CN213454880U - Heat treatment apparatus - Google Patents

Abstract

The utility model provides a heat treatment device, wherein the gas of being supplied with in the muffle furnace is in the muffle furnace flows uniformly. The heat treatment device (10) comprises: a pressure vessel (12); a heat insulator (16) disposed inside the pressure vessel (12); a heater (20) disposed in the internal space (18) of the heat insulator (16); a muffle (24) disposed in the internal space (18) of the heat insulator (16) and accommodating the object (22) to be treated; a gas source (54, 60); a first supply tube (56) connected from the gas source (54) to the interior space (18) of the insulator (16); a second supply tube (62) connected from the gas source (60) to the interior space (28) of the muffle (24); an opening (80) formed in the second supply pipe (62) in the internal space (18) of the heat insulator (16); and a differential pressure control valve (82).

Description

Heat treatment apparatus

Technical Field

The utility model relates to a heat treatment device.

Background

Conventionally, there has been disclosed a heat treatment apparatus for heat-treating an object to be treated including a superhard metal, a magnetic material, or the like. For example, japanese patent laid-open publication No. 2011-: a pressure vessel; an insulator provided in the pressure vessel; a heater disposed in an internal space formed by the heat insulator; and a muffle (inner box) disposed in an internal space formed by the heat insulator. In order to supply gas to the muffle, a pipe (pipe) is connected from a gas source to the muffle, or a differential pressure control valve is provided in the muffle. The differential pressure control valve is a valve for supplying gas from the internal space of the insulator to the internal space of the muffle furnace by using a differential pressure between the pressure of the internal space of the insulator and the pressure of the internal space of the muffle furnace. For example, the pipe is connected to an upper portion of the muffle furnace, and the differential pressure control valve is mounted to a lower portion of the muffle furnace. The gas supplied into the muffle furnace is exhausted from a pipe connected to a lower portion of the muffle furnace.

The object to be processed is stored in a muffle furnace and subjected to heat treatment at a predetermined temperature, pressure, and gas atmosphere. For example, when degreasing an object to be treated, wax (wax) contained in the object to be treated evaporates as a gas. The gas supplied to the muffle furnace becomes a carrier, and the gaseous wax is discharged from the muffle furnace.

SUMMERY OF THE UTILITY MODEL

[ problem to be solved by the utility model ]

If the differential pressure introduction valve and the pipe for discharging the gas are provided in the lower portion of the muffle furnace as described above, the gas may not uniformly flow in the muffle furnace. If the flow of the gas supplied to the muffle furnace is deviated, the gaseous wax may be accumulated in the muffle furnace. The object cannot be subjected to a predetermined treatment.

Therefore, an object of the present invention is to provide a heat treatment apparatus in which gas supplied to a muffle furnace flows uniformly in the muffle furnace.

[ means for solving problems ]

In order to solve the above problems, the heat treatment apparatus of the present invention has the following configuration.

The heat treatment device of the utility model comprises: a pressure vessel; a heat insulator disposed inside the pressure vessel; a heater disposed in the internal space of the heat insulator; a muffle furnace disposed in the inner space of the heat insulator and accommodating an object to be processed; a gas source; a first supply tube connected from the gas source to the interior space of the insulator; a second supply pipe for supplying a gas to an inner space of the muffle furnace; an opening formed in the second supply pipe in the internal space of the heat insulator; and a differential pressure control valve for opening and closing an opening formed in the second supply pipe by using a difference between a pressure of the gas in the internal space of the heat insulator and a pressure of the gas in the internal space of the muffle furnace.

[ effects of the utility model ]

According to the present invention, the differential pressure control valve is installed in the second supply pipe, so that the gas supplied to the muffle furnace becomes one place. The gas can be supplied from a predetermined place to the muffle furnace, and the flow of the gas can be easily made uniform.

Drawings

FIG. 1 is a view showing the structure of a heat treatment apparatus according to the present invention.

FIG. 2 is a front cross-sectional view of the muffle.

FIG. 3 is a side cross-sectional view of the muffle.

Fig. 4 is a sectional view of the differential pressure control valve.

Fig. 5 is a sectional view of a differential pressure control valve using an elastic body.

FIG. 6 is a sectional view of the differential pressure control valve in which the pressure block is rotated by the shaft.

Fig. 7 is a front cross-sectional view of a muffle furnace in which a plurality of second exhaust pipes are provided.

Fig. 8 is a front cross-sectional view of a muffle furnace in which a plurality of second supply pipes are provided.

Fig. 9 is a diagram showing the configuration of the heat treatment apparatus in the case where the second gas supply device is omitted.

Fig. 10 is a sectional view of the differential pressure control valve in a case where the second gas supply device is omitted.

Description of the symbols

10. 130, 130: heat treatment apparatus

12: pressure vessel

14: inner space of pressure vessel

16: heat insulator

18: inner space of heat insulator

20: heating device

22: object to be treated

24: muffle furnace

26. 30: gas supply device

28: inner space of muffle furnace

32. 34: gas discharge device

36: pressure vessel body

38: pressure vessel cover

40: inner wall

42: outer wall

46: heat insulator body

48: heat insulator cover

50: muffle furnace body

52: muffle furnace cover

54. 60: gas source

56. 62: supply pipe

58. 64, 70, 74: valve with a valve body

66: pump and method of operating the same

68. 72: exhaust pipe

76: wax pot

78: filter

80. 98: opening of the container

82. 110, 120: differential pressure control valve

84. 128: cover

86. 122: gas path hole

88. 124: pressing block

90: annular space of gas path hole

92: bottom surface of the annular space

94: nozzle with a nozzle body

96: clamp apparatus

100: end of the second exhaust pipe

102: end of the second supply pipe

112: elastic body

126: rotating shaft

Detailed Description

The heat treatment apparatus of the present invention will be described with reference to the drawings. Although a plurality of embodiments are described, the same components are denoted by the same reference numerals and description thereof may be omitted in different embodiments.

[ embodiment 1]

The heat treatment apparatus 10 of the present embodiment shown in fig. 1 includes: a container-shaped pressure vessel 12; an insulator 16 disposed in the internal space 14 of the pressure vessel 12; a heater 20 disposed in the internal space 18 formed by the heat insulator 16; a muffle (inner box) 24 for accommodating the object 22; a first gas supply device 26 for supplying a gas into the internal space 18 of the heat insulator 16; a second gas supply device 30 for supplying gas into the internal space 28 of the muffle 24; a first gas exhaust device 32 that exhausts gas from the internal space 18 of the insulator 16; and a second gas exhaust device 34 for exhausting gas from the internal space 28 of the muffle 24.

The heat treatment apparatus 10 is an apparatus for performing degreasing, sintering, semi-sintering, baking, brazing, metallizing, quenching, solution (dissolving) treatment, tempering, annealing, aging heat treatment, or the like. For example, when the object 22 is degreased, wax contained in the object 22 is released from the object 22 as gas. The gaseous wax is discharged from the muffle 24 with the gas supplied to the muffle 24 as a carrier.

[ pressure vessel ]

The pressure vessel 12 includes a cylindrical pressure vessel body 36 and a pressure vessel lid 38 that closes both sides of the pressure vessel body 36. The pressure vessel body 36 and the pressure vessel lid 38 include an inner wall 40 and an outer wall 42. A cooling fluid flows through the space between the inner wall 40 and the outer wall 42. The interior space 14 of the pressure vessel 12 is depressurized or pressurized. The pressure vessel 12 has a pressure resistance of, for example, about 10MPa or more, and is changed by various designs.

[ Heat insulator ]

The insulator 16 includes a cylindrical insulator main body 46 and an insulator cover 48 for closing both sides of the insulator main body 46. The heat insulator 16 is made of a heat-resistant material such as graphite felt (graphite felt) or graphite foil (graphite foil). The insulator 16 may be disposed apart from the inner wall 40 of the pressure vessel 12, or may be attached to the inner wall of the inner wall 40. A heater 20 and a muffle 24 are disposed in an internal space 18 formed by the insulator 16.

[ Heater ]

The heater 20 may be a rod heater (rod heater) made of graphite. The electrodes of the heater 20 are passed through the pressure vessel 12 and the heat insulator 16, and the electrodes are connected to a power supply circuit outside the pressure vessel 12. When current is supplied to the heater 20, the heater 20 is heated. The temperature of the internal space 18 of the heat insulator 16 and the internal space 28 of the muffle 24 is raised to about 1000 to 2300 ℃ by the heater 20.

[ muffle furnace ]

The muffle 24 includes a cylindrical or square-shaped muffle body 50 and a muffle cover 52 (fig. 2 and 3) that closes both sides of the muffle body 50. The interior space 28 of the muffle 24 has a cylindrical shape, a cubic shape, a rectangular parallelepiped shape, a prismatic shape, or the like. The muffle cover 52 opens and closes both sides of the muffle body 50. A muffle lid 52 may also be mounted to the inner wall of the insulator cover 48. The muffle 24 is made of graphite or the like. The muffle 24 accommodates the object 22. The heat of the heater 20 reaches the object 22 via the muffle 24. The muffle 24 may be provided with a shelf on which the object 22 to be processed is placed. By housing the object 22 in the muffle 24, the gas-like wax and powder generated from the object 22 are confined in the muffle 24.

[ treated article ]

The material of the object 22 is a superhard metal, an iron-based metal, a nonferrous metal, a magnetic material, a ceramic, graphite, high speed steel (high speed steel), die steel, low alloy steel, or the like, and the metal includes an alloy. The object to be treated is a powder, a granule, or a solid having a predetermined shape.

[ gas supply device ]

The scheme includes: a first gas supply device 26 for supplying a gas into the internal space 18 of the heat insulator 16; and a second gas supply device 30 for supplying gas into the internal space 28 of the muffle 24. The first gas supply device 26 includes a first gas source 54 for storing a gas, a first supply pipe 56 for supplying the gas to the internal space 18 of the heat insulator 16, and a valve 58 provided in the middle of the first supply pipe 56. The second gas supply device 30 includes a second gas source 60 for storing gas, a second supply pipe 62 for supplying gas to the internal space 28 of the muffle 24, and a valve 64 provided in the middle of the second supply pipe 62.

The gas stored in the first gas source 54 and the second gas source 60 is nitrogen, argon, hydrogen, carbon monoxide, helium, methane, or the like. The end of the first supply pipe 56 is disposed in the internal space 14 of the pressure vessel 12 or the internal space 18 of the heat insulator 16. When the end of the first supply pipe 56 is disposed in the internal space 14 of the pressure vessel 12, the gas is introduced into the internal space 18 of the insulator 16 by opening the insulator cover 48. An end of the second supply pipe 62 is disposed in the internal space 28 of the muffle 24. The first gas supply device 26 and the second gas supply device 30 control the supply of gas by opening and closing the valves 58 and 64. The gas type may be plural, and in this case, the gas source 54 and the gas source 60 may be included for each gas type.

[ gas discharge device ]

The scheme includes: a first gas exhaust device 32 that exhausts gas from the internal space 18 of the insulator 16; and a second gas exhaust device 34 for exhausting gas from the internal space 28 of the muffle 24. The first gas discharge device 32 includes a pump 66, a first gas discharge pipe 68 for discharging gas from the internal space 14 of the pressure vessel 12, and a valve 70 provided in the middle of the first gas discharge pipe 68. The second gas discharge device 34 includes a pump 66, a second gas discharge pipe 72 for discharging gas from the internal space 28 of the muffle 24, and a valve 74, a wax tank (wax tank)76, and a filter (filter)78 provided midway in the second gas discharge pipe 72.

The first gas discharge device 32 and the second gas discharge device 34 may share the pump 66, or each of the gas discharge devices 32, 34 may include the pump 66. Examples of the pump 66 include a dry pump, a turbo-molecular pump, an oil rotary pump, and an oil diffusion pump. The gas may be pumped from the interior space 14 of the pressure vessel 12 and the interior space 28 of the muffle 24 using a pump 66. Since the heat insulator 16 is not completely airtight, when gas is sucked from the internal space 14 of the pressure vessel 12, gas is also sucked from the internal space 18 of the heat insulator 16.

An end of the first exhaust pipe 68 is disposed in the internal space 14 of the pressure vessel 12 or the internal space 18 of the heat insulator 16. When the end of the first exhaust pipe 68 is disposed in the internal space 14 of the pressure vessel 12, the gas is exhausted from the internal space 18 of the insulator 16 by opening the insulator cover 48. The end of the second exhaust pipe 72 is located in the muffle 12. The discharge of gas can be controlled by opening and closing the valves 70 and 74 of the exhaust pipes 68 and 72.

The wax tank 76 located in the middle of the second exhaust pipe 72 is used to cool and liquefy the gaseous wax generated from the object 22 and store the wax. The gaseous wax does not reach the pump 66. The filter 78 located in the middle of the second exhaust pipe 72 collects powder generated from the object 22. The powder does not reach the pump 66.

The scheme includes: an opening 80 formed in the second supply pipe 62; and a differential pressure control valve 82 that opens and closes the opening 80 (fig. 4).

[ opening ]

An opening 80 is formed in the second supply pipe 62 in the internal space 18 of the heat insulator 16. Gas can be supplied from the internal space 18 of the insulator 16 to the internal space 28 of the muffle 24 through the opening 80 and the second supply pipe 62. The plurality of openings 80 are formed in a circumferential direction of the second supply pipe 62.

[ differential pressure control valve ]

The differential pressure control valve 82 opens and closes the opening 80 of the second supply pipe 62. The differential pressure control valve 82 includes: a cover 84 attached to the second supply pipe 62; a gas path hole 86 formed in the cover 84 and connecting the internal space 18 of the heat insulator 16 to the opening 80 of the second supply pipe 62; and a pressure block 88 for opening and closing the gas passage hole 86. The cover 84 is wound once in the circumferential direction of the second supply pipe 62. The cover 84 shields the opening 80 of the second supply pipe 62. The cover 84 may also comprise a plurality of members. The gas path hole 86 is a hollow formed in the cover 84.

An annular space 90 is provided in the middle of the gas passage hole 86, and an annular pressure block 88 is disposed in the space 90. The gas path holes 86 are connected to the bottom surface 92 of the annular space 90. The pressure block 88 is placed by gravity on the bottom surface 92 of the annular space 90, and blocks the gas passage hole 86. The height of the annular space 90 is higher than that of the pressing piece 88 so that the pressing piece 88 can move up and down. The gas entering from the internal space 18 of the heat insulator 16 pushes up the annular pressure block 88 from below, thereby opening the differential pressure control valve 82. If the pressure of the gas in the internal space 18 of the insulator 16 is higher than the pressure of the gas in the internal space 28 of the muffle 24, the gas enters the gas passage hole 86 from the internal space 18 of the insulator 16, and pushes up the briquette 88. The weight of the briquette 88 is such that the briquette 88 is pushed up by the gas when the differential pressure between the gas pressure in the internal space 18 of the insulator 16 and the gas pressure in the internal space 28 of the muffle 24 becomes a predetermined value.

Conversely, even if gas attempts to flow from the opening 80 of the second supply pipe 62 to the internal space 18 of the insulator 16, the briquette 88 does not move, and gas does not flow. The gas is supplied to the internal space 28 of the muffle 24 without leaking from the second supply pipe 62 to the internal space 18 of the heat insulator 16.

[ nozzle ]

A nozzle 94 is attached to an end of the second supply pipe 62. The nozzle 94 may also be mounted via a fixture 96, as in fig. 4. The nozzle 94 is a linear pipe. The longitudinal direction of the nozzle 94 is the same as the longitudinal direction of the muffle 24. The plurality of openings 98 of the nozzle 94 are formed in a row in the longitudinal direction of the nozzle 94. The nozzle 94 directs an opening 98 toward the inner wall of the muffle 24. In fig. 2, the nozzle 94 is positioned in the upper portion of the interior space 28 of the muffle 24, with the nozzle 94 having an opening 98 facing upward. The gas released from the opening 98 contacts the inner wall of the muffle 24 and descends along the inner wall of the muffle 24.

In the internal space 28 of the muffle 24, an end portion 100 of the second exhaust pipe 72 is disposed at a position facing an end portion 102 of the second supply pipe 62. Specifically, the end 102 of the second supply pipe 62 is disposed above the muffle 24, and the end 100 of the second exhaust pipe 72 is disposed below the muffle 24. The gas discharged from the nozzle 94 makes a half turn along the inner wall of the muffle 24.

[ others ]

The heat treatment apparatus 10 may include a fan and a cooler for cooling the internal space 18 of the heat insulator 16. The cooler may be a water-cooled heat exchanger. The fan is rotated to circulate the gas, and the gas is cooled by the cooler. The fan may be rotated to make the gas in the internal space 18 of the heat insulator 16 uniform during the heat treatment.

A temperature gauge may also be included that measures the temperature of the interior space 18 of the insulator 16 and the interior space 28 of the muffle 24. The thermometer may use a thermocouple thermometer. The temperature of the internal space 18 and the internal space 28 is controlled by applying current to the heater 20 according to the temperature. Pressure gauges may also be included that measure the pressure of the gas in the interior space 18 of the insulator 16 and the interior space 28 of the muffle 24. The pressure gauge may be a diaphragm type pressure gauge. The pressure of the gas in the internal space 18 and the internal space 28 can be controlled by supplying and discharging the gas according to the pressure.

[ Heat treatment ]

Next, a process using the heat treatment apparatus 10 of the present embodiment will be described. (1) Preparation for heat treatment of the object 22 to be treated is performed. In the preparation, the pressure container cover 38, the insulator cover 48, and the muffle cover 52 are opened, and the object 22 to be treated is accommodated in the muffle 24. The muffle lid 52, insulator lid 48, and pressure vessel lid 38 are then closed.

(2) The valves 58 and 64 of the first gas supply device 26 and the second gas supply device 30 are operated to supply gas from the first gas source 54 and the second gas source 60 to the internal space 18 of the insulator 16 and the internal space 28 of the muffle 24. The gas supply to the internal space 28 of the muffle 24 is performed by the following method: (a) a method of supplying gas from a second gas source 60 through a second supply pipe 62; or (b) a method of supplying a gas from the first gas source 54 through the first supply pipe 56, the internal space 18 of the heat insulator 16, the differential pressure control valve 82, and the second supply pipe 62.

In the case of the above (a), the gas is supplied from the second gas supply source 60 to the internal space 28 of the muffle 24 by opening the valve 64 of the second supply pipe 62. The valve 58 of the first supply pipe 56 can be opened or closed arbitrarily according to the processing method.

In the case of (b), the valve 58 of the first supply pipe 56 is opened, and the valve 64 of the second supply pipe 62 is closed. Gas is supplied to the interior space 18 of the insulator 16 from the first gas source 54 and no gas is supplied to the interior space 28 of the muffle 24 from the second gas source 60. Therefore, the pressure of the gas in the internal space 18 of the insulator 16 becomes higher than the pressure of the gas in the internal space 28 of the muffle 24. The pressure block 88 of the differential pressure control valve 82 is pushed up, and the gas enters the second supply pipe 62 from the internal space 18 of the heat insulator 16. The gas entering the second supply pipe 62 enters the muffle 24.

The pump 66 is driven to operate the valves 70 and 74 of the first and second gas discharge devices 32 and 34 while supplying the gas, thereby discharging the gas from the internal space 14 of the pressure vessel 12 and the internal space 28 of the muffle 24. By discharging the gas, the gas initially filled can be discharged, and the internal space 28 of the muffle 24, the internal space 14 of the pressure vessel 12, and the internal space 18 of the heat insulator 16 can be filled with a predetermined gas.

(3) Current is supplied to the heater 20 to heat the heater 20. The temperature of the internal space 18 of the insulator 16 and the internal space 28 of the muffle 24 is raised to a predetermined temperature. The valves 58, 64, 70, and 74 are opened and closed to continue the supply and discharge of the gas. The gaseous wax generated from the object to be treated 22 is discharged together with the gas supplied to the internal space 28 of the muffle 24. The gaseous wax is liquefied and stored by the wax tank 76. The powder generated from the object 22 is also discharged together with the gas supplied to the internal space 28 of the muffle 24. The powder is collected by a filter 78.

The object 22 to be processed is processed by setting the internal space 28 of the muffle 24 to a predetermined temperature, gas atmosphere, and pressure. In the treatment, the temperature, gas atmosphere, and pressure may be adjusted to change the values. In the step (2), the current may be supplied to the heater 20 to start the heat treatment of the object 22 to be treated from before the internal space 28 of the muffle 24 is brought into the predetermined gas atmosphere.

(4) When the treatment of the object 22 is completed, the heating by the heater 20 is completed, and the object 22 is cooled. The supply and discharge of the gas are also terminated, and the pressure vessel cover 38, the heat insulator cover 48, and the muffle cover 52 are opened to take out the object 22.

As described above, in the present embodiment, the differential pressure control valve 82 is attached to the second supply pipe 62, so that the gas passing through the differential pressure control valve 82 can be supplied from the same location as the second supply pipe 62. When the gas is supplied to the muffle 24 through the differential pressure control valve 82, the gas does not flow unevenly, but flows uniformly along the inner wall of the muffle 24. When the gaseous wax generated from the object 22 is discharged by the supplied gas, the gaseous wax is uniformly discharged to uniformly treat the object 22.

[ embodiment 2]

In contrast to the differential pressure control valve 82 of fig. 4, the differential pressure control valve 110 shown in fig. 5 has an elastic body 112 attached to the pressure block 88. The elastic body 112 adjusts the gas pressure when the briquette 88 floats upward. The elastic body 112 is a coil spring, a plate spring, or the like.

[ embodiment 3]

As in the differential pressure control valve 120 of fig. 6, a pressure block 124 provided in the gas passage hole 122 may be rotatably attached to the gas passage hole 122. A rotating shaft 126 is attached to an upper portion of the pressing block 124, and the pressing block 124 rotates about the rotating shaft 126. When the pressure of the gas in the internal space 18 of the insulator 16 becomes higher than the pressure of the gas in the internal space 28 of the muffle 24, the gas enters the gas passage hole 122 from the internal space 18 of the insulator 16, the gas pushes the briquette 124, and the briquette 124 rotates about the rotation shaft 126. The briquette 124 is rotatable from the internal space 18 of the heat insulator 16 to the second supply pipe 62 by the flow of the gas, but is not rotatable by contacting the inner wall of the lid 128 forming the gas path hole 122. In the gas path hole 122, the flow of the gas becomes one direction.

[ embodiment 4]

In fig. 7, a plurality of second exhaust pipes 72 are attached to the muffle 24. By providing the second exhaust pipe 72 in plural, the gas flow in the lower portion of the muffle 24 is caused not to be collected at one place but to be dispersed to plural places. The gas emitted from the plurality of openings 98 of the nozzle 94 descends uniformly in the muffle 24. The flow of the gas is maintained as uniform as possible even in the lower portion of the muffle 24.

Further, in fig. 8, a plurality of second supply pipes 62 are attached to the muffle 24. The gas is uniformly supplied into the muffle 24 by providing a plurality of second supply pipes 62, except for uniformly supplying the gas into the muffle 24 by the plurality of openings 98 of the nozzle 94.

In combination with the structure shown in fig. 7 and 8, a plurality of second supply pipes 62 and a plurality of second exhaust pipes 72 may be attached to the muffle 24.

[ embodiment 5]

The second gas supply device 30 shown in fig. 1 may be omitted. At this time, as in the heat treatment apparatus 130 shown in fig. 9, the two supply pipes 56 and 62 are connected to the first gas source 54. The flow rates of the gases flowing through the two supply pipes 56 and 62 are adjusted by opening and closing the two valves 58 and 64.

When the second gas supply device 30 shown in fig. 1 is omitted, the second supply pipe 62 may be sealed in the differential pressure control valve 82 as shown in fig. 10. By sealing the second supply tube 62, the second supply tube 62 is rendered unconnected to the first gas source 54. The gas is supplied from the first gas supply device 26 to the internal space 18 of the heat insulator 16, and the gas is supplied to the internal space 28 of the muffle 24 through the differential pressure control valve 82 as in the above-described embodiment.

In fig. 1, the first supply pipe 56 is connected to the internal space 18 of the heat insulator 16, but may be connected to the internal space 14 of the pressure vessel 12, and supplies gas to the internal space 18 of the heat insulator 16 through the internal space 14 of the pressure vessel 12.

A heat treatment apparatus according to a first aspect includes: a pressure vessel; a heat insulator disposed inside the pressure vessel; a heater disposed in the internal space of the heat insulator; a muffle furnace disposed in the inner space of the heat insulator and accommodating an object to be processed; a gas source; a first supply tube connected from the gas source to the interior space of the insulator; a second supply pipe for supplying a gas to an inner space of the muffle furnace; an opening formed in the second supply pipe in the internal space of the heat insulator; and a differential pressure control valve for opening and closing an opening formed in the second supply pipe by using a difference between a pressure of the gas in the internal space of the heat insulator and a pressure of the gas in the internal space of the muffle furnace.

According to the heat treatment apparatus described in the first aspect, the differential pressure control valve is attached to the second supply pipe, and thus the gas can be supplied from the second supply pipe to the muffle furnace. The flow of the gas supplied to the muffle furnace can be easily controlled, and the gas can be easily and uniformly supplied to the muffle furnace.

(second item) the differential pressure control valve includes: a cover attached to the second supply pipe; a gas path hole formed in the cover and connecting an inner space of the heat insulator to an opening of the second supply pipe; and a pressure block disposed in the gas passage hole, and configured to open and close the gas passage hole by using a difference between a pressure of the gas in the internal space of the heat insulator and a pressure of the gas in the internal space of the muffle furnace.

According to the heat treatment apparatus described in the second aspect, the gas passage hole is opened and closed by moving or rotating the briquette vertically. Since the internal space of the heat insulator is at a high temperature, the differential pressure control valve is less likely to be defective by a simple structure.

(third item) the heat treatment apparatus comprises: a nozzle attached to a tip end of the second supply pipe; and a plurality of openings arranged in the longitudinal direction of the nozzle.

According to the heat treatment apparatus described in the third aspect, since the gas is supplied to the muffle furnace from a plurality of places through the opening of the nozzle, the flow of the gas in the muffle furnace can be easily made uniform.

(fourth) the nozzle is disposed in parallel with the inner wall of the muffle, and the nozzle is disposed so as to open toward the inner wall of the muffle.

According to the heat treatment apparatus described in the fourth aspect, the gas discharged from the opening of the nozzle contacts the inner wall of the muffle furnace and flows along the inner wall of the muffle furnace. Since the gas flows around the object to be treated, the gas easily discharges the gaseous wax released from the object to the outside of the muffle furnace.

(fifth) in the muffle furnace, an exhaust pipe for exhausting gas is disposed at a position facing the second supply pipe.

According to the heat treatment apparatus described in the fifth aspect, the gas supplied to the muffle furnace is circulated in the muffle furnace by a half turn. The flow of gas can be made uniform throughout the muffle.

(sixth item) in the differential pressure control valve, the second supply pipe has been sealed.

According to the heat treatment apparatus described in the sixth aspect, the gas can be supplied from the internal space of the heat insulator to the internal space of the muffle furnace, and the number of gas sources can be reduced.

In addition, the present invention can be implemented in various forms of improvement, modification, and change based on the knowledge of those skilled in the art without departing from the gist thereof. The embodiments described are not independent and can be implemented in appropriate combinations based on the knowledge of those skilled in the art.

Claims (6)

1. A thermal processing apparatus, comprising:

a pressure vessel;

a heat insulator disposed inside the pressure vessel;

a heater disposed in the internal space of the heat insulator;

a muffle furnace disposed in the inner space of the heat insulator and accommodating an object to be processed;

a gas source;

a first supply tube connected from the gas source to the interior space of the insulator;

a second supply pipe for supplying a gas to an inner space of the muffle furnace;

an opening formed in the second supply pipe in the internal space of the heat insulator; and

and a differential pressure control valve for opening and closing the opening formed in the second supply pipe by using a difference between a pressure of the gas in the internal space of the heat insulator and a pressure of the gas in the internal space of the muffle furnace.

2. The thermal processing device of claim 1,

the differential pressure control valve includes:

a cover attached to the second supply pipe;

a gas path hole formed in the cover and connecting an inner space of the heat insulator to an opening of the second supply pipe; and

and a pressure block disposed in the gas passage hole, and configured to open and close the gas passage hole by using a difference between a pressure of the gas in the internal space of the heat insulator and a pressure of the gas in the internal space of the muffle furnace.

3. The heat treatment apparatus according to claim 1 or 2, characterized by comprising:

a nozzle attached to a tip end of the second supply pipe; and

and a plurality of openings formed in a row in a longitudinal direction of the nozzle.

4. The thermal processing device of claim 3,

the nozzle is arranged parallel to the inner wall of the muffle,

the nozzle is provided with an opening facing the inner wall of the muffle.

5. The heat treatment apparatus according to claim 1 or 2,

in the muffle furnace, an exhaust pipe for exhausting gas is disposed at a position facing the second supply pipe.

6. The heat treatment apparatus according to claim 1 or 2,

in the differential pressure control valve, the second supply pipe has been sealed.

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