of the approaching pole portion 39A-1 protrudes upwardly above the cylindrically curved surface 153 of the approaching pole portion. The nose 39n-1 abuts on the remote pole portion 39A-2 at the nose 39n-2 and includes a connecting passage 92-1 which communicates the intermediate passage 92A with the conduit passage 92. At the same time, the nose 39n-1 assists in securing the distant and close pole sections 39A-2 and 39A-1 together by means of a mechanical bolt 188 which passes through a nose 39n-2 of the distant pole section 39A-2. And screw into the socket 189 of the first nose 39n-1.

The structure and operation of a modified magnet rotating device 145A (only one is shown) will now be described. The magnets 32 are assembled in a plurality of strips 177 ( FIGS. 16 and 19 ) within each rotor 147 of the magnet rotation device 145A. For example, Figure 16 shows a rotor with three magnet strips 177-1, 177-2, 177-3. The two axially aligned magnet strips 177-2 and 177-3 each include three magnets. The rotor is shown with the third furthest upstream side strip 177-1 containing four magnets. This last strip 177 - 1 extends to the bite area line 110 upstream.

The illustrated magnet 32 (FIGS. 17 and 18) is shaped to have a pair of flattened sides and has a pair of parallel keyways 190, one on each side. These keyways extend longitudinally in the direction of the elongated cylindrical rotor 147, ie they extend parallel to the axis of rotation of the rotor. The magnets in each of the strips 177-1, 177-2 and 177-3 are fastened to a pair of parallel elongated side fittings 146 of non-magnetic material formed in the magnet's slot housing. The inner surfaces of these side fittings 146 conform to the sides of the magnets in the strip. Each fitting has an elongated rib (key) projecting radially inwardly and fits into the keyway 190 of the magnet in the strip.

The perimeter of the side fitting 146 and the perimeter of the poles N' and S' are shaped to form a cylindrical outer surface for the rotor against the curved cylindrical surface 153 of the adjacent and distant pole sections 39A-1 and 39A-2. surface.

As shown on the right in FIGS. 17 and 18 , the ends of the side fittings 146 are mounted by mounting bolts 191 into the halves of the end fittings 192 . As best shown in FIG. 19 , the end fitting of the intermediate strip 177 - 2 has a receptacle 193 for connection to the shaft of the rotor 147 . Journals 194 project axially from the end fittings of the upstream and downstream strips 177 - 1 and 177 - 3 , the ends of which fit into sockets 193 and are secured in these sockets with pins 195 . These journals 194 are supported and are rotatable on sleeves 195 which are fastened by a housing 196 .

The upstream end journal 194 on the upstream side end fitting of the first strip 177-1 is mounted in a bushing supported by a housing 197 secured to the remote pole by a mechanical bolt 198. Part 39A-2 on. A downstream end journal projects axially through bushing 196 which is secured by a mounting bolt 198 to a bracket 199 on remote pole portion 39A-2.

In order to enable the ferrous cast belt 52 to be removed and replaced, each magnetic rotary device 145A is turned from the "on" position shown in FIGS. At this position, the magnetic poles N' and S' are in a direction parallel to the cast strip, that is, the magnetic poles N' and N' of the same polarity and the magnetic poles S' and S' of the same polarity become turned to face each other thereby greatly reducing the Attractive force in the middle of the pole surface 34 and the cast strip 52 . An actuating lever arm 162 ( FIG. 16 ) is fastened to the axially protruding downstream end journal 194 of each magnetic rotary device 145A in the array 51 . A common lever 201 is connected to the end of each actuation lever arm 162 by a pivot connection 203 throughout the array. All strips in the entire array 51 can thus be rotated to their "on" or "off" positions simultaneously by moving the common joystick 201 .

While certain embodiments of the invention have been disclosed in detail, it should be understood that these examples of the invention are for purposes of illustration. This disclosure should not be seen as limiting the present invention, because persons familiar with the field of continuous casting can change the details of the described method and equipment or use equivalent permanent ones without departing from the scope of the following claims Magnetic material so that these apparatuses and methods are suitable for maintaining a rotating annular flexible heat-conducting ferromagnetic material containing magnetically soft ferromagnetic material with suitable straightness during continuous casting and in a continuous casting machine during continuous casting of metals The straight state of the casting belt in the middle, and further make it available for various specific belt casting machines or various belt continuous casting equipment.

Claims (62)

1, a kind of method of stablizing and cooling off the ring-type flexible thin heat conduction Cast Strip of containing the soft magnetism ferromagnetic material, advance in the crystallizer space that wherein casts along a motlten metal in this Cast Strip, this Cast Strip has a front surface and the reverse side that deviates from this crystallizer space towards the crystallizer space simultaneously, said method comprising the steps of:

Have the ferromagnetic pole pieces array of soft magnetism that is arranged on the pole surface in the coplane array of Cast Strip reverse side by one the Cast Strip is applied the power of stretching out, applying this method of stretching out power and be by adopting provides enough suitable permanent magnets of stablizing the power of stretching out of this Cast Strip to magnetize described pole pieces to the Cast Strip to realize; And

Meanwhile inject by the multiply supercharging cooling agent stream that ejects near the pole surface place to the Cast Strip reverse side, described cooling agent stream makes the Cast Strip float with pole surface and separates certain clearance with it, advances in the gap that described cooling agent stream of while passes between Cast Strip reverse side and the pole surface.

2, the method for claim 1 comprises:

Before described multiply supercharging cooling agent stream is injected into the Cast Strip reverse side, with they throttlings regularly.

3, the method for claim 1 comprises:

Guide one basically the uniaxially cooling agent stream that passes the gap between the pole pieces along the Cast Strip reverse side be used for removing the cooling agent that has passed described gap from the Cast Strip reverse side.

4, the method for claim 1 comprises:

Utilization in described coplane array, have north and south poles alternately pole surface permanent magnet with described pole pieces magnetize,

5, the method for claim 1 comprises:

The liquid coolant flow that pumps into is ejected into the head tank that is close to pole surface in the face of the Cast Strip reverse side, simultaneously

Before the liquid coolant that will pump into is ejected into head tank with the liquid coolant throttling that pumps into.

6, method as claimed in claim 4 comprises:

With the liquid coolant that pumps into spurt into by pole surface around head tank, and

Before spurting into each head tank respectively with liquid coolant throttling regularly.

7, the method for claim 1 comprises:

Before the described multiply cooling agent stream of throttling regularly, provide the liquid coolant of suitable pressurization to be used for making it and pole surface certain interval at interval the Cast Strip is floating.

8, the method for claim 1 comprises:

Utilize permanent magnet that described pole pieces is magnetized, wherein, at least one magnet has a mid point differential demagnetization magnetic conductivity that is equal to or less than about 4 Δs Gauss/Δ oersted.

9, method as claimed in claim 8 comprises:

Utilize the described pole pieces of permanent magnet magnetization, wherein, at least one magnet has a residual magnetic flux density that is equal to or greater than about 8,000 Gausses.

10, the method for claim 1 comprises:

Utilize the described pole pieces of permanent magnet magnetization, wherein, at least one magnet has the mid point differential demagnetization magnetic conductivity that is equal to or less than about 2.5 Δs Gauss/Δ oersted.

11, method as claimed in claim 10 comprises:

Utilize the described pole pieces of permanent magnet magnetization, wherein, at least one magnet has a residual magnetic flux density that is equal to or greater than about 10,000 Gausses.

12, the method for claim 1 comprises:

With the described pole pieces of permanent magnet magnetization, wherein at least one magnet has one and is equal to or greater than about 10,000 Gausses' residual magnetic flux density and has the mid point differential demagnetization magnetic conductivity that is equal to or less than about 1.2 Δs Gauss/Δ oersted.

13, the method for claim 1 comprises:

By a large amount of magnetic lines of force is departed from out the Cast Strip, make and easily the Cast Strip to be removed from the crystallizer space.

14, the method for claim 1 comprises:

Before motlten metal being fed into described crystallizer space, supply coolant stream under the pressure that is used to form the described cooling agent stream that pumps into;

Before the Cast Strip is removed from the crystallizer space and before the cooling agent in stop supplies, the feed-disabling melt metal; And

Be used to make the pressure of liquid coolant of magnetic force tape and utilization that described pressure is not existed by utilization and the magnetic line of force is departed from the Cast Strip, automatically optionally the magnetic line of force is turned to the Cast Strip and depart from the Cast Strip, so that can easily the Cast Strip be removed from the crystallizer space.

15, a kind of method of stablizing and cooling off the ring-type flexible thin heat conduction Cast Strip of containing the soft magnet magnetic material, advance in the crystallizer space that wherein casts along a motlten metal in this Cast Strip, this Cast Strip has a front surface and the reverse side that deviates from this crystallizer space towards the crystallizer space simultaneously, said method comprising the steps of:

The Cast Strip reverse side is placed array place near a soft magnet magnetic material pole pieces, and these pole pieces have pole surface, and these pole surface are arranged in one in the coplane array of Cast Strip reverse side;

Utilize permanent magnet that described magnetic pole is magnetized, make the pole surface with north and south poles alternately be positioned at described coplane array, the enough strong magnetic attraction that stretches out by being stretched out by pole pieces is stabilized in straightened condition with the Cast Strip,

Meanwhile, by cooling agent stream being pumped in the head tank that is centered on by pole surface, so that cooling agent stream is added to the reverse side of Cast Strip, the cooling agent stream that utilization is discharged from head tank, make it the Cast Strip to be supported on the position of leaving pole surface by the reverse side of Cast Strip and the gap between the pole surface.

16, a kind of equipment of stablizing and cooling off the ring-type flexible thin heat conduction Cast Strip of containing the soft magnet magnetic material, advance in the crystallizer space that wherein casts along a motlten metal in this Cast Strip, this Cast Strip has a front surface and the reverse side that deviates from this crystallizer space towards the crystallizer space simultaneously, and described equipment comprises:

A plurality of hydromagnetic devices;

Each hydromagnetic device comprises a pole pieces of being made by the soft magnet magnetic material with pole surface;

Described pole surface is positioned at one can be in the face of the coplane array of Cast Strip reverse side;

Each hydromagnetic device comprises that at least one can and comprise a path that is used for the liquid coolant that supply pumps in head tank towards the head tank of the contiguous pole surface of Cast Strip reverse side;

A plurality of permanent magnets magnetize described pole pieces, make them have the pole surface of the north and south poles that replaces that is positioned at described array; And

Described magnet provides the magnetic pull that stretches out of enough sensing pole surface, is suitable for the Cast Strip is stabilized in straightened condition, makes it to be suspended in groove simultaneously and ejects and can pass on the cooling agent of the supercharging of advancing in the gap between Cast Strip reverse side and the pole surface.

17, equipment as claimed in claim 16, wherein:

A plurality of cooling agents are removed nozzle with direction in the unidirectional basically cooling agent adfluxion, utilize enough big momentum to remove along the Cast Strip reverse side, will remove away from the surface, Cast Strip by the cooling agent between Cast Strip reverse side and the pole surface.

18, equipment as claimed in claim 17, wherein:

Each hydromagnetic device comprises a plurality of head tanks towards the Cast Strip reverse side, and described head tank is near a pole surface, and described hydromagnetic device comprises that a plurality of described paths will be fed into the cooling agent stream throttling of each independent pressure groove simultaneously.

19, equipment as claimed in claim 16, wherein:

Pole pieces is that elongated and parallel at certain intervals relation forms the elongated pole surface coplane array that the space is parallel;

Each pole pieces comprises a plurality of head tanks, and these head tanks are positioned at the position that is spaced apart from each other along elongated pole pieces, and each head tank is centered on by the each several part of the pole surface of pole pieces, and head tank is positioned within the pole pieces.

20, equipment as claimed in claim 19, wherein:

Described cooling agent remove nozzle with described unidirectional basically cooling agent conductance to by the slender space between the elongated pole pieces.

21, equipment as claimed in claim 16 comprises:

The magnetic line of force arrangement for deflecting that can between the position of " leading to " and " breaking ", move;

The position that " leads to " can produce the described enough strong magnetic attracting force that stretches out to pole surface;

The position of " breaking " reduces the magnetic pull of pole surface, makes it possible to easily the Cast Strip be removed from the crystallizer space.

22, equipment as claimed in claim 21 comprises:

Pressure-responsive mechanism, existence response to the pressure of the liquid coolant that pumps into, described magnetic line of force deflecting apparatus is moved to the position of " leading to ", and to the pressure of liquid coolant do not have a response, described magnetic line of force deflecting apparatus is moved to the position of " breaking ".

23, a kind of method of stablizing and cooling off the ring-type flexible thin heat conduction Cast Strip of containing the soft magnet magnetic material, advance in the crystallizer space that wherein casts along a motlten metal in this Cast Strip, this Cast Strip has a front surface and the reverse side that deviates from this crystallizer space towards the crystallizer space simultaneously, said method comprising the steps of:

The Cast Strip of motion is pulled to the coplane array of a pole surface with the magnetic attracting force that stretches out, this array surface is to the reverse side of motion Cast Strip and have alternately north and south magnetic pole on the pole pieces of soft magnet magnetic material, these pole pieces can be provided the enough strong permanent magnet magnetization that stretches out magnetic attraction, are used for the Cast Strip is stabilized in straightened condition; And

Simultaneously the Cast Strip is floated, leave the certain interval of pole surface, be suspended in by on the liquid coolant of the supercharging of throttling, cooling agent is by advancing near the ejection of the nozzle of pole surface and by the reverse side of the Cast Strip of being floated and the gap between the pole surface.

24, method as claimed in claim 23 comprises:

By liquid coolant in the face of a plurality of nozzle ejection superchargings in the pole pieces of Cast Strip reverse side.

25, method as claimed in claim 24 comprises:

The elongated pole pieces that each has an elongated pole surface is set,

Described pole pieces come with the space and be provided with abreast, between about 3/4 inch adjacent pole member in about 2 inches scopes, limit a slender space in adjacent spacing.

26, method as claimed in claim 25 comprises:

By spraying independently by the liquid coolant of throttling along each longitudinally-spaced individual nozzle of each pole pieces, wherein each nozzle is centered on by the part of an elongated pole surface.

27, a kind of method of stablizing and cooling off the ring-type flexible thin heat conduction Cast Strip of containing the soft magnet magnetic material, advance in the crystallizer space that wherein casts along a motlten metal in this Cast Strip, this Cast Strip has a front surface and the reverse side that deviates from this crystallizer space towards the crystallizer space simultaneously, said method comprising the steps of:

A plurality of elongated soft magnet magnetic material pole pieces are set, and each member has an elongated pole surface;

Pole pieces with the parallel relation location of each interval, is limited elongated space between adjacent pole pieces, the elongated pole surface of elongated pole pieces is arranged in the coplane array;

A plurality of permanent magnets that stretch out that each has the north and the South Pole are set;

With magnet pole pieces is magnetized, make adjacent pole surface in the array have north and South Pole polarity alternately;

Pole surface coplane array by the described pole pieces of facing the Cast Strip reverse side that is magnetized applies the magnetic attracting force that stretches out to the Cast Strip; And

Apply multiply by the liquid coolant flow that pumps into of throttling to the Cast Strip reverse side, the Cast Strip is floated, leave the certain interval of pole surface, described cooling agent stream is from being close to that pole surface ejects and advancing forward by the gap between Cast Strip reverse side and the pole surface.

28, method as claimed in claim 27 comprises:

Elongated pole pieces to be spaced apart from each other and parallel relation location, is limited the slender space between the adjacent magnetic sheet member, wherein, described pole pieces space approximately from 3/4 inch to about 2 inches distance.

29, method as claimed in claim 28 comprises:

Be applied to the liquid coolant of removing along the Cast Strip reverse side in the slender space between the adjacent pole member.

30, method as claimed in claim 28 comprises:

In adjacent each described slender space that is spaced apart from each other between the parallel elongated pole pieces, insert at least one permanent magnet; And

Described permanent magnet is arranged in the described slender space, and the permanent magnet pole that makes identical polar is to the reverse side towards each pole pieces.

31, method as claimed in claim 30 comprises:

A plurality of north (N ') and south (S ') pole surface that to stretch out permanent magnet place near adjacent pole pieces side.

32, method as claimed in claim 30 comprises:

Insert a plurality of elongated near the permanent magnet of arranging the effect of stretching out in line along each; And

In each slender space, their polarity is arranged along same direction.

33, method as claimed in claim 27 comprises:

Setting has residual magnetic flux density and is equal to or greater than about 8,000 Gausses and has the permanent magnet that mid point differential demagnetization magnetic conductivity is equal to or less than the effect of stretching out of about 4 Δs Gauss/Δ oersted.

34, method as claimed in claim 33 comprises:

Make the magnetic line of force depart from out the Cast Strip, so that can easily the Cast Strip be removed in the crystallizer space.

35, a kind of equipment of stablizing and cooling off the ring-type flexible thin heat conduction Cast Strip of containing the soft magnet magnetic material, advance in the crystallizer space that wherein casts along a motlten metal in this Cast Strip, simultaneously this Cast Strip have one towards the front surface in crystallizer space and one towards reverse side away from this crystallizer space, described equipment comprises:

Separate each other, parallel, the ferromagnetic pole pieces of elongated soft magnetism;

Each pole pieces has an elongated pole surface, along the pole pieces longitudinal extension;

The described pole surface of described pole pieces is arranged on one in the pole surface coplane array of Cast Strip reverse side;

Each pole pieces has a plurality of nozzles in its elongated pole surface;

Described nozzle is positioned on the position that the each interval of pole surface comes;

Each pole pieces has a service duct, from this passage to described nozzle supply coolant; And

A plurality of permanent magnets that stretch out effect are used to magnetize described pole pieces, and these pole pieces form the pole surface array of north that replaces and south magnetic pole, by the magnetic attraction that stretches out the Cast Strip are pulled to pole surface.

36, equipment as claimed in claim 35, wherein, partly advance around wing shape belt wheel roller of nipping in porch, crystallizer space in the Cast Strip, wherein:

The wing shape belt wheel roller of nipping is nonmagnetic and has the non magnetic wing; And

Elongated pole pieces has narrow nose, and this nose protrudes with respect to the upstream side of the direct of travel of Cast Strip and is assembled in the groove on the belt wheel roller of nipping between the adjacent foil.

37, equipment as claimed in claim 36, wherein:

The nose of elongated pole pieces upstream protrudes into after the district of nipping of crystallizer space inlet, disengages in this Cast Strip, place and the wing.

38, equipment as claimed in claim 36, wherein:

Each nose comprises the removing nozzle of a sensing with respect to the downstream of Cast Strip direct of travel, described removing nozzle points to the reverse side of Cast Strip with an acute angle, be used for the cooling agent conductance to, side is removed along the Cast Strip reverse side between elongated pole pieces downstream.

39, as equipment as described in the claim 38, wherein:

Remove nozzle and place after the district of nipping of upstream side crystallizer space inlet, at this place, the Cast Strip and the wing disengage.

40, equipment as claimed in claim 35, wherein:

The permanent magnet that stretches out effect has the residual magnetic flux density that is equal to or greater than about 8,000 Gausses; And

The permanent magnet that stretches out effect has the mid point differential demagnetization magnetic conductivity that is equal to or less than about 4 Δs Gauss/Δ oersted.

41, equipment as claimed in claim 35, wherein:

Each nozzle comprises a head tank, and this head tank is centered on by a zone of the pole surface of pole pieces towards the reverse side of Cast Strip, and nozzle then is arranged in pole pieces; And

Each nozzle comprises that a throttling path is fed into cooling agent the head tank from service duct.

42, equipment as claimed in claim 40 comprises:

Can be at the magnetic line of force arrangement for deflecting of " leading to " and " breaking " position intermediary movements;

Can produce the enough strong attraction of stretching out in the position of " leading to ", be used for revolting aptly thermal deformation, stablize the Cast Strip to pole surface; And

At the magnetic attraction of the position of " breaking " reduction, thereby can easily the Cast Strip be removed in the crystallizer space to pole surface.

43, equipment as claimed in claim 35, wherein:

An end of each pole pieces comprises that is removed a nozzle, its downstream side point to the reverse side of Cast Strip, be used for the cooling agent guiding, along the reverse side of Cast Strip downstream skidding advance, the end of described pole pieces is positioned at the downstream with respect to the direct of travel of Cast Strip.

44, equipment as claimed in claim 41, wherein:

From feed path to being positioned at a throttling passage of a downstream pressure groove supply coolant of the downstream of close each elongated pole pieces, its cross-sectional area is bigger than the cross-sectional area of other throttling passage in the pole pieces, described other throttling path other head tank supply coolant in pole pieces; And

Downstream head tank downstream is opened and is formed a removing nozzle that points to the downstream, is used to make cooling agent along Cast Strip reverse side flow further downstream.

45, equipment as claimed in claim 44, wherein:

The downstream of each pole pieces has a flange surface towards the Cast Strip reverse side, and assembles to the Cast Strip reverse side along downstream direction; And

Downstream pressure groove downstream is opened, and its sidewall is dispersed and described flange surface is diverged along downstream direction.

46, equipment as claimed in claim 35, wherein partly advance around the belt wheel roller of nipping in the Cast Strip simultaneously, the belt wheel roller of nipping can and have along the belt wheel roll shaft to the identical a plurality of circular wing of isolated diameter around an axle rotation, these wings radially protrude from the belt wheel roller, between the adjacent wing, limit groove, wherein:

Described belt wheel roller is non magnetic;

The described circular wing is made of the soft magnet magnetic material; And

Each elongated pole pieces has an elongated narrow nose, and the updrift side of advancing to the Cast Strip is protruded, and is assembled in the groove between the adjacent foil.

47, adopt at least one annular flexible thin heat conduction Cast Strip of containing the motion of soft magnet magnetic material, the belt caster advanced along the crystallizer space of moving in this Cast Strip at one, this Cast Strip have one towards motlten metal in the front surface in crystallizer space of wherein casting and a reverse side that is used to cool off this Cast Strip, be used for equipment stable and that cool off this motion Cast Strip and comprise:

One is spaced from each other, parallel water cushion apparatus array;

Each described water cushion device comprises a slender member, and it has an elongate surface of extending along this member;

The described elongate surface of described member be positioned at one be spaced from each other, the coplane array of parallel elongate surface in the face of the Cast Strip reverse side;

Each slender member has a plurality of nozzles on its elongate surface;

Described nozzle is positioned at along elongate surface position spaced apart;

Each slender member has a service duct, by this passage to described nozzle supply coolant;

Each nozzle comprises that one centers in the face of the outlet of Cast Strip reverse side and by a zone on surface; And

Each member comprises the throttling path, is used for from service duct to the export supply cooling agent.

48, equipment as claimed in claim 47, wherein:

Described water cushion device is a magnetic water cushion device;

Described slender member is made of the soft magnet magnetic material;

Described elongate surface is elongated pole surface;

A plurality of permanent magnets that stretch out effect magnetize described slender member, and there is surperficial array in the formation that forms the north that replaces and the South Pole, by the magnetic attracting force that stretches out the Cast Strip are attracted to elongated pole surface;

The permanent magnet that stretches out effect has the residual magnetic flux density that is equal to or greater than about 8,000 Gausses; And

The permanent magnet that stretches out effect has the mid point differential demagnetization magnetic conductivity that is equal to or less than about 4 Δs Gauss/Δ oersted.

49, equipment as claimed in claim 47, wherein:

Resilient installing mechanism carries out resilient installation with described hydromagnetic apparatus array, make it towards with move smoothly away from the direction in crystallizer space.

50, equipment as claimed in claim 48, wherein:

At least the permanent magnet that stretches out effect is inserted in the slender space between the adjacent elongated member;

Magnet makes the side orientation of its each pole surface in the face of the adjacent elongated member; And

Each slender member has the subtend of the magnetic pole strength of identical polar to slender member, with the slender member magnetization, is used to provide the elongated pole surface array of alternately northern and south magnetic pole.

51, equipment as claimed in claim 48 also comprises:

Space comes, parallel water cushion apparatus array;

Each described water cushion device comprises a slender member, and this slender member has an elongated pad surface along the slender member longitudinal extension;

Described elongated pad surface is positioned at that come in a space towards the Cast Strip reverse side, the parallel surperficial array of the elongated pad of coplane;

Each slender member has a plurality of nozzles that are positioned at its elongated pad surface;

Described nozzle is positioned at along elongated pad surface to be gone up on the spaced position;

Each slender member has a service duct, thus to described nozzle supply coolant;

Each nozzle comprises one in the face of the Cast Strip reverse side and by the outlet that the zone centers on pad surface;

Described member comprises that throttling passage is used for from service duct to the export supply cooling agent;

Described throttling passage in described water cushion device has the throttling passage big cross-sectional area of a ratio in described hydromagnetic device; And for the direct of travel of motion Cast Strip, described water cushion apparatus array is positioned at the downstream of described magnetic water cushion apparatus array.

52, equipment as claimed in claim 51, wherein:

The described slender member of described water cushion device extends downstream from the pole pieces of magnetic water-cushion device; And

The permanent magnet that stretches out effect only is included in the magnetic water cushion device.

53, a kind of method of stablizing and cooling off the ring-type flexible thin heat conduction Cast Strip of containing the soft magnet magnetic material, advance in the crystallizer space that wherein casts along a motlten metal in this Cast Strip, simultaneously this Cast Strip have one towards the front surface in crystallizer space and one towards reverse side away from this crystallizer space, said method comprising the steps of:

A plurality of magnetic circuits that stretch out are set;

Each magnetic circuit comprises a part that is positioned at the Cast Strip, and extends along a path between the obverse and reverse of Cast Strip, extends abreast with the obverse and reverse of Cast Strip basically simultaneously;

Each magnetic circuit also comprises a part, and this part is roughly the U-shaped pattern with one extends, and this U-shaped pattern has the shank of the pattern of U-shaped, and these shanks extend to the subtend in described path to the reverse side of Cast Strip;

The liquid coolant that applies supercharging to the Cast Strip reverse side is used to cool off the Cast Strip and the Cast Strip is floated with the fluid dynamic educational level of the liquid coolant of supercharging, and cooling agent increases the length of the shank of described U-shaped pattern; And

Weaken and describedly stretch out the magnetic flux in the magnetic circuit in the crystallizer cavity so that can easily the Cast Strip be shifted out.

54, method as claimed in claim 53, wherein:

Described magnetic circuit path is with respect to Cast Strip direct of travel horizontal expansion; And

The adjacent leg of U-shaped pattern have same pole polarity make the shank of north magnetic to that replace and shank South Pole magnetic to horizontal expansion with respect to the Cast Strip direct of travel.

55, method as claimed in claim 53, wherein, the belt wheel roller of nipping is positioned at the district of nipping of crystallizer space upstream extremity, the described belt wheel roller of nipping is made of nonmagnetic substance and has a plurality of circular wings of being made by nonmagnetic substance, they equably along the belt wheel roll shaft of nipping to being spaced and all having an identical external diameter, simultaneously, described Cast Strip near the crystallizer space time partly around the belt wheel roller of nipping advance with the contact of the described wing then the Qu Yuyi that nips separate with being oriented in a tangential direction and along the crystallizer cavity to be roughly the shape advanced downstream on plane, described method comprises:

The described magnetic circuit that stretches out is guided through the non magnetic circular wing of the non magnetic belt wheel roller of nipping and passes the small the air gap of the both sides that are positioned at each wing simultaneously.

56, method as claimed in claim 55, wherein:

Described each of stretching out magnetic circuit is all by a plurality of permanent magnet excitations that stretch out effect, the described permanent magnet that stretches out effect aligns in line and is arranged in the magnet tandem, and these magnets are inserted between the successively contiguous wing and in the Cast Strip with nip between the belt wheel roller.

57, method as claimed in claim 56, wherein:

Stretching out the magnet tandem can extend around being parallel to each other and parallel with the Cast Strip, plane basically axle rotation;

In order to apply the attraction of stretching out to the downstream, Cast Strip from the district of nipping, stretching out the magnet tandem of effect rotates, pass the tandem that replaces that the Cast Strip width has alternately north (N ') and south (S ') utmost point in the face of the Cast Strip by making, make north (N ')-Nan (S ') magnetic line of force path of their inside be substantially perpendicular to the Cast Strip that is roughly the plane and be orientated; And

Reduce and describedly stretch out the magnetic flux in the magnetic circuit in the crystallizer cavity, comprise the steps: so that easily the Cast Strip is shifted out

While rotating magnet tandem, point to north (N ') utmost point of adjacent tandem by north (N ') utmost point that makes each tandem, make south (S ') utmost point of each tandem point to south (S ') utmost point of adjacent tandem, make north (N ')-Nan (S ') magnetic line of force path of their inside be arranged essentially parallel to the Cast Strip orientation that is roughly the plane.

58, equipment as claimed in claim 36, wherein:

Described elongated pole pieces comprises:

First, its close Cast Strip,

And second portion, it is away from the Cast Strip;

Described first and second parts of pole pieces are assembled in the groove of the belt wheel roller of nipping between the adjacent foil;

In the described elongated pole pieces each comprises an elongate rotor, between described first and second parts of pole pieces;

Each elongate rotor is along elongated pole pieces longitudinal extension;

Each elongate rotor has a rotating shaft, and this axle is along elongated pole pieces longitudinal extension;

Each elongate rotor comprises that at least one permanent magnet tandem and their north, inside (N ')-Nan (S ') magnetic line of force path are orientated along same direction;

Whole described inner magnet line of forces path all is orientated perpendicular to the rotating shaft of rotor.

59, equipment as claimed in claim 58, wherein:

Described first and second parts of each pole pieces have cylindrical surface, these surfaces in the face of and band certain distance ground near the elongate rotor in the pole pieces and

Described cylindrical surface is concentric with the rotating shaft of rotor.

60, equipment as claimed in claim 59, wherein, a common actuation device is connected with all rotors, being used for stretching out the orientation of attraction and " breaking " in " leading to " reduces between the orientation of attraction and rotates all rotors simultaneously, when stretching out the attraction orientation in " leading to ", north, inside (N ')-Nan (S ') magnetic line of force path of the magnet tandem in the alternately adjacent rotors in traversing the pole pieces array of Cast Strip horizontal expansion has the Cast Strip of sensing and points in the array in succession the polarity that replaces of pole pieces first pole parts and is used for applying to the Cast Strip from described first and stretches out attraction, and when the reduction attraction orientation of " breaking ", be greatly diminished to the attraction that the Cast Strip applies from described first pole parts, north, inside (N ')-Nan (S ') magnetic line of force path of rotor inner magnet tandem is parallel with the Cast Strip basically simultaneously.

61, equipment as claimed in claim 58, wherein:

Each rotor comprises a plurality of permanent magnet tandems of stretching out arranged in a straight line vertically; And

At least one described tandem in each rotor is positioned at downstream enough far away, that is, it is positioned at the downstream of the described wing.

62, equipment as claimed in claim 58, wherein:

Described elongated pole pieces is distinguished the downstream position that extends to the downstream that is positioned at the described wing downstream together with their elongate rotor from nipping.

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