JPH10158750A - Continuous heat treatment for metallic strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute the checking, repairing and changing of a constituting member in a short time by arranging a seal gate respectively on upstream side and on the downstream side of a metallic strip carrying way in a heat treatment furnace, forming a pure chamber, supplying an inert gas into the purge chamber and holding a positive pressure. SOLUTION: In the continuous heat treatment furnace, the seal gate 32 on the upstream side and the seal gate 33 on the downstream side are arranged in an intermediate cylinder 31 connected with a furnace cylinder 21. In the case of changing worn seal rolls 11, 12, the carrying of the metallic strip M in the furnace is stopped and opening/closing doors 41-44 are closed. As a result, the purge chamber 71 closed in the intermediate cylinder 31 is formed. A valve 81 is opened and the inert gas is supplied into the purge chamber 71 and an inner part in the purge chamber 71 is held to the positive pressure with the inert gas. Since the metallic strip carrying way 22 in shut out in this condition, the atmospheric gas is filled up in the carrying way 22, and in this condition, the seal rolls 11, 12 are changed. By this constitution, an effect to eliminate the waste of atmospheric gas at the time of working is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a continuous heat treatment furnace for metal strip. When a strip of stainless steel, copper, iron, or the like is subjected to, for example, an annealing treatment, a furnace is used in which such a metal strip is heat-treated under a predetermined atmospheric gas while being conveyed in the furnace. The present invention relates to the improvement of such a continuous heat treatment furnace.

[0002]

2. Description of the Related Art Conventionally, a continuous heat treatment furnace for a metal strip as described above is provided with an inlet seal portion, an outlet seal portion, a heating zone and a cooling zone, etc., and conveys the metal strip vertically or horizontally in the furnace. While heat treatment is performed under a predetermined atmosphere gas (Japanese Patent Publication No. 55-21818,
JP-A-62-177126). However, such conventional furnaces have the disadvantage that it takes a long time to perform operations such as inspection, repair, and replacement of the components of the furnace, and wastes the atmosphere gas in such operations.

[0003] The components of the furnace, such as the inlet seal, the outlet seal, and the direction-changing roll, are worn out due to use, and in some cases suddenly fail to perform their functions sufficiently for some reason. In each case, it is necessary to perform inspection, repair, replacement, etc. of the corresponding components.However, in the conventional furnace where the metal strip transfer path is always in communication, dangerous hydrogen gas or All of the furnace atmosphere gas including carbon monoxide gas and the like must be replaced, and after the work, the whole furnace atmosphere must be replaced with a predetermined atmosphere gas. It takes time and wastes the atmosphere gas in such operations.

[0004]

The problem to be solved by the present invention is that in a conventional continuous heat treatment furnace for metal strip, it takes a long time to inspect, repair, and replace the components of the furnace, and such work is difficult. At that time, the atmosphere gas is wasted.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a furnace for continuously heat treating metal strips under a predetermined atmospheric gas. Continuous heat treatment of a metal strip, characterized in that an upstream seal gate and a downstream seal gate which form chambers are provided, and the formed purge chamber is maintained at an elevated pressure by supplying an inert gas. Pertaining to the furnace.

[0006] In the continuous heat treatment furnace according to the present invention, an upstream seal gate and a downstream seal gate for blocking the metal strip carrying path are provided at various points in the furnace. These seal gates do not block the metal strip path when they are open, but block the metal strip path when they are closed, creating a sealed purge chamber between the two. Has become. For example, a furnace bottom inlet seal, pre-tropical, furnace top direction change rolls, a heating zone, a cooling zone and a furnace bottom outlet seal are provided. Rise straight through → change direction with the direction change roll → linearly fall through the heating zone and cooling zone → carry out the furnace from the outlet seal part to the outside of the furnace, under the predetermined atmosphere gas while carrying in the furnace in the above route In the case of a vertical continuous heat treatment furnace for heat treatment, when an upstream seal gate and a downstream seal gate are provided in the vicinity of the downstream side of the inlet seal portion and a purge chamber is formed between the two, the purge chamber forms the inlet seal portion. Cut off from other transport ways. Similarly, when a purge chamber is formed near the upstream side of the outlet seal portion, the purge chamber blocks the outlet seal portion from another transport path. Further, when purging chambers are formed near the upstream and downstream sides of the pre-tropical zone, the diverting roll, and the heating zone or the cooling zone in the same manner, these purge chambers correspond to the corresponding pre-tropical zone, the diverting roll, the heating zone, respectively. Isolate the tropics or cooling zones from other carriageways. The purge chamber can be formed between the furnace by providing an upstream seal gate and a downstream seal gate at both locations, and particularly, near the downstream of the inlet seal, which is frequently replaced, near the upstream of the outlet seal, or Is more effectively formed near the upstream and downstream sides of the direction change roll.

[0007] The purge chamber formed between the upstream seal gate and the downstream seal gate is configured to maintain the interior at a raised pressure by supplying an inert gas, for example, nitrogen gas, to the interior of the purge chamber. . By keeping the purge chamber at an elevated pressure, it is possible to prevent atmospheric gas from leaking from the upstream transport path blocked by the upstream seal gate forming the purge chamber, and to prevent the downstream side blocked by the downstream seal gate. Leakage of the atmospheric gas from the carrying path can be prevented.

When the upstream seal gate and the downstream seal gate are open, they do not block the carrying path of the metal strip, and the metal strip passes through the open upstream seal gate and the downstream seal gate. Conveyed in the furnace,
Only when these are closed, the metal strip carrying path is shut off, and a purge chamber is formed between the closed upstream seal gate and the downstream seal gate. Therefore, the upstream seal gate and the downstream seal gate are usually
Any type of door, such as a motor-driven or cylinder-driven door system, sliding door system, double door system, etc., as long as it is an opening / closing door that shuts off the transport path with the metal strip stopped in the furnace stopped. However, it is preferable that the double-door type is used, and it is particularly preferable that the upstream seal gate includes a pair of open / close doors that open in the downstream side, and that the downstream seal gate includes a pair of open / close doors that open in the upstream side. . When the inert gas is supplied to the purge chamber formed between the upstream seal gate and the downstream seal gate by closing the upstream seal gate and the two chambers are maintained at an elevated pressure, the double-opening system as described above constituting the upstream seal gate is provided. The pressing force in the upstream direction is applied to the pair of opening and closing doors, and the opening and closing doors are more closely adhered to each other. Also, the pair of double-sided opening and closing doors as described above that constitute the downstream side seal gate are in the downstream direction. Pressure, and the opening and closing doors also adhere more strongly, so that the atmospheric gas leaks from the upstream transport path blocked by the upstream seal gate and leaks from the downstream transport path blocked by the downstream seal gate. This is because leakage of the atmospheric gas can be more reliably prevented.

According to the present invention, the upstream seal gate blocks the metal strip transport path upstream of the upstream seal gate, and the downstream seal gate blocks the metal strip transport path downstream of the metal strip transport path. Since an inert gas is supplied to the purge chamber formed between the two and the chamber is kept at a raised pressure, for example, if a purge chamber is formed near the downstream side of the inlet seal portion of the furnace, the purge chamber is Also, the operation such as inspection, repair, and replacement of the inlet seal portion can be performed while leaving the atmospheric gas in the transport path on the downstream side as it is. The same operation can be performed by forming a purge chamber in the vicinity of the upstream side of the outlet seal portion with respect to the outlet seal portion, and in the vicinity of the upstream side and downstream side of the pre-tropical zone, the direction change roll, the heating zone or the cooling zone. The same operation can be performed if a purge chamber is formed in the above. Therefore, according to the present invention, operations such as inspection, repair, and replacement of furnace components can be performed in a short time, and there is no waste of atmospheric gas.

[0010]

FIG. 1 is a longitudinal sectional view schematically showing a continuous heat treatment furnace according to the present invention. FIG. 1 shows a vertical continuous heat treatment furnace. The vertical continuous heat treatment furnace constructed vertically as a whole has, from the upstream side to the downstream side, an inlet seal portion 1 at a furnace bottom, a pre-tropical zone 2, direction change rolls 3 and 4 at a furnace top, a heating zone 5, It has a cooling zone 6 and an outlet seal 7 at the bottom of the furnace, and carries the metal strip M into the furnace from the inlet seal 1 → rises straight through the pre-tropical zone 2 → changes the direction with the direction change rolls 3 and 4 → Linearly descends via heating zone 5 and cooling zone 6 →
The heat treatment is carried out under a predetermined atmospheric gas while being carried out of the furnace from the outlet seal part 7 and conveyed in the furnace through the above-described route. Although not shown in FIG. 1, the upstream seal gate and the downstream seal gate that form the purge chamber are located near the downstream side A of the inlet seal part 1, near the upstream side B and near the downstream side of the pre-tropical zone 2. C, near the upstream side D of the direction change roll 3, near the downstream side E of the direction change roll 4, near the upstream side F and near the downstream side G of the heating zone 5, near the upstream side H and near the downstream side I of the cooling zone 6, It can be provided near the upstream side J of the outlet seal portion 7.

FIG. 2 is a partially enlarged longitudinal sectional view schematically showing the inlet seal portion and the vicinity of the downstream side of the vertical continuous heat treatment furnace of FIG. The inlet seal portion 1 itself has the same configuration as a conventionally known one, and includes a pair of seal rolls 11 and 12 that rotate in different directions.
The seal roll 11 and the seal roll 12 are conveyed into the furnace while being brought into contact with them. Furnace tube 2 connected to pre-tropical zone 2 downstream of inlet seal 1
An intermediate tube 31 is interposed between the inlet seal portion 1 and the furnace tube 21 in the vicinity A of the downstream side of the inlet seal portion 1. The inside of the furnace tube 21 is a carrying path 22 for the metal strip M, and the carrying path 22 is filled with a predetermined atmospheric gas.
The inlet seal portion 1 and the intermediate cylinder 31 are bolted to each other with a peripheral flange (not shown).
1 is connected via a telescopic member 23 to the furnace tube 21.
Are supported by a furnace frame (not shown). Therefore, the inlet seal portion 1 can be removed from the intermediate cylinder 31.

The intermediate cylinder 31 is provided with an upstream seal gate 32 and a downstream seal gate 33. The upstream seal gate 32 has a pair of double doors 41, 42 in the intermediate cylinder 31. Also, the downstream seal gate 33
Is a pair of doors 43, 4 of the double door type in the intermediate cylinder 31.
4 is provided. The opening and closing doors 41 and 42 open in the downstream side by the operation of the cylinders 51 and 52 outside the intermediate cylinder 31 (open to the position shown by the broken line in FIG. 2), and the opening and closing doors 43 and 44 are cylinders 53 and By the operation of 54, the double opening is performed on the upstream side (opens to the position indicated by the broken line in FIG. 2). The doors 41 to 44 are covered with silicone rubber,
When they are closed (when they are closed at the position shown by the solid line in FIG. 2), they come into contact with the elastic seal members 61 to 64 at the tips of the partition plates extending from the intermediate cylinder 31.

When the open / close doors 41 to 44 are open, the inlet seal portion 1 and the furnace tube 21 communicate with each other through the intermediate tube 31. Therefore, while the metal strip M is conveyed in the furnace, a predetermined atmospheric gas Can be heat treated below. For example, when replacing the seal rolls 11 and 12 worn out by use, the transfer of the metal strip M in the furnace is stopped, and the door 4 is closed.
Close 1-44. When the doors 41 to 44 are closed, a purge chamber 71 is formed in the intermediate cylinder 31 between the doors 41 and 42 and the doors 43 and 44. Intermediate cylinder 31
Is provided with an inert gas supply pipe 83 which faces the purge chamber 71 and is connected to an inert gas supply source 82 via a valve 81, so that the inert gas is supplied to the purge chamber 71 formed by opening the valve 81. A gas is supplied, and the inside of the purge chamber 71 is maintained at an elevated pressure with an inert gas. In this state, since the transport path 22 is shut off, the seal rolls 11 and 12 can be replaced while leaving the atmospheric gas filling the transport path 22 as it is.

[0014]

As is clear from the above, according to the present invention described above, operations such as inspection, repair, and replacement of furnace components can be performed in a short time, and there is no waste of atmosphere gas in such operations. This has the effect.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a continuous heat treatment furnace according to the present invention.

FIG. 2 is a partially enlarged longitudinal sectional view schematically showing an inlet seal portion and the vicinity of a downstream side of the continuous heat treatment furnace of FIG.

[Explanation of symbols]

1 ... entrance seal part, 2 ... pre-tropical, 3, 4 ...
Direction changing roll, 5: heating zone, 6: cooling zone, 7
... Outlet seal part, 11, 12 ... Seal roll,
22: carrying path, 32: upstream seal gate, 33
... Downstream seal gate, 41-44 ...
71: purge chamber, 82: inert gas supply source

Claims (3)

[Claims] In a furnace for continuously heat-treating a metal strip under a predetermined atmospheric gas, an upstream seal for blocking a metal strip carrying path at various points in the furnace and forming a purge chamber therebetween. A continuous heat treatment furnace for metal strips, comprising a gate and a downstream seal gate, wherein the purge chamber formed is maintained at an elevated pressure by supplying an inert gas. 2. The continuous heat treatment furnace for metal strip according to claim 1, wherein a purge chamber is formed in the vicinity of one or more selected from an inlet seal portion, an outlet seal portion, and a direction changing roll. 3. The upstream-side seal gate includes a pair of openable and closable doors on the downstream side, and the downstream-side seal gate includes a pair of openable and closable doors on the upstream side. A continuous heat treatment furnace for the metal strip according to the above.