JP2000055566A - Cooling device for multi-chamber type heat treatment furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device in which inconvenience state caused by a thermal deformation of a heat shielding plate can be eliminated, a vacuum cooling time or a static gas cooling time can be shortened and then a cooling operation can be carried out from a temperature which is not restricted by a melting point of the material of the heat shielding plate or a cooling gas guiding passage. SOLUTION: There is provided a cooling device arranged at a cooling chamber 4 of a multi-chamber type heat treatment furnace having heating chambers 2, 3 and the cooling chamber 4. The cooling device is comprised of a cooling gas guiding passage 19 into which material 1 to be processed is fed and cooling gas is flowed around it and a cooling fan 22 for circulating the cooling gas passed through the cooling gas guiding passage 19. The cooling gas guiding passage 19 is constituted of a water-cooled panel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cooling apparatus for a multi-chamber heat treatment furnace for performing heat treatment, sintering, firing, and the like.

[0002]

2. Description of the Related Art A multi-chamber heat treatment furnace is used for heat treatment, sintering, and firing of metals, ceramics, magnetic materials, composite materials, and the like. FIG. 5 shows a three-chamber type as an example of a conventional multi-chamber heat treatment furnace. In this three-chamber heat treatment furnace, a first heating chamber 2, a second heating chamber 3, and a cooling chamber 4 are arranged in this order from the entrance side, and the workpiece 1 is heated to a predetermined temperature in the first heating chamber 2. If further heating is required, heating is performed in the second heating chamber 3 and cooling processing such as cooling or rapid cooling is performed in the cooling chamber 4.
It is discharged from the outlet side in the following manner.

The cooling chamber 4 is provided with a cooling gas guide passage 19 in the direction of transport of the workpiece 1, into which the workpiece 1 is carried and cooled. A cooling fan 22 is provided above the cooling chamber 4.
The cooling gas is circulated through the cooling gas guide passage 19 from above, descending downward, and returning upward.

FIG. 6 is a sectional view of a conventional cooling chamber 4. A cooling gas guide passage 19 is provided at the center of the water-cooled furnace 15, and the workpiece 1 is carried into the cooling gas guide passage 19. A heat shield plate 20 is provided inside the cooling gas guide passage 19 to thermally protect the cooling gas guide passage 19. Arrows indicate that the cooling gas that has passed through the cooling gas guide passage 19 falls downward, returns upward, and circulates again. A cooling fin tube 16 is provided between the furnace body 15 and the cooling gas guide passage 19 to cool the circulating cooling gas.

FIG. 7 is a cross-sectional view of a conventional cooling chamber 4 in which another cooling passage is used. The cooling gas guide passage 19a guides the cooling gas upward from below,
A heat shield plate 20a corresponding to this shape is provided. Other configurations are the same as those in FIG.

[0006]

SUMMARY OF THE INVENTION A cooling gas guide passage 1
9 and 19a are made of steel, and stainless steel plates or molybdenum plates are used as the heat shield plates 20 and 20a. Heat shield plate 2
Since 0 and 20a are high in temperature, thermal deformation is apt to occur, and when this thermal deformation occurs, interference occurs when the workpiece 1 is transported. For this reason, damage to the heat shield plates 20 and 20a may cause thermal damage to the cooling gas guide passages 19 and 19a in some cases. Therefore, operations such as inspection, maintenance, and replacement of the heat shield plates 20 and 20a are frequently required.

[0007] Further, depending on the material properties of the object 1 to be processed,
After the transfer from the second heating chamber 3 to the cooling chamber 4, the cooling may be performed slowly in a vacuum or in a stationary cooling gas to a certain temperature and then rapidly cooled by a cooling fan. , The cooling cycle time becomes longer, and the productivity does not increase. Further, the cooling process of the workpiece 1 cannot be performed at a temperature equal to or higher than the melting point of the material forming the heat shield plates 20, 20a and the cooling gas guide passages 19, 19a.

The present invention has been made in view of the above-mentioned problems, and eliminates inconvenience due to thermal deformation of a heat shield plate, shortens vacuum cooling or static gas cooling time, and provides a heat shield plate and a cooling gas guide passage. An object of the present invention is to provide a cooling device capable of cooling from a temperature that is not restricted by the melting point of a material.

[0009]

According to a first aspect of the present invention, there is provided a cooling apparatus provided in a cooling chamber of a multi-chamber heat treatment furnace having a heating chamber and a cooling chamber. The apparatus includes: a cooling gas guide passage through which an object to be processed is introduced, and a cooling gas flowing around the cooling gas guide passage; and a cooling fan that circulates the cooling gas through the cooling gas guide passage. The gas guide passage is constituted by a water-cooled panel.

Since the cooling gas guide passage in which the object to be processed is installed is constituted by a water-cooled panel, the temperature can be kept low, thermal deformation can be eliminated, and interference with the object during transport can be prevented. . Further, since the cooling gas guide passage is cooled, the time for vacuum cooling and circulation gas cooling is reduced.

According to the invention of claim 2, the water cooling panel is provided with cooling fins.

By providing fins on the water cooling panel,
The cooling gas can be efficiently cooled, and the cooling time by the cooling fan can be reduced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a multi-chamber heat treatment furnace including a cooling chamber according to an embodiment of the present invention. FIG. 2 is a cross section taken along line XX of FIG.
2 shows a cross section of a cooling chamber. The three-chamber heat treatment furnace includes a first heating chamber 2, a second heating chamber 3, and a cooling chamber 4 in order from an entrance door 6, and discharges the workpiece 1 from an exit door 7 of the cooling chamber 4. A conveyor 5 is provided from the place where the entrance door 6 has been entered, and is disposed up to the cooling chamber 4. The first heating chamber 2 is heated to a predetermined temperature, for example, 800 ° C. Entrance door 8
And an exit door 9 are provided.
0 is provided. The second heating chamber 3 has a higher temperature,
For example, heating at about 1500 to 2000 ° C. is performed. An entrance door 11 and an exit door 12 are provided in the second heating chamber 3, and a heater 13 is provided in the room.

The cooling chamber 4 also has an entrance door 14 and an exit door 7. The cooling chamber 4 is provided with a cooling gas guide passage 19 through which the workpiece 1 passes in the loading / unloading direction. Also this passage 1
A cooling fan 22 circulating a cooling gas through 9 is provided, and is rotated by a driving device 21. Each of the doors 6, 7, 8, 9, 11, 12, and 14 is opened and closed by a cylinder.

As shown in FIG. 2, the furnace body 15 has a cylindrical shape so as to withstand a vacuum, and a cooling gas guide passage 19 is arranged at the center, through which the workpiece 1 is conveyed. It has become. Although the cross section of the cooling gas guide passage 19 is shown as a square, it may be circular depending on the shape of the workpiece 1. A water-cooled fin tube 16 is provided between the furnace body 15 and the side wall of the cooling gas guide passage 19 in the carry-out direction, and cools the furnace body 15 and the cooling gas guide passage 19.
The workpiece 1 is supported by a hearth 17, and the hearth 17 is supported from a furnace body 15 by a hearth support 18. The hearth 17 is made of graphite, and allows the object 1 to be cooled in an extremely high temperature state exceeding 1500 ° C. The arrow indicates that the cooling gas passing through the cooling gas guide passage 19 turns downward and is cooled by the water-cooled fin tubes 16 so that the cooling fan 22
It shows how to return to.

FIGS. 3A and 3B show the water cooling panel 23 constituting the cooling gas guide passage 19, wherein FIG. 3A is a plan view and FIG.
FIG. The water cooling panel 23 connects two steel plates with ribs to form three water channels, and connects the water channels so as to form a zigzag as shown in FIG. Further, fins 24 are provided on the surface inside the cooling gas guide passage 19 to improve heat transfer. Water cooling panel 2
3 may be provided with fins 24 on both surfaces. The top plate, the bottom plate, and both side plates of the cooling gas guide passage 19 are constituted by water cooling panels 23. The water-cooled panel absorbs radiant heat of the processing object 1 and absorbs heat of the circulating cooling gas by convective heat transfer. Therefore, no heat shield is required. The material of the water-cooled panel is not limited to steel, but can be appropriately selected depending on the case, for example, when the cooling performance is further improved by using copper having excellent heat conduction. Also,
Since the structure including the cooling water channel of the water cooling panel is determined by the acting pressure, heat load, size of the device, cooling water conditions,
It is not limited to the illustrated shape. Further, the fin structure is similarly not limited to the illustrated shape.

FIG. 4 is a diagram showing a heat treatment pattern of the present multi-chamber heat treatment furnace in comparison with the present invention and the conventional heat treatment pattern.
When the object 1 is heated in the first heating chamber 2 and the second heating chamber 3 and this temperature exceeds 1500 ° C., conventionally, the temperature is reduced to 1500 ° C. or less in the second heating chamber 3 as shown in a and b. After cooling, it is transferred to the cooling chamber 4 and vacuum-cooled as shown by b to c to ensure the quality of the heat treatment, and then rapidly cooled by fan cooling that circulates a cooling gas as shown by cd. On the other hand, in the present invention, even when the object 1 exceeds 1500 ° C., a to c
Transfer to a cooling chamber as shown in FIG. 1 and ensure the quality of the heat treatment by vacuum cooling.
Rapid cooling as indicated by d1. This shortens the cooling time as shown in FIG. Note that vacuum cooling is cooling in a vacuum, static cooling gas cooling is cooling in a cooling gas atmosphere, and fan cooling is forced cooling gas circulation cooling.
The person is slowly cooled while the person is slowly cooled. The cooling rate is higher in the order of fan cooling, still cooling gas cooling, and vacuum cooling.
The conventional temperature limit is 1500 ° C. for fan cooling and 1200 ° C. for still cooling gas cooling and vacuum cooling.

[0018]

As is apparent from the above description, the present invention has the following effects by constituting the cooling gas guide passage with a water cooling panel and eliminating the heat shield plate. Thermal damage to the cooling gas guide passage is eliminated, and thermal protection of the furnace internal structure becomes possible. Since the cooling gas guide passage structure has been cooled with water, the heat-resistant temperature of the structure is no longer limited, so that the cooling of the object to be processed exceeding 2000 ° C. in vacuum or still cooling gas can be performed in the cooling chamber. Conventionally, when the temperature of the workpiece is high, the heat shield plate temperature also rises, so the cooling performance of vacuum cooling or static cooling gas cooling is poor, and it takes time for the workpiece to cool to the temperature at which fan cooling can be started. This time can be reduced by adopting a water-cooled panel. Since the temperature of the circulating cooling gas can be lowered by the water-cooled panel, the fan cooling start temperature can be greatly increased as compared with the conventional case. As a result, the temperature range for cooling by the fan increases, and the cooling time can be reduced. Since the cooling gas guide passage itself has a cooling effect, the number of cooling fin tubes can be reduced or omitted, and the furnace body can be made compact.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a multi-chamber heat treatment furnace including a cooling chamber of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a diagram showing a configuration of a water cooling panel.

FIG. 4 is a view showing a heat treatment pattern of a multi-chamber heat treatment furnace.

FIG. 5 is a diagram showing a configuration of a conventional multi-chamber heat treatment furnace including a cooling chamber.

FIG. 6 is a sectional view of a conventional cooling chamber.

FIG. 7 is a cross-sectional view of another conventional cooling chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processed object 2 1st heating room 3 2nd heating room 4 Cooling room 5 Conveyor 6,8,11,14 Entrance door 7,9,12 Exit door 10,13 Heater 15 Furnace 16 Water-cooled fin tube 17 Hearth 18 Hearth support 19, 19a Cooling gas guide passage 20, 20a Heat shield plate 21 Drive unit 22 Cooling fan 23 Water cooling panel 24 Fin

Claims (2)

[Claims] 1. A cooling device provided in a cooling chamber of a multi-chamber heat treatment furnace having a heating chamber and a cooling chamber, wherein the cooling device receives an object to be processed and allows a cooling gas to flow therearound. And a cooling fan for circulating a cooling gas through the cooling gas guide passage, wherein the cooling gas guide passage is constituted by a water-cooled panel. Cooling equipment for heat treatment furnace. 2. The cooling apparatus for a multi-chamber heat treatment furnace according to claim 1, wherein cooling fins are provided on the water cooling panel.