CN219797935U

CN219797935U - Reaction tube and reaction tube assembly

Info

Publication number: CN219797935U
Application number: CN202320999811.1U
Authority: CN
Inventors: 张勇; 邓金生; 宋强; 黄元俊
Original assignee: Shenzhen Headquarter SC New Energy Technology Corp
Current assignee: Shenzhen Headquarter SC New Energy Technology Corp
Priority date: 2023-04-26
Filing date: 2023-04-26
Publication date: 2023-10-03
Anticipated expiration: 2033-04-26

Abstract

The utility model discloses a reaction tube and a reaction tube assembly, wherein the reaction tube comprises a furnace body, a furnace mouth flange and an air blowing unit, a reaction chamber is arranged in the furnace body, an opening is arranged at one end of the reaction chamber, a through hole is arranged on the furnace mouth flange, the furnace mouth flange is sleeved at one end of the furnace body with the opening, the through hole is communicated with the reaction chamber, a sealing ring is arranged on the furnace mouth flange, the sealing ring surrounds the through hole, and the air blowing unit is positioned at one side of the furnace mouth flange close to a furnace door and is used for blowing hot air flowing to the sealing ring from the reaction chamber. The reaction tube assembly comprises a reaction tube and a furnace door, and the furnace door is covered on the furnace mouth flange. According to the reaction tube and the reaction tube assembly, the blowing unit is arranged on one side of the furnace mouth flange and blows air to the through hole, so that part of hot air flowing to the sealing ring from the reaction chamber can be blown away, the environment near the sealing ring can be cooled, and the service life of the sealing ring can be prolonged.

Description

Reaction tube and reaction tube assembly

Technical Field

The utility model relates to the technical field of photovoltaic material processing, in particular to a reaction tube and a reaction tube assembly.

Background

The processing of semiconductor or photovoltaic materials is typically accomplished by feeding sheet materials into a furnace and reacting them under conditions of temperature and pressure, and during the processing of the semiconductor or photovoltaic materials, some placement structure is typically used to load or move the material to be processed, during processing, or after processing, such loaded or moved devices are commonly referred to in the industry as boats, ark, graphite boats, or baskets.

In the photovoltaic industry, photovoltaic panels and photovoltaic modules are an important part of the photovoltaic industry. Therefore, the production quality of the photovoltaic cell panel is always focused on by various groups of factories. The fabrication of the panel includes a boron diffusion process requiring the use of a furnace, the furnace chamber seal of which is typically an O-ring between the furnace port flange and the furnace door. The temperature of the boron diffusion process is generally over 1000 ℃, the high temperature of the boat and the silicon wafer can bake the O-shaped sealing ring in the boat discharging process, but the O-shaped sealing ring can resist the temperature of 240 ℃ for a long time, and the service life of the sealing ring is short.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides a reaction tube and a reaction tube assembly, which solve the problem that the O-shaped sealing ring is baked at high temperature in the boat discharging process in the prior art, and the service life of the sealing ring is short.

A reaction tube according to an embodiment of the present utility model includes:

the device comprises a furnace body, wherein a reaction chamber is arranged in the furnace body, and an opening is formed in one end of the reaction chamber;

the furnace mouth flange is provided with a through hole, the furnace mouth flange is sleeved at one end of the furnace body, which is provided with an opening, and is communicated with the reaction chamber, the furnace mouth flange is also provided with a sealing ring which is arranged around the through hole, and the sealing ring is arranged at one side of the furnace mouth flange, which is close to the furnace door;

the blowing unit is positioned on one side of the furnace mouth flange close to the furnace door and is used for blowing away the hot gas flowing to the sealing ring from the reaction chamber.

The reaction tube provided by the embodiment of the utility model has at least the following beneficial effects:

the furnace mouth flange is provided with the blowing unit on one side, the furnace door is opened, namely, the furnace door is opened, hot air in the reaction chamber is emitted along the through hole, the blowing unit blows air to the through hole, part of hot air flowing to the sealing ring from the reaction chamber can be blown away, the environment near the sealing ring can be cooled, and the service life of the sealing ring can be prolonged.

According to some embodiments of the utility model, a flange is arranged on one side of the furnace mouth flange, which is close to the furnace door, in a protruding way, the flange is arranged around the through hole, and the sealing ring is arranged around the flange.

According to some embodiments of the utility model, the blowing direction of the blowing unit is inclined to the radial direction of the furnace body, and the blowing direction of the blowing unit is along the outer edge of the furnace mouth flange towards the flange and is close to one end of the furnace door.

According to some embodiments of the utility model, the blowing unit comprises a blowing pipe, wherein a plurality of blowing holes are arranged on the blowing pipe, and the blowing holes are positioned on one side of the blowing pipe close to the sealing ring.

According to some embodiments of the utility model, the gas blowing pipe is horizontally arranged, and the gas blowing pipe is positioned at the upper end of the furnace mouth flange.

According to some embodiments of the utility model, the lance is arranged in a ring shape, the lance being arranged around the furnace mouth flange.

Another object of the present utility model is to provide a reaction tube assembly including a furnace door and the reaction tube, the furnace door being detachably covered at the opening.

The reaction tube assembly provided by the embodiment of the utility model has at least the following beneficial effects:

According to some embodiments of the utility model, a flange is convexly arranged on one side of the furnace mouth flange, which is close to the furnace door, the flange is arranged around the through hole, and the sealing ring is arranged around the flange;

the furnace door is provided with a clearance groove, and when the furnace door cover is arranged on the furnace mouth flange, the flange extends into the clearance groove.

Or, be provided with annular protruding on the furnace gate, when the furnace gate lid is in on the fire door flange, annular protruding butt sealing washer, the second flange is located annular protruding inboard.

According to some embodiments of the utility model, the opening end of the inner wall surface of the reaction chamber is provided with a notch groove, the junction of the notch groove and the inner wall surface of the reaction chamber is in a step shape, the furnace door is connected with a heat insulating piece, and when the furnace door covers the furnace mouth flange, the heat insulating piece is abutted against the side wall of the notch groove, which is close to the inner wall surface of the reaction chamber.

According to some embodiments of the utility model, an elastic piece is arranged between the heat insulating piece and the furnace door, and when the furnace door is covered on the furnace mouth flange, the elastic piece pushes the heat insulating piece to be abutted against the side wall of the notch groove close to the inner wall surface of the reaction chamber.

According to some embodiments of the utility model, the door is provided with a door, and the door is provided with a door opening, and the door opening is provided with a door opening.

According to some embodiments of the utility model, a carrier is connected to the heat insulating member, and the carrier is used for placing the substitute product to extend into the reaction chamber for heating.

According to some embodiments of the utility model, the furnace mouth flange is annular, the furnace mouth flange is sleeved at the open end of the furnace body, and a gap exists between the outer wall of the open end of the furnace body and the inner wall of the through hole.

According to some embodiments of the utility model, the width of the notch of the annular groove is smaller than the width of the bottom wall, and the cross section of the annular groove is trapezoid.

According to some embodiments of the utility model, a connecting ring is arranged on the outer side of the furnace body in a protruding mode, the furnace mouth flange is sleeved at the opening end of the furnace body, the furnace mouth flange is abutted to the connecting ring, a sealing groove is arranged on one side, close to the connecting ring, of the furnace mouth flange, and a sealing element is arranged in the sealing groove and is abutted to the connecting ring.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The utility model is further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic view showing a structure in which a door is opened in a reaction tube assembly according to an embodiment of the present utility model;

FIG. 2 is an enlarged view of a portion of FIG. 1A;

FIG. 3 is a schematic view showing a structure of a reaction tube assembly in which a door is closed according to an embodiment of the present utility model;

FIG. 4 is a schematic view showing the structure of a furnace mouth flange of a reaction tube assembly according to an embodiment of the present utility model;

FIG. 5 is a schematic view showing the structure of a furnace door with an annular protrusion in a reaction tube assembly according to an embodiment of the present utility model;

FIG. 6 is a schematic view showing the installation of a gas blowing pipe of a reaction tube according to an embodiment of the present utility model;

FIG. 7 is a schematic diagram showing the installation of a gas blowing pipe of a reaction tube according to an embodiment of the present utility model.

Reference numerals:

100. a furnace body; 110. a reaction chamber; 111. a notch groove; 120. a connecting ring;

200. a furnace mouth flange; 210. a through hole; 220. an annular groove; 221. a seal ring; 230. a flange; 240. sealing grooves; 241. a seal;

300. a furnace door; 310. a clearance groove; 320. an annular protrusion; 330. a heat insulating member; 331. a carrier; 340. an elastic member; 341. a limit screw;

400. a blowing unit; 410. an air blowing pipe;

B. the blowing direction of the blowing unit.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and to simplify the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model. Furthermore, features defining "first", "second" may include one or more such features, either explicitly or implicitly. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

Referring to fig. 1, 2 and 3, a reaction tube according to an embodiment of the present utility model includes a furnace body 100, a furnace mouth flange 200 and a blowing unit 400. The furnace body 100 is internally provided with a reaction chamber 110, and one end of the reaction chamber 110 is provided with an opening. The furnace mouth flange 200 is sleeved at the open end of the furnace body 100, a through hole 210 is arranged in the middle of the furnace mouth flange 200, and the through hole 210 is communicated with the reaction chamber 110. The furnace mouth flange 200 is also provided with a sealing ring 221, the sealing ring 221 is arranged around the through hole 210, and the sealing ring 221 is positioned on one side of the furnace mouth flange 200 close to the furnace door 300. The blowing unit 400 is located at a side of the furnace mouth flange 200 remote from the furnace body 100, and the blowing unit 400 is used for blowing off the hot gas flowing toward the sealing ring 221 from the reaction chamber 110.

A blowing unit 400 is provided at one side of the furnace mouth flange 200. The furnace door 300 is opened, namely, the boat discharging process is performed, hot air of the reaction chamber 110 is emitted along the through holes 210, the air blowing unit 400 blows air to the through holes 210, part of the hot air flowing to the sealing ring 221 from the reaction chamber 110 can be blown away, the environment near the sealing ring 221 can be cooled, and the service life of the sealing ring 221 can be prolonged.

In some embodiments, referring to fig. 1, 2 and 3, the furnace mouth flange 200 is provided with a flange 230 protruding near the side of the furnace door 300, the flange 230 being arranged around the through hole 210. The flange 230 is arranged in a protruding manner, the flange 230 is annular, and a plane of the flange 230, which is close to one end of the furnace door 300, is closer to the furnace door 300 than a plane of the sealing ring 221. When the furnace door 300 is opened, namely, the boat discharging process is performed, hot air of the reaction chamber 110 is emitted along the through hole 210, and the flange 230 can shield hot air flow, so that the hot air flow is far away from the sealing ring 221 as far as possible, the sealing ring 221 can not be impacted by hot air flow in the opening process of the furnace door 300, and the service life of the sealing ring 221 is prolonged.

In some embodiments, referring to fig. 1, 2 and 3, the blowing direction of the blowing unit 400 is inclined to the radial direction of the furnace body 100, and the blowing direction of the blowing unit 400 is along the outer edge of the furnace mouth flange 200 toward the flange 230 away from the end of the furnace body 100. The plane of the edge of the furnace mouth flange 200 is farther away from the furnace door 300 than the plane of the flange 230 at the end far away from the furnace body 100, so that the gas blown out by the blowing unit 400 is closer to the sealing ring 221. The furnace door 300 is opened, namely, the process of discharging the boat, the hot air of the reaction chamber 110 is emitted along the through holes 210, and the hot air blown by the air blowing unit 400 blows the hot air to the direction far away from the sealing ring 221 as much as possible, so that the service life of the sealing ring 221 is prolonged.

In some embodiments, referring to fig. 1, 2 and 3, an annular groove 220 is provided on the furnace mouth flange 200, the annular groove 220 is provided around the through hole 210, the sealing ring 221 is connected to the furnace mouth flange 200 through the annular groove 220, and by providing the annular groove 220, the sealing ring 221 can be limited and connected, so that the sealing ring 221 is prevented from being displaced on the furnace mouth flange 200.

In some embodiments, referring to fig. 1, 2 and 3, the blowing unit 400 includes a blowing pipe 410, and a plurality of blowing holes are provided on the blowing pipe 410, the blowing holes facing the through holes 210. When the furnace door 300 is opened, the gas pipe 410 is externally connected with a gas pipe, the gas pipe supplies gas to the gas pipe 410, the gas is blown out along the gas hole, the gas is blown to the position of the through hole 210, part of hot gas flowing to the sealing ring 221 from the reaction chamber 110 can be blown away, the environment near the sealing ring 221 can be cooled, and the service life of the sealing ring 221 can be prolonged.

In some embodiments, referring to fig. 1, 2 and 6, the lance 410 is disposed horizontally and the lance 410 is positioned at the upper end of the furnace mouth flange 200. The furnace door 300 is opened, i.e., the process of discharging the boat, the hot gas of the reaction chamber 110 is emitted along the through holes 210, the heat is mainly diffused upwards, and the silicon wafers are all positioned above the boat, and are taken out from the boat. The gas blowing pipe 410 is horizontally arranged, and the gas blowing pipe 410 is positioned at the upper end of the furnace mouth flange 200, so that the length of the gas blowing pipe 410 can be reduced, and the gas transportation required by gas blowing is reduced.

In some embodiments, referring to fig. 1, 2 and 7, the lance 410 is disposed in an annular configuration, with the lance 410 disposed about the furnace mouth flange 200. The gas blow pipe 410 is disposed around the furnace mouth flange 200, with one end externally connected to a gas pipe and the other end capped. When the furnace door 300 is opened, the gas transmission pipeline transmits gas to the gas blowing pipe 410, the gas is blown out along the gas blowing hole, the gas is blown to the position of the through hole 210, the gas blowing pipe 410 is arranged around the furnace mouth flange 200, the gas blown out by the gas blowing pipe 410 is blown to the through hole 210, the sealing ring 221 is circumferentially protected, part of hot gas flowing to the sealing ring 221 from the reaction chamber 110 can be blown away, the environment around the sealing ring 221 can be cooled, and the service life of the sealing ring 221 can be prolonged.

Referring to fig. 1, 2, 3 and 5, another object of the present utility model is to provide a reaction tube assembly including a reaction tube and a door 300, wherein the door 300 is detachably disposed on the opening. The oven door 300 is covered on the opening of the oven body 100 by the oven port flange 200, and when the oven door 300 is covered on the oven port flange 200 (the oven door 300 is closed), the oven door 300 abuts against the sealing ring 221.

Referring to fig. 1, 2, 3 and 5, a flange 230 is convexly provided at a side of the furnace mouth flange 200 adjacent to the furnace door 300, and the flange 230 is disposed around the through hole 210. The flange 230 is arranged in a protruding manner, the flange 230 is annular, and a plane of the flange 230, which is close to one end of the furnace door 300, is closer to the furnace door 300 than a plane of the sealing ring 221. When the furnace door 300 is opened, namely, the boat discharging process is performed, hot air of the reaction chamber 110 is emitted along the through hole 210, and the flange 230 can shield hot air flow, so that the hot air flow is far away from the sealing ring 221 as far as possible, the sealing ring 221 can not be impacted by hot air flow in the opening process of the furnace door 300, and the service life of the sealing ring 221 is prolonged.

The door 300 is provided with a clearance groove 310, and when the door 300 is covered on the furnace mouth flange 200, the flange 230 extends into the clearance groove 310. The avoidance groove 310 is annular, the avoidance groove 310 is arranged corresponding to the flange 230, and when the furnace door 300 is covered on the furnace mouth flange 200, the flange 230 extends into the avoidance groove 310, so that the flange 230 cannot interfere with the furnace door 300.

The furnace door 300 may further be provided with an annular protrusion 320, when the furnace door 300 is covered on the furnace mouth flange 200, the annular protrusion 320 abuts against the sealing ring 221, and the second flange is located inside the annular protrusion 320. The annular bulge 320 is arranged at a position corresponding to the sealing ring 221, when the furnace door 300 is covered on the furnace mouth flange 200, the annular bulge 320 abuts against the sealing ring 221 to realize sealing, and the second flange is positioned at the inner side of the annular bulge 320, so that the second flange cannot interfere with the furnace door 300.

In some embodiments, referring to fig. 1, 2 and 3, the open end of the inner wall of the reaction chamber 110 is provided with a notch groove 111, and the junction between the notch groove 111 and the inner wall of the reaction chamber 110 is stepped. The heat insulator 330 is connected to the furnace door 300, and when the furnace door 300 is covered on the furnace mouth flange 200, the heat insulator 330 abuts against the side wall of the notch groove 111 close to the inner wall surface of the reaction chamber 110. The notch groove 111 extends to the direction away from the furnace door 300, when the furnace door 300 is covered on the furnace mouth flange 200, the heat insulation piece 330 is clamped in the notch groove 111, the heat insulation piece 330 is abutted against the side wall of the notch groove 111, heat transfer to the open end of the furnace body 100 during the operation of the reaction chamber 110 can be reduced, and the heat flow to the sealing ring 221 during the operation of the reaction chamber 110 is avoided. The heat insulator 330 is arranged to be in sealing connection with the notch groove 111, so that the protection effect of the sealing ring 221 is improved.

In some embodiments, referring to fig. 1, 2 and 6, an elastic member 340 is disposed between the heat insulating member 330 and the furnace door 300, and when the furnace door 300 is covered on the furnace mouth flange 200, the elastic member 340 pushes the heat insulating member 330 to abut against a side wall of the notch groove 111 near the inner wall surface of the reaction chamber 110. The elastic piece 340 can ensure that the heat insulating piece 330 is tightly connected with the side wall of the notch groove 111, which is close to the inner wall surface of the reaction chamber 110, so that the heat insulating effect of the heat insulating piece 330 is improved, and the protection effect of the sealing ring 221 is improved.

In some embodiments, referring to fig. 1, 2 and 5, the reactor tube assembly further comprises a limit screw 341, and the elastic member 340 comprises a spring, with a limit hole provided on the insulation. The furnace door 300 is provided with a threaded hole, and the limit screw 341 passes through the limit hole and is in threaded connection with the spring in the threaded hole. The limit screw 341 can connect the heat insulating piece 330 on the furnace door 300, and the heat insulating piece 330 can only move along the axial direction of the limit screw 341, and the limit screw 341 can also limit the movement of the spring, so that the thrust of the spring to the heat insulating piece 330 is ensured to be stable, and the heat insulating piece 330 is ensured to be pushed by the spring to be connected with the notch groove 111 in a sealing way.

In some embodiments, referring to fig. 1, 2 and 3, a carrier 331 may be coupled to the thermal shield 330, the carrier 331 being configured to receive the processing product to be heated into the reaction chamber 110. The carrier 331 is a boat, and the carrier 331 is connected to the heat insulator 330, and the door 300 is opened to drive the heat insulator 330 out of the reaction chamber 110 and drive the carrier 331 out of the reaction chamber 110.

In some embodiments, referring to fig. 1, 2 and 3, the furnace mouth flange 200 is annular, the furnace mouth flange 200 is sleeved on the open end of the furnace body 100, and a gap exists between the outer wall of the open end of the furnace body 100 and the inner wall of the through hole 210. The furnace mouth flange 200 is sleeved at the opening end of the furnace body 100, and the furnace mouth flange 200 is convenient to connect with the furnace body 100. Gaps exist between the outer wall of the open end of the furnace body 100 and the inner wall of the through hole 210, so that heat transfer from the furnace body 100 to the furnace mouth flange 200 can be reduced, heat transfer from the furnace body 100 to the sealing ring 221 is reduced, and the service life of the sealing ring 221 is prolonged.

In some embodiments, referring to fig. 1, 2 and 4, the width of the slot of annular groove 220 is smaller than the width of the bottom wall, and the cross section of annular groove 220 is trapezoidal. The sealing ring 221 is clamped in the annular groove 220, the upper part of the annular groove 220 is narrow, the lower part of the annular groove 220 is wide, the sealing ring 221 can be better clamped, and the sealing ring 221 is prevented from falling off from the annular groove 220.

In some embodiments, referring to fig. 1, 2 and 4, a connecting ring 120 is convexly arranged on the outer side of the furnace body 100, a furnace mouth flange 200 is sleeved on the opening end of the furnace body 100, and the furnace mouth flange 200 abuts against the connecting ring 120. The furnace mouth flange 200 is provided with seal groove 240 near adapter ring 120 one side, is provided with sealing member 241 in the seal groove 240, and sealing member 241 butt adapter ring 120. The connecting ring 120 is arranged to limit the axial position of the furnace mouth flange 200 on the furnace body 100, so that one end of the furnace mouth flange 200 far away from the furnace body 100 is ensured to be conveniently connected with the furnace door 300. The connecting ring 120 is abutted against the sealing element 241, so that the sealing between the furnace mouth flange 200 and the furnace body 100 is ensured.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present utility model have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. A reaction tube, comprising:

2. The reactor tube of claim 1, wherein the furnace mouth flange is provided with a flange protruding from a side thereof adjacent to the furnace door, the flange is disposed around the through hole, and the seal ring is disposed around the flange.

3. The reactor tube according to claim 2, wherein the blowing direction of the blowing unit is inclined to the radial direction of the furnace body, and the blowing direction of the blowing unit is along the outer edge of the furnace mouth flange toward the flange near one end of the furnace door.

4. The reaction tube of claim 1 wherein the furnace mouth flange is provided with an annular groove on a side thereof adjacent to the furnace door, the annular groove being disposed around the through hole, and the seal ring being mounted on the furnace mouth flange through the annular groove.

5. The reaction tube of claim 1, wherein the blowing unit comprises a blowing tube, and a plurality of blowing holes are formed in the blowing tube and are positioned on one side of the blowing tube close to the sealing ring.

6. The reactor tube of claim 5, wherein the lance tube is disposed horizontally and is positioned at the upper end of the furnace mouth flange.

7. The reactor tube of claim 5, wherein said lance tube is annularly disposed and said lance tube is disposed about said furnace opening flange.

8. A reactor tube assembly, comprising:

the reaction tube according to any one of claims 1 to 7;

the furnace door is detachably covered on the opening.

9. The reactor tube assembly of claim 8, wherein the furnace port flange is provided with a flange protruding from a side thereof adjacent to the furnace door, the flange is provided around the through hole, and the sealing ring is provided around the flange;

the furnace door is provided with a clearance groove, and the flange extends into the clearance groove.

10. The reaction tube assembly according to claim 8, wherein the open end of the inner wall surface of the reaction chamber is provided with a notch groove, the junction of the notch groove and the inner wall surface of the reaction chamber is stepped, the furnace door is connected with a heat insulating member, and when the furnace door is covered on the furnace mouth flange, the heat insulating member is abutted against the side wall of the notch groove, which is close to the inner wall surface of the reaction chamber.