JP5041723B2 - Atmospheric heat treatment furnace - Google Patents

Description

  The present invention relates to an atmosphere heat treatment furnace for heat-treating an object to be processed such as an electronic component material in a specific atmosphere gas.

  In an atmosphere heat treatment furnace, tar content may be contained in the exhaust gas. The tar content is combusted in a secondary combustion furnace arranged separately from the atmospheric heat treatment furnace (see, for example, Patent Documents 1 to 3).

  Immediately after the heat treatment, the tar content is vaporized because the exhaust gas is at a high temperature. However, the exhaust gas is mixed with the cooling air while being transferred from the atmospheric heat treatment furnace to the secondary combustion furnace. For this reason, the temperature of exhaust gas falls. Therefore, the tar content may solidify and adhere to the pipe between the atmosphere heat treatment furnace and the secondary combustion furnace.

When tar content adheres to the inside of the pipe, the ventilation resistance increases. Moreover, there exists a possibility that piping may be obstruct | occluded. For this reason, it is necessary to periodically clean or replace the piping. Thus, conventionally, the operating rate of the atmospheric heat treatment furnace has been relatively low.
JP-A-11-290817 JP-A-11-290818 Japanese Patent Laid-Open No. 11-290819 JP 2001-65835 A JP 2002-1285 A

  In view of this point, Patent Document 4 introduces a heat treatment facility in which a cooling air supply port is disposed close to the secondary combustion furnace. According to the heat treatment equipment described in the document, the exhaust gas cooled by the cooling air is immediately burned in the secondary combustion furnace. For this reason, adhesion of a tar part can be suppressed.

  However, the exhaust gas is naturally cooled while being transferred from the heat treatment furnace to the secondary combustion furnace. For this reason, there is a possibility that tar content adheres in the pipe between the heat treatment furnace and the cooling air supply port. Moreover, the equipment cost of the heat treatment equipment is increased by the amount required for the secondary combustion furnace. In addition, since it is necessary to supply fuel and combustion air to the secondary combustion furnace, the equipment is complicated accordingly.

  Further, Patent Document 5 introduces a heat treatment facility in which a pipe between a heat treatment furnace and a secondary combustion furnace is covered with a heat insulation jacket. The hot gas after heating the heat treatment furnace circulates inside the heat insulation jacket. According to the heat treatment equipment described in this document, the temperature of the pipe between the heat treatment furnace and the secondary combustion furnace is unlikely to decrease. For this reason, adhesion of a tar part can be suppressed.

  However, if the hot gas is circulated inside the heat insulation jacket, the route of the hot gas piping becomes complicated. Moreover, if the hot gas circulation heat insulation jacket is arranged over the entire length of the pipe between the heat treatment furnace and the secondary combustion furnace, the equipment cost increases.

  The atmosphere heat treatment furnace of the present invention has been completed in view of the above problems. Accordingly, an object of the present invention is to provide an atmosphere heat treatment furnace that can reduce the equipment cost of heat treatment equipment and has a simple structure, but can suppress adhesion of tar to the exhaust gas passage. .

  (1) In order to solve the above-mentioned problems, an atmosphere heat treatment furnace according to the present invention is provided with a furnace body having a heat treatment chamber for heat-treating an object to be processed under a predetermined atmosphere gas, and heat exchange with the heat treatment chamber. A combustion chamber, a furnace inner communication port communicating the combustion chamber and the heat treatment chamber, a furnace outer communication port communicating the combustion chamber and the outside of the furnace, the furnace inner communication port and the furnace outer communication port And at least one combustion case having an oxygen supply port for supplying oxygen to the combustion chamber, and during heating for heating the workpiece, the exhaust gas in the heat treatment chamber is It flows into the combustion chamber through the furnace inner communication port, is mixed with oxygen supplied through the oxygen supply port, is combusted by at least heat transfer from the heat treatment chamber, and passes through the furnace outer communication port. Out of the furnace.

  Here, “oxygen” supplied from the oxygen supply port to the combustion chamber may be supplied as pure oxygen or may be supplied as air (atmosphere). That is, it suffices to contain oxygen to such an extent that combustion can be maintained in the combustion chamber.

  That is, the atmospheric heat treatment furnace of the present invention burns the tar content in the exhaust gas by utilizing at least the heat of the heat treatment chamber. The heat treatment chamber of the furnace body and the combustion chamber of the combustion case are arranged so as to be able to exchange heat. During heating, the combustion chamber is arranged on the exhaust side of the heat treatment chamber. The exhaust gas is mixed with oxygen in the combustion chamber, and is heated using at least heat transfer from the heat treatment chamber. For this reason, the tar content in the exhaust gas burns.

  According to the atmospheric heat treatment furnace of the present invention, it is not necessary to install a secondary combustion furnace separately from the atmospheric heat treatment furnace. Further, since it is not necessary to take in fuel for the secondary combustion furnace, combustion air, or cooling air into the exhaust gas flow path, the flow rate of exhaust gas in the entire heat treatment facility is reduced. For this reason, the processing capability of equipment (for example, a bag filter, a blower, etc.) disposed downstream of the atmospheric heat treatment furnace in the heat treatment facility may be small. Therefore, the installation cost of the heat treatment facility can be reduced. In addition, the route of piping for heat treatment equipment is simplified by the amount that does not require a secondary combustion furnace. In addition, according to the atmospheric heat treatment furnace of the present invention, the structure is simple because only the combustion case is arranged in the furnace body.

  Further, according to the atmospheric heat treatment furnace of the present invention, the exhaust gas is heated using the heat of the heat treatment chamber that has been radiated from the furnace body to the outside of the furnace. For this reason, thermal efficiency becomes high. Further, even if the temperature of the exhaust gas decreases after flowing out of the atmosphere heat treatment furnace, the tar content is already burned in the atmosphere heat treatment furnace, so that the possibility of the tar content attaching to the exhaust gas flow path is small. For this reason, generation | occurrence | production of the down time resulting from adhesion of a tar part can be suppressed. Accordingly, the operating rate of the atmosphere heat treatment furnace and the heat treatment equipment is increased.

  (2) Preferably, the oxygen supply port is preferably arranged close to the furnace inner communication port among the furnace inner communication port and the furnace outer communication port. The exhaust gas passes through the combustion case along the flow path of the furnace inner communication port → the combustion chamber → the furnace outer communication port. According to this configuration, the oxygen supply port is disposed in the vicinity of the furnace inner communication port. For this reason, the combustion section for tar in the combustion chamber becomes long. Therefore, a larger amount of tar can be burned.

  (3) Preferably, the combustion case further includes an atmospheric gas supply port that supplies the atmospheric gas to the combustion chamber, and includes a first combustion case and a second combustion case as the combustion case, During the heating, the first combustion case is used to supply the atmospheric gas to the heat treatment chamber, and the second combustion case is used to discharge the exhaust gas from the heat treatment chamber, respectively, The second combustion case is used to supply the atmospheric gas to the heat treatment chamber and the first combustion case is used to discharge the exhaust gas from the heat treatment chamber during cooling to cool the object. Is better.

  In other words, this configuration switches the supply direction of the atmospheric gas and the discharge direction of the exhaust gas between heating and cooling. At the time of heating, the atmospheric gas is supplied from the combustion chamber of the first combustion case to the heat treatment chamber. In addition, the exhaust gas is discharged from the heat treatment chamber to the combustion chamber of the second combustion case. In contrast, during cooling, the atmospheric gas is supplied from the combustion chamber of the second combustion case to the heat treatment chamber. In addition, the exhaust gas is discharged from the heat treatment chamber to the combustion chamber of the first combustion case.

  According to this configuration, a pair of combustion cases (first combustion case, second combustion case) can be switched and used during heating and cooling. For example, at the time of heating, the first combustion case can be used for atmospheric gas preheating and the second combustion case can be used for exhaust gas firing. For example, during cooling, the second combustion case can be used for heat exchange between the heat treatment chamber and the atmospheric gas, and the first combustion case can be used for heat exchange between the heat treatment chamber and the exhaust gas.

  (4) Preferably, in the configuration of (3) above, during the heating, the atmospheric gas is heated by heat transfer from at least the heat treatment chamber when passing through the combustion chamber of the first combustion case, The exhaust gas is mixed with oxygen supplied through the oxygen supply port when passing through the combustion chamber of the second combustion case, and is combusted by at least heat transfer from the heat treatment chamber. In this case, when the atmospheric gas passes through the combustion chamber of the second combustion case, heat exchange is performed at least by heat transfer from the heat treatment chamber, and the exhaust gas passes through the combustion chamber of the first combustion case. In doing so, it is better to have a configuration in which heat exchange is performed by at least heat transfer from the heat treatment chamber.

  According to this configuration, during heating, the atmospheric gas can be preheated in the first combustion case by heat transfer from the heat treatment chamber. Since the atmospheric gas flows into the heat treatment chamber after preheating, the heat treatment chamber can recover the heat. On the other hand, the exhaust gas is mixed with oxygen in the second combustion case. Then, the tar content is combusted using at least heat transfer from the heat treatment chamber.

  In contrast, during cooling, the atmospheric gas is heated in the second combustion case by heat transfer from the heat treatment chamber. In other words, the heat of the heat treatment chamber is taken away by the heating of the atmospheric gas. On the other hand, the exhaust gas is heated by at least heat transfer from the heat treatment chamber in the first combustion case. In other words, the heat of the heat treatment chamber is taken away by the heating of the exhaust gas.

  Thus, according to this configuration, at the time of heating, it is possible to perform the preheating of the atmospheric gas and the combustion treatment for the tar using the heat transfer from the heat treatment chamber. Further, at the time of cooling, the heat treatment chamber having the residual heat at the time of heating is exchanged with the atmosphere gas and the exhaust gas, whereby the cooling of the heat treatment chamber can be promoted.

  (5) Preferably, in the configuration of (4) above, during the cooling, when the exhaust gas passes through the combustion chamber of the first combustion case, oxygen supplied through the oxygen supply port It is better to have a configuration in which they are mixed and combusted by at least heat transfer from the heat treatment chamber.

  According to this configuration, the exhaust gas can be combusted not only during heating but also during cooling. For this reason, the possibility that tar content adheres to the exhaust gas flow path is further reduced. This configuration is particularly suitable for heat-treating an object that still generates tar even after heating.

  (6) Preferably, in the configuration of the above (3), the atmosphere gas supply port is disposed close to the furnace outer side communication port among the furnace inner side communication port and the furnace outer side communication port. Better to do.

  The atmospheric gas passes through the combustion case along the flow path of the atmospheric gas supply port → the combustion chamber → the furnace inner communication port. According to this configuration, the atmospheric gas supply port is arranged in the vicinity of the furnace outside communication port. For this reason, the preheating section of the atmospheric gas in the combustion chamber becomes long. Therefore, the atmospheric gas can be preheated to a higher temperature.

  (7) Preferably, in the configuration of (3), the first combustion case is disposed above the heat treatment chamber, and the second combustion case is disposed below the heat treatment chamber. Good.

  In other words, this configuration utilizes convection due to the temperature distribution in the heat treatment chamber. At the time of heating, the atmospheric gas flows from the upper combustion chamber of the first combustion case into the heat treatment chamber. Here, although the atmospheric gas is preheated by heat transfer from the heat treatment chamber, the temperature of the atmospheric gas is often equal to or lower than the temperature of the upper portion of the heat treatment chamber. For this reason, the atmospheric gas tends to descend in the heat treatment chamber. Therefore, it is easy to fill the heat treatment chamber with the atmospheric gas.

  At the time of cooling, the residual gas in the heat treatment chamber follows the flow path from the furnace inner communication port → the combustion chamber → the furnace outer communication port of the first combustion case, and is discharged out of the furnace. Here, the furnace inner communication port of the first combustion case is opened above the heat treatment chamber. That is, the furnace inner communication port is arranged in a high temperature region in the temperature distribution of the heat treatment chamber. For this reason, high temperature residual gas can be discharged | emitted out of a furnace preferentially. Therefore, the heat treatment chamber after heating can be cooled more rapidly.

  At the time of cooling, the atmospheric gas flows from the combustion chamber of the lower second combustion case into the heat treatment chamber. Here, since the atmospheric gas is heated by heat transfer from the heat treatment chamber, it tends to rise in the heat treatment chamber. Therefore, the residual gas in the heat treatment chamber can easily be driven into the furnace inner communication port of the first combustion case.

  (8) Preferably, the combustion case further includes a heating device for heating the combustion chamber. According to this configuration, when the exhaust gas is combusted, heat can be applied from the heating device in addition to the heat transfer from the heat treatment chamber. For this reason, combustion of a tar part can be further promoted.

  According to the present invention, it is possible to provide an atmospheric heat treatment furnace that can reduce the equipment cost of the heat treatment equipment and has a simple structure, but can suppress the adhesion of tar to the exhaust gas passage.

  Hereinafter, embodiments of the atmospheric heat treatment furnace of the present invention will be described.

<First embodiment>
First, the structure of the heat treatment equipment in which the atmospheric heat treatment furnace of this embodiment is used will be described. FIG. 1 shows a schematic diagram of a heat treatment facility in which the atmospheric heat treatment furnace of the present embodiment is used. For convenience of explanation, the first combustion case 3U, the second combustion case 3D, and the heat treatment heaters 24L and 24R of the atmospheric heat treatment furnace 1 are shown in a simplified manner.

  As shown in FIG. 1, the heat treatment facility 9 includes an atmosphere heat treatment furnace 1, a bag filter 90, a blower 91, and a chimney 92. These devices are connected by an exhaust gas flow path L. The exhaust gas flow path L includes a branched first flow path L1, a branched second flow path L2, and an integrated flow path L3. The downstream end of the branched first flow path L1 and the downstream end of the branched second flow path L2 are branched and connected to the upstream end of the integrated flow path L3.

  The upstream end of the branched first flow path L1 is connected to the furnace outside communication port 33U of the first combustion case 3U described later. A cooling air first flow path AL1 is branched and connected to the branched first flow path L1. On the downstream side of the branch connection point, a valve (the same applies to solenoid valves and other valves) V1A is arranged. A valve V1B is disposed in the cooling air first flow path AL1.

  Similarly, the upstream end of the branched second flow path L2 is connected to the furnace outside communication port 33D of the second combustion case 3D described later. A cooling air second flow path AL2 is branched and connected to the branched second flow path L2. A valve V2A is disposed downstream of the branch connection point. A valve V2B is arranged in the cooling air second flow path AL2.

  Next, the configuration of the atmospheric heat treatment furnace of this embodiment will be described. The atmospheric heat treatment furnace 1 of the present embodiment includes a furnace body 2, a first combustion case 3U, and a second combustion case 3D. The furnace body 2 includes a furnace shell 20, a heat insulating material 21, and heaters 24L and 24R for heat treatment.

  The furnace shell 20 is made of a steel plate and has a rectangular parallelepiped box shape. The heat insulating material 21 is made of refractory bricks and has a thick rectangular parallelepiped box shape. The heat insulating material 21 is accommodated and arranged inside the furnace shell 20. A heat treatment chamber 22 is defined inside the heat insulating material 21. The heat treatment chamber 22 has a rectangular parallelepiped shape. A table 23 is disposed on the lower surface of the heat treatment chamber 22 (the upper surface of a second combustion case 3D described later). The table 23 has a rectangular plate shape with legs. A workpiece W is mounted on the upper surface of the table 23. The workpiece W is a battery material.

  The heat treatment heaters 24L and 24R include a heater body and a protective tube (not shown). The heater body is accommodated and arranged in a protective tube. The heat treatment heaters 24L and 24R are arranged so as to penetrate vertically in both sides of the heat treatment chamber 22 with the table 23 interposed therebetween. The heat treatment heaters 24L and 24R will be described in detail later.

  The first combustion case 3U is disposed above the heat treatment chamber 22. The first combustion case 3U includes a case body 30U and a combustion heater 36U. The case body 30U is made of stainless steel and has a rectangular box shape. A combustion chamber 31U is defined inside the case body 30U. Further, the lower surface of the case body 30U is exposed to the upper part of the heat treatment chamber 22. A furnace inner communication port 32U is opened on the lower surface of the case body 30U. The heat treatment chamber 22 and the combustion chamber 31U are connected via the furnace inner communication port 32U. The heat treatment chamber 22 and the combustion chamber 31U can exchange heat via the lower wall of the case body 30U. On the other hand, a furnace outer side communication port 33U is opened on the upper surface of the case main body 30U. As described above, the furnace outside communication port 33U is connected to the upstream end of the branch first flow path L1.

  The combustion heater 36U includes a heater body and a protective tube (not shown). The heater body is accommodated and arranged in a protective tube. The combustion heater 36U is arranged to pass through the combustion chamber 31U.

  A downstream end of the combustion air first flow path OL1 and a downstream end of the nitrogen gas first flow path NL1 are connected to the upper wall of the case body 30U. The downstream end of the combustion air first flow path OL1 corresponds to the oxygen supply port 34U of the first combustion case 3U. In addition, the downstream end of the nitrogen gas first flow path NL1 corresponds to the atmospheric gas supply port 35U of the first combustion case 3U. Here, the oxygen supply port 34U is disposed close to the furnace inner communication port 32U. Further, the atmospheric gas supply port 35U is disposed in the vicinity of the furnace outside communication port 33U. That is, these four openings are arranged from the inside of the furnace to the outside of the furnace in the order of the furnace inner communication port 32U, the oxygen supply port 34U, the atmospheric gas supply port 35U, and the furnace outer communication port 33U.

  A valve V1C is arranged in the combustion air first flow path OL1 capable of introducing combustion air (that is, oxygen) into the oxygen supply port 34U. In addition, the nitrogen gas is supplied from the atmospheric gas supply port 35U to the combustion chamber 31U through the nitrogen gas first flow path NL1. A valve V1D is disposed in the nitrogen gas first flow path NL1.

  The second combustion case 3D is disposed below the heat treatment chamber 22 so as to face the first combustion case 3U in the vertical direction. The second combustion case 3D includes a case body 30D and a combustion heater 36D. Combustion heater 36D is included in the heating device of the present invention. The case main body 30D is made of stainless steel and has a rectangular box shape. A combustion chamber 31D is defined inside the case body 30D. Further, the upper surface of the case main body 30 </ b> D is exposed to the lower part of the heat treatment chamber 22. A furnace inner communication port 32D is provided on the upper surface of the case body 30D. The heat treatment chamber 22 and the combustion chamber 31D are connected via the furnace inner communication port 32D. The heat treatment chamber 22 and the combustion chamber 31D can exchange heat via the upper wall of the case body 30D. On the other hand, a furnace outside communication port 33D is opened on the lower surface of the case body 30D. As described above, the furnace outside communication port 33D is connected to the upstream end of the branched second flow path L2.

  The combustion heater 36D includes a heater body and a protective tube (not shown). The heater body is accommodated and arranged in a protective tube. The combustion heater 36D is arranged to pass through the combustion chamber 31D.

  The downstream end of the combustion air second flow channel OL2 and the downstream end of the nitrogen gas second flow channel NL2 are connected to the lower wall of the case body 30D. The downstream end of the combustion air second flow path OL2 corresponds to the oxygen supply port 34D of the second combustion case 3D. In addition, the downstream end of the nitrogen gas second flow path NL2 corresponds to the atmospheric gas supply port 35D of the second combustion case 3D. Here, the oxygen supply port 34D is disposed close to the furnace inner communication port 32D. Further, the atmospheric gas supply port 35D is disposed in the vicinity of the furnace outside communication port 33D. That is, these four openings are arranged in the order of the furnace inner communication port 32D, the oxygen supply port 34D, the atmospheric gas supply port 35D, and the furnace outer communication port 33D from the inside of the furnace to the outside of the furnace.

  Combustion air (that is, oxygen) is supplied from the oxygen supply port 34D to the combustion chamber 31D via the combustion air second channel OL2. A valve V2C is arranged in the combustion air second flow path OL2. In addition, the nitrogen gas is supplied from the atmospheric gas supply port 35D to the combustion chamber 31D via the nitrogen gas second flow path NL2. A valve V2D is disposed in the nitrogen gas second flow path NL2.

  Next, the structure of the combustion case of the atmospheric heat treatment furnace of this embodiment will be described. FIG. 2 is a transparent perspective view of the vicinity of the heat treatment chamber of the atmospheric heat treatment furnace of the present embodiment. For convenience of explanation, the heat treatment heaters 24L and 24R (see FIG. 1) are omitted. Further, hatching is applied to the portion exposed in the heat treatment chamber.

  As shown in FIG. 2, a protective tube 360U of the combustion heater 36U penetrates in a U shape in the upper wall of the case main body 30U of the first combustion case 3U. A total of seven combustion heaters 36 </ b> U are arranged along the longitudinal direction of the heat treatment chamber 22. On the upper surface of the case body 30U, a combustion air first flow path OL1 (that is, the oxygen supply port 34U in FIG. 1) and a nitrogen gas first flow path NL1 (that is, the atmosphere gas supply port 35U in FIG. 1) are provided. It is arranged at a substantially diagonal position. Further, a furnace outer side communication port 33U (upper surface) and a furnace inner side communication port 32U (lower surface) are arranged at substantially diagonal positions on the upper and lower surfaces of the case body 30U.

  A protective tube 360D of the combustion heater 36D penetrates the lower wall of the case body 30D of the second combustion case 3D in a U shape. A total of seven combustion heaters 36 </ b> D are arranged along the longitudinal direction of the heat treatment chamber 22. On the lower surface of the case body 30D, a combustion air second channel OL2 (that is, the oxygen supply port 34D in FIG. 1) and a nitrogen gas second channel NL2 (that is, the atmosphere gas supply port 35D in FIG. 1) are provided. Are arranged at substantially diagonal positions. Further, a furnace outer side communication port 33D (lower surface) and a furnace inner side communication port 32D (upper surface) are arranged at substantially diagonal positions on the upper and lower surfaces of the case body 30D.

  FIG. 3 shows a vertical sectional view of the second combustion case. For convenience of explanation, the furnace inner communication port 32D disposed on the upper wall of the case body 30D is indicated by a dotted line. Further, as shown in FIG. 2, the structure of the first combustion case 3U and the structure of the second combustion case 3D are the same (when the first combustion case 3U is rotated 180 °, the second combustion case 3D is formed). ). Therefore, only the internal structure of the second combustion case 3D will be described here, and the internal structure of the first combustion case 3U will also be described.

  As shown in FIG. 3, a stainless steel partition plate 37D is erected in the second combustion case 3D. The partition plate 37D extends substantially parallel to the short direction of the case body 30D. The partition plates 37D are arranged to be staggered by a total of six sheets, spaced apart by a predetermined interval in the longitudinal direction of the case body 30D. A combustion chamber 31D extending in a zigzag shape is formed inside the case main body 30D by the six partition plates 37D. As described above, the furnace inner communication port 32D is disposed at one end of the combustion chamber 31D. An oxygen supply port 34D is juxtaposed inside the furnace inner communication port 32D. A furnace outside communication port 33D is arranged at the other end of the combustion chamber 31D. An atmosphere gas supply port 35D is juxtaposed inside the furnace outside communication port 33D. Protective tubes 360D of the combustion heater 36D are exposed on the total seven straight portions 310D of the combustion chamber 31D.

  Next, the configuration of the heat treatment heater of the atmospheric heat treatment furnace of this embodiment will be described. FIG. 4 is a transparent perspective view of the vicinity of the heat treatment chamber of the atmospheric heat treatment furnace of the present embodiment. For convenience of explanation, the first combustion case 3U and the second combustion case 3D (see FIG. 1 above) are omitted. Further, hatching is applied to the portion exposed in the heat treatment chamber.

  As shown in FIG. 4, the protection tube 240L of the heat treatment heater 24L and the protection tube 240R of the heat treatment heater 24R face each other on both sides of the table 23 of the heat treatment chamber 22 and the workpiece W in the short direction. Are arranged. The protective tubes 240L and 240R extend in the vertical direction. Ten protective tubes 240 </ b> L and 240 </ b> R are arranged along the longitudinal direction of the heat treatment chamber 22.

  Next, the movement of the heat treatment equipment using the atmospheric heat treatment furnace of the present embodiment when the workpiece is heated will be described. FIG. 5 shows a schematic diagram of the heat treatment equipment in which the atmospheric heat treatment furnace of this embodiment is used (corresponding to FIG. 1). In FIG. 5, the opened flow path is indicated by a solid line, and the blocked flow path is indicated by a dotted line.

  As shown in FIG. 5, the valves V1A, V1B, V1C, and V2D are closed during heating. For this reason, the branched first flow path L1, the cooling air first flow path AL1, the combustion air first flow path OL1, and the nitrogen gas second flow path NL2 are blocked. On the other hand, the valves V2A, V2B, V2C, V1D are open. For this reason, the branched second flow path L2, the cooling air second flow path AL2, the combustion air second flow path OL2, and the nitrogen gas first flow path NL1 are opened.

  Further, during heating, the heat treatment heaters 24L and 24R are turned on. In addition, the combustion heater 36D of the second combustion case 3D is also turned on. On the other hand, the combustion heater 36U of the first combustion case 3U is off.

  First, the flow of nitrogen gas will be described. Nitrogen gas flows into the combustion chamber 31U from the atmospheric gas supply port 35U of the first combustion case 3U through the nitrogen gas first flow path NL1. As can be seen with reference to FIG. 3 (FIG. 3 shows the second combustion case 3D), the atmospheric gas supply port 35U (35D) is disposed close to the furnace outside communication port 33U (33D). On the other hand, the furnace inner communication port 32U (32D) serving as the nitrogen gas outlet is disposed opposite to the end of the combustion chamber 31U (31D) where the furnace outer communication port 33U (33D) is not disposed. . For this reason, nitrogen gas moves zigzag substantially the entire length of the combustion chamber 31U (31D).

  Returning to FIG. 5, the combustion chamber 31 </ b> U is close to the heat treatment chamber 22 with the lower wall of the case body 30 </ b> U interposed therebetween. For this reason, the nitrogen gas moves in the combustion chamber 31U while being heated by the heat of the heat treatment chamber 22 transmitted from the lower wall of the case body 30U. The heated nitrogen gas flows into the heat treatment chamber 22 from the furnace inner communication port 32U. Then, the heat treatment chamber 22 is filled so that the inside of the heat treatment chamber 22 becomes a nitrogen gas atmosphere.

  Next, the state of the heat treatment of the workpiece W will be described. The workpiece W is heated by the heat treatment heaters 24L and 24R in a nitrogen gas atmosphere. The heating temperature is about 900 ° C to 1000 ° C. With the heating, exhaust gas is generated in the heat treatment chamber 22. In the exhaust gas, a tar component evaporated from the workpiece W is mixed.

  Next, the flow of exhaust gas will be described. The exhaust gas flows into the combustion chamber 31D from the furnace inner communication port 32D of the second combustion case 3D. On the other hand, combustion air flows into the combustion chamber 31D from the oxygen supply port 34D via the combustion air second flow path OL2. For this reason, the exhaust gas is mixed with combustion air. As shown in FIG. 3, the oxygen supply port 34D is disposed close to the furnace inner communication port 32D. On the other hand, the furnace outside communication port 33D serving as the exhaust gas outlet is disposed opposite to the end of the combustion chamber 31D where the furnace inside communication port 32D is not disposed. For this reason, the exhaust gas mixed with the combustion air zigzags along substantially the entire length of the combustion chamber 31D.

  Returning to FIG. 5, the combustion chamber 31 </ b> D is close to the heat treatment chamber 22 across the upper wall of the case body 30 </ b> D. For this reason, the exhaust gas mixed with the combustion air moves in the combustion chamber 31D while being heated by the heat of the heat treatment chamber 22 transmitted from the upper wall of the case body 30D. In addition, as described above, the combustion heater 36D is on. Therefore, the exhaust gas mixed with the combustion air moves in the combustion chamber 31D while being heated by the heat of the combustion heater 36D in addition to the heat of the heat treatment chamber 22. Due to the oxygen contained in the combustion air and the heat of the heat treatment chamber 22 and the combustion heater 36D, the tar component that is a combustible component in the exhaust gas is combusted. The exhaust gas after the combustion treatment flows into the branched second flow path L2 from the furnace outside communication port 33D. The exhaust gas is mixed with cooling air introduced through the cooling air second flow path AL2. The exhaust gas after mixing the cooling air flows into the bag filter 90 via the integrated flow path L3. In the bag filter 90, dust (such as ash after combustion) in the exhaust gas is separated and removed. The exhaust gas after the dust is removed is discharged to the outside from the chimney 92 through the exhaust gas suction blower 91.

  As described above, during heating, the nitrogen gas is supplied from the nitrogen gas first flow path NL1 → atmospheric gas supply port 35U (first combustion case 3U) → combustion chamber 31U → furnace inside communication port 32U through the heat treatment chamber. 22 flows in. On the other hand, the exhaust gas generated in the heat treatment chamber 22 is combusted through the furnace inner communication port 32D (second combustion case 3D) → the combustion chamber 31D (here, the combustion air second flow path OL2 → the oxygen supply port 34D). → mixed with the cooling air) → outer side communication port 33D → the branched second flow path L2 (here, mixed with the cooling air flowing through the cooling air second flow path AL2) → the integrated flow path L3 (bug) It is discharged to the outside through the filter 90, the blower 91, and the chimney 92).

  Next, the movement of the heat treatment equipment using the atmospheric heat treatment furnace of the present embodiment when the workpiece is cooled will be described. FIG. 6 shows a schematic diagram during cooling of a heat treatment facility in which the atmospheric heat treatment furnace of the present embodiment is used (corresponding to FIG. 1). In FIG. 6, the open channel is indicated by a solid line, and the blocked channel is indicated by a dotted line.

  As shown in FIG. 6, the valves V1A, V1B, and V2D are open during cooling. For this reason, the branched first flow path L1, the cooling air first flow path AL1, and the nitrogen gas second flow path NL2 are opened. On the other hand, the valves V2A, V2B, V2C, V1C, and V1D are closed. For this reason, the branched second flow path L2, the cooling air second flow path AL2, the combustion air first flow path OL1, the combustion air second flow path OL2, and the nitrogen gas first flow path NL1 are blocked.

  During cooling, the heat treatment heaters 24L and 24R are turned off. In addition, the combustion heater 36U of the first combustion case 3U and the combustion heater 36D of the second combustion case 3D are also turned off.

  First, the flow of nitrogen gas will be described. Nitrogen gas flows into the combustion chamber 31D from the atmosphere gas supply port 35D of the second combustion case 3D via the nitrogen gas second flow path NL2. As shown in FIG. 3, the atmospheric gas supply port 35D is disposed close to the furnace outside communication port 33D. On the other hand, the furnace inner communication port 32D serving as the nitrogen gas outlet is disposed opposite to the end of the combustion chamber 31D where the furnace outer communication port 33D is not disposed. For this reason, the nitrogen gas moves in a zigzag manner over substantially the entire length of the combustion chamber 31D.

  Returning to FIG. 6, the combustion chamber 31 </ b> D is close to the heat treatment chamber 22 across the upper wall of the case body 30 </ b> D. For this reason, the nitrogen gas moves in the combustion chamber 31D while being heated by the heat of the heat treatment chamber 22 transmitted from the upper wall of the case body 30D. The heated nitrogen gas flows into the heat treatment chamber 22 from the furnace inner communication port 32D. Then, the heat treatment chamber 22 rises and diffuses.

  Next, how the workpiece W is cooled will be described. Even if the heating by the heat treatment heaters 24L and 24R is stopped, the workpiece W is heated by the residual heat in the heat treatment chamber 22. For this reason, exhaust gas is generated in the heat treatment chamber 22. The tar content of the workpiece W has been degassed during the heating. Therefore, tar is not mixed in the exhaust gas during cooling.

  Next, the flow of exhaust gas will be described. The exhaust gas flows into the combustion chamber 31U from the furnace inner communication port 32U of the first combustion case 3U. As can be seen with reference to FIG. 3 (FIG. 3 shows the second combustion case 3D), the furnace outside communication port 33U (33D) serving as the exhaust gas outlet is connected to the furnace inside communication port in the combustion chamber 31U (31D). 32U (32D) is arranged so as to face the end on which the 32U (32D) is not arranged. For this reason, the exhaust gas moves in a zigzag manner over substantially the entire length of the combustion chamber 31U (31D).

  Returning to FIG. 6, the combustion chamber 31 </ b> U is close to the heat treatment chamber 22 with the lower wall of the case body 30 </ b> U interposed therebetween. For this reason, the exhaust gas moves in the combustion chamber 31U while being heated by the heat of the heat treatment chamber 22 transmitted from the lower wall of the case body 30U. The exhaust gas that has passed through the combustion chamber 31U flows into the branched first flow path L1 from the furnace outside communication port 33U. The exhaust gas is mixed with the cooling air introduced through the cooling air first flow path AL1. The exhaust gas after mixing the cooling air flows into the bag filter 90 via the integrated flow path L3. In the bag filter 90, dust in the exhaust gas is separated and removed. The exhaust gas after the dust is removed is discharged to the outside from the chimney 92 through the exhaust gas suction blower 91.

  As described above, during cooling, the nitrogen gas is heat-treated through the nitrogen gas second flow path NL2 → the atmosphere gas supply port 35D (second combustion case 3D) → the combustion chamber 31D → the furnace inner communication port 32D. It flows into the chamber 22. On the other hand, the exhaust gas generated in the heat treatment chamber 22 is the furnace inner communication port 32U (first combustion case 3U) → combustion chamber 31U → furnace outer communication port 33U → branch first flow path L1 (here, cooling air first flow path) (Mixed with cooling air flowing in through AL1) → discharged to the outside through the integrated flow path L3 (bag filter 90, blower 91, chimney 92).

  Next, the effect of the atmosphere heat treatment furnace of this embodiment will be described. According to the atmospheric heat treatment furnace 1 of this embodiment, it is not necessary to install a secondary combustion furnace separately from the atmospheric heat treatment furnace 1. Further, since it is not necessary to take in fuel for the secondary combustion furnace, combustion air, or cooling air into the exhaust gas flow path L, the flow rate of the exhaust gas in the entire heat treatment equipment 9 is reduced. For this reason, the processing capability of the equipment (for example, the bag filter 90 and the blower 91) disposed on the downstream side of the atmospheric heat treatment furnace 1 in the heat treatment facility 9 may be small. Therefore, the installation cost of the heat treatment equipment 9 can be reduced. Further, the piping route of the heat treatment equipment 9 is simplified by the amount that does not require the secondary combustion furnace. In addition, according to the atmospheric heat treatment furnace 1 of the present embodiment, the first combustion case 3U and the second combustion case 3D are only arranged in the furnace body 2, so that the structure is simple. For this reason, it is easy to add on to the existing atmosphere heat treatment furnace. That is, the atmosphere heat treatment furnace 1 of the present embodiment has high versatility.

  Further, according to the atmospheric heat treatment furnace 1 of the present embodiment, the exhaust gas is heated using the heat of the heat treatment chamber 22 that has been radiated from the furnace shell 20 to the outside of the furnace. For this reason, thermal efficiency becomes high. Further, even if the temperature of the exhaust gas is lowered, the tar content is burned in the combustion chamber 31D, and therefore the possibility that the tar content adheres to the exhaust gas flow path L is small. For this reason, generation | occurrence | production of the down time resulting from adhesion of a tar part can be suppressed. Therefore, the operating rate of the atmosphere heat treatment furnace 1 and the heat treatment equipment 9 is increased.

  Further, according to the atmospheric heat treatment furnace 1 of the present embodiment, the oxygen supply port 34D is disposed in the vicinity of the furnace inner communication port 32D (see FIG. 3 above). For this reason, the combustion section for tar in the combustion chamber 31D becomes longer. Therefore, a larger amount of tar can be burned. The combustion chamber 31D itself is also formed in a zigzag manner. Also in this point, the combustion section for tar becomes long.

  Moreover, according to the atmospheric heat treatment furnace 1 of this embodiment, the supply direction of nitrogen gas and the discharge direction of exhaust gas are switched between heating and cooling. During heating, nitrogen gas is supplied from the combustion chamber 31U of the first combustion case 3U to the heat treatment chamber 22. In addition, the exhaust gas is discharged from the heat treatment chamber 22 to the combustion chamber 31D of the second combustion case 3D. On the other hand, during cooling, nitrogen gas is supplied to the heat treatment chamber 22 from the combustion chamber 31D of the second combustion case 3D. In addition, the exhaust gas is discharged from the heat treatment chamber 22 to the combustion chamber 31U of the first combustion case 3U. Thus, according to the atmospheric heat treatment furnace 1 of the present embodiment, the pair of combustion cases (the first combustion case 3U and the second combustion case 3D) can be used by switching between heating and cooling. Specifically, during heating, the first combustion case 3U can be used for nitrogen gas preheating and the second combustion case 3D can be used for exhaust gas combustion. In cooling, the second combustion case 3D can be used for heat exchange between the heat treatment chamber 22 and nitrogen gas, and the first combustion case 3U can be used for heat exchange between the heat treatment chamber 22 and exhaust gas.

  Moreover, according to the atmospheric heat treatment furnace 1 of this embodiment, nitrogen gas can be preheated in the first combustion case 3U by heat transfer from the heat treatment chamber 22 during heating. Since the nitrogen gas flows into the heat treatment chamber 22 after preheating, the heat treatment chamber 22 can recover the heat. On the other hand, the exhaust gas is mixed with combustion air (oxygen) in the second combustion case 3D. Then, the tar content is combusted using heat transfer from the heat treatment chamber 22 and heat generated by the combustion heater 36D.

  On the other hand, during cooling, the nitrogen gas is heated in the second combustion case 3D by heat transfer from the heat treatment chamber 22. In other words, the heat of the heat treatment chamber 22 is taken away by the heating of the nitrogen gas. On the other hand, the exhaust gas is heated by heat transfer from the heat treatment chamber 22 in the first combustion case 3U. In other words, the heat of the heat treatment chamber 22 is taken away by the heating of the exhaust gas.

  Thus, according to the atmospheric heat treatment furnace 1 of the present embodiment, during heating, the heat transfer from the heat treatment chamber 22 can be used to perform preheating of nitrogen gas and combustion treatment for tar. Further, at the time of cooling, the heat treatment chamber 22 having residual heat at the time of heating is exchanged with the nitrogen gas and the exhaust gas, whereby the cooling of the heat treatment chamber 22 can be promoted.

  Further, according to the atmosphere heat treatment furnace 1 of the present embodiment, the atmosphere gas supply port 35U (35D) is disposed in the vicinity of the furnace outside communication port 33U (33D) (see FIG. 3 above). For this reason, the preheating section of the nitrogen gas in the combustion chamber 31U (31D) becomes long. Therefore, the nitrogen gas can be preheated to a higher temperature. The combustion chamber 31U (31D) itself is also formed in a zigzag manner. Also in this point, the nitrogen gas preheating section becomes longer.

  Further, according to the atmospheric heat treatment furnace 1 of the present embodiment, the first combustion case 3U is disposed above the heat treatment chamber 22, and the second combustion case 3D is disposed below the heat treatment chamber 22, respectively. During heating, nitrogen gas flows into the heat treatment chamber 22 from the combustion chamber 31U of the upper first combustion case 3U. Here, the temperature of the nitrogen gas is equal to or lower than the temperature of the upper part of the heat treatment chamber 22. For this reason, the nitrogen gas tends to descend and diffuse in the heat treatment chamber 22. Therefore, it is easy to fill the heat treatment chamber 22 with nitrogen gas.

  At the time of cooling, the residual gas in the heat treatment chamber 22 follows the flow path of the furnace inner communication port 32U → the combustion chamber 31U → the furnace outer communication port 33U of the first combustion case 3U and flows into the branch first flow path L1. Here, the furnace inner communication port 32 </ b> U of the first combustion case 3 </ b> U is opened above the heat treatment chamber 22. That is, the furnace inner communication port 32U is arranged in a high temperature region in the temperature distribution of the heat treatment chamber 22. For this reason, the high temperature residual gas can be preferentially discharged out of the furnace before being mixed with the low temperature residual gas. Therefore, the heat treatment chamber 22 after heating can be cooled more rapidly.

  Further, during cooling, nitrogen gas flows into the heat treatment chamber 22 from the combustion chamber 31D of the lower second combustion case 3D. Here, since the nitrogen gas is heated by heat transfer from the heat treatment chamber 22, the nitrogen gas tends to rise in the heat treatment chamber 22. Therefore, it is easy to drive the residual gas in the heat treatment chamber 22 into the furnace inner communication port 32U of the first combustion case 3U.

  Further, according to the atmospheric heat treatment furnace 1 of the present embodiment, the combustion heater 36D is arranged in the second combustion case 3D. For this reason, when the exhaust gas is subjected to the combustion treatment, in addition to the heat transfer from the heat treatment chamber 22, heat can be applied from the combustion heater 36D. Therefore, the combustion of tar can be further promoted.

  Moreover, according to the atmospheric heat treatment furnace 1 of this embodiment, the to-be-processed object W is heat-processed in a non-oxidizing atmosphere (nitrogen gas atmosphere). Conventionally, there has been no idea that the combustion chamber 31D for performing the combustion treatment (oxidation treatment) is intentionally arranged adjacent to the heat treatment chamber 22 in which a non-oxidizing atmosphere must be maintained. That is, as shown in the above-mentioned patent documents 1-5, the secondary combustion process after heat processing was performed outside the heat processing furnace.

  On the other hand, the atmosphere heat treatment furnace 1 of the present embodiment arranges the combustion chamber 31D on the downstream side of the heat treatment chamber 22 during heating, thereby maintaining the nitrogen gas atmosphere in the heat treatment chamber 22 and the exhaust gas combustion treatment. And both. Since there is a pressure difference between the heat treatment chamber 22 and the combustion chamber 31D (at the time of heating, the heat treatment chamber 22 has a positive pressure and the combustion chamber 31D has a negative pressure), there is no possibility that the combustion air will flow back into the heat treatment chamber 22.

  Further, according to the atmospheric heat treatment furnace 1 of the present embodiment, during cooling, the nitrogen gas flows into the heat treatment chamber 22 after exchanging heat with the heat treatment chamber 22 in the combustion chamber 31D of the second combustion case 3D. For this reason, compared with the case where nitrogen gas is directly introduced into the heat treatment chamber 22, the temperature difference between the nitrogen gas (low temperature) and the room temperature (high temperature) of the heat treatment chamber 22 is reduced. Therefore, there is little risk of a problem occurring in members (for example, the heat insulating material 21, the table 23, the protective tubes 240L, 240R, etc.) disposed near the heat treatment chamber 22 due to the heat shock. Moreover, since it is hard to produce a malfunction, the lifetime of these members can be lengthened.

<Second embodiment>
The difference between the atmospheric heat treatment furnace of the present embodiment and the atmospheric heat treatment furnace of the first embodiment is only the structure of the first combustion case and the second combustion case. Therefore, only the differences will be described here.

  FIG. 7 shows a vertical cross-sectional view of the second combustion case of the atmospheric heat treatment furnace of the present embodiment. In addition, about the site | part corresponding to FIG. 3, it shows with the same code | symbol. For convenience of explanation, the furnace inner communication port 32D disposed on the upper wall of the case body 30D is indicated by a dotted line. The structure of the first combustion case and the structure of the second combustion case 3D are the same (when the first combustion case is rotated 180 °, the second combustion case 3D is formed). Therefore, here, only the structure of the second combustion case 3D will be described, and the structure of the first combustion case will also be described.

  As shown in FIG. 7, the second combustion case 3 </ b> D has a wide hexagonal shape in the middle in the longitudinal direction. A combustion chamber 31D is defined inside the case body 30D. A furnace inside communication port 32D is disposed at one end in the longitudinal direction of the combustion chamber 31D, and a furnace outside communication port 33D is disposed at the other end. In the combustion chamber 31D, four partition plates 38D made of stainless steel are erected. These four partition plates 38D form five branch flow paths 311D between the furnace inner communication port 32D and the furnace outer communication port 33D.

  The atmosphere heat treatment furnace of the present embodiment has the same effects as the atmosphere heat treatment furnace of the first embodiment with respect to the parts common to the first embodiment. Further, according to the atmospheric heat treatment furnace of the present embodiment, the exhaust gas, combustion air, and nitrogen gas are diverted by the branch flow path 311D when passing through the combustion chamber 31D. For this reason, although the distance between the furnace inner side communication port 32D and the furnace outer side communication port 33D is short, the exhaust gas can be sufficiently burned. In addition, the nitrogen gas can be sufficiently preheated. Further, since the cross-sectional area of the combustion chamber 31D is large, the ventilation resistance is small.

<Third embodiment>
The difference between the atmospheric heat treatment furnace of the present embodiment and the atmospheric heat treatment furnace of the first embodiment is that only one combustion case is disposed (only the second combustion case in the first embodiment is disposed). ). Further, the atmosphere gas supply port and the combustion heater are not arranged in the combustion case. Therefore, only the differences will be described here.

  FIG. 8 shows a schematic diagram of a heat treatment facility in which the atmospheric heat treatment furnace of the present embodiment is used. In addition, about the site | part corresponding to FIG. 1, it shows with the same code | symbol. For convenience of explanation, the combustion case 3 of the atmospheric heat treatment furnace 1 and the heat treatment heaters 24L and 24R are shown in a simplified manner.

  As shown in FIG. 8, a single combustion case 3 is arranged in the atmospheric heat treatment furnace 1. The combustion case 3 is disposed below the heat treatment chamber 22. The configuration of the combustion case 3 is substantially the same as the second combustion case 3D (see FIGS. 1 to 3) of the first embodiment (however, the atmosphere gas supply port 35D and the combustion heater 36D are not arranged). ).

  During heating, nitrogen gas flows directly into the heat treatment chamber 22 via the nitrogen gas flow path NL. In the heat treatment chamber 22, the workpiece W is heated by the heat treatment heaters 24L and 24R. The exhaust gas generated in the heat treatment chamber 22 flows into the combustion chamber 31 of the case body 30 through the furnace inner communication port 32. On the other hand, combustion air (that is, oxygen) flows into the combustion chamber 31 from the oxygen supply port 34 via the combustion air passage OL. For this reason, the exhaust gas is mixed with combustion air. The mixed exhaust gas is combusted by heat transfer from the heat treatment chamber 22 when passing through the combustion chamber 31. Specifically, the tar content that is a combustible component in the exhaust gas burns. The exhaust gas after combustion flows into the exhaust gas flow path L from the furnace outside communication port 33. In the exhaust gas passage L, the exhaust gas is mixed with the cooling air supplied via the cooling air passage AL. The mixed exhaust gas is discharged from the chimney 92 through the bag filter 90 and the blower 91. During cooling, the heat treatment heaters 24L and 24R are turned off, and the supply of combustion air is shut off (specifically, the valve V2C is closed). The flow of nitrogen gas and exhaust gas is the same as that during heating.

  The atmosphere heat treatment furnace 1 of the present embodiment has the same effects as the atmosphere heat treatment furnace of the first embodiment with respect to the parts common to the first embodiment. Further, according to the atmospheric heat treatment furnace 1 of the present embodiment, tar is attached to equipment (for example, the exhaust gas flow path L, the bag filter 90) on the downstream side of the atmospheric heat treatment furnace 1 by the single combustion case 3. Can be suppressed. Further, since the atmosphere gas supply port and the combustion heater are not provided, the structure of the atmosphere heat treatment furnace 1 is simple because the combustion case 3 extends.

<Fourth embodiment>
The difference between this embodiment and the first embodiment is that the exhaust gas is subjected to a combustion process during cooling. Therefore, only the differences will be described here with reference to FIG. During cooling, the valves V1A, V1B, V1C, and V2D are open in FIG. 6 (schematic diagram when cooling the heat treatment equipment using the atmospheric heat treatment furnace of the first embodiment). For this reason, the branched first flow path L1, the cooling air first flow path AL1, the combustion air first flow path OL1, and the nitrogen gas second flow path NL2 are opened. On the other hand, the valves V2A, V2B, V2C, V1D are closed. For this reason, the branched second flow path L2, the cooling air second flow path AL2, the combustion air second flow path OL2, and the nitrogen gas first flow path NL1 are blocked.

  During cooling, the heat treatment heaters 24L and 24R are turned off. In addition, the combustion heater 36D of the second combustion case 3D is also turned off. On the other hand, the combustion heater 36U of the first combustion case 3U is turned on. In the present embodiment, the combustion heater 36U is included in the heating device of the present invention.

  First, the flow of nitrogen gas will be described. Nitrogen gas flows into the combustion chamber 31D from the atmosphere gas supply port 35D of the second combustion case 3D via the nitrogen gas second flow path NL2. As shown in FIG. 3, the atmospheric gas supply port 35D is disposed close to the furnace outside communication port 33D. On the other hand, the furnace inner communication port 32D serving as the nitrogen gas outlet is disposed opposite to the end of the combustion chamber 31D where the furnace outer communication port 33D is not disposed. For this reason, the nitrogen gas moves in a zigzag manner over substantially the entire length of the combustion chamber 31D.

  Returning to FIG. 6, the combustion chamber 31 </ b> D is close to the heat treatment chamber 22 across the upper wall of the case body 30 </ b> D. For this reason, the nitrogen gas moves in the combustion chamber 31D while being heated by the heat of the heat treatment chamber 22 transmitted from the upper wall of the case body 30D. The heated nitrogen gas flows into the heat treatment chamber 22 from the furnace inner communication port 32D. Then, the heat treatment chamber 22 rises and diffuses.

  Next, how the workpiece W is cooled will be described. Even if the heating by the heat treatment heaters 24L and 24R is stopped, the workpiece W is heated by the residual heat in the heat treatment chamber 22. For this reason, exhaust gas is generated in the heat treatment chamber 22. In the exhaust gas, a tar component evaporated from the workpiece W is mixed. That is, in the present embodiment, tar content is generated from the workpiece W not only during heating but also during cooling.

  Next, the flow of exhaust gas will be described. The exhaust gas flows into the combustion chamber 31U from the furnace inner communication port 32U of the first combustion case 3U. On the other hand, combustion air flows into the combustion chamber 31U from the oxygen supply port 34U via the combustion air first flow path OL1. For this reason, the exhaust gas is mixed with combustion air. As can be seen with reference to FIG. 3 (FIG. 3 shows the second combustion case 3D), the oxygen supply port 34U (34D) is disposed close to the furnace inner communication port 32U (32D). On the other hand, the furnace outer side communication port 33U (33D) serving as the exhaust gas outlet is disposed opposite to the end of the combustion chamber 31U (31D) where the furnace inner side communication port 32U (32D) is not disposed. . For this reason, the exhaust gas mixed with the combustion air zigzags along substantially the entire length of the combustion chamber 31U (31D).

  Returning to FIG. 6, the combustion chamber 31 </ b> U is close to the heat treatment chamber 22 with the lower wall of the case body 30 </ b> U interposed therebetween. For this reason, the exhaust gas mixed with the combustion air moves in the combustion chamber 31U while being heated by the heat of the heat treatment chamber 22 transmitted from the lower wall of the case body 30U. In addition, as described above, the combustion heater 36U is turned on. Therefore, the exhaust gas mixed with the combustion air moves in the combustion chamber 31U while being heated by the heat of the combustion heater 36U in addition to the heat of the heat treatment chamber 22. Due to the oxygen contained in the combustion air and the heat of the heat treatment chamber 22 and the combustion heater 36U, the tar component that is a combustible component in the exhaust gas is combusted. The exhaust gas after the combustion treatment flows into the branched first flow path L1 from the furnace outside communication port 33U. The exhaust gas is mixed with the cooling air introduced through the cooling air first flow path AL1. The exhaust gas after mixing the cooling air flows into the bag filter 90 via the integrated flow path L3. In the bag filter 90, dust (such as ash after combustion) in the exhaust gas is separated and removed. The exhaust gas after the dust is removed is discharged to the outside from the chimney 92 through the exhaust gas suction blower 91.

  As described above, during cooling, the nitrogen gas is heat-treated through the nitrogen gas second flow path NL2 → the atmosphere gas supply port 35D (second combustion case 3D) → the combustion chamber 31D → the furnace inner communication port 32D. It flows into the chamber 22. On the other hand, the exhaust gas generated in the heat treatment chamber 22 is for combustion flowing in via the furnace inner communication port 32U (first combustion case 3U) → combustion chamber 31U (here, combustion air first flow path OL1 → oxygen supply port 34U). → mixed with the air) → outer side communication port 33U → branched first flow path L1 (here mixed with cooling air flowing through the cooling air first flow path AL1) → integrated flow path L3 (bag filter 90, It is discharged to the outside through the blower 91 and the chimney 92).

  The atmosphere heat treatment furnace 1 of the present embodiment has the same effects as the atmosphere heat treatment furnace of the first embodiment with respect to the parts common to the first embodiment. Moreover, according to the atmospheric heat treatment furnace 1 of the present embodiment, even when the tar content remains in the workpiece W after the heating, the tar content can be burned during cooling. For this reason, the possibility that tar will adhere to the exhaust gas flow path L is further reduced.

  Further, according to the atmospheric heat treatment furnace 1 of the present embodiment, the combustion heater 36U of the first combustion case 3U is turned on during cooling. For this reason, when the exhaust gas is combusted, in addition to the heat transfer from the heat treatment chamber 22, heat can be applied from the combustion heater 36U. Therefore, the combustion of tar can be further promoted.

<Others>
The embodiment of the atmospheric heat treatment furnace of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, the type of atmospheric gas is not particularly limited. In addition to nitrogen gas, argon, hydrogen gas, or ammonia gas may be used. Further, heat treatment (combustion treatment) in an oxidizing atmosphere may be performed in the heat treatment chamber 22. Even in this case, the incomplete combustion in the heat treatment chamber 22 can be supplemented by the combustion treatment in the combustion chambers 31, 31U, 31D.

  Further, the heat treatment temperature in the heat treatment chamber 22 is not particularly limited. What is necessary is just to set it as an appropriate temperature according to the physical property of the to-be-processed object W. Further, the material of the exhaust gas, the combustion air, the piping that becomes the flow path of the nitrogen gas, and the combustion cases 3, 3U, and 3D are not particularly limited. An appropriate material may be used according to the heat treatment temperature of the workpiece W and the atmosphere of the heat treatment chamber 22.

  In the above embodiment, the heat treatment heaters 24L and 24R and the combustion heaters 36U and 36D are used for heating. For example, heat treatment or combustion heating is performed by flowing a hot gas into the pipe. May be. Moreover, you may arrange | position a thermal storage body instead of the heater for combustion.

  Further, the shape and path of the combustion chambers 31, 31U, 31D are not particularly limited. Moreover, you may arrange | position an uneven | corrugated | grooved part and a baffle plate (not partition plates 37D and 38D) inside the combustion chambers 31, 31U, and 31D. This increases the residence time of exhaust gas, combustion air, and nitrogen gas in the combustion chamber. In addition, the heat transfer area can be increased. Further, for example, heat transfer from the heat treatment chamber 22 may be facilitated by forming the case main bodies 30, 30U, and 30D to be thin. Further, heat transfer from the heat treatment chamber 22 may be facilitated by forming the case body 30, 30U, 30D from a material having a high heat transfer coefficient.

  Further, the workpiece W may be other electronic component materials such as a multilayer capacitor in addition to the battery material. Moreover, not only an electronic component material but various wastes etc. may be sufficient. Further, instead of the fixed table 23, a movable carriage may be arranged.

  In the first, second, and fourth embodiments, nitrogen gas is supplied from the second combustion case 3D to the heat treatment chamber 22 during cooling. However, nitrogen gas may not be supplied during cooling. In the first embodiment, the oxygen supply port 34U and the combustion air first flow path OL1 for introducing oxygen into the oxygen supply port 34U are arranged. However, when the exhaust gas is not subjected to the combustion treatment during cooling, the oxygen supply port 34U and the combustion air first flow path OL1 need not be arranged. If it carries out like this, the structure of the 1st combustion case 3U, by extension, the atmosphere heat treatment furnace 1, and the heat processing equipment 9 will become easier.

It is the schematic of the heat processing equipment in which the atmospheric heat treatment furnace of 1st embodiment is used. It is a permeation | transmission perspective view of the heat treatment chamber vicinity of the same atmosphere heat treatment furnace (combustion case). It is an up-down direction sectional view of the 2nd combustion case of the atmosphere heat treatment furnace. It is a permeation | transmission perspective view of the heat processing chamber vicinity of the same atmosphere heat processing furnace (heat processing heater). It is the schematic at the time of the heating of the heat processing equipment in which the same atmosphere heat processing furnace is used. It is the schematic at the time of cooling of the heat processing equipment. It is an up-down direction sectional view of the 2nd combustion case of the atmosphere heat treatment furnace of a 2nd embodiment. It is the schematic of the heat processing equipment in which the atmospheric heat treatment furnace of 3rd embodiment is used.

Explanation of symbols

1: atmosphere heat treatment furnace, 2: furnace body, 20: furnace shell, 21: heat insulating material, 22: heat treatment chamber, 23: table, 24L: heat treatment heater, 240L: protective tube, 24R: heat treatment heater, 240R: protection tube.
3: combustion case, 30: case main body, 31: combustion chamber, 32: furnace inner side communication port, 33: furnace outer side communication port, 34: oxygen supply port.
3U: first combustion case, 30U: case main body, 31U: combustion chamber, 32U: furnace inner side communication port, 33U: furnace outer side communication port, 34U: oxygen supply port, 35U: atmospheric gas supply port, 36U: heater for combustion ( (Heating device) 360U: protective tube.
3D: second combustion case, 30D: case main body, 31D: combustion chamber, 310D: straight section, 311D: branch flow path, 32D: furnace inside communication port, 33D: furnace outside communication port, 34D: oxygen supply port, 35D: Atmospheric gas supply port, 36D: combustion heater (heating device), 360D: protective tube, 37D: partition plate, 38D: partition plate.
9: Heat treatment equipment, 90: Bag filter, 91: Blower, 92: Chimney.
AL: cooling air flow path, NL: nitrogen gas flow path, OL: combustion air flow path.
AL1: Cooling air first flow path, AL2: Cooling air second flow path, L: Exhaust gas flow path, L1: Branching first flow path, L2: Branching second flow path, L3: Integrated flow path, NL1: Nitrogen Gas first flow path, NL2: Nitrogen gas second flow path, OL1: Combustion air first flow path, OL2: Combustion air second flow path, V1A to V1D: Valve, V2A to V2D: Valve, W: Workpiece .

Claims (7)

A furnace body having a heat treatment chamber for heat-treating an object to be treated under a predetermined atmospheric gas;
A heat exchange chamber disposed so as to be capable of exchanging heat, a combustion chamber, a furnace inner communication port communicating the combustion chamber and the heat treatment chamber, and a furnace outer communication port communicating the combustion chamber and the outside of the furnace; A first combustion case and a second combustion case having an oxygen supply port that is disposed between the furnace inner communication port and the furnace outer communication port and supplies oxygen to the combustion chamber;
With
The first combustion case and the second combustion case further include an atmospheric gas supply port for supplying the atmospheric gas to the combustion chamber,
The first combustion case is used to supply the atmospheric gas to the heat treatment chamber and the second combustion case is used to exhaust the exhaust gas from the heat treatment chamber during heating to heat the object to be processed. The exhaust gas in the heat treatment chamber flows into the combustion chamber through the furnace inner communication port, is mixed with oxygen supplied through the oxygen supply port, and at least by heat transfer from the heat treatment chamber Combusted, and flows out of the furnace through the furnace outside communication port,
During cooling to cool the workpiece, the second combustion case supplies the atmospheric gas to the heat treatment chamber, and the first combustion case discharges the exhaust gas from the heat treatment chamber, respectively. Atmospheric heat treatment furnace used .   The atmosphere heat treatment furnace according to claim 1, wherein the oxygen supply port is disposed in proximity to the furnace inner communication port among the furnace inner communication port and the furnace outer communication port.   During the heating, the atmospheric gas is heated by at least heat transfer from the heat treatment chamber when passing through the combustion chamber of the first combustion case, and the exhaust gas is heated in the combustion chamber of the second combustion case. When passing through, is mixed with oxygen supplied through the oxygen supply port, and at least burned by heat transfer from the heat treatment chamber,
  During the cooling, the atmospheric gas is heat-exchanged by at least heat transfer from the heat treatment chamber when passing through the combustion chamber of the second combustion case, and the exhaust gas is burned in the combustion chamber of the first combustion case. The atmosphere heat treatment furnace according to claim 1, wherein heat exchange is performed by at least heat transfer from the heat treatment chamber when passing through the chamber.   During the cooling, the exhaust gas is mixed with oxygen supplied through the oxygen supply port when passing through the combustion chamber of the first combustion case, and is subjected to a combustion process by heat transfer from at least the heat treatment chamber. An atmosphere heat treatment furnace according to claim 3.   The atmosphere heat treatment furnace according to claim 1, wherein the atmosphere gas supply port is disposed in proximity to the furnace outside communication port among the furnace inside communication port and the furnace outside communication port.   The atmosphere heat treatment furnace according to claim 1, wherein the first combustion case is disposed above the heat treatment chamber, and the second combustion case is disposed below the heat treatment chamber.   The atmosphere heat treatment furnace according to claim 1, wherein the first combustion case and the second combustion case further include a heating device that heats the combustion chamber.

Images