Water sealing device for walking beam type heating furnace

Abstract

To prevent damage such as cracks and fissures from occurring in a seal box immersed in seal water contained in a moving trough around each drive through hole provided in the hearth in a walking beam type heating furnace. [Solution] A movable trough (50) containing seal water (x) is provided on a drive frame (41) driven by a drive mechanism (40) along the furnace length direction, and each drive support (31) of the drive beam (30) is held on the drive frame through a drive through hole (11a) provided in the hearth (11). The seal box (14) is immersed in the seal water of the movable trough from around the drive through hole (11a). A fixed trough (60) that does not move up and down is connected to the movable trough by a seal water guide pipe (61) having a flexible section (61a). The seal water is moved between the movable trough and the fixed trough, and the position of the seal box immersed in the seal water and in contact with the water surface is kept constant.

Description

[Technical Field]

[0001] The present invention relates to a water sealing device for a walking beam furnace, which includes a plurality of rows of fixed beams and drive beams arranged along the furnace length and spaced apart across the furnace width, drive columns arranged on each row of drive beams at predetermined intervals along the furnace length and extending below the hearth through drive through holes in the hearth, a movable trough containing seal water mounted on a drive frame driven by a drive mechanism along the furnace length, the drive columns supported on the drive frame by the movable troughs, and seal boxes immersed in the water in the movable troughs around the drive through holes. In particular, the present invention is characterized in that, in the walking beam furnace, when the drive beams are moved by the drive mechanism via the drive frame to transport the workpieces in sequence for heat treatment, the seal boxes immersed in the seal water in the movable troughs around the drive through holes are prevented from cracking or breaking. [Background technology]

[0002] BACKGROUND ART Walking beam heating furnaces have been known as heating furnaces in which workpieces such as steel billets and steel plates are moved sequentially through the heating furnace to be continuously heated.

[0003] Such walking beam heating furnaces generally have fixed beams and drive beams arranged in multiple rows along the length of the furnace and spaced apart at required intervals across the width of the furnace. A drive mechanism located below the hearth drives a drive frame, causing each row of drive beams to perform a walking motion (repeated movements of rising, moving forward, falling, and moving backward), thereby transporting the materials placed inside the heating furnace in sequence and performing heat treatment.

[0004] In a walking beam heating furnace as described above, when each row of drive beams is caused to walk via a drive frame driven by a drive mechanism provided under the hearth, a plurality of drive pillars are extended downward from each row of drive beam at the required intervals in the furnace length direction, and drive through holes are provided in the hearth corresponding to each drive pillar in each row of drive beam. In addition, a plurality of rows of movable troughs containing seal water are provided in the furnace width direction on the drive frame so as to extend along the furnace length direction, and each drive pillar in each row of drive beam is supported on the drive frame via each movable trough containing the seal water from each drive through hole.

[0005] In order to prevent the atmosphere inside the heating furnace from leaking to the outside through the drive through-holes or the outside air from entering the heating furnace, a cylindrical seal box with a rectangular cross section is provided around each of the drive through-holes so as to be immersed in the seal water in the moving trough. Note that the cross section is not limited to a rectangle and may be other shapes such as an oval.

[0006] Here, in the walking beam type heating furnace, when the drive beam is caused to walk by a drive mechanism via the drive frame provided with a movable trough containing sealing water as described above, the movable trough moves up and down relative to the seal box immersed in the sealing water as described above, thereby changing the depth to which the seal box is immersed in the sealing water in the movable trough, and particularly in the part of the seal box where it is immersed in the sealing water in the movable trough and lifted up, it repeatedly comes into contact with the sealing water and the outside air.

[0007] In the areas where the seal box is immersed in the sealing water in the moving trough or lifted out of the sealing water, the plate material that makes up the seal box corrodes and deteriorates due to stresses such as evaporation of the sealing water and temperature fluctuations, causing damage such as cracks and fissures in the seal box.This causes the atmosphere inside the heating furnace to leak out from these damaged areas, or outside air to flow into the heating furnace, which has a negative impact on the heating treatment of the workpiece.

[0008] For this reason, Patent Document 1 shows that the lower part of a seal box that is immersed in seal water contained in a moving trough is made of a flexible sheet such as rubber.

[0009] However, if the lower part of the seal box that is immersed in the sealing water is made of a flexible sheet, corrosion does not occur, but there is a problem that the flexible sheet does not have sufficient heat resistance to the high temperatures inside the furnace, and the parts of the flexible sheet that are not immersed in the sealing water deteriorate.

[0010] Furthermore, Patent Document 2 discloses a double-structured seal box that is immersed in seal water contained in a moving trough.

[0011] However, even if the seal box has a double structure in this way, the depth to which the seal box is immersed in the seal water contained in the movable trough changes as described above, and loads due to temperature fluctuations are applied to the area where the seal box is immersed in the seal water in the movable trough or raised, which still presents the problem of corrosion and deterioration of the seal box.

[0012] Furthermore, Patent Document 3 shows a system in which a proximity switch is provided in the trough to detect the up and down movement of a movable trough containing sealing water and a seal box immersed in the sealing water, and a water supply valve is provided to supply sealing water into the movable trough and a drain valve to drain the sealing water in the movable trough, and by switching the water supply valve and drain valve based on the proximity switch, the water level in the trough is raised and lowered, and the position where the seal box contacts the water surface is kept constant.

[0013] However, in this case, as the movable trough containing the seal water moves downward, the water supply valve must be opened and an appropriate amount of seal water must be supplied to the movable trough using a pump or the like, while as the movable trough containing the seal water moves upward, the drain valve must be opened and an appropriate amount of seal water must be drained from the movable trough, which creates problems such as complicated operation and control of the water supply and drainage, and providing such a mechanism for each trough makes the structure complex and expensive. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-294332 [Patent Document 2] Japanese Utility Model Application Publication No. 56-23663 [Patent Document 3] Japanese Utility Model Application Publication No. 1-26357 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0015] The present invention aims to solve the above-mentioned problems in a water sealing device for a walking beam type heating furnace, in which fixed beams and drive beams are arranged in multiple rows along the furnace length direction within the heating furnace at required intervals in the furnace width direction, and each drive support pillar is arranged on each row of drive beams at required intervals in the furnace length direction and extends below the hearth through each drive through hole provided in the hearth, and a movable trough containing seal water is arranged on a drive frame driven by a drive mechanism along the furnace length direction, and each drive support pillar is held on the drive frame via the movable trough, and a seal box is immersed in water in the movable trough from around each drive through hole.

[0016] In other words, the objective of the present invention is to easily prevent damage such as cracks and fissures from occurring in each sealing box immersed in sealing water contained in a moving trough from around each drive through hole when, in a water sealing device of a walking beam type heating furnace as described above, each drive beam held on a drive frame is caused to walk by a drive mechanism as described above to transport the workpieces in sequence and perform heat treatment. [Means for solving the problem]

[0017] In order to solve the above-mentioned problems, the water sealing device for a walking beam type heating furnace according to the present invention has a structure in which fixed beams and drive beams are arranged in a plurality of rows in the furnace length direction at required intervals in the furnace width direction within the heating furnace, and each drive column is arranged on each row of drive beams at required intervals in the furnace length direction and extends below the hearth through each drive through hole in the hearth, and a movable trough containing seal water is arranged on a drive frame driven by a drive mechanism along the furnace length direction, and each drive column is held on the drive frame via the movable trough, and a seal box is immersed in the water in the movable trough from around each drive through hole. In this water sealing device for a walking beam type heating furnace, the fixed trough, which does not move up and down, and the movable trough are connected by a seal water guide pipe having a flexible portion, and the seal water is moved between the movable trough and the fixed trough through the seal water guide pipe, and is immersed in the seal water contained in the movable trough. The seal box moves to the surface of the seal water contained in the moving trough. The position of contact with the object is made constant.

[0018] In the water sealing device of the walking beam type heating furnace of the present invention, when the movable trough is connected to a fixed trough that does not move up and down by a connecting pipe and the seal water contained in the movable trough is moved between the movable trough and the fixed trough, even when the movable trough is moved up and down together with the drive frame by the drive mechanism, the seal water contained in the movable trough is moved between the movable trough and the fixed trough, and the water surface position of the seal water contained in the movable trough matches the water surface position of the seal water contained in the fixed trough, and the seal water is immersed in the seal water contained in the movable trough. The seal box moves to the surface of the seal water contained in the moving trough. This makes it possible to eliminate the need for portions that are immersed in the seal water of the moving trough or lifted out of the seal water, which causes corrosion, as in the conventional case.

[0019] In addition, in the water sealing device of the walking beam type heating furnace of the present invention, the sealing water is immersed in the sealing water contained in the moving trough as described above. The seal box moves to the surface of the seal water contained in the moving trough.In order to keep the contact position of the movable trough constant, a water level adjusting means can be provided to keep the water level of the seal water contained in the fixed trough constant. In this way, when the water level adjusting means is used to keep the water level of the seal water contained in the fixed trough constant, the water surface of the seal water contained in the movable trough is aligned with the water surface of the seal water contained in the fixed trough, and the movable trough is immersed in the seal water contained in the movable trough, even when the movable trough is moved up and down by the drive mechanism as described above. The seal box moves to the surface of the seal water contained in the moving trough. The position of contact with the object becomes constant.

[0020] In the water sealing device of the walking beam type heating furnace of the present invention, an overflow section and an overflow tank are provided as the water level adjustment means to stabilize the water level of the seal water contained in the fixed trough, and excess seal water can be circulated between the fixed trough and the overflow tank.

[0021] In addition, in the water sealing device of the walking beam type heating furnace of the present invention, a water level detection sensor is provided as the water level adjustment means for detecting the water level of the seal water contained in the fixed trough, and when the water level of the seal water in the fixed trough detected by the water level detection sensor falls below a predetermined value, the seal water is supplied to the fixed trough from a seal water supply pipe, while when the water level of the seal water in the fixed trough detected by the water level detection sensor rises above a predetermined value, the seal water is drained from the fixed trough by a seal water drain pipe, thereby maintaining a constant water level of the seal water contained in the fixed trough.

[0022] In addition, in the water sealing device of the walking beam type heating furnace of the present invention, the movable troughs are arranged in a plurality of rows in the furnace width direction, and the movable troughs are connected to each other by a communication pipe, and the seal water is moved between the movable troughs through the communication pipe, and the seal water is moved between the movable troughs and the fixed troughs provided with the seal water guide pipe. In this way, the seal water contained in the plurality of movable troughs connected by the communication pipes is moved between the fixed troughs, and each of the movable troughs immersed in the seal water contained in each movable trough can be immersed in the seal water contained in each movable trough. The seal box moves the water surface of the seal water contained in each moving trough. The position of contact with the object can be made constant.

[0023] In addition, in the water sealing device of the walking beam type heating furnace of the present invention, the movable troughs are arranged in a plurality of rows in the furnace width direction, and each movable trough is connected to a fixed trough by a seal water guide pipe having a flexible portion, and the seal water can be moved between each movable trough and the fixed trough through each seal water guide pipe. In this way, the seal water contained in each movable trough is moved between the fixed trough through each seal water guide pipe, and each of the movable troughs is immersed in the seal water contained in each movable trough. The seal box moves the water surface of the seal water contained in each moving trough. The position of contact with the object can be made constant. [Effects of the Invention]

[0024] In the water sealing device of the walking beam type heating furnace of the present invention, as described above, the movable trough is connected to a fixed trough that does not move up and down so that the water surface position is constant through a seal water guide pipe, and the seal water is moved between the movable trough and the fixed trough through the seal water guide pipe. Therefore, even when the movable trough is moved up and down by the drive mechanism, the seal water is moved between the movable trough and the fixed trough through the seal water guide pipe, and the water surface position of the seal water contained in the movable trough is adjusted to a position that matches the water surface position of the seal water contained in the fixed trough (for example, the water surface height H from the floor as shown in Figure 2(A)), and is immersed in the seal water contained in the movable trough. The seal box moves to the surface of the seal water contained in the moving trough. The position of contact with the object becomes constant.

[0025] As a result, in the present invention, when the workpieces are transported in order by the walking motion of each drive beam via the drive frame by the drive mechanism as described above, the workpieces are heated by being transported in order by the walking motion of each drive beam via the drive frame as described above. The seal box moves the water surface of the seal water contained in each moving trough. This prevents the contact position from changing, making it easy to prevent damage such as cracks and fissures from occurring in each seal box. [Brief explanation of the drawings]

[0026] [Figure 1] This is a schematic plan view showing a water sealing device for a walking beam type heating furnace in one embodiment of the present invention, in which multiple rows of fixed beams and drive beams are arranged to transport the workpiece within the heating furnace. [Figure 2] In the above embodiment, an example is shown in which a seal box immersed in the seal water contained in a movable trough maintains a constant position at which it comes into contact with the water surface of the seal water contained in the movable trough, where (A) is a cross-sectional explanatory diagram showing a state in which, when the movable trough is moved downward together with the drive frame by the drive mechanism, the seal water contained in the fixed trough is moved to the movable trough through a seal water guide pipe, and the water surface position of the seal water contained in the movable trough is adjusted to a position that matches the water surface position of the seal water contained in the fixed trough, and (B) is a cross-sectional explanatory diagram showing a state in which, when the movable trough is moved upward together with the drive frame by the drive mechanism, the seal water contained in the movable trough is moved to the fixed trough through a seal water guide pipe, and the water surface position of the seal water contained in the movable trough is adjusted to a position that matches the water surface position of the seal water contained in the fixed trough. [Figure 3] This is a cross-sectional explanatory diagram showing the state in which, in the above embodiment, when the amount of seal water contained in the movable trough or fixed trough decreases due to evaporation, etc., the water supply valve provided on the seal water supply pipe is opened to supply seal water to the fixed trough. [Figure 4]This is a schematic plan view showing the state in the above embodiment in which multiple rows of movable troughs arranged in the furnace width direction are connected to each other by multiple communicating pipes, and multiple seal water guide pipes are provided between the movable troughs and the fixed troughs to move seal water between them. [Figure 5] This is a schematic plan view showing the state in the above embodiment in which fixed troughs are provided perpendicular to the movable troughs arranged in multiple rows in the furnace width direction, and each movable trough is provided with a seal water guide pipe for moving seal water between the movable trough and the fixed trough. [Figure 6] In the above embodiment, another example is shown in which the seal box immersed in the seal water contained in the movable trough keeps the position where it comes into contact with the water surface of the seal water contained in the movable trough constant. (A) shows a water level detection sensor, and when the movable trough is moved downward together with the drive frame by the drive mechanism, the water supply valve provided on the seal water supply pipe is opened to supply seal water to the fixed trough so that the water level does not change. The seal water contained in the fixed trough is moved to the movable trough through the seal water guide pipe, and the water surface position of the seal water contained in the movable trough is kept constant in the fixed trough. (A) is a cross-sectional explanatory diagram showing the state in which the water level detection sensor is used to move the movable trough upward together with the drive frame by the drive mechanism, and (B) is a cross-sectional explanatory diagram showing the state in which the water level detection sensor is used to move the seal water drain valve on the seal water drain pipe to drain the seal water from the fixed trough so that the water level does not change, and the seal water contained in the movable trough is moved to the fixed trough through the seal water guide pipe, and the water level of the seal water contained in the movable trough is adjusted to a position that matches the water level of the seal water contained in the fixed trough. BEST MODE FOR CARRYING OUT THE INVENTION

[0027] The following describes in detail the water sealing device for a walking beam heating furnace according to an embodiment of the present invention with reference to the accompanying drawings. Note that the water sealing device for a walking beam heating furnace according to the present invention is not limited to the embodiment shown below, and can be modified as appropriate within the scope of the invention.

[0028] 1, in the water sealing device for a walking beam type heating furnace according to this embodiment, fixed beams 20 and driving beams 30 are provided alternately in multiple rows at required intervals across the width of the heating furnace 10 on the hearth 11 of the heating furnace 10, extending in the furnace length direction from a charging port 12 through which the workpieces W to be treated are charged into the heating furnace 10 to an unloading port 13 through which the heated workpieces W are unloaded from the heating furnace 10. The charging port 12 is provided with a charging door 12a for opening and closing the charging port 12, and the unloading port 13 is provided with an unloading door 13a for opening and closing the unloading port 13.

[0029] In this embodiment, a plurality of fixing pillars 21 are erected on the hearth 11 at required intervals in the furnace length and width directions, and fixing beams 20 extending in the furnace length direction are provided on each row of fixing pillars 21 arranged along the furnace length direction.

[0030] In addition, when providing each row of drive beams 30, a plurality of drive pillars 31 are extended downward from each row of drive beams 30 at the required intervals in the furnace length direction, and drive through holes 11a are provided in the hearth 11 corresponding to each drive pillar 31, so that each drive pillar 31 on each drive beam 30 is guided under the hearth 11 through each drive through hole 11a.

[0031] 2(A), (B), etc., below the hearth 11, a drive frame 41 is provided which is driven up and down by a drive mechanism 40 using an eccentric wheel 80, and on this drive frame 41, multiple rows of movable troughs 50 containing seal water x are provided at required intervals along the furnace length direction and in the furnace width direction, corresponding to the rows of each drive beam 30.

[0032] As described above, each drive support 31 is led from each row of drive beams 30 through each drive through hole 11a to below the hearth 11, and is supported on the drive frame 41 via each moving trough 50 provided at a position corresponding to each row of drive beams 30.

[0033] In addition, each seal box 14 is immersed in the seal water x contained in the movable trough 50 from around each drive through hole 11a, thereby preventing the atmosphere inside the heating furnace 10 from leaking to the outside through each drive through hole 11a and preventing outside air from entering the heating furnace 10.

[0034] In this embodiment, as shown in Figures 2(A), (B), etc., adjacent movable troughs 50 arranged on the drive frame 41 to correspond to the rows of each drive beam 30 are connected by connecting pipes 51, and the seal water x contained in each movable trough 50 connected by the connecting pipes 51 moves through the connecting pipes 51 so that the water surface positions of the seal water x contained in these adjacent movable troughs 50 coincide with each other.

[0035] In addition, in this embodiment, the movable trough 50 located at the end connected by the connecting pipe 51 as described above and the fixed trough 60 that does not move up and down are connected by a seal water guide pipe 61 having a flexible portion (for example, a bellows-shaped expandable pipe) 61a, and the seal water x contained in each movable trough 50 connected by the connecting pipe 51 as described above is moved between the movable trough 50 located at the end and the fixed trough 60 through the seal water guide pipe 61 so that the water surface position xa of the seal water x contained in each movable trough 50 connected by the connecting pipe 51 coincides with the water surface position xa of the seal water x contained in the fixed trough 60.

[0036] In this embodiment, an overflow tank 70 is provided continuous with the fixed trough 60 to accommodate the seal water x overflowing from the overflow section 62 of the fixed trough 60, and the seal water x accommodated in the overflow tank 70 is circulated between the fixed trough 60 and the overflow tank 70 through a circulation pipe 64 by a circulation pump 63.

[0037] In this embodiment, as shown in Figure 2(A), when each movable trough 50 is moved downward together with the drive frame 41 by the drive mechanism 40, the seal water x contained in the fixed trough 60 is moved to each movable trough 50 through the seal water guide pipe 61 and the connecting pipe 51, and the seal water x contained in the overflow tank 70 is supplied to the fixed trough 60 through the circulation pipe 64 by the circulation pump 63 and caused to overflow from the overflow section 62, so that the water surface position xa of the seal water x contained in the fixed trough 60 is always kept at the same position as the upper end of the overflow section 62, and the water surface position xa of the seal water x contained in each movable trough 50 is adjusted to a position that matches the water surface position xa of the seal water x contained in the fixed trough 60.

[0038] On the other hand, as shown in Figure 2 (B), when each movable trough 50 is moved upward together with the drive frame 41 by the drive mechanism 40, the seal water x contained in each movable trough 50 is moved to the fixed trough 60 through the connecting pipe 51 and the seal water guide pipe 61, and the excess seal water x moved to the fixed trough 60 overflows from the overflow section 62 of the fixed trough 60 and is contained in the overflow tank 70, so that the water surface position xa of the seal water x contained in the fixed trough 60 is always kept at the same position as the upper end of the overflow section 62, and the water surface position xa of the seal water x contained in each movable trough 50 is adjusted to a position that matches the water surface position xa of the seal water x contained in the fixed trough 60.

[0039] In this embodiment, a water supply valve 66 is provided on a seal water supply pipe 65 that supplies seal water x to the fixed trough 60, and when the amount of seal water x contained in each of the movable troughs 50 and the fixed trough 60 decreases due to evaporation or the like, the water supply valve 66 is opened to supply the seal water x to the fixed trough 60 through the seal water supply pipe 65, as shown in Fig. 3, so that the seal water x always overflows from the overflow portion 62 into the overflow tank 70. The water supply valve 66 is shown in black when closed and in white when open.

[0040] In this embodiment, whether each movable trough 50 is moved downward or upward together with the drive frame 41 by the drive mechanism 40 as described above, the water surface position xa of the seal water x contained in each movable trough 50 is adjusted to a position that matches the constant water surface position xa of the seal water x contained in the fixed trough 60, and the position at which each seal box 14 immersed in the seal water x contained in each movable trough 50 comes into contact with the water surface is made constant.

[0041] As a result, in the water sealing device of the walking beam type heating furnace of this embodiment, when the drive frame 41 is driven by the drive mechanism 40 to cause each drive beam 30 to perform a walking motion and the workpiece W is transported sequentially within the heating furnace 10 for heat treatment, the position of contact with the water surface of each seal box 14 immersed in the seal water x contained in each movable trough 50 as described above is kept constant, preventing the seal box from corroding and deteriorating due to changes in the position of contact with the water surface of each seal box 14 immersed in the seal water x contained in each movable trough 50 as in the conventional case, and making it possible to easily prevent damage such as cracks and fissures from occurring in each seal box.

[0042] In addition, in the water sealing device of the walking beam type heating furnace according to this embodiment, a plurality of rows of the movable troughs 50 containing the seal water x as described above are provided in the furnace width direction, and the plurality of movable troughs 50 are connected by connecting pipes 51, and the movable troughs 50 located at the ends connected by the connecting pipes 51 and the fixed troughs 60 are connected by seal water guide pipes 61, and the seal water x contained in each movable trough 50 connected by the connecting pipes 51 is guided from the movable troughs 50 located at the ends through the seal water guide pipes 61 to the fixed troughs 60. 0 to match the water surface position xa of the seal water x contained in each movable trough 50 with the water surface position xa of the seal water x contained in the fixed trough 60, in order to ensure that the seal water x is moved quickly between each movable trough 50 and the fixed trough 60, as shown in Figure 4, multiple connecting pipes 51 (three in the example shown in the figure) are provided to connect each movable trough 50, and multiple seal water guide pipes 61 (three in the example shown in the figure) are also provided to connect the movable troughs 50 located at the ends with the fixed trough 60.

[0043] In addition, in the water sealing device of the walking beam type heating furnace of this embodiment, movable troughs 50 containing seal water x are arranged in multiple rows in the furnace width direction, and the seal water x is moved from each movable trough 50 to a fixed trough 60 through a seal water guide pipe 61.In order to move the seal water x from each movable trough 50 to a fixed trough 60 through a seal water guide pipe 61, as shown in Figure 5, a fixed trough 60 is arranged in a direction perpendicular to each movable trough 50 arranged in multiple rows in the furnace width direction, and each movable trough 50 and the fixed trough 60 are individually connected by each seal water guide pipe 61, and the seal water x contained in each movable trough 50 can be moved to and from the fixed trough 60 through each seal water guide pipe 61.

[0044] In addition, in the water sealing device of the walking beam type heating furnace according to this embodiment, the movable trough 50 located at the end connected by the connecting pipe 51 as described above and the fixed trough 60 that does not move up and down are connected by a seal water guide pipe 61 having a flexible portion 61a, and the seal water x contained in each movable trough 50 connected by the connecting pipe 51 as described above is moved between the movable trough 50 located at the end and the fixed trough 60 through the seal water guide pipe 61, so that the water surface position xa of the seal water x contained in each movable trough 50 connected by the connecting pipe 51 is contained in the fixed trough 60. 6(A) and (B), in order to make the water level of the seal water x coincide with the water level xa of the seal water x stored in the fixed trough 60, a water supply valve 66 is provided in a seal water supply pipe 65 that supplies the seal water x to the fixed trough 60, and a drain valve 68 is provided in a seal water drain pipe 67 that drains the seal water x stored in the fixed trough 60, and the water level of the seal water x stored in the fixed trough 60 is detected by a water level detection sensor 69. By controlling the opening and closing of the water supply valve 66 and the drain valve 68 using this water level detection sensor 69, the water level of the drain valve 68 can be made constant. As with the water supply valve 66, the closed state of the drain valve 68 is shown in black, and the open state is shown in white.

[0045] When each movable trough 50 is moved downward together with the drive frame 41 by the drive mechanism 40, the seal water x contained in the fixed trough 60 is moved to each movable trough 50 through the seal water guide pipe 61 and connecting pipe 51, and the water level of the seal water x in the fixed trough 60 detected by the water level detection sensor 69 drops.Therefore, as shown in Figure 6(A), the drain valve 68 provided on the seal water drain pipe 67 is closed, while the water supply valve 66 is opened, and the seal water x is supplied to the fixed trough 60 through the seal water supply pipe 65, thereby adjusting the water surface position xa of the seal water x in the fixed trough 60 and the water surface position xa of the seal water x contained in each movable trough 50 to constant positions, so that the position of contact with the water surface of each seal box 14 immersed in the seal water x contained in each movable trough 50 is constant.

[0046] On the other hand, when each movable trough 50 is moved upward together with the drive frame 41 by the drive mechanism 40, the seal water x contained in each movable trough 50 is moved to the fixed trough 60 through the connecting pipe 51 and the seal water guide pipe 61, and the water level of the seal water x in the fixed trough 60 detected by the water level detection sensor 69 rises. Therefore, as shown in FIG. 6(B), the water supply valve 66 provided on the seal water supply pipe 65 is closed, and the seal water is supplied from the seal water supply pipe 65. The seal water x is not supplied to the fixed trough 60, and the drain valve 68 provided on the seal water drain pipe 67 is opened to drain the seal water x in the fixed trough 60 through the seal water drain pipe 67, thereby adjusting the water surface position xa of the seal water x in the fixed trough 60 and the water surface position xa of the seal water x contained in each movable trough 50 to constant positions, thereby making the position of contact with the water surface of each seal box 14 immersed in the seal water x contained in each movable trough 50 constant.

[0047] In this way, as in the above embodiment, when the drive frame 41 is driven by the drive mechanism 40 to cause each drive beam 30 to perform a walking motion and the workpiece W is transported sequentially within the heating furnace 10 for heat treatment, the position of contact with the water surface of each seal box 14 immersed in the seal water x contained in each movable trough 50 as described above is kept constant, and the seal box is prevented from corroding and deteriorating due to changes in the position of contact with the water surface of each seal box 14 immersed in the seal water x contained in each movable trough 50 as in the conventional case, and damage such as cracks and fissures can be easily prevented from occurring in each seal box.

[0048] Furthermore, since natural phenomena are used to move the seal water x between the movable trough 50 and the fixed trough 60, no power such as a pump is required, resulting in energy savings, space savings, and cost savings. [Explanation of symbols]

[0049] 10:Heating furnace 11: Hearth 11a: Drive through hole 12:Charging port 12a: Charging door 13: Extraction port 13a: Removal door 14: Seal box 20: Fixed beam 21:Fixing support 30: Drive beam 31: Drive support 40: Drive mechanism 41: Drive frame 50: Moving trough 51: Connecting pipe 60: Fixed trough 61: Seal water guide pipe 61a:Flexible part 62: Overflow section 63: Circulation pump 64: Circulation pipe 65: Seal water supply pipe 66: Water supply valve 67: Seal water drainage pipe 68: Drain valve 69: Water level detection sensor 70: Overflow tank 80: Eccentric wheel H: Height from floor to water surface W: object to be treated x: Seal water xa: water surface position

Claims

1. In a water sealing device for a walking beam type heating furnace, a plurality of rows of fixed beams and drive beams are arranged in the furnace length direction at required intervals in the furnace width direction, and each drive support column is arranged on each row of drive beams at required intervals in the furnace length direction and extends below the hearth through each drive through hole in the hearth, and a movable trough containing seal water is mounted on a drive frame driven by a drive mechanism along the furnace length direction, and each drive support column is held on the drive frame via the movable trough, and a seal box is immersed in the water in the movable trough from around each drive through hole. In this water sealing device for a walking beam type heating furnace, a fixed trough that does not move up and down and the movable trough are connected by a seal water guide pipe having a flexible portion, and the seal water is moved between the movable trough and the fixed trough through the seal water guide pipe, so that the position at which the seal box, immersed in the seal water contained in the movable trough, comes into contact with the surface of the seal water contained in the movable trough is constant.

2. In the water sealing device for a walking beam type heating furnace as described in claim 1, a water level adjustment means is provided to constant the water level of the seal water contained in the fixed trough when constantizing the position at which the seal box immersed in the seal water contained in the movable trough comes into contact with the water surface of the seal water contained in the movable trough.

3. In the water sealing device for a walking beam type heating furnace described in claim 2, the water level adjustment means comprises an overflow section and an overflow tank that maintain the water level of the seal water contained in the fixed trough constant, and excess seal water is circulated between the fixed trough and the overflow tank.

4. In the water sealing device for a walking beam type heating furnace described in claim 2, the water level adjustment means is a water level detection sensor that detects the water level of the seal water contained in the fixed trough, and when the water level of the seal water contained in the fixed trough detected by the water level detection sensor becomes lower than a predetermined value, seal water is supplied to the fixed trough from a seal water supply pipe, while when the water level of the seal water contained in the fixed trough detected by the water level detection sensor becomes higher than the predetermined value, seal water is drained from the fixed trough by a seal water drain pipe.

5. 3. A water sealing device for a walking beam type heating furnace as described in claim 1 or claim 2, characterized in that the movable troughs are arranged in multiple rows in the furnace width direction, the movable troughs are connected to each other by connecting pipes, seal water is moved between the movable troughs through the connecting pipes, and seal water is moved between the movable troughs provided with the seal water guide pipes and the fixed troughs.

6. 3. A water sealing device for a walking beam type heating furnace as described in claim 1 or claim 2, characterized in that the movable troughs are arranged in multiple rows in the furnace width direction, each movable trough is connected to a fixed trough by a seal water guide pipe having a flexible portion, and seal water is moved between each movable trough and the fixed trough through each seal water guide pipe.

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