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 a foreign matter prevention device for a hot-rolled strip, which prevents foreign matter from being mixed into the strip being wound into a coil in a coiling 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 certain temperature in a heating furnace, then passed continuously 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 raw materials 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 a 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, causing surface defects in the strip. Summary of the Invention [Problem to be solved by the invention]

[0005] One aspect of the disclosed invention provides 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.

[0006] One aspect of the disclosed invention provides a foreign matter prevention device for a hot-rolled strip that can prevent foreign matter from being mixed into the 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, there is provided a foreign matter prevention device for a hot-rolled strip 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 winder during a hot rolling process from being mixed into the strip, and the device includes a reverse direction jetting unit that jets high-pressure water toward the strip as it moves to the entrance side of the winder by the side guide in a direction reverse to the movement direction of the strip, the reverse direction jetting unit including a plurality of upper reverse direction jetting 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 jetting nozzles may be spaced closer together at a center of 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 both ends.

[0009] The upper reverse jet nozzles may have a diameter that is larger in the center along the arrangement direction than in the ends.

[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 side injection unit may be provided to adjust the flow rate of injected high-pressure water, and the flow rate of injected high-pressure water may be increased in proportion to the critical temperature at which sparks occur in the strip depending on the steel grade.

[0012] The side guide may include 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, and the lateral jetting unit may include 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 configured to be able to adjust the jet flow rate of high-pressure water, and the first lateral jetting unit and the second lateral jetting unit may adjust the jet flow rate of high-pressure water so that the jet amount of high-pressure water is increased toward one of the first side guide and the second side guide that has greater friction with the strip.

[0013] The device may further include a first sensor that senses a frictional force between the first side guide and the strip, a second sensor that senses 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, 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 jet flow rates of the first lateral jetting unit and the second lateral jetting unit so that the amount of high-pressure water jetted toward the side guide having greater friction with the strip, out of the first and second side guides, based on the comparison result.

[0014] The device for preventing foreign matter from entering the hot-rolled strip further includes a forward direction injection unit that is upstream of the side guides and that injects high-pressure water toward an upper surface of the strip in a moving direction of the strip, the side guides including a first side guide that supports one side of the strip in a width direction and a second side guide that supports 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 jet high-pressure water onto the upper surface of the strip, each of which is arranged so that the jet flow rate of the high-pressure water can be adjusted, 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 increases toward either the first side guide or the second side guide which has greater friction with the strip.

[0016] The apparatus may further include a first sensor that senses a frictional force between the first side guide and the strip, a second sensor that senses 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-direction spray 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 spray flow rate of the plurality of forward-direction spray nozzles so that the amount of high-pressure water sprayed is increased toward the first side guide or the second side guide that has greater friction with the strip. [Effects of the Invention]

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

[0019] [Figure 1] 1 shows a side view of a foreign matter prevention device for a hot-rolled strip according to one embodiment of the disclosed invention. [Figure 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. [Figure 3]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 operating state of a side injection unit in an apparatus for preventing foreign matter from entering a hot rolled strip according to an embodiment of the disclosed invention. [Figure 5] FIG. 1 is a plan view illustrating an operating state of a forward 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 critical spark generation temperatures for each steel type applied to a foreign matter prevention device for a hot-rolled strip according to one embodiment of the disclosed invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The same reference numerals 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 that is redundant in the examples will be omitted. The terms "unit, module, component, block" used in the specification may be embodied in software or hardware, and depending on the example, multiple "units, modules, components, blocks" may be embodied as one component, or one "unit, module, component, block" may include multiple components.

[0021] Throughout this specification, when a part is said to be "coupled" to another part, this includes not only direct coupling but also indirect coupling, and indirect coupling includes 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, and means that other components may also be included.

[0023] Throughout this 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, and the components are not limited to the terms mentioned 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 principles 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 to which the foreign matter contamination 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 strip 1, and the direction of arrow X2 indicates the opposite direction to the moving direction of 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 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] A plurality of support rolls 6 are provided upstream of the pinch rolls 4 to support the strip 1 that is guided to the winder 5, and side guides 2 and 3 can support both sides of the strip 1 that moves along the support rolls 6 to ensure that the strip 1 is guided correctly to the winder 5. The winder 5 may wind the strip 1 that 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 may occur between the strip 1 and the side guides 2 and 3, causing sparks and the formation of foreign matter. Such foreign matter may 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 may be formed on the surface of the strip, causing surface defects of the strip.

[0035] The foreign matter contamination prevention device 10 according to one embodiment is designed to prevent such foreign matter from being mixed into the strip 1, and may be equipped with reverse direction injection units 100, 200 that inject 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 the side guides 2, 3.

[0036] The high-pressure water sprayed onto the surface of the strip 1 by the reverse direction spray units 100, 200 can remove foreign matter from the surface of the strip 1 before it passes through the pinch roll 4, thereby preventing foreign matter from getting 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 top of the moving path of the strip 1 to jet high-pressure water onto the upper surface of the strip 1, and a lower reverse direction jetting unit 200 located at the bottom of the moving path of the strip 1 to jet 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 so as 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 so as 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 toward the pinch roll 4. A plurality of upper reverse direction jet nozzles 110 may be provided in the header 120 inclined downward 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 direction jetting 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 direction jetting nozzles 210 may be provided on the header 220 inclined upward with a predetermined inclination to jet 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 spray 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 disturbance to the measuring device (not shown).

[0043] To prevent this, the 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 this arrangement of the upper reverse injection nozzles 110, the injection pressure of the high-pressure water injected through the central injection nozzles 110 arranged at close intervals can be relatively higher than the injection pressure of the high-pressure water injected through the end injection nozzles 110 arranged at wide intervals.

[0045] Therefore, the injection pressure of the high-pressure water that pushes 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 on both sides in the Y1 and Y2 directions along the width direction of both sides of the strip 1 based on the central part, 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 nozzles 110 located at the ends.

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

[0048] Of course, even if all the upper reverse injection nozzles 110 have the same diameter and only the intervals between them are different, or even if all the upper reverse injection nozzles 110 have the same intervals and the diameters between them are different, the upper reverse injection unit 100 can generate a higher injection pressure of high-pressure water 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 accumulated 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 a 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 and 400 that inject high-pressure water between the side guides 2 and 3 and the strip 1 .

[0051] 2, the high-pressure water sprayed 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 mixed in with the strip 1 being guided to the winding machine 5.

[0052] The lateral spraying units 300, 400 may include a first lateral spraying unit 300 that sprays high-pressure water between the first side guide 2 and one side of the strip 1, and a second lateral spraying unit 400 that sprays 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 include a header 320 , 420 and a plurality of lateral injection nozzles 310 , 410 provided on the header 320 , 420 along the direction of movement of the strip 1 .

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

[0055] The first lateral jetting unit 300 is disposed above 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. The second lateral jetting unit 400 is disposed above 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 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 jetting units 300, 400 is not limited to the above-described configuration. Each lateral jetting unit 300, 400 may be arranged to jet high-pressure water directly downward, with the first lateral jetting unit 300 positioned above the first side guide 2 and the second lateral jetting unit 400 positioned above the second side guide 3.

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

[0059] Figure 6 shows the relationship between the critical temperature at which sparks occur and time 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. Furthermore, 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 occurrence of sparks, the flow rate of the high-pressure water for cooling between the strip 1 and the side guides 2 and 3 may be changed depending on the steel grade of the strip 1.

[0061] The side injection units 300, 400 are capable of adjusting the high-pressure water injection flow rate, and are configured 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 enabling the high-pressure water flow rate that suppresses sparks to be used efficiently.

[0062] That is, 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 lateral injection units 300, 400 include flow control valves 330, 430 for adjusting the flow rate of high-pressure water supplied to the lateral injection nozzles 310, 410, and the flow control valves 330, 430 may be electrically connected to and controlled by the control unit 11. The flow control valves 330, 430 may be provided in the headers 320, 420.

[0064] The steel grade 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 injection nozzles 310, 410 is adjusted according to the steel grade of the strip input via the input unit (not shown).

[0065] In addition, the lateral injection units 300, 400 are arranged to deflect the injection flow rate of high-pressure water to either the first side guide 2 or the second side guide 3, thereby increasing the injection flow rate of high-pressure water to the side guide that has greater friction with the strip 1.

[0066] Therefore, the lateral injection units 300, 400 can more effectively cool the area between the strip 1 and the side guides 2, 3, 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 sensor 12 that senses the frictional force between the first side guide 2 and the strip 1, and a second sensor 13 that senses the frictional force between the second side guide 3 and the strip 1, in order to measure the frictional force between the strip 1 and the side guides 2 and 3 on both sides.

[0068] The first and second sensors 12 and 13 may be provided on the first and second side guides 2 and 3, respectively, and each of the sensors 12 and 13 may be electrically connected to the control unit 11. The first and second sensors 12 and 13 may sense the magnitude of the frictional force between the strip 1 and the side guides 2 and 3 by measuring the magnitude of vibrations generated in the side guides 2 and 3 when they are rubbed against the strip 1, or the temperature change of the side guides 2 and 3 due to the 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 and 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. If the comparison of the frictional forces identifies one of the side guides 2 and 3 as having greater friction with the strip 1, the control unit 11 controls the flow control valves 330 and 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 of the first or second side guide 2 or 3 that has greater friction with the strip 1.

[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 injection flow rate of high-pressure water injected from the second lateral injection unit 400 toward the second side guide 3 is greater than the injection flow rate of high-pressure water injected from the first lateral injection unit 300 toward the first side guide 2.

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

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

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

[0074] The header 520 is arranged upstream of the side guides 2 and 3 above the movement path of the strip 1, and the multiple forward direction injection units 510 may be provided on the header 520 at a downward incline so as to have a predetermined inclination to inject 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 jetting units 510 may be arranged along the width direction of the strip 1, and each forward direction jetting unit 510 may be provided so that the jet flow rate of the high-pressure water is individually adjusted.

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

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

[0078] Therefore, the forward injection unit 500 can more effectively cool the area between the strip 1 and the side guides 2 and 3, where there is a relatively high possibility of sparks occurring between the side guides 2 and 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 side guides 2 and 3 that have greater friction with the strip 1, the control unit 11 may control the flow rate adjustment valve 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 high-pressure water toward the side guide 2 or the second side guide 3 that has greater friction with the strip 1.

[0080] 5 shows an example in which 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 adjustment valve 530 so that the high-pressure water jet flow rate of the forward direction jet unit 510 adjacent to the second side guide 3 is greater than the high-pressure water jet flow rate of the forward direction jet 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 foreign matter contamination prevention device 10 in which lateral injection units 300, 400 and forward injection unit 500 can deflect the injection flow rate of high-pressure water toward one of side guides 2, 3, respectively, even if either lateral injection units 300, 400 or forward injection unit 500 is omitted, the effect of using high-pressure water to improve cooling performance on the side of side guides 2, 3 where friction between the strip and 1 is relatively high can be achieved.

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, a reverse direction jetting unit that jets high-pressure water in a direction opposite to the moving direction of the strip toward the strip moving to the inlet side of the winding machine by the side guide, the reverse jet unit includes a plurality of upper reverse jet nozzles arranged along the width direction of the strip to jet high-pressure water onto the upper surface of the strip; the plurality of upper reverse jet nozzles are spaced closer together at a center portion along the direction of the arrangement than at both ends, The device for preventing foreign matter from getting into a hot rolled strip, wherein the upper reverse jet nozzles positioned in the center along the direction of arrangement jet high-pressure water at a flow rate greater than those positioned 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 located at a central portion along the direction of arrangement have a larger diameter than the upper reverse jet nozzles located at both ends.

3. 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, a reverse direction jetting unit that jets high-pressure water in a direction opposite to the moving direction of the strip toward the strip moving to the inlet side of the winding machine by the side guide, the reverse jet unit includes a plurality of upper reverse jet nozzles arranged along the width direction of the strip to jet high-pressure water onto the upper surface of the strip; the plurality of upper reverse jet nozzles are spaced closer together at a center portion along the direction of the arrangement than at both ends, a lateral injection unit for injecting high-pressure water between the side guide and the strip; The side injection unit is provided to be able to adjust the flow rate of high-pressure water injection, and the flow rate of the injected high-pressure water is increased in proportion to the critical temperature at which sparks occur in the strip depending on the steel type.

4. the side guides include a first side guide supporting one widthwise side of the strip and a second side guide supporting the other widthwise side of the strip; the lateral jetting units include a first lateral jetting unit that jets high-pressure water between the first side guide and one side of the strip, and a second lateral jetting unit that jets high-pressure water between the second side guide and the other side of the strip, the first lateral direction jetting unit and the second lateral direction jetting unit are each provided to be adjustable in high-pressure water jet flow rate; 4. The device for preventing foreign matter from entering a hot-rolled strip according to claim 3, wherein the first lateral direction injection unit and the second lateral direction injection unit adjust the high-pressure water injection flow rates so that the 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.

5. The device further includes a first sensor that senses a frictional force between the first side guide and the strip, a second sensor that senses a frictional force between the second side guide and the strip, and a controller that is electrically connected to the first sensor, the second sensor, the first lateral spray unit, and the second lateral spray unit, The control unit 5. The device for preventing foreign matter from entering a hot rolled strip according to claim 4, further comprising: a friction force sensed via the first sensing unit and a friction force sensed via the second sensing unit; and, based on the comparison result, adjusting the high-pressure water injection flow rates of the first lateral injection unit and the second lateral injection unit so that the injection 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.

6. 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, a reverse direction jetting unit that jets high-pressure water in a direction opposite to the moving direction of the strip toward the strip moving to the inlet side of the winding machine by the side guide, the reverse jet unit includes a plurality of upper reverse jet nozzles arranged along the width direction of the strip to jet high-pressure water onto the upper surface of the strip; the plurality of upper reverse jet nozzles are spaced closer together at a center portion along the direction of the arrangement than at both ends, The method further includes a forward jetting 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 guides include 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 forward direction injection unit can deflect the injection flow rate of high-pressure water toward either the first side guide or the second side guide.

7. the forward jetting unit includes a plurality of forward jetting nozzles arranged along the width direction of the strip so as to jet high-pressure water onto the upper surface of the strip, each nozzle being capable of adjusting the jet flow rate of the high-pressure water; 7. The device for preventing foreign matter from entering a hot-rolled strip according to claim 6, wherein the plurality of forward-direction injection nozzles adjust the injection flow rates 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.

8. The device further includes a first sensor that senses a frictional force between the first side guide and the strip, a second sensor that senses a frictional force between the second side guide and the strip, and a controller that is electrically connected to the first sensor, the second sensor, and a plurality of forward-direction injection nozzles, The control unit 8. The device for preventing foreign matter from entering a hot-rolled strip according to claim 7, wherein the device adjusts the high-pressure water injection flow rates of the plurality of forward injection nozzles so that, as a result of comparing the friction force sensed via the first sensing unit and the friction force sensed via the second sensing unit, the amount of high-pressure water injected is increased toward one of the first side guide and the second side guide having greater friction with the strip.

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