Device for preventing foreign matter from entering hot rolled strip

Abstract

The present invention provides a foreign matter prevention device for a hot-rolled strip, which prevents foreign matter formed by friction between a side guide that guides the movement of the strip to the inlet side of a winder during a hot rolling process from being mixed into the strip, and includes a reverse direction jet unit that jets high-pressure water toward the strip moving to the inlet side of the winder by the side guide in a direction reverse to the moving direction of the strip, the reverse direction jet unit including a plurality of upper reverse direction jet nozzles arranged along a width direction of the strip to jet high-pressure water onto an upper surface of the strip, and the plurality of upper reverse direction jet nozzles may have a narrower interval between the nozzles located at a center in the arrangement direction than between the nozzles located at both ends.

Description

[Technical field]

[0001] The disclosed invention relates to an apparatus for preventing foreign matter from being mixed into a hot-rolled strip, which prevents foreign matter from being mixed into the strip being wound into a coil in a winding section of a hot rolling process. [Background technology]

[0002] In hot rolling plants, slabs produced in steelmaking and continuous casting plants are heated to a constant temperature in heating furnaces, then continuously passed between rolls to roll them into a thin strip, and then wound into coils to produce hot-rolled coils, which can be used as products desired by consumers or as material for the subsequent cold rolling process.

[0003] The main equipment used in the hot rolling process includes a heating furnace, a roughing mill, a finishing mill, a winding machine, a side guide, etc. The side guide serves to guide the movement of the strip to the inlet side of the winding machine.

[0004] On the other hand, if the strip is biased to one side, friction between the strip and the side guide can cause sparks and foreign matter to form, which can then adhere to the surface of the strip. When the strip in this state is wound by a winding machine, press-fit scratches caused by the foreign matter can form on the surface of the strip, which can cause surface defects of the strip. Summary of the Invention [Problem to be solved by the invention]

[0005] One aspect of the disclosed invention provides an apparatus for preventing foreign matter from entering a hot-rolled strip, which can effectively prevent foreign matter from entering the strip being wound into a coil in a winding section of a hot rolling process.

[0006] One aspect of the disclosed invention provides an apparatus for preventing foreign matter from entering a hot-rolled strip, which can prevent foreign matter from entering a strip being wound into a coil in a winding section of a hot rolling process. [Means for solving the problem]

[0007] According to one aspect of the disclosed invention, a foreign matter prevention device for a hot-rolled strip is provided for preventing foreign matter formed by friction between the strip and a side guide that guides the movement of the strip to the entrance side of a winding machine during a hot rolling process from being mixed into the strip, and includes a reverse direction jet unit that jets high-pressure water toward the strip as it moves to the entrance side of the winding machine by the side guide in a direction reverse to the movement direction of the strip, the reverse direction jet unit including a plurality of upper reverse direction jet nozzles arranged along the width direction of the strip so as to jet high-pressure water onto an upper surface of the strip, and the plurality of upper reverse direction jet nozzles may be spaced closer to each other at a central position along the arrangement direction than at both ends.

[0008] The upper reverse jet nozzles may be arranged so that the nozzles positioned at the center in the arrangement direction jet high-pressure water at a flow rate greater than the nozzles positioned at either end.

[0009] The upper reverse jet nozzles may have a larger diameter in the central portion along the arrangement direction than those at either end.

[0010] The device for preventing foreign matter from entering the hot rolled strip may further include a lateral injection unit for injecting high-pressure water between the side guide and the strip.

[0011] The lateral injection unit may be provided to adjust a flow rate of high-pressure water injection, and the flow rate of the injected high-pressure water may be increased in proportion to a critical temperature at which sparks occur in the strip according to a steel grade.

[0012] The side guide includes a first side guide supporting one side of the strip in the width direction and a second side guide supporting the other side of the strip in the width direction, the lateral jetting unit includes a first lateral jetting unit configured to jet high-pressure water between the first side guide and one side of the strip, and a second lateral jetting unit configured to jet high-pressure water between the second side guide and the other side of the strip, the first lateral jetting unit and the second lateral jetting unit being provided so as to be able to adjust the high-pressure water jetting flow rate, and the first lateral jetting unit and the second lateral jetting unit may adjust the high-pressure water jetting flow rate so that the amount of high-pressure water jetted is increased toward one of the first side guide and the second side guide which has greater friction with the strip.

[0013] The strip cutting apparatus may further include a first sensor for sensing a frictional force between the first side guide and the strip, a second sensor for sensing a frictional force between the second side guide and the strip, and a controller electrically connected to the first sensor and the second sensor, the first lateral jetting unit, and the second lateral jetting unit, wherein the controller compares the frictional force sensed via the first sensor with the frictional force sensed via the second sensor, and adjusts the high-pressure water jetting flow rates of the first lateral jetting unit and the second lateral jetting unit so that an amount of high-pressure water is increased toward one of the first side guide and the second side guide having greater friction with the strip as a result of the comparison.

[0014] The device for preventing foreign matter from entering the hot rolled strip further includes a forward direction injection unit that injects high-pressure water in a moving direction of the strip toward an upper surface of the strip upstream of the side guide, the side guide including a first side guide supporting one side of the strip in a width direction and a second side guide supporting the other side of the strip in the width direction, and the forward direction injection unit can deflect an injection flow rate of the high-pressure water toward either the first side guide or the second side guide.

[0015] The forward direction jet unit may include a plurality of forward direction jet nozzles arranged along the width direction of the strip so as to spray high pressure water onto an upper surface of the strip, each of which is arranged so as to be able to adjust the jet flow rate of the high pressure water, and the plurality of forward direction jet units may adjust the jet flow rate of the high pressure water so that the jet flow rate of the high pressure water is increased toward one of the first and second side guides which has greater friction with the strip.

[0016] The apparatus may further include a first sensor for sensing a frictional force between the first side guide and the strip, a second sensor for sensing a frictional force between the second side guide and the strip, and a controller electrically connected to the first sensor, the second sensor, and a plurality of forward jet nozzles, wherein the controller may compare the frictional force sensed via the first sensor with the frictional force sensed via the second sensor and adjust the high-pressure water jet flow rate of the plurality of forward jet nozzles so that the jet amount of high-pressure water is increased toward the first side guide or the second side guide having greater friction with the strip. Effect of the Invention

[0017] According to one aspect of the disclosed invention, it is possible to provide a foreign matter prevention device for a hot-rolled strip that can effectively prevent foreign matter from being mixed into the strip being wound into a coil in a winding section of a hot rolling process.

[0018] According to one aspect of the disclosed invention, it is possible to provide an apparatus for preventing foreign matter from being mixed into a hot-rolled strip, which can prevent foreign matter from being mixed into the strip being wound into a coil in a winding section of a hot rolling process. [Brief description of the drawings]

[0019] [Figure 1] 1 shows a side structure of a foreign matter prevention device for a hot rolled strip according to one embodiment of the disclosed invention. [Diagram 2] 1 shows a plan view of a foreign matter prevention device for a hot-rolled strip according to one embodiment of the disclosed invention. [Diagram 3]FIG. 1 is a plan view illustrating the operation of an upper reverse injection unit in a foreign matter prevention device for a hot rolled strip according to an embodiment of the disclosed invention; [Figure 4] FIG. 1 is a plan view illustrating an operation state of a side injection unit in a foreign matter prevention device for a hot rolled strip according to an embodiment of the disclosed invention; [Diagram 5] FIG. 1 is a plan view illustrating an operation state of a forward-direction injection unit in a foreign matter prevention device for a hot-rolled strip according to an embodiment of the disclosed invention; [Figure 6] 1 shows the spark generation critical temperatures for each steel type applied to a foreign matter prevention device for a hot rolled strip according to an embodiment of the disclosed invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The same reference numbers refer to the same components throughout the specification. This specification does not describe all elements of the embodiments, and content that is common in the technical field to which the present invention belongs or overlapping content in the examples is omitted. The terms "part, module, member, block" used in the specification may be embodied in software or hardware, and depending on the example, multiple "parts, modules, members, blocks" may be embodied as one component, or one "part, module, member, block" may include multiple components.

[0021] Throughout the specification, when a part is said to be "coupled" to another part, this includes not only direct coupling but also indirect coupling, including coupling via a wireless communication network.

[0022] Furthermore, when a part is described as "comprising" a certain component, this does not mean that other components are excluded, unless otherwise specified to the contrary, but rather that the part may further include other components.

[0023] Throughout the specification, when an element is referred to as being "on" another element, this includes not only when the element is in contact with the other element, but also when there is another element between the two elements.

[0024] The terms "first", "second", etc. are used to distinguish one component from another component, and the components are not limited to the terms described above.

[0025] The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0026] In each step, the identifying numbers are used for convenience of description, and the identifying numbers do not dictate the order of the steps, and the steps may be performed in a manner other than the order specified, unless the context clearly dictates a particular order.

[0027] The principle of operation and embodiments of the present invention will be described below with reference to the accompanying drawings.

[0028] 1 and 2 show a coiling section of a hot rolling process to which a foreign matter prevention device 10 for a hot rolled strip (hereinafter, referred to as a foreign matter prevention device) according to one embodiment of the disclosed invention is applied.

[0029] As shown in Figures 1 and 2, in the winding section of the hot rolling process in which the foreign matter prevention device 10 is applied, side guides 2 and 3, a pinch roll 4, and a winder 5 may be arranged along the moving direction of the strip 1.

[0030] In the hot rolling process, a number of measuring instruments (not shown) for measuring surface defects and width of the strip 1 may be provided upstream of the coiling section.

[0031] For reference, in the drawings, the direction of arrow X1 indicates the moving direction of the strip 1, and the direction of arrow X2 indicates the opposite direction to the moving direction of the strip 1. The direction of X1 may be the downstream direction of the hot rolling process line, and the direction of X2 may be the upstream direction of the hot rolling process line. In addition, the directions of arrows Y1 and Y2 indicate one side and the other side of the width direction of the strip 1, respectively.

[0032] The side guides 2, 3 may be provided as a pair, including a first side guide 2 that supports and guides one widthwise side of the strip 1, and a second side guide 3 that supports and guides the other widthwise side of the strip.

[0033] Upstream of the pinch rolls 4 are provided a number of support rolls 6 which support the strip 1 which is guided to the winder 5, and the side guides 2, 3 can support both sides of the strip 1 which moves along the support rolls 6 so that the strip 1 is guided correctly to the winder 5. The winder 5 can wind the strip 1 which is guided through the pinch rolls 4 to form a hot rolled coil.

[0034] On the other hand, if the strip 1 moving to the winding machine 5 is biased to one side, friction between the strip 1 and the side guides 2 and 3 can cause sparks and the formation of foreign matter. Such foreign matter can adhere to the surface of the strip, and when the strip in this state is wound by the winding machine, press-fit scratches caused by the foreign matter can be formed on the surface of the strip, causing surface defects in the strip.

[0035] The foreign matter contamination prevention device 10 in one embodiment is intended to prevent such foreign matter from becoming mixed into the strip 1, and may be equipped with reverse direction injection units 100, 200 that spray high-pressure water in the opposite direction to the movement of the strip 1 toward the strip 1 moving toward the entrance side of the winding machine 5 by side guides 2, 3.

[0036] The high-pressure water sprayed onto the surface of the strip 1 by the reverse direction jet units 100, 200 can remove foreign matter from the surface of the strip 1 before it passes through the pinch roll 4, thereby preventing the foreign matter from being mixed into the strip 1 being wound by the winding machine 5.

[0037] The reverse direction jetting units 100, 200 may include an upper reverse direction jetting unit 100 located at the upper part of the moving path of the strip 1 to spray high pressure water onto the upper surface of the strip 1, and a lower reverse direction jetting unit 200 located at the lower part of the moving path of the strip 1 to spray high pressure water onto the lower surface of the strip 1.

[0038] The upper reverse jet unit 100 may include a plurality of upper reverse jet nozzles 110 arranged along the width direction of the strip 1 to spray high-pressure water onto the upper surface of the strip 1, and the lower reverse jet unit 200 may include a plurality of lower reverse jet nozzles 210 arranged along the width direction of the strip 1 to spray high-pressure water onto the lower surface of the strip 1.

[0039] The upper reverse direction jet unit 100 includes a header 120 to which high pressure water is supplied, and the header 120 may be provided in an entry guide 7 located at an upper portion between the side guides 2, 3 and the pinch roll 4 in order to guide the strip 1 towards the pinch roll 4. The multiple upper reverse direction jet nozzles 110 may be provided in the header 120 inclined downwardly so as to have a predetermined inclination in order to jet high pressure water toward the upper surface of the strip 1 in a direction opposite to the moving direction of the strip 1.

[0040] The lower reverse jet unit 200 includes a header 220 arranged between the support rolls 6 downstream of the side guides 2, 3, and a plurality of lower reverse jet nozzles 210 may be provided on the header 220 inclined upwardly with a predetermined inclination to spray high-pressure water toward the underside of the strip 1 in a direction opposite to the moving direction of the strip 1.

[0041] For reference, the sector shape in front of the injection nozzle in the drawing indicates the injection direction and injection flow rate of the high-pressure water injected through the injection nozzle.

[0042] A portion of the high-pressure water sprayed onto the strip 1 through the upper reverse-direction jet unit 100 may remain on the upper surface of the strip 1. Over time, this remaining water may form a flow in the opposite direction to the moving direction of the strip 1 and may be transmitted to a measuring device (not shown) upstream of the winding section, thereby causing a disturbance to the measuring device (not shown).

[0043] To prevent this, the multiple upper reverse jet nozzles 110 may be arranged such that the upper reverse jet nozzles 110 located in the center along the arrangement direction are spaced closer together than the upper reverse jet nozzles 110 located at both ends, as shown in FIG. 3.

[0044] According to such an arrangement of the upper reverse injection nozzles 110, the injection pressure of the high-pressure water injected through the central injection nozzles 110 arranged closely spaced from each other may be relatively higher than the injection pressure of the high-pressure water injected through the end injection nozzles 110 arranged widely spaced from each other.

[0045] Therefore, the injection pressure of the high-pressure water pushing out the stagnant water in the X2 direction is greater in the central region of the upper reverse injection nozzle 110 than in the end regions on both sides, so that the stagnant water is separated in the Y1 and Y2 directions along the width direction of both sides of the strip 1 based on the center, and is smoothly removed on the strip 1, eliminating the risk of it flowing into a measuring instrument (not shown).

[0046] In order to form a higher injection pressure of high pressure water in the central region of the upper reverse jet unit 100 than in the end regions, each jet nozzle 110 may be arranged so that the jet nozzle 110 located in the central portion of the arrangement direction injects high pressure water at a higher flow rate than the jet nozzles 110 located at both ends. For this purpose, the upper reverse jet nozzle 110 located in the central portion may have a diameter t1 larger than the diameter t2 of the upper reverse jet nozzle 110 located at the end.

[0047] As an example, the multiple upper reverse jet nozzles 110 may be arranged such that the spacing between the jet nozzles 110 is continuously smaller from both ends toward the center along the arrangement direction, and the diameter of the jet nozzles 110 is continuously larger from the ends toward the center.

[0048] Of course, even if all the upper reverse jet nozzles 110 have the same diameter and only the intervals between them are different, or even if all the upper reverse jet nozzles 110 have the same intervals and the diameters between them are different, the upper reverse jet unit 100 can generate a high-pressure water injection pressure that is greater in the central region than in the end regions.

[0049] By varying the spacing and diameter of the upper reverse jet nozzles 110 in this manner, the upper reverse jet unit 100 can smoothly discharge stagnant water containing foreign matter on the strip 1 without changing the shape of the header 120 or the length of the upper reverse jet nozzles 110, and can be smoothly installed inside the narrow entry guide 7 without changing the design of the entry guide 7.

[0050] The foreign matter contamination prevention device 10 may also include lateral injection units 300, 400 that inject high-pressure water between the side guides 2, 3 and the strip 1.

[0051] 2, high-pressure water jetted from the lateral jet units 300, 400 can cool the gap between the side guides 2, 3 and the strip 1, thereby preventing sparks from occurring between the side guides 2, 3 and the strip 1. Therefore, the lateral jet units 300, 400 can prevent foreign matter from getting into the strip 1 being guided to the winding machine 5.

[0052] The lateral jetting units 300, 400 may include a first lateral jetting unit 300 that jets high-pressure water between the first side guide 2 and one side of the strip 1, and a second lateral jetting unit 400 that jets high-pressure water between the second side guide 3 and the other side of the strip 1.

[0053] Each lateral injection unit 300 , 400 may comprise a header 320 , 420 and a number of lateral injection nozzles 310 , 410 provided on the header 320 , 420 along the direction of movement of the strip 1 .

[0054] The lateral jet nozzles 310, 410 may be divided into a first lateral jet nozzle 310 provided in the first lateral jet unit 300 and a second lateral jet nozzle 410 provided in the second lateral jet unit 400.

[0055] The first lateral jetting unit 300 is disposed on an upper portion of the second side guide 3 and can jet high-pressure water between the first side guide 2 and the strip 1 on the opposite side. And the second lateral jetting unit 400 is disposed on an upper portion of the first side guide 2 and can jet high-pressure water between the second side guide 3 and the strip 1 on the opposite side.

[0056] The first lateral jet nozzle 310 and the second lateral jet nozzle 410 may be arranged alternately with each other so as to prevent mutual interference between the high pressure water jetted from the first lateral jet unit 300 and the high pressure water jetted from the second lateral jet unit 400.

[0057] The arrangement of the lateral jet units 300, 400 is not limited to the above-mentioned embodiment. Each lateral jet unit 300, 400 may be provided to jet high-pressure water directly downward, and the first lateral jet unit 300 may be located above the first side guide 2, and the second lateral jet unit 400 may be located above the second side guide 3.

[0058] Meanwhile, the critical temperature at which sparks occur when friction occurs between the side guides 2 and 3 and the strip 1 may vary depending on the steel type of the strip 1.

[0059] Figure 6 shows the relationship between the critical temperature and time at which sparks occur for each type of steel. As shown in Figure 6, it can be seen that stainless steel generates sparks at a higher critical temperature than mild steel or carbon steel. Even in the case of stainless steel, the critical temperature at which sparks occur varies depending on the type.

[0060] Therefore, in order to suppress the generation of sparks, the flow rate of the high-pressure water for cooling between the strip 1 and the side guides 2, 3 may vary depending on the steel type of the strip 1.

[0061] The side injection units 300, 400 are capable of adjusting the high-pressure water injection flow rate and are installed so that the flow rate of the injected high-pressure water increases in proportion to the critical temperature at which sparks occur in the strip 1 depending on the steel type, thereby making it possible to efficiently use the high pressure flow rate that suppresses sparks.

[0062] In other words, the side injection units 300, 400 relatively increase the flow rate of high-pressure water when the steel type of the strip 1 has a higher critical temperature at which sparks occur than when the critical temperature is low, thereby enabling the flow rate of high-pressure water that suppresses sparks to be used efficiently.

[0063] 4, the foreign matter contamination prevention device 10 may include a control unit 11 and an input unit (not shown). The side direction injection units 300, 400 include flow rate control valves 330, 430 for adjusting the flow rate of high-pressure water supplied to the side direction injection nozzles 310, 410, and the flow rate control valves 330, 430 may be electrically connected to the control unit 11 and controlled by the control unit 11. The flow rate control valves 330, 430 may be provided in the headers 320, 420.

[0064] The steel type of the strip 1 may be input via an input unit (not shown), and the control unit 11 may control the flow rate control valves 330, 430 so that the flow rate of high-pressure water sprayed from the side jet nozzles 310, 410 is adjusted in accordance with the steel type of the strip input via the input unit (not shown).

[0065] In addition, the lateral injection units 300, 400 are provided so as to be able to deflect the injection flow rate of high-pressure water to either the first side guide 2 or the second side guide 3, thereby enabling the injection flow rate of high-pressure water to be increased toward either the first side guide 2 or the second side guide 3 which has greater friction with the strip 1.

[0066] Therefore, the lateral injection units 300, 400 can more effectively cool the gap between the side guides 2, 3 and the strip 1, where there is a relatively high risk of sparks occurring between the side guides 2, 3 on both sides, with high-pressure water.

[0067] The foreign matter contamination prevention device 10 may be provided with a first sensing unit 12 that senses the friction force between the first side guide 2 and the strip 1, and a second sensing unit 13 that senses the friction force between the second side guide 3 and the strip 1, in order to measure the friction force between the strip 1 and the side guides 2 and 3 on both sides.

[0068] The first and second sensors 12 and 13 are provided on the first and second side guides 2 and 3, respectively, and each sensor 12, 13 may be electrically connected to the controller 11. The first and second sensors 12, 13 may sense the magnitude of the frictional force between the strip 1 and the side guides 2, 3 by measuring the magnitude of vibrations generated in the side guides 2, 3 when friction occurs with the strip 1, or the temperature change of the side guides 2, 3 due to friction with the strip 1.

[0069] The first and second sensors 12 and 13 constantly sense the frictional force between the corresponding side guides 2, 3 and the strip 1, and the control unit 11 can compare the frictional force sensed through the first sensor 12 with the frictional force sensed through the second sensor 13. When the comparison of the frictional forces indicates that the side guides 2, 3 have a large friction with the strip 1, the control unit 11 controls the flow rate control valves 330, 430 so that the flow rates of the high-pressure water sprayed through the injection nozzle 310 of the first lateral injection unit 300 and the injection nozzle 410 of the second lateral injection unit 400 are different, thereby increasing the amount of high-pressure water sprayed toward the side guide having a larger friction with the strip 1 out of the first and second side guides 2, 3.

[0070] As an example, Figure 4 shows a state in which, when the frictional force between the second side guide 3 and the strip 1 is greater than the frictional force between the first side guide 2 and the strip 1, the jet flow rate of high-pressure water jetted from the second lateral direction jet unit 400 toward the second side guide 3 is greater than the jet flow rate of high-pressure water jetted from the first lateral direction jet unit 300 toward the first side guide 2.

[0071] The foreign matter contamination prevention device 10 may further include a forward-direction jetting unit 500 that jets high-pressure water from the upstream of the side guides 2, 3 toward the upper surface of the strip 1 in the direction of movement of the strip 1.

[0072] As shown in FIG. 1, the forward direction jet unit 500 jets high-pressure water onto the upper surface of the strip 1 from the opposite side of the upper reverse direction jet unit 100 via side guides 2 and 3, thereby more reliably blocking the water stagnating on the strip 1 from flowing upstream of the winding section where a measuring device (not shown) is located.

[0073] The forward jet unit 500 may include a header 520 and a number of forward jet units 510 provided on the header 520 along the width of the strip 1 .

[0074] The header 520 is disposed upstream of the side guides 2 and 3 and above the movement path of the strip 1, and the multiple forward direction jetting units 510 may be provided on the header 520 at a downward incline so as to have a predetermined inclination to jet high-pressure water toward the upper surface of the strip 1 in the movement direction of the strip 1.

[0075] The plurality of forward direction jet units 510 may be arranged along the width direction of the strip 1, and each forward direction jet unit 510 may be provided so that the jet flow rate of the high-pressure water is individually adjusted.

[0076] 5, the forward injection unit 500 includes a flow rate control valve 530 for controlling the flow rate of high-pressure water supplied to the forward injection unit 510, and the flow rate control valve 530 may be electrically connected to the control unit 11 and controlled by the control unit 11. The flow rate control valve 530 may be provided in the header 520.

[0077] The forward direction injection unit 500 is provided so as to deflect the injection flow rate of high-pressure water to either the first side guide 2 or the second side guide 3, and can increase the injection flow rate of high-pressure water to the side guide having greater friction with the strip 1, out of the first side guide 2 and the second side guide 3.

[0078] Therefore, the forward injection unit 500 can more effectively cool the area between the strip 1 and the side guides 2, 3, where there is a relatively high possibility of sparks occurring between the side guides 2, 3 on both sides, with high-pressure water.

[0079] The control unit 11 may compare the frictional force sensed through the first sensing unit 12 with the frictional force sensed through the second sensing unit 13. If the comparison of the frictional forces identifies the side guides 2 and 3 that have greater friction with the strip 1, the control unit 11 may control the flow rate adjustment valves 530 to adjust the injection flow rate of the high-pressure water injected through each forward injection nozzle 510, thereby increasing the injection amount of the high-pressure water toward the side guide having greater friction with the strip 1 out of the first side guide 2 and the second side guide 3.

[0080] 5 shows a case where the frictional force between the second side guide 3 and the strip 1 is greater than the frictional force between the first side guide 2 and the strip 1. In this case, the control unit 11 controls the flow rate regulating valve 530 so that the high-pressure water jetting flow rate of the forward direction jetting unit 510 adjacent to the second side guide 3 is greater than the high-pressure water jetting flow rate of the forward direction jetting unit 510 adjacent to the first side guide 2, thereby making it possible to make the cooling performance between the second side guide 3 and the strip 1 relatively greater than that between the first side guide 2 and the strip 1.

[0081] As described above, in the structure of the foreign matter contamination prevention device 10 in which the lateral direction jet units 300, 400 and the forward direction jet unit 500 can each deflect the jet flow rate of high-pressure water toward one of the side guides 2, 3, even if either the lateral direction jet units 300, 400 or the forward direction jet unit 500 is omitted, the effect of using high-pressure water to improve the cooling performance on the side guides 2, 3 sides where friction between the strip and 1 is relatively large can be obtained.

Claims

1. A foreign matter prevention device for a hot-rolled strip, which prevents foreign matter formed by friction between a side guide that guides the movement of the strip to the inlet side of a winder in a hot rolling process from being mixed into the strip, comprising: a reverse direction jet unit that jets high-pressure water toward the strip moving toward the inlet side of the winding machine by the side guide in a direction opposite to the moving direction of the strip, the reverse jet unit includes a plurality of upper reverse jet nozzles arranged along a width direction of the strip to jet high-pressure water onto an upper surface of the strip; The device for preventing foreign matter from entering a hot rolled strip, wherein the upper reverse jet nozzles are spaced apart from one another at a central portion along the arrangement direction by a narrower spacing than the nozzles at both ends.

2. 2. The device for preventing foreign matter from entering a hot rolled strip according to claim 1, wherein the upper reverse jet nozzles are arranged so that the nozzles located at a central portion along the arrangement direction jet high-pressure water at a flow rate greater than the nozzles located at both ends.

3. 3. The device for preventing foreign matter from entering a hot rolled strip according to claim 2, wherein the upper reverse jet nozzles located at a central portion along the arrangement direction have a larger diameter than those located at both ends.

4. The apparatus for preventing foreign matter from entering a hot rolled strip according to claim 1 , further comprising a lateral injection unit for injecting high-pressure water between the side guide and the strip.

5. 5. The device for preventing foreign matter from entering a hot rolled strip according to claim 4, wherein the lateral injection unit is provided to be capable of adjusting a flow rate of the high-pressure water injection, and the flow rate of the injected high-pressure water is increased in proportion to a critical temperature at which sparks occur in the strip according to a steel type.

6. The side guide includes a first side guide supporting one side of the strip in a width direction and a second side guide supporting the other side of the strip in the width direction, the lateral jetting unit includes a first lateral jetting unit configured to jet high-pressure water between the first side guide and one side of the strip, and a second lateral jetting unit configured to jet high-pressure water between the second side guide and the other side of the strip, The first lateral direction jet unit and the second lateral direction jet unit are each provided so as to be capable of adjusting a high-pressure water jet flow rate, 5. The device for preventing foreign matter from entering a hot rolled strip according to claim 4, wherein the first lateral direction injection unit and the second lateral direction injection unit adjust high-pressure water injection flow rates so that an injection amount of the high-pressure water is increased toward one of the first side guide and the second side guide which has greater friction with the strip.

7. a first sensor for sensing a frictional force between the first side guide and the strip, a second sensor for sensing a frictional force between the second side guide and the strip, and a controller electrically connected to the first sensor, the second sensor, the first lateral jetting unit, and the second lateral jetting unit, The control unit is 7. The device for preventing foreign matter from entering a hot rolled strip according to claim 6, further comprising: a friction force sensed through the first sensing unit and a friction force sensed through the second sensing unit; and based on a comparison result, adjusting high-pressure water injection flow rates of the first lateral injection unit and the second lateral injection unit so that an injection amount of high-pressure water is increased toward one of the first side guide and the second side guide having a larger friction with the strip.

8. The strip further includes a forward jet unit that jets high-pressure water toward an upper surface of the strip in a moving direction of the strip upstream of the side guide, The side guide includes a first side guide supporting one side of the strip in a width direction and a second side guide supporting the other side of the strip in the width direction, 2. The device for preventing foreign matter from entering a hot rolled strip according to claim 1, wherein the positive direction jet unit is capable of deflecting a jet flow rate of the high-pressure water toward either one of the first side guide or the second side guide.

9. the forward jet unit includes a plurality of forward jet nozzles arranged along the width direction of the strip so as to jet high-pressure water onto an upper surface of the strip, the nozzles being each provided to be capable of adjusting a jet flow rate of the high-pressure water; 9. The device for preventing foreign matter from entering a hot rolled strip according to claim 8, wherein the plurality of forward direction injection nozzles adjust the injection flow rate of the high-pressure water so that the injection flow rate of the high-pressure water is increased toward one of the first side guide and the second side guide which has greater friction with the strip.

10. a first sensor for sensing a frictional force between the first side guide and the strip, a second sensor for sensing a frictional force between the second side guide and the strip, and a controller electrically connected to the first sensor, the second sensor and a plurality of forward injection nozzles, The control unit is 10. The device for preventing foreign matter from entering a hot rolled strip according to claim 9, further comprising: a friction force sensed through the first sensing unit and a friction force sensed through the second sensing unit; and a high-pressure water injection flow rate of the plurality of forward injection nozzles is adjusted so that an amount of high-pressure water is increased toward one of the first side guide and the second side guide having a larger friction with the strip as a result of comparing the friction force sensed through the first sensing unit and the friction force sensed through the second sensing unit.

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