WO2019134782A1 - Band edge blow-off - Google Patents

Abstract

The invention relates to a device (10) and method for blowing off a band (1) moving in a transport direction (T), preferably a metal band coming out of a roll stand, and having two edge surfaces (4, 5) extending perpendicular to a band plane (E) and substantially parallel to the transport direction (T), wherein the device (10) has one or more nozzles (11, 11a) which are designed to form a gas flow (L), preferably an air flow, that at least partially flows along in parallel with at least one of the two edge surfaces (4, 5) or is directed towards same.

Description

 strip edge blower

Technical area

The invention relates to an apparatus and a method for blowing off a belt moving in a transport direction, preferably a metal belt running out of a rolling stand. Background of the invention

In the production of rolled metal products, strips and / or the roll gap are subjected to a coolant and / or lubricant. The expiring from the rolling mill metal strip can therefore be wetted with coolant and possibly other residues, such as a lubricant. For this reason, it is common to dry the metal strip by blowing off with air. For this purpose, Bandabblasvorrichtungen be used having a plurality of compressed air nozzles to dry the metal strip on one side or both sides.

EP 0 873 800 A2 describes a device for blowing off a metal strip, the device having, in addition to nozzles of a central zone and two edge zones, a section which is referred to as strip edge blowdown. The belt edge blast has nozzle bars in the region of the edge zones of the belt blower to blow off and dry the edge areas of the belt.

A difficulty in blowing off the strip edges is that the edges of thick strips are not dried sufficiently, which can cause discoloration after annealing. With thick tapes, so much liquid, such as oil, can accumulate on the edges, so that they are in the wound state the tape due to the capillary action between the windings device and thus also causes far inside on the top and bottom surfaces of the band discoloration. Presentation of the invention

An object of the invention is to provide an apparatus and a method for blowing off a belt moving in a transporting direction, preferably a metal belt running out of a rolling stand, which allow improved belt edge blowing, particularly with thick belts.

The object is achieved with a device for blowing off a belt with the features of claim 1, and a method having the features of claim 10. Advantageous developments follow from the subclaims, the following description of the invention and the description of preferred embodiments.

The device according to the invention serves to blow off a belt moving in a transport direction. The tape is preferably one

Metal band. For example, the strip may be a metal strip that runs out of a rolling stand. The band has two edge surfaces which extend perpendicular to a band plane and substantially parallel to the transport direction. It should be noted that the term "edge" is not uniformly used in the prior art. It happens that this means the edge area of the main areas. If in the present text of the "edges" or "edge surfaces" is mentioned, those surfaces are referred to, which are substantially perpendicular to the band plane. In this case, the band plane is a plane which characterizes the main extension of the band. Thus, the band plane may be that imaginary plane that runs centrally between two major surfaces and extends parallel to them. The main surfaces and edge surfaces preferably form an approximately rectangular cross-section perpendicular to the transport direction. Deviations from a strictly rectangular cross section are possible. The extent of the edge surfaces in the direction perpendicular to the band plane defines the thickness of the band.

The device has one or more nozzles, which are designed to form a gas flow, preferably an air flow, which flows along or is directed at least partially parallel on at least one of the two edge surfaces. So the edge surface is blown dry. It is aimed for this purpose, a stable gas stream. However, irregularities, minor turbulence, etc. can not be completely excluded and do not pose a problem as long as reliable drying of the edge surface (s) is maintained. In order to minimize the likelihood of liquid residue being blown from the edge surface onto one of the major surfaces, bleeding preferably takes place at a shallow angle of, for example, significantly less than 15 °. Particularly preferably, the gas flows parallel or substantially parallel along the respective edge surface.

The device enables a reliable drying of the strip edge (s) with a simple construction, especially with thick strips.

The execution of the nozzles can be done in different ways. However, a preferred embodiment uses flat jet nozzles, since they have the lowest gas consumption. Preferably, therefore, at least one of the nozzles is designed as a flat jet nozzle, which is designed to form a gas curtain, which overlaps at least one edge region of the band such that a part of the gas flows along or is directed onto the relevant edge surface. In other words, the gas curtain defines a particular shape of the gas flow such that it has a defined and stable extension in the direction perpendicular to the edge surfaces. The gas curtain preferably has no or only slight expansion in this direction, whereby it has a substantially parallel flow characteristic. This will normally cause part of the gas to hit one major surface while another part will flow past the band laterally. In this way, the respective edge surface is not only effectively dried, but variations in the bandwidth or the position of the edge surface (in the direction perpendicular to the edge surfaces) are compensated, without the need for complex adjustment of the nozzle would be required. Because the fact that the gas curtain in the above-defined direction of extension has an approximately parallel flow behavior, regardless of any variations of the edge surface position, a portion of the gas always flows in a well-defined manner on the edge surface or is directed to this. It should be noted that the nozzles and the gas pressure should be set so that the surface (s) to be dried are within the described flow characteristics. Preferably, the flat jet nozzle has a plurality of openings which are set up so that the gas curtain has a substantially parallel flow behavior. The gas curtain may be approximately linear in cross-section of the belt plane or may also have a clear extension along the transport direction. For this purpose, the openings of the flat jet nozzle (s) may be arranged linearly or flatly. Alternatively or additionally, a plurality of nozzles may be arranged in the transport direction of the belt.

Preferably, at least one of the nozzles is arranged so that the gas stream strikes the belt at an angle opposite to the transport direction, in order to improve the drying performance. The gas stream then exits the nozzle at an angle of, for example, less than 45 °, or preferably less than 15 °.

The device is preferably set up such that a volume flow of 30 to 90 Nm ³ / h, preferably approximately 70 Nm ³ / h, is output per nozzle. For this purpose, the nozzles may be connected to one or more compressed gas sources. By the described nozzle arrangement, in particular under Use of flat jet nozzles achieves excellent reliability in lateral drying of thicker strips. At the same time, the gas consumption can be minimized because the nozzles with a comparatively low gas pressure between 3 and 10 bar, preferably 4 to 7 bar, can be operated

Preferably, a plurality of the above-defined nozzles are provided, wherein on each side of the belt plane at least one such nozzle is arranged, whereby in addition to the drying of the edge surface (s), the edge regions of both main planes are mitgetrocknet. For this purpose, it is important that the seemingly opposite gas flows do not cancel each other out. In order to obtain a stable, non-vanishing gas flow along the edge surfaces, the volume flow and / or the flow rates of the gas streams may differ. Alternatively or additionally, the position of the gas streams along the transport direction may be different and / or the gas streams may be differently inclined in the transport direction, so that the gas streams lead past each other.

Preferably, one or more inner nozzles are provided in addition to the above-defined nozzles, which are arranged so that their gas flows in

Substantially completely hit one or both main surfaces, causing them to be dried purposefully.

The inventive method is used as the device for blowing off a moving in the transport direction belt, which is preferably a leaking from a rolling mill metal strip. The band has two edge surfaces which extend perpendicular to a band plane and substantially parallel to the transport direction. According to the method, at least one gas stream, preferably air stream, is formed by a nozzle which flows along or is directed at least partially parallel on at least one of the two edge surfaces. Preferably, the gas flow is in the form of a gas curtain that overlaps at least one edge region of the belt such that at least part of the gas flows along or is directed towards the edge surface concerned, the gas curtain preferably having a substantially parallel flow behavior.

Preferably, the gas stream hits the belt at an angle opposite to the transport direction

Preferably, the gas stream has a volume flow of 30 to 90 Nm ³ / h, preferably about 70 Nm ³ / h.

Preferably, a plurality of gas streams, preferably air streams, are formed by nozzles which flow along or are directed at least partially parallel on at least one of the two edge surfaces, at least one gas stream being directed onto the band on each side of the belt plane.

Preferably, the volumetric flows and / or the flow rates of the gas streams differ from nozzles on different sides of the belt plane, and / or the gas flows of nozzles on different sides of the belt plane substantially past each other, preferably in that the position of the gas flows along the transport direction is different and / or the gas streams are inclined differently in the transport direction.

The technical effects, preferred embodiments, and contributions to the prior art described with respect to the device apply analogously to the method. The apparatus and method are particularly suitable for blowing relatively thick metal strips in the field of cold or hot rolling. However, the invention can also be implemented in other areas, as far as a reliable drying of the edge surfaces of tapes is sought.

Further advantages and features of the present invention will be apparent from the following description of preferred embodiments. The features described therein may be implemented alone or in combination with one or more of the features set forth above insofar as the features do not conflict. The following description of preferred embodiments will be made with reference to the accompanying drawings.

Brief description of the figures

FIG. 1A schematically shows a detail of a device for blowing off a strip in a cross section perpendicular to the transport direction of the strip according to a first exemplary embodiment. FIG. 1B shows an enlargement of the edge region of the band according to the exemplary embodiment of FIG. 1A.

FIG. 2A schematically shows a section of a device for blowing off a strip in a cross section perpendicular to the transport direction of the strip according to a second exemplary embodiment. FIG. 2B shows an enlargement of the edge region of the band according to the exemplary embodiment of FIG. 2A.

FIG. 3A schematically shows a top view of the device for blowing off a strip according to the second exemplary embodiment. FIG. 3B schematically shows a side view of the device for blowing off a strip according to the second exemplary embodiment.

Detailed description of preferred embodiments In the following, preferred embodiments will be described with reference to the figures. In this case, identical, similar or equivalent elements are provided with identical reference numerals, and a repetitive description of these elements is partially omitted in order to avoid redundancies.

FIG. 1A schematically shows a section of a device 10 for blowing off a strip 1, for example a metal strip leaving a rolling stand (not shown). FIG. 1B shows an enlargement of the edge region of the band 1 according to the exemplary embodiment of FIG. 1A.

The belt 1 moves along a transporting or conveying direction T, which is perpendicular to the plane of the drawing. The band 1 has two parallel main surfaces 2 and 3 which, in the case of a very thin band 1, lie approximately at the same level and thus define a band plane. In the case of a band 1 of non-negligible thickness, the two main surfaces 2 and 3 extend parallel to an imaginary band plane E which extends centrally between the main surfaces 2, 3 and extends parallel to them. Perpendicular to the two Flauptflächen 2, 3 and parallel to the transport direction T extend two substantially parallel edge surfaces 4 and 5. Thus, the rectangular cross-section of the belt shown in the figures 1. The extension of the edge surfaces 4, 5 in the direction perpendicular to the belt plane E defines the thickness D of the band 1. In the present case, the band 1 preferably has a comparatively large thickness D, for example of more than 1 mm. In the transporting direction T, the band 1 may have a quasi-endless extension or a certain length, which results, for example, from a band material, formed by a rolling process.

In order to free the band 1 of a liquid component R, such as residues of a previously applied cooling and / or lubricating fluid or other residues, are on one or both sides of the belt plane E nozzles 11 so provided that they blow a gas, preferably air, to the surface of the belt 1. The nozzles 11 are aligned so that the gas flow L blows the liquid R from the surface of the belt 1 to dry the belt 1. The nozzles 11 are supplied by compressed gas, preferably compressed air, from one or more compressed gas sources (not shown). In order to dry the edge surfaces 4 and 5, one or more of the nozzles 11 are arranged to produce a gas flow L which is parallel or substantially parallel to the edge surfaces 4, 5. In the exemplary embodiment of FIGS. 1A and 1B, the nozzles 11 comprise two flat-jet nozzles which have a plurality of openings, so that the respective gas flow L has the shape of a gas curtain, preferably an air curtain, with a certain extent in the direction perpendicular to the edge surfaces 4, 5. The gas curtain has no or only a slight expansion in this direction and overlaps the edge region of the band 1 such that at least part of the gas flows along the edge surface 4 or 5 substantially parallel to one another. In this way, the edge surfaces 4 and 5 are dried effectively. The flat-jet nozzles 11 may have, in the direction perpendicular to the edge surfaces 4, 5, an extension of, for example, 30 mm to 70 mm, preferably approximately 50 mm, with a number of openings in this direction of 10 to 20, preferably approximately 15. However, there is no limitation in this regard as long as the nozzles 11 are adapted to form a gas curtain having a quasi-parallel flow behavior.

The gas curtain may be approximately linear in cross-section of the band plane E or may also have a clear extension along the transport direction T. For this purpose, the openings of the flat jet nozzle (s) 11 may be arranged linear or planar. Alternatively or additionally, a plurality of nozzles 11 may be arranged in the transport direction T of the belt 1. The orientation, ie the Angle, the gas flow L in the transport direction T can be suitably selected. Preferably, the gas flow L is directed in the embodiment of Figures 1A and 1 B opposite to the transport direction T to improve the drying performance. The gas stream then exits the nozzle at an angle of, for example, less than 45 °, or preferably less than 15 °.

FIGS. 2A and 2B show a second exemplary embodiment in which nozzles 11 a, 11 i, designed as flat-jet nozzles, are provided on both sides of the strip 1. The nozzles 11a, 11i include inner nozzles 11i and outer nozzles 11a. The outer nozzles 11 a are arranged and aligned such that their gas flow L, which forms a gas curtain, overlaps the corresponding edge region of the belt 1 such that at least part of the gas flows along the edge surface 4 or 5 substantially parallel. For this purpose, it is important that the apparently opposite gas flows L according to FIG. 2A are not canceled out. In order to obtain a stable, non-vanishing resulting gas flow along the edge surfaces 4, 5, as indicated by arrows in FIG. 2B, the volumetric flow and / or the flow velocities of the opposite gas flows L may differ.

Alternatively or additionally, the position of the gas streams L along the transport direction T may be different and / or the gas streams L may be inclined differently in the transport direction T, so that the gas streams L pass one another. This is apparent from Figures 3A and 3B, which show a schematic plan view and side view of the device 10 according to an embodiment accordingly. The inner nozzles 11 i are disposed more inward relative to the outer nozzles 11 a in the direction perpendicular to the edge surfaces 4, 5 to dry the peripheral area of the main surfaces 2, 3. The removal of the residual liquid R is indicated by arrows in FIG. 2B. Due to the described arrangement of the flat jet nozzles 11, 11 a, 11 i excellent reliability in the lateral drying of relatively thicker bands 1 is achieved. In addition, the gas consumption can be minimized because the nozzles 11, 11 a, 11 i can be operated in comparison to conventional high-pressure nozzles with a lower gas pressure. A volume flow per nozzle 11, 11 a, 11 i of 30 to 90 Nm ³ / h, preferably about 70 Nm ³ / h, has proved to be suitable, the amount of air required, inter alia, the thickness D of the tape 1, the type and quantity the liquid residues R depends. The formation of a gas curtain by means of the flat jet nozzles 11, 11a, 11i is also advantageous in that variations of the bandwidth or the positions of the edge surfaces 4, 5 (in the direction perpendicular to the edge surfaces 4, 5) are compensated without a readjustment the nozzles 11, 11a, 11i is required. The illustrated device 10 is particularly suitable for drying the strip edges of a strip 1 with a thickness D of more than 1 mm, preferably between 2mm and 8mm. Technically effective it is used from a thickness D of 0.7mm. It may optionally be combined with a conventional belt blower for drying the major surfaces 2, 3. The apparatus 10 may also be part of a multi-stage blowdown, such as to accomplish cascading blow-off with different nozzle types and / or nozzle arrangements.

Where applicable, all individual features illustrated in the embodiments may be combined and / or interchanged without departing from the scope of the invention. LIST OF REFERENCE NUMBERS

1 band

 2, 3 main surfaces

 4, 5 edge surfaces

 10 Device for blowing off a band

11 nozzles

11 a Outer nozzles

 11 i Inner nozzles

T transport direction

 D thickness of the band

E band level

 L gas stream

 R Liquid residue on the tape

Claims

claims 1. Device (10) for blowing off a in a transport direction (T) moving belt (1), preferably of a rolling mill expiring metal strip having two edge surfaces (4, 5) perpendicular to a band plane (E) and extend substantially parallel to the transport direction (T), wherein the device (10) comprises:  one or more nozzles (11, 11 a) arranged to be one Gas stream (L), preferably air flow form, at least partially parallel to at least one of the two edge surfaces (4, 5) flows along or is directed to this. 2. Device (10) according to claim 1, characterized in that at least one of the nozzles (11, 11 a) is designed as a flat jet nozzle, which is adapted to form a gas curtain, which overlaps at least one edge region of the band (1) such that a part of the gas flows along the respective edge surface (4, 5) or is directed onto it. 3. Device (10) according to claim 2, characterized in that the Flat jet nozzle (11, 11 a) has a plurality of openings which are arranged so that the gas curtain has a substantially parallel flow behavior. 4. Device (10) according to one of the preceding claims, characterized in that the at least one nozzle (11, 11 a) is arranged so that the gas stream (L) at an angle opposite to the transport direction (T) on the tape (1 ) meets. 5. Device (10) according to any one of the preceding claims, characterized in that it is arranged so that the at least one nozzle (11, 11 a) a volume flow of 30 to 90Nm ³ / h, preferably about 70Nm ³ / h, outputs , 6. Device (10) according to any one of the preceding claims, characterized in that a plurality of nozzles (11 a) are provided and each to a gas flow (L), preferably air stream, form, at least partially parallel to at least one of the two Edge surfaces (4, 5) flows along or directed to this, with on each side of the Band level (E) at least one such nozzle (11 a) is arranged. 7. Device (10) according to claim 6, characterized in that the nozzles (11a) are arranged so that the volume flows and / or the flow rates of the gas streams (L) of nozzles (11 a) on different sides of the band plane (E ). 8. Device (10) according to claim 6 or 7, characterized in that the nozzles (11a) are arranged so that the gas flows (L) of nozzles (11 a) on different sides of the band plane (E) substantially past each other, wherein preferably the position of the gas streams (L) along the transport direction (T) is different and / or the gas streams (L) in the transport direction (T) are inclined differently. 9. Device (10) according to any one of the preceding claims, characterized in that further one or more inner nozzles (11 i) are provided, which are arranged so that their gas flows substantially completely on one or both major surfaces (2, 3) to meet. 10. A method for blowing off in a transport direction (T) moving belt (1), preferably one of a rolling stand leaking metal strip having two edge surfaces (4, 5) extending perpendicular to a band plane (E) and substantially parallel to the transport direction (T), wherein  at least one gas stream (L), preferably air stream, is formed by a nozzle (11, 11a) which flows along or is directed at least partially parallel on at least one of the two edge surfaces (4, 5). 11. The method according to claim 10, characterized in that the gas stream (L) has the shape of a gas curtain which overlaps at least one edge region of the band (1) such that at least a portion of the gas flows along the respective edge surface (4, 5) or directed to this, wherein the gas curtain preferably has a substantially parallel flow behavior. 12. The method according to claim 10 or 11, characterized in that the Gas stream (L) at an angle opposite to the transport direction (T) on the tape (1) meets. 13. The method according to any one of claims 10 to 12, characterized in that the gas stream (L) has a volume flow of 30 to 90 Nm ³ / h, preferably about 70 Nm ³ / h. 14. The method according to any one of claims 10 to 13, characterized in that a plurality of gas streams (L), preferably air streams, of nozzles (11a) are formed, at least partially parallel flow along at least one of the two edge surfaces (4, 5) or are directed to this, wherein on each side of the belt plane (E) at least one gas stream (L) is directed to the belt (1). 15. The method according to claim 14, characterized in that the flow rates and / or the flow rates of the gas streams (L) of nozzles (11 a) differ on different sides of the band plane (E), and / or the gas flows (L) of nozzles (11a) on different sides of the belt plane (E) substantially past each other, preferably by the position of the gas streams (L) along the transport direction (T) is different and / or the gas streams (L) in the transport direction (T) are inclined differently.