JP3820950B2 - Atmospheric heat treatment furnace and its seasoning method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an atmospheric heat treatment furnace, and more particularly, to an atmospheric heat treatment furnace and a seasoning method thereof that can easily perform furnace drying (seasoning) before the start of heat treatment.
[0002]
[Prior art]
The atmosphere heat treatment furnace supplies an atmosphere gas such as H2 + N2 into the furnace and performs bright annealing of the stainless steel material in a non-oxidizing atmosphere. In such a heat treatment furnace, seasoning for sufficiently drying the inside of the furnace is performed prior to the start of heat treatment in order to prevent moisture oxidation of the material being processed. In this case, unlike seasoning, in order to season an annealing chamber or cooling chamber that does not have a heat source, the processing material heated in the heating chamber to a high temperature is passed through the annealing chamber and the cooling chamber to dissipate heat from the material. The cooling room or the like is dried by the above, or a seasoning-specific heater or the like is provided in the cooling room or the like.
[0003]
On the other hand, in order to reduce the amount of use of the atmospheric gas and reduce the cost, a circulation regenerating apparatus for recirculating the atmospheric gas is provided, and an example is shown in FIG. FIG. 3 shows a horizontal atmosphere heat treatment furnace having a front chamber 1, a heating chamber 2, a slow cooling chamber 3, a cooling chamber 4, and a rear chamber 5. Then, it passes through the heating chamber 2, the slow cooling chamber 3, the cooling chamber 4, and the rear chamber 5 from the front chamber 1, and is heat-treated in a non-oxidizing atmosphere. A flow path 6 that connects the front chamber 1 and the cooling chamber 4 is provided, and a circulation and regeneration device 7 is interposed in the flow path 6. The circulation regenerator 7 is provided with a filter, a cooler, a circulation fan, a deoxidation reaction tower, and a dryer from the inlet 71 side communicating with the front chamber 1. The clean atmospheric gas supplied to the cooling chamber 4 flows from the slow cooling chamber 3 to the heating chamber 2 and the front chamber 1, and then reaches the inlet 71 of the circulation regenerator 7 through the flow path 6. Dehydration and deoxidation are performed, and the product is returned from the outlet 72 to the cooling chamber 4 through the flow path 6 again.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional atmospheric heat treatment furnace, there is a problem that flowing a dummy processing material for seasoning requires labor and waste of materials, and there is a problem that a heater dedicated to seasoning is provided. There is a problem that installation space needs to be secured and the cost is increased.
[0005]
Therefore, the present invention solves such a problem, an atmosphere heat treatment furnace capable of easily performing seasoning without causing labor and material waste, no need to install a special heater, and the like. An object is to provide a seasoning method.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an atmospheric gas having at least a heating chamber (2) and a cooling chamber (4) and flowing from the cooling chamber (4) side to the heating chamber (2) side is provided. The recirculation gas is supplied from the heating chamber (2) side to the inlet (71) of the circulation regenerator (7) provided outside the furnace, and the regenerated atmospheric gas is again supplied from the outlet (72) of the circulation regenerator (7) to the cooling chamber ( 4) In an atmosphere heat treatment furnace provided with a flow path (6) that circulates to the side, the inlet (71) of the circulation regenerator (7) communicates with the cooling chamber (4) side and the outlet of the circulation regenerator (7) ( 72) is provided with channel switching means (8A, 8B) for switching the channel (6) so as to communicate with the heating chamber (2).
[0007]
In the first aspect of the invention, during seasoning before the start of heat treatment, the flow path of the circulation regenerator is switched by the flow path switching means, the atmospheric gas is sent from the circulation regenerator to the heating chamber, and indirectly heated by a burner or the like of the heating chamber. By circulating the atmosphere gas thus made to the cooling chamber side, the seasoning of the cooling chamber can be easily performed without providing the cooling chamber with the trouble of flowing a dummy processing material and providing a special heat source.
[0008]
Further, according to the seasoning process of the second aspect of the invention comprises at least a heating chamber in the furnace circulation reproducing apparatus for atmospheric gas regeneration outside Rutotomoni furnace equipped with (2) and the cooling chamber (4) (7), the atmosphere during the heat treatment Seasoning of an atmospheric heat treatment furnace in which gas is circulated from the cooling chamber (4) to the heating chamber (2) and then circulated again from the heating chamber (2) to the cooling chamber (4) through the circulation regenerator (7). In the method, at the time of seasoning, atmospheric gas is circulated from the cooling chamber (4) to the circulation regenerator (7) and then circulated from the circulation regenerator (7) to the cooling chamber (4) again through the heating chamber (2). To. Also by this method, the same effect as the first invention can be obtained.
[0009]
In addition, the code | symbol in the said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The horizontal atmosphere heat treatment furnace shown in FIG. 1 has a front chamber 1, a heating chamber 2, a slow cooling chamber 3, a cooling chamber 4, and a rear chamber 5, and a strip material such as a stainless steel strip is a sealing device (not shown). Then, the front chamber 1 is passed through the heating chamber 2, the slow cooling chamber 3, the cooling chamber 4, and the rear chamber 5, and heat treatment is performed in a non-oxidizing atmosphere. A flow path 6 that connects the front chamber 1 and the cooling chamber 4 is provided, and a circulation / regeneration device 7 similar to that described in the prior art is interposed in the flow path 6, and a three-way switching valve 8 </ b> A is provided at the front and rear positions thereof. , 8B are provided. A bypass flow path 61 is provided between the three-way switching valve 8B and the inlet 71 side of the circulation regenerator 7, and a bypass flow path 62 is provided between the three-way switching valve 8A and the outlet 72 side of the circulation regenerator 7. ing.
[0011]
During normal material heat treatment, as shown in FIG. 1, the a-port and b-port of each of the three-way switching valves 8A, 8B are communicated, and the c-port is shut off. Thereby, as shown by the arrow in FIG. 1, the atmospheric gas supplied to the cooling chamber 4 passes through the slow cooling chamber 3, the heating chamber 2, the front chamber 1, the flow path 6, and the inlet 71 of the circulation regenerator 7. Then, dehydration and deoxidation are performed in the circulation regenerator 7 and returned to the cooling chamber 4 again from the outlet 72 of the circulation regenerator 7 through the flow path 6. As described above, the belt-shaped material is passed from the front chamber 1 to the heating chamber 2, the slow cooling chamber 3, the cooling chamber 4, and the rear chamber 5, and is heat-treated in a non-oxidizing atmosphere.
[0012]
When seasoning is performed prior to the start of the heat treatment, the three-way switching valves 8A and 8B are set in the switching state shown in FIG. Thereby, the connection between the port b of the three-way switching valve 8A and the inlet 71 of the circulation regenerator 7 and the connection between the port a of the three-way switching valve 8B and the outlet 72 of the circulation regenerator 7 are blocked. At the same time, the flow path 6 portion connected to the front chamber 1 and the bypass flow path 62 communicate with each other via the ports a and c of the three-way switching valve 8A, and the cooling via the ports b and c of the three-way switching valve 8B. The portion of the flow path 6 connected to the chamber 4 and the bypass flow path 61 communicate with each other. In this state, when the radiant tube burner that is an indirect heating source of the heating chamber 2 is ignited and the circulation regenerator 7 is operated, the atmospheric gas in the furnace is discharged from the outlet 72 of the circulation regenerator 7 as indicated by the arrow in FIG. To the front chamber 1 through the three-way switching valve 8A, the temperature is raised in the heating chamber 2, flows to the slow cooling chamber 3 and the cooling chamber 4, and the cooling chamber 3 and the cooling chamber 4 are dried by heat radiation. The atmospheric gas then reaches the inlet 71 of the circulation regenerator 7 from the cooling chamber 4 via the three-way switching valve 8B.
[0013]
Thus, in the present embodiment, the flow path to the circulation regenerator 7 is switched by the three-way switching valve, and the atmospheric gas heated in the heating chamber 2 is circulated to the slow cooling chamber 3 and the cooling chamber 4. Thus, seasoning of each of the chambers 3 and 4 can be easily performed without providing a troublesome flow of a dummy processing material and a special heat source in the slow cooling chamber 3 and the cooling chamber 4 as in the prior art.
[0014]
【The invention's effect】
As described above, according to the atmospheric heat treatment furnace and the seasoning method of the present invention, it is possible to easily perform seasoning without causing labor and material waste and without needing to install a special heater or the like. .
[Brief description of the drawings]
FIG. 1 is a system diagram of an atmospheric heat treatment furnace during heat treatment, showing an embodiment of the present invention.
FIG. 2 is a system diagram of an atmosphere heat treatment furnace during seasoning, showing an embodiment of the present invention.
FIG. 3 is a system diagram of a conventional atmospheric heat treatment furnace.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Heating chamber, 4 ... Cooling chamber, 6 ... Flow path, 61, 62 ... Bypass flow path, 7 ... Circulation reproduction | regeneration apparatus, 71 ... Inlet, 72 ... Outlet, 8A, 8B ... Three-way switching valve.

Claims (2)

At least the heating chamber and cooling chamber are provided, and the atmosphere gas circulated from the cooling chamber side to the heating chamber side is supplied from the heating chamber side to the inlet of the circulation regenerator provided outside the furnace, and the regenerated atmosphere gas is circulated. In an atmospheric heat treatment furnace provided with a flow path that circulates again from the outlet of the regenerator to the cooling chamber, the inlet of the regenerator is connected to the cooling chamber and the outlet of the regenerator is connected to the heating chamber. An atmosphere heat treatment furnace provided with flow path switching means for switching a path. Comprising a circulating reproducing apparatus for atmospheric gas regeneration, at least, outside Rutotomoni furnace comprises a cooling chamber and the heating chamber in the furnace and allowed to flow into the heating chamber atmospheric gas from the cooling chamber during the heat treatment, the circulation reproducing apparatus from the heating chamber In the seasoning method of the atmospheric heat treatment furnace that is circulated again to the cooling chamber, after seasoning, the atmospheric gas is circulated from the cooling chamber to the circulation regenerator, and then circulated from the circulation regenerator to the cooling chamber again through the heating chamber. A seasoning method for an atmospheric heat treatment furnace, characterized in that :

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