DE2364610A1 - HEATING CONTROL SYSTEM FOR FIBER GLASS NOZZLE OPENING PIPES - Google Patents

Description

Patent attorney December 20 , 1972

Dr. Michael Harm H / Wa (602)

63 casting

Ludwigstrasse 67 2364610

PPG Industries, Inc., Pittsburgh, Pennsylvania, USA

HEATING CONTROL SYSTEM FOR FIBERGLASS NOZZLE OPENING TUBES

Priority: January 2, 1973 / USA / Serial No. 320.381

In conventional glass fiber production facilities, molten glass is supplied to electrically heated bushings which have a plurality of nozzles with openings for the flow of glass to pass through. The streams of glass are drawn into fibers which are combined into strands and collected as bundles. Generally, the bushings are made of an alloy such as an alloy of 90 % platinum and 10 % rhodium. The nozzles (tips) are created with great effort in that molten alloy is dripped onto a socket plate and the openings are drilled into the alloy that is then built up. Although this device is widely used, it has serious shortcomings in that only a relatively small number of nozzle orifices can be accommodated in a given area.

There is a later and different solution to this problem in that small, closely spaced holes are drilled in the wall of a metal pipe, and that the molten glass is fed to this tube under pressure so that it is squeezed out through the openings.

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It was found that the number of openings or holes per unit area of the pipe by far the Number of nozzles for the same unit area of a conventional socket exceeds. Besides, they are The cost of the openings in a pipe of the type just described is significantly lower than that of the conventional ones Sockets. In such devices it is common to have at least a partial sheathing of the nozzle opening tube provide and apply a controlled atmosphere to the jacket to encase the pipe and to be dispensed near the openings to the Protect pipe against oxidation.

2. If instead of the usual pressure of about 0.07 kg / cm If much higher pressures are used, the glass fibers can be pulled out of much smaller nozzle openings, whereby a fiber is obtained with a lower tension than when pulling it out of large openings in sockets comparable speeds. One such orifice tube fiberising unit is in the TTS-PS 3 625 025.

With the usual fiber production systems, the. Jacks generally 1500 to 3000 amps under service conditions. In order to deliver this energy, is in general uses a step-down transformer that supplies a high strength, low voltage circuit, of the current being delivered to the sockets, the high voltage side of the transformer being the Takes control. In conventional systems, the primary side of the transformer can therefore be a saturable nuclear reactor or a solid — semiconductor— system for regulating the flow of energy to the socket in order to control its temperature. Vegen the physical size of the components "of such a control system, this means that the control is extreme becomes cumbersome when looking for items like the ones above

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"nozzle orifice tubes described especially when these elements are in close proximity because of the small size of the nozzle opening tube requires only about 1/10 the space of a comparable conventional socket. Also needed the nozzle opening tube is only about 1/5 of the force required for normal equipment to operate, thus the usual power supply and control for the. Glass fiber production with a nozzle orifice tube is not required is.

It is therefore an object of the present invention to provide an improved device for regulating temperature a nozzle tube fiber production unit available.

Another object of the invention is to provide a compact, convenient and more effective heating control system for the nozzle orifice tubes for fiberglass manufacture.

Another object of the invention is an improved one Heating control device, which is adapted to the lower power requirement of the small nozzle opening tube fiber production and which is designed so that means for easy mounting and holding of the fiber production units are in proper relationship with the other parts of the device.

Yet another object of the invention is to provide a heating element control system for a plurality of fiberglass nozzle orifice tubes in which the heating elements of all tubes are connected in parallel to the secondary winding of a single supply transformer, and each element is individually controlled from the secondary of the transformer will.

In short, the device according to the invention contains

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a nozzle orifice tube fiber production unit, which under Pressure between a combination bracket and a spring-loaded one electrical connection and one under high DruoA standing glass source that provides molten glass to the unit. The fiber manufacturing unit includes a tube with a variety of small. Nozzle openings formed on a part of its surface a material softened by heating, such as glass, is extruded through these openings. To one: The end of the pipe is provided with a flanged coupling, which is designed so that it fits on a. Cavity of the glass source rests with the other end of the The nozzle orifice tube engages a bracket. Which includes the electrical connector for the tube. The clamp and the connection piece can be changed with one-piece Busbar connected, both for a fixed flontation of the entire arrangement as well as for power supply serves for the unity.

The busbar is at one end with a transformer sufficient capacity to be able to supply all fiber production units connected to the busbar can be connected, connected. Embedded in the busbar and in contact with the electrical connection. piece for each unit is a pair of half-wave thyristors, through which the current from the busbar to the Connector flows and which serve to supply the current regulate to maintain the force required the desired temperature in the nozzle opening tube deliver. The busbar and connector assembly are water cooled to protect the semiconducting thyristors to protect. The connector also has a ribbed cooling block to prevent overheating.

There is a thermocouple on the spring nozzle opening tube, which emits a signal proportional to its temperature, which is passed through a suitable control system,

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so that there is an output signal indicating the mode of operation of the corresponding thyristor controls. The control system, which can be a common three-oscillation system, controls the required control effect to each individual nozzle opening tube at a predetermined level or point. Each of the numerous nozzle opening tubes, which may be connected to a single busbar is electrically in parallel with the secondary winding of the transformer and each pipe is provided with an individual control device, the energy supplied as a function of the requirements to regulate the particular pipe. The energy supply and control system is simple and efficient, it allows the arrangement of adjacent nozzle opening tube units in close proximity and can from the secondary side of the supply transformer, which enables significant savings.

In the following the invention with reference to the Drawings explained in more detail, which show the following:

FIG. 1 is a front view, partly in section, of FIG a nozzle orifice tube, a bracket and an electrical connector in accordance with the invention} ·

FIG. 2 is a side view, partly in section, of FIG The apparatus of Figure 1 showing similar nozzle orifice tubes attached to a bus bar and

Figure 3 is a partially schematic and partially Block diagram of the control system according to the invention.

Referring to Figures 1 and 2, there are two orifice tube fiberising units 10 and 12 are available, each with a plurality of nozzle openings for the Having extruded streams of molten glass, the glass to the tubes from a pressurized Source 14 · is funded. As detailed in US Pat. No. 3,625,025, the nozzle orifice tube 16 is

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is referred to only as a nozzle tube, the fiber production unit made of platinum or a platinum alloy, with a Large number of nozzle openings or nozzles in its lower part, generally designated by 18 ', in a narrow Field is arranged. One end 20 of the tube 16 is open, while the other end 22 is closed and with a Flanged coupling 24 is provided, which engages with a complementary coupling 26 of the delivery line 28 stands. The tube 16 is heated by electric current flowing through it, as will be described in more detail later will be.

The nozzle tube 16 is sheathed by a line 30, the Cooling air is supplied via a supply 32 (FIG. 1). The conduit partially covers the nozzle orifice tube and ends at an opening 34, the edges of which from the nozzle opening tube for the passage of the cooling air protrude slightly. The air cools the fibers as they arise and enables the fibers to be drawn out stably.

In order to prevent the nozzle opening tube from warping or breaking under the relatively high pressure of the conveyed glass protect, a protective tube 36 partially surrounds the tube 16, but is covered by a layer of an insulating material separated, which serves to isolate the pipe 16 from the cooling air in the line 30. An air umbrella 40 over that Protective tube 36 also helps to disperse the cooling air so that cooling of the nozzle tube is avoided. With this structural arrangement, changes in flow velocity or temperature have no effect on the temperature of the nozzle pipe. To disperse the air flowing out of conduit 30 'and along the length Distributing the nozzle pipe is a variety of diffusing screens and deflectors 42 within conduit 30 between inlet 32 and the conduit opening 34 arranged.

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Because of the small size of the nozzle tube structure, it is possible to achieve a considerable saving in space in the manufacture of a given number of fibers. In some cases, up to ten nozzle orifice tubes can be used be accommodated in the space that is otherwise required for a single conventional socket for the production of a comparable number of fibers. Around To use substantial space savings, can with the invention a single device for mounting the nozzle pipe. This facility includes a new electrical one A connector and comprises an electrical Control circuit that uses the significantly lower energy requirements of the nozzle tube construction. Like Figures 1 and 2 10, the fiberising unit 10 is at one end with the source 14- of the high pressure glass connected via the flanged coupling 24. The opposite The end of this unit is with an elongated pressure beam "or an elongated pressure bar 44- connected, the end 20 of the tube passing through the beam and in Connection to a spring-loaded electrical connector 4-6 stands. The connector 4-6 is used for manufacture a good electrical contact is pressed against the end of the tube, taking an electrical current from a selected one Amplitude is introduced into the nozzle pipe and flows through the pipe to a fixed point at the coupling 26 in order to ' heat the tube to the desired temperature.

The pressure bar 44 is adjustable and electrically insulated connected to a fixed busbar 48, which on the one hand as a suspension device for a large number of fiber production units and on the other hand as a joint Energy source for the units connected in this way is used. A bolt 50 secures the pressure beam in its place, wherein the bolt by a spring arm 52 (Figure 1) a first web part 54- of a curved contact arm 56, a elongated through opening 58 in the busbar, one

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second web part 60 of the contact arm 56, a pressure plate 62 • and the pressure beam 44 goes. The bolt 70 serves to hold the spring arm 52, the contact arm 56 and the busbar together and to create a pivot point for the pressure beam 44. When the nut is screwed onto the pin 50 66, it tends to push the upper part of the beam 44 against the bent ¹ contact 56 and the busbar 48 (Figure 1). The middle portion of the pressure beam 44 abuts the insulating spacer 74 which provides contact between the pressure beam. and the bent contact arm 56 prevented. Tightening the nut 66 causes the lower part of the pressure bar 44 to move away from the contact arm 56 and better contact with the fiber production unit 10. This allows the fiber production unit to be firmly clamped between the busbar 48 and the glass source 14 by the pressure bar 44 so that the? ase? production unit can be brought into the desired position. The through-openings 58 and 72 in the busbar enable the precise position of the fiber production unit to be set and also enable adjacent cells to be arranged at a close spacing, as can be seen from FIG. In addition, this arrangement has the advantage that a single fiberising unit can be easily removed or installed without disturbing the adjacent units, with only the nut 66 and electrical contact 46 being loosened.

The contact arm 56 is generally "J" shaped, this "J" being reversed and positioned above the busbar 48 with the shorter web portion 54 adjacent one side of the busbar and the longer one Web portion 60 is adjacent to the other side of the busbar. In corresponding notches 76 and 78 on opposite sides of bus 48 are a pair of thyristor elements 80 and 82.

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These elements are thicker than the depth of the indentations, so that the thyristors on each side over the corresponding side surface of the busbar also extend. So the thyristor 80 extends beyond the notch 76 of the busbar 48 and contacts the inner surface of the web portion 54 cLes contact arms 56. Similarly, the thyristor 82 extends beyond the bus bar 48 and contacts the inner surface of the web portion 60 of the contact arm.

In the middle of the notches 76 and 78 are projections and 86 provided that with the center of the thyristors and 82 come into engagement. The contact arm 56 is similar Way with projections 88 and. 90 are provided which with the outer surfaces of the thyristors 80 and 82 in engagement stand and whereby the position of the contact arms with respect to the thyristors and the busbar is determined. The bolts 50 and 70 hold the various "elements tightly together in firm electrical contact, clamping the inner surfaces of the contact arm against the outer Surfaces the thyristors and hold the thyristors tightly against the busbar, with current from the busbar through one or the other thyristor 80 and 82, depending on which is currently conducting, in the. corresponding web of the contact arm 56 flows.

The longer web 60 of the contact arm 56 extends downward and carries the electrical at its lower end 92 Connection part 46 which is designed so that it makes electrical contact with the nozzle tube 16. That Terminal 46 includes a contact block 94, the is connected to the end 92 of the web 60, the Block has a cavity 96 on one side, which the receives closed end 20 of the nozzle tube. At. the other side of the block 94 is through the screws 98 and 100 a finned cooling block 102 is attached, which ensures that the connector is within acceptable!

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temperature remains, but without excessive cooling to effect the nozzle tube. .

The adjustment of the pressure of the connection part 46 against the nozzle pipe 16 is carried out by the spring arm 52. whose upper end 104 is firmly connected to the busbar by bolts 50 and 70 o The spring arm tapers downwards at shoulder 106 to a thin, relatively flexible central part 108. The spring arm extends even further downwards to the nozzle tube, the lower part 110 being thickened and provided with a threaded opening through which a pressure adjusting screw 112 extends. This screw is roughly aligned with the axis of the nozzle tube and extends through the lower part 110 of the spring arm in contact with the connector bloom 46 <, B®-v © ssugt. the end of the screw extends into an opening 114, which is located in the cooling fins 102 and in contact with a bore chuck 116 at the bottom of this opening »

When the screw 112 is screwed into the spring arm, and presses against the contact block, it tends to the Separate terminal block 46 from the end 110 of the spring arm. The spring action of the arm 52 tends to hit the contact block 46 to press against the end of the nozzle tube ^ whereby the Force from the strength of the arm 52 to the extent of the attraction of the visual hood in the lower part 110 of the spring. arms depends.

As indicated in Figure 2, is a temperature measuring device 124 _? example _8, a Pt-PTHH thermocouple disposed on the nozzle tube 16, 'to give a Ausgaägssignal via lines 120 and 122 proportional% u of the temperature of the .exferudierten glass A Eontrollsystem that includes ein® Temperat-urkontrolleinrichtung, are required. Control effect to make the nozzle pipe 16 at a predetermined level or predetermined

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Keep point. The control device regulates a thyristor heating circuit 126 in a known manner via the lines 128 and 130, with their output signal on the lines 132 and 134- the thyristors 80 and 82 is applied as this can be seen from FIG.

The control system is of the usual type and possesses prefers three mode types, as is well known. As can be seen from Figures 2 and 3, are the fiber production units 10, 12 etc. essentially identical and these units are individually controlled by appropriate control systems. ' In Figure 2 shown that the unit 12 is in close proximity to the Unit 10 is mounted with all units attached to the busbar through through holes 58 and 72 are. In practicing the invention, it has been found that numerous units are connected in parallel to one single busbar can be arranged, with a distance from center to center in the order of magnitude can be about 3.8 cm or less. In Figures 2 and 3 are the elements of the fiber manufacturing Unit 12 Duplicates or similar items to those of Unit 10.

As shown in Figure 3, the busbar 48 is with the secondary bond 136 of a power supply transformer 138 connected, the power of which is sufficient to meet the maximum demand of all fiber production units, which can be connected to the busbar to be able to cover. The primary winding 140 is powered off a voltage source, not shown, which can be varied to the desired voltage level to the To supply busbar 48. Each of the fiber manufacturing units 10, 12 etc. is connected in parallel to or via the (across) secondary winding 136 of the transformer. -closed, being connected at one end to the busbar 48 and at the other end to a ground reference point

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reference point) 142 is connected. The two thyristors 80 and 82 are half-wave controlled rectifiers connected in parallel, one end of the thyristor combination being connected to the busbar 48 and the other end of the combination being connected through the contact arm 56 to the nozzle tube 16, here referred to as Resistance heating element ¹ 144 is shown.

The thermocouple 118 displays the temperature of the nozzle tube 16 and provides a signal to the temperature controller 124 which can be amplified by the main lines 146, 148 and which compares the measured temperature signal with a precision reference voltmeter set at the desired temperature. Any difference between these signals is magnified and fed to a conventional three-wave controller which sends a signal to heating circuit 126 to regulate the length of time that each thyristor ^{conducts input voltage during half cycle 1 of Λ C.} This regulation is carried out by applying a suitable control signal to control the control electrodes of the controlled rectifiers 8o and 82 by means of lines 132 and 134 in a known manner. Similarly, each fiberising unit that can be connected to transformer 138 can be connected to the secondary winding and can be individually controlled, with maximum control being achieved for each nozzle tube.

From the foregoing it can be seen that after connecting the desired number of fiber units to the busbar the voltage of the secondary winding of the transformer is adjusted to such a level that sufficient excess Energy is available for adequate control of all units, with the voltage afterwards is kept constant. When the temperature of the nozzle tube 16 drops below the desired point, the causes Control device 124 via the heating circuit 126 that the

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Thyristors 80 and 82 alternate each over a half cycle of the supply current, whereby a controlled amount of current flows through the nozzle tube. This flow of current increases the temperature of the nozzle tube until the desired point is reached and then switches the control device from the thyristors until additional energy is required .., as long as the primary Force system of the secondary winding 136 a constant voltage provides, each individual fiber production unit, can be regulated from zero to maximum force independently of the neighboring units.

The busbar 48 is shown in Figure 2 by suitable means such as bolts 150 and 152 ,. attached to the transformer 138 via a stop 154-, which stop connects to the secondary winding of the transformer and thereby acts as an output termination point for the transformer. ·

It is clear to those skilled in the art that numerous additional auxiliary devices can be present, such as cooling devices, to avoid overheating of the thyristors. For example, cooling lines through which water is circulated, be arranged in the busbar. As can be seen from Figure 1, the source 14- of the molten Glases not only supply the parallel units and 12, but it can also supply an additional row of tubes 156 which extend in the opposite direction from the glass source.

It is an advantage of the invention that it provides completely independent temperature control for a variety of closely spaced heating elements is possible, without the need to install a space-consuming step-down transformer and a saturable, able to use reactor, as is the case with the usual socket systems. In the invention a single power source to supply energy to a multitude of

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number of such elements are used, with a connection arrangement, is present which enables the individual fiber production units to be installed and removed quickly and easily.

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Claims (1)

Claims ; Heating control system for a variety of fiberglass nozzle tubes, characterized by
a power supply transformer with a secondary winding, Means for connecting each nozzle tube in parallel with this secondary winding, and Means for independently regulating the flow of electrical current through each nozzle tube. 2. System according to claim 1, characterized in that the means for connecting include a bus bar (48) which is in communication with all of the nozzle tubes (16) stands, with the busbar with the secondary winding (136) is connected and supplied with energy through them. 3 · System according to claim 2, characterized in that the means for connecting for each nozzle tube further includes a contact arm (56) extending therebetween the busbar (48) and the nozzle tube (16) extends, this contact arm is connected at one end to the busbar and at the other end to Contact with the nozzle tube (16) is brought. 4. System according to claim 3? characterized in that the means for connecting each nozzle tube includes a spring arm (52) spaced from and generally parallel to the contact arm (56), the spring arm being attached at one end to the busbar (48) and at its opposite End has means for establishing contact between the contact arm and the nozzle tube (16). 5. System according to claim 4, characterized in that the means for connecting each nozzle tube is a pressure 409828/08 10 include arm (44) attached to one end of the pressure beam (48) is rotatably mounted and at its other end has means for fastening the nozzle tube (16). 6. System according to claim 5 »characterized in that the pressure arm (44) is electrically isolated from the bus bar. [• ι 7i system according to claim 5 »characterized in that the means for regulating the flow of electric current through each nozzle tube are controllable semi-conductive Means (80), (82) included interposed between the busbar (48) and the contact arm (56) and switching means for controlling the semiconducting means. 8. System according to claim 7 _5, characterized in that the switching means contain a temperature measuring device (118) and a corresponding temperature control device (124) for each nozzle tube (16), all nozzle tubes being heated by an electrical current flow from the secondary winding (136) and the Stream to each nozzle pipe independently of the others in Ab- ' . depending on its measured temperature will. 9 · System according to claim 8, characterized in that the controllable semiconducting agent contains at least one thyristor (80), (82) * 10. System according to claim 8, characterized in that the controllable semiconducting agent at least includes a pair of half-wave thyristors (80), (82). 11. System according to claim 10, characterized in that the Thyristors (80), (82) have projections (84), (86) which fit into corresponding notches in the busbar (48) engage, wherein the contact arm (56) to the thyristors 409828/0810 adjoins and keeps them in firm electrical contact with the busbar. 12. System according to claim 11, characterized in that the contact arm (56) is in the shape of an inverted J with one land of the J having a thyristor on one side the busbar and the other bridge of the J the other Thyristor touches on the other side of the busbar. · 13 · System according to claim 1, characterized in that the means for regulating the flow of current includes controllable semiconducting means (80), (82) between the secondary winding and each nozzle tube. 14-. System according to claim 13 »characterized in that the means for regulating the flow of current are a temperature measuring device (118) and a corresponding temperature control device (124 ·) for each nozzle tube (16), wherein the nozzle tubes by an electrical current flow from the secondary winding (136) a transformer (138) and the current to each tube independently in accordance is controlled with its measured temperature. 15. System according to claim 14, characterized in that the semiconducting means include thyristor means. 16. System according to claim 14-., Characterized in that the controllable semiconducting means a pair of half-wave thyristors (80), (82) connected between the secondary winding (136) and each nozzle tube (16) are connected. 17. System according to claim 16, characterized in that all nozzle pipes (16) with a common collecting 409828/0810 rail (4-8) are electrically connected, which in turn is connected to the secondary winding (136) of the transformer (138), whereby all tubes (16) electrically connected in parallel. 18. Heizkontroll syst em for a large number of closely spaced heating elements, marked by. a single electrical power source for the plurality of heating elements, said power source having a transformer (138) having a secondary winding (136). ■ ■ Means for connecting the heating elements in series with controllable means for regulating the current intensity, Means for connecting each heating element connected in series and continuous control means in parallel with the secondary winding across all of the heating elements in parallel to arrange the secondary winding and switching means for independent control of the current flow in each heating element by controlling the conduction of the current regulating means, which are in series with are connected to the "heating element in question. 19 · system according to claim 18, characterized in that the means for connecting the heating elements in parallel with the secondary winding (136) a busbar (48) include, this busbar providing an electrical and mechanical support for the heating elements forms. 20. System according to claim 19, characterized in that the controllable means for regulating the current include thyristor means (80), (82) interposed between the busbar (48) and the heating element are arranged, wherein the entire ■ current flow through each'Heiz- 409828 / Ö81Q element flows through its corresponding thyristor means. 409828 / D81Q