Cooling unit of bright annealing furnace

Abstract

A cooling unit (2) of a bright annealing furnace (1), comprising: a cooling duct (21); a cooler (22) which is provided inside the cooling duct (21) and cools the furnace atmosphere gas that has passed through the inside of the cooling duct (21); and a gas injection device (24) that injects a cleaning gas toward the cooler (22).

Description

Technical Field

[0001] The invention relates to a cooling unit of a bright annealing furnace. Background Art

[0002] In the past, in a bright annealing furnace, the components of the processed material and / or the impurities contained in the material react with the furnace atmosphere (hydrogen) to produce white powder (white powder), which blocks the cooler in the cooling path (cooling pipeline) for cooling the furnace atmosphere, and reduces the ventilation volume and cooling capacity, which becomes a technical problem. Therefore, Patent Document 1 discloses the following structure: in the cooling pipeline, a filter is set on the downstream side of the furnace atmosphere flow of the cooler to reduce the amount of white powder circulating in the furnace and also reduce the amount of white powder attached to the cooler. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 10-72624 Summary of the invention Technical problem to be solved by the invention

[0004] However, even if a filter is provided in the cooling duct, it is difficult to completely remove the white powder, and the white powder that passes through the filter adheres to the cooler over time. Furthermore, in order to remove the white powder attached to the cooler, the following operations are required: the atmosphere in a large-capacity furnace, which is mainly composed of hydrogen and nitrogen, is replaced with nitrogen to form a nitrogen atmosphere, and then replaced with air, and the cooler is removed from the cooling duct, and the white powder is removed from the cooler outside the furnace. Cleaning the cooler requires a large-scale project.

[0005] Therefore, an object of the present invention is to provide a cooling unit for a bright annealing furnace, which can remove white powder adhering to a cooler without removing the cooler from a cooling duct. Means for solving technical problems

[0006] The present invention is a cooling unit of a bright annealing furnace, comprising: Cooling pipes; a cooler, which is disposed in the cooling pipe and cools the atmosphere gas in the furnace passing through the cooling pipe; and A gas injection device injects a purge gas toward the cooler.

[0007] According to the above configuration, the cooler can be cleaned by the jet gas from the gas jet device, so that the white powder adhering to the cooler can be removed without removing the cooler from the cooling duct. Effects of the Invention

[0008] According to the present invention, it is possible to provide a cooling unit for a bright annealing furnace, which can remove white powder adhering to a cooler without removing the cooler from a cooling duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of a bright annealing furnace including a cooling unit according to an embodiment of the present invention. Figure 2 It is a partial schematic diagram of the cooling unit. Figure 3 It includes Figure 2 A schematic diagram of the exhaust portion of the cooling unit as viewed from another side is shown. Figure 4 Another embodiment of the present invention is a partial schematic diagram of a cooling unit in which a gas injection device can move between a cleaning position and a retreat position. Figure 5 It includes Figure 4 A schematic diagram of the exhaust portion of the cooling unit as viewed from another side is shown. Figure 6 It is a partial schematic diagram of a cooling unit according to another embodiment of the present invention. DETAILED DESCRIPTION

[0010] Figure 1 Schematic diagram of a bright annealing furnace 1 including a cooling unit according to an embodiment of the present invention. Figure 1 As shown, the bright annealing furnace 1 is a furnace for bright annealing a strip-shaped treated material S such as a stainless steel strip obtained by cold rolling, and includes an inlet sealing portion 11, a heating zone 12, a cooling zone 13, and an outlet sealing portion 14. The treated material S is guided to the heating zone 12 through the inlet sealing portion 11, is heated in the heating zone 12, is cooled in the cooling zone 13, and is taken out through the outlet sealing portion 14. The bright annealing furnace 1 is filled with an atmosphere gas for bright annealing having hydrogen and nitrogen as main components.

[0011] The cooling belt 13 includes a cooling unit 2 for cooling the atmosphere in the cooling belt 13. The cooling unit 2 includes: a cooling pipe 21, which is installed on the wall surface of the cooling belt 13 and allows the atmosphere in the cooling belt 13 to pass through; a cooler 22, which is arranged in the cooling pipe 21 and cools the atmosphere passing through the cooling pipe 21; and a circulation fan 23, which is arranged in the cooling pipe 21 and circulates the atmosphere in the cooling belt 13. The cooler 22 includes a plurality of pipes (not shown) through which a cooling medium such as water flows, and the atmosphere flows between these pipes and is cooled by heat exchange with the cooling medium.

[0012] Figure 2 is a partial schematic diagram of the cooling unit 2, Figure 3 It includes Figure 2Schematic diagram of the exhaust portion viewed from another side of the cooling unit 2 shown. Figure 2 and Figure 3 As shown, the cooling unit 2 includes a gas injection device 24 for injecting a purge gas toward the cooler 22. In the gas injection device 24, an injection nozzle 24a is located at a position sandwiching the cooler 22, and a plurality of injection nozzles 24a are provided at equal intervals toward the cooler 22 along the up-down direction of the cooler 22. The gas injection device 24 is configured to be able to swing in the up-down and / or left-right directions.

[0013] A cooler box 25 for accommodating the cooler 22 is provided in the cooling pipe 21, and a water supply port 25a for supplying water for cooling the cooler 22 and a water discharge port 25b for draining the water are provided in the cooler box 25. In addition, a discharge portion 3 is provided at the lower portion of the cooler box 25, and the discharge portion 3 receives the white powder removed from the cooler 22 together with the gas from the gas injection device 24.

[0014] In the cooling duct 21, a first damper 26a and a second damper 26b are respectively provided on the upstream side and the downstream side of the atmosphere gas flow of the cooler box 25. In addition, a first thermometer 27a and a first pressure gauge 28a are provided on the upstream side of the atmosphere gas flow of the first damper 26a, and a second thermometer 27b and a second pressure gauge 28b are provided on the downstream side of the atmosphere gas flow of the second damper 26b.

[0015] The discharge part 3 includes: a discharge pipe 31 connected to the lower part of the cooler box 25 at one end; a bubbler 32 inserted into the other end of the discharge pipe 31; and an exhaust pipe 33 for exhausting gas from the bubbler 32. The bubbler 32 stores water, and while sealing the atmosphere in the furnace from the outside, the gas injected from the gas injection device 24 is discharged to the outside air through the exhaust pipe 33. In addition, the white powder removed from the cooler 22 may be received together with the gas through the discharge pipe 31, and the gas and the white powder may be separated in water, and only the separated gas may be discharged to the outside air through the exhaust pipe 33, and the separated white powder may be recovered separately.

[0016] The cooling unit 2 operates as follows.

[0017] When the treated material S is bright annealed in the bright annealing furnace 1, the treated material S heated by the heating belt 12 is cooled by the cooling belt 13. At the cooling belt 13, the atmosphere gas in the cooling belt 13 is sucked into the cooling duct 21 by the circulation fan 23, cooled by the cooler 22, and then returned to the cooling belt 13.

[0018] At the upstream and downstream sides of the cooler box 25 where the atmosphere flows, the temperature and pressure of the atmosphere in the cooling duct 21 are measured by a first thermometer 27 a , a second thermometer 27 b , a first pressure gauge 28 a , and a second pressure gauge 28 b .

[0019] As the atmosphere passes through the cooler 22, the white powder contained in the atmosphere adheres to the cooler 22. When a predetermined amount of white powder or more adheres to the cooler 22, the cooling performance of the cooler 22 decreases, and by measuring the temperature difference between the first thermometer 27a and the second thermometer 27b, the decrease in the cooling performance of the cooler 22 can be grasped. In addition, by measuring the pressure difference (air permeability) between the first pressure gauge 28a and the second pressure gauge 28b, the decrease in the cooling performance of the cooler 22 can also be grasped.

[0020] When the temperature difference between the first thermometer 27a and the second thermometer 27b is greater than a specified value, or the pressure difference between the first pressure gauge 28a and the second pressure gauge 28b is greater than a specified value, it is determined that the cooling performance of the cooler 22 has decreased, and the operation of cleaning the cooler 22 is started. First, the circulation fan 23 is stopped, and the first damper 26a and the second damper 26b provided on the upstream and downstream sides of the flow of the atmosphere gas of the cooler box 25 are closed.

[0021] Then, the cleaning gas is sprayed from the spray nozzle 24a of the gas spray device 24 from the outer sides of the cooler 22 to the two side surfaces to remove the white powder attached to the cooler 22. Here, the cleaning gas uses nitrogen stored in an emergency nitrogen tank provided in the bright annealing furnace 1. When the cooler 22 is cleaned by the gas spray device 24, the gas spray device 24 is swung in the up-down direction and / or the left-right direction, and the spray nozzle 24a is swung in the up-down direction and / or the left-right direction to improve the removal efficiency of the white powder.

[0022] The gas injected from the gas injection device 24 is discharged to the outside air through the exhaust pipe 33. In addition, the white powder removed from the cooler 22 is received by the bubbler 32 through the exhaust pipe 31 together with the gas, and the gas and the white powder are separated in water. Only the separated gas is discharged to the outside air through the exhaust pipe 33, and the separated white powder is recovered separately. The bubbler is usually used to discharge the remaining atmosphere gas in the furnace to appropriately maintain the pressure in the furnace, but here the bubbler 32 can be used as its mechanism.

[0023] When the gas injection device 24 finishes cleaning the cooler 22, the remaining water in the cooler box is discharged from the drain port 25b. Then, the first damper 26a and the second damper 26b provided on the upstream and downstream sides of the flow of the atmosphere gas of the cooler box 25 are opened, and the circulation fan 23 is started. At this time, the atmosphere gas of the cooling belt 13 is sucked into the cooling duct 21, cooled by the cooler 22, and the circulation of the atmosphere gas returning to the cooling belt 13 begins again.

[0024] According to the cooling unit 2 of the bright annealing furnace 1 having the above-described structure, the following effects can be achieved.

[0025] (1) Since the cooling duct 21 includes the gas injection device 24 for injecting cleaning gas toward the cooler 22, the cooler 22 can be cleaned by the injected gas from the gas injection device 24, and the white powder attached to the cooler 22 can be removed without removing the cooler 22 from the cooling duct 21.

[0026] (2) Since the white powder and the gas are separated by the bubbler 32 and the separated gas is discharged from the exhaust pipe 33 of the bubbler, the purge gas can be discharged to the outside of the furnace while preventing air from intruding into the cooling duct 21 through the bubbler 32. In addition, the white powder removed from the cooler 22 can be recovered and only the separated gas can be discharged.

[0027] (3) By measuring the pressure difference between the upstream side and the downstream side of the cooler 22 with the first pressure gauge 28a and the second pressure gauge 28b, it is possible to confirm the reduction in cooling performance caused by the reduction in air permeability of the cooler 22. When the reduction in cooling performance (air permeability) of the cooler 22 is confirmed and the cooler 22 is cleaned, the first damper 26a and the second damper 26b on the upstream side and the downstream side of the cooler 22 are closed, so that the white powder removed from the cooler 22 can be suppressed from diffusing from the cooling duct 21 into the cooling zone 13.

[0028] (4) By measuring the temperature difference between the upstream side and the downstream side of the cooler 22 with the first thermometer 27a and the second thermometer 27b, it is possible to confirm the reduction in the cooling performance of the cooler 22. When the reduction in the cooling performance (air permeability) of the cooler 22 is confirmed and the cooler 22 is cleaned, the first damper 26a and the second damper 26b on the upstream side and the downstream side of the cooler 22 are closed, so that the white powder removed from the cooler 22 can be suppressed from diffusing from the cooling duct 21 into the cooling zone 13.

[0029] (5) Since the gas injection device 24 is configured to be able to swing in the up-down direction and / or left-right direction in the cleaning position, the gas injection device 24 is swung in the up-down direction and left-right direction during cleaning, so that the gas injected from the gas injection device 24 hits both side surfaces of the cooler 22 without omission, thereby removing more white powder attached to the cooler 22.

[0030] (6) Since the gas injected from the gas injection device 24 is nitrogen stored in an emergency nitrogen tank provided in the bright annealing furnace 1, it is not necessary to prepare a separate nitrogen tank for the gas injection device 24, thereby reducing costs.

[0031] (Other embodiments) In addition to the above-described embodiment, the gas injection device 24 may be movable between the cleaning position and the escape position.

[0032] Figure 4 1 is another embodiment of the present invention, and is a schematic diagram of a cooling unit 2 in which a gas injection device 24 can move between a cleaning position and a retreat position. Another embodiment is different from the above embodiment in that the gas injection device 24 can move between the cleaning position and the retreat position, and the other structures are the same as the above embodiment. Therefore, in the description of another embodiment, the same reference numerals are given to the same parts as the above embodiment, and detailed description of these contents is omitted. Figure 5 It includes Figure 4 A schematic diagram of the exhaust portion of the cooling unit 2 as viewed from another side is shown.

[0033] like Figure 4 and Figure 5 As shown, the cooling unit 2 has an escape chamber 25c above the cooler box 25 for the gas injection device 24 to escape from the cooler 22. On the upper wall of the escape chamber 25c, a working device 29 such as a hydraulic cylinder for moving the gas injection device, which is connected to the upper end of the gas injection device 24 and moves the gas injection device 24 in the up-down direction, is provided. Through the working device 29, the gas injection device 24 can move in the up-down direction between a cleaning position located at a position opposite to the cooler 22 and an escape position located in the escape chamber 25c by escaping upward from the cooler 22.

[0034] The gas injection device is usually arranged in the flow path of the cooling duct, which hinders the flow of the atmosphere gas in the furnace. However, according to the above structure, the gas injection device 24 can move between the cleaning position and the avoidance position. Therefore, except when cleaning the cooler 22, the gas injection device 24 is located in the avoidance position, which can prevent the flow of the atmosphere gas in the furnace from being obstructed.

[0035] In the above embodiment, the injection gas of the gas injection device 24 is nitrogen, but a gas having the same composition as the atmosphere in the furnace may be used. In this case, compared with nitrogen, the change in the composition of the atmosphere in the furnace after the cooler cleaning is completed can be suppressed. In addition, in the above embodiment, the injection gas of the gas injection device 24 is nitrogen stored in an emergency nitrogen tank provided in the bright annealing furnace, but a gas tank for the gas injection device 24 may be provided separately.

[0036] Figure 6 FIG. 2 is a partial schematic diagram of a cooling unit 2 according to another embodiment of the present invention. Figure 6 As shown, the cooling unit 2 may include: a bypass duct 41 connecting the upstream side of the first damper 26a and the downstream side of the second damper 26b; and a closing damper 42 disposed in the middle of the bypass duct 41. At this time, when cleaning the cooler, when the first damper 26a and the second damper 26b are closed, the closing damper 42 that is normally closed is opened, so that the circulation fan 23 is not stopped, and the cooler 22 can be cleaned while continuing the operation of the bright annealing furnace 1.

[0037] The present invention and its embodiments are summarized as follows.

[0038] (a) One embodiment of the present invention is a cooling unit of a bright annealing furnace, comprising: Cooling pipes; a cooler, which is disposed in the cooling pipe and cools the atmosphere gas in the furnace passing through the cooling pipe; and A gas injection device injects a purge gas toward the cooler.

[0039] According to the above configuration (a), the cooler can be cleaned by the jet gas from the gas jet device, so that the white powder adhering to the cooler can be removed without removing the cooler from the cooling duct.

[0040] (b) In the configuration (a), the gas injection device is movable between a cleaning position facing the cooler and a retreat position retreated from the cooler.

[0041] According to the above configuration (b), the gas injection device can move between the cleaning position and the escape position. Therefore, when cooling the atmosphere in the furnace, the gas injection device is located at the escape position, which can prevent the flow of the atmosphere in the furnace from being obstructed.

[0042] (c) In the above configuration (a) or (b), a discharge portion is included, wherein the discharge portion receives the white powder removed from the cooler together with the gas from the gas injection device, The discharge part includes a bubbler, and the pressure in the furnace is maintained by the bubbler, while the white powder and gas are discharged from an exhaust pipe of the bubbler.

[0043] According to the configuration (c), the bubbler can be used to discharge the injected gas while preventing air from entering the cooling duct. Alternatively, the white powder removed from the cooler can be recovered with water, and only the separated gas can be discharged.

[0044] (d) In any one of the above structures (a) to (c), a pressure gauge and a damper are provided on the upstream side and the downstream side of the flow of the furnace atmosphere gas of the cooler, respectively. When the pressure difference of the pressure gauge on the upstream side and the downstream side of the cooler is equal to or larger than a predetermined value, the dampers on the upstream side and the downstream side of the cooler are closed, and the cooler is cleaned by the gas injection device.

[0045] According to the structure (d), by measuring the pressure difference between the upstream side and the downstream side of the cooler, it is possible to confirm the reduction in the cooling performance of the cooler. When the cooler is cleaned after confirming the reduction in the cooling performance of the cooler, by closing the dampers on the upstream side and the downstream side of the cooler, it is possible to suppress the white powder removed from the cooler from spreading into the cooling duct or the cooling zone.

[0046] (e) In any one of the above structures (a) to (d), a thermometer and a damper are provided on the upstream side and the downstream side of the flow of the furnace atmosphere gas of the cooler, respectively. When the temperature difference between the thermometers on the upstream side and the downstream side of the cooler is equal to or greater than a predetermined value, the dampers on the upstream side and the downstream side of the cooler are closed, and the cooler is cleaned by the gas injection device.

[0047] According to the configuration (e), by measuring the temperature difference between the upstream side and the downstream side of the cooler, it is possible to confirm the decrease in the cooling performance of the cooler. When the cooler is cleaned after confirming the decrease in the cooling performance of the cooler, by closing the dampers on the upstream side and the downstream side of the cooler, it is possible to suppress the white powder removed from the cooler from spreading into the cooling duct or the cooling zone.

[0048] (f) In the above configuration (b), the gas injection device is configured to be able to swing in the vertical direction and / or the horizontal direction at the cleaning position.

[0049] According to the above configuration (f), the gas injection device is swung in the vertical direction or the horizontal direction during cleaning so that the gas injected from the gas injection device hits the cooler without omission, thereby removing more attached white powder.

[0050] (g) In any one of the above configurations (a) to (f), the gas injected from the gas injection device is nitrogen stored in an emergency nitrogen tank provided in the bright annealing furnace.

[0051] According to the above configuration (g), it is not necessary to separately prepare nitrogen gas for the gas injection device, thereby reducing costs.

[0052] Various modifications and changes can be made without departing from the spirit and scope of the present invention as described in the claims. Industrial Applicability

[0053] The present invention can provide a cooling unit for a bright annealing furnace, which can remove white powder attached to a cooler without removing the cooler from a cooling pipe, and thus has great industrial utilization value. Explanation of symbols

[0054] 1 Bright annealing furnace 2 Cooling unit 3. Discharge section 11 inlet sealing part 12 heating belt 13 cooling belt 14 outlet sealing part 21 Cooling pipe 22 Cooler 23 Circulation fan 24 Gas injection device 24a injection nozzle 25 Cooler box 25a Water supply port 25b Drain port 25c Refuge room 26a First damper 26b Second damper 27a First thermometer 27b Second thermometer 28a First pressure gauge 28b Second pressure gauge 29 Working equipment 31 Exhaust pipe 32 Bubble generator 33 Exhaust pipe 41 Bypass pipe 42 Close the damper S Processing Materials

Claims

1. A cooling unit is a cooling unit of a bright annealing furnace, characterized in that: include: Cooling pipes; A cooler, which is arranged in the cooling pipe and cools the atmosphere gas in the furnace passing through the cooling pipe; as well as a gas injection device for injecting a purge gas toward the cooler, The gas injection device is movable between a cleaning position facing the cooler and a retreat position retreated from the cooler.

2. The cooling unit according to claim 1, characterized in that The device comprises a discharge part for receiving the white powder removed from the cooler together with the gas from the gas injection device, The discharge portion includes a bubbler.

3. The cooling unit according to claim 1 or 2, characterized in that: A pressure gauge and a damper are respectively provided on the upstream side and the downstream side of the flow of the atmosphere gas in the furnace of the cooler. When the pressure difference of the pressure gauge on the upstream side and the downstream side of the cooler is equal to or larger than a predetermined value, the dampers on the upstream side and the downstream side of the cooler are closed, and the cooler is cleaned by the gas injection device.

4. The cooling unit according to claim 1 or 2, characterized in that: A thermometer and a damper are respectively provided on the upstream side and the downstream side of the flow of the atmosphere gas in the furnace of the cooler. When the temperature difference between the thermometers on the upstream side and the downstream side of the cooler is equal to or greater than a predetermined value, the dampers on the upstream side and the downstream side of the cooler are closed, and the cooler is cleaned by the gas injection device.

5. The cooling unit according to claim 1 or 2, characterized in that: The gas injection device is configured to be able to swing in the vertical direction and / or the horizontal direction at the cleaning position.

6. The cooling unit according to claim 1 or 2, characterized in that: The gas injected from the gas injection device is nitrogen stored in an emergency nitrogen tank provided in the bright annealing furnace.

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