CN220489681U - Air inlet assembly of vertical furnace and vertical furnace - Google Patents

Abstract

The utility model discloses an air inlet assembly of a vertical furnace and the vertical furnace using the same, wherein the air inlet assembly of the vertical furnace comprises an air inlet pipe and an air supply pipe, the air inlet pipe is made of metal materials, the air inlet pipe is a bent pipe comprising a first pipe section and a second pipe section, and one end of the first pipe section is connected with one end of the second pipe section; the air supply pipe is made of quartz material, the inner diameter of the air supply pipe is larger than the outer diameter of the second pipe section, and the air supply pipe is sleeved at the other end of the second pipe section. The air inlet component of the vertical furnace has the advantages of being high in reliability and convenient to install.

Description

Air inlet assembly of vertical furnace and vertical furnace

Technical Field

The utility model relates to the technical field of semiconductor equipment, in particular to an air inlet component of a vertical furnace and the vertical furnace.

Background

The vertical furnace tube is a semiconductor device for performing a heat treatment on a wafer. When a heat treatment process such as annealing and diffusion is performed on a wafer, a specific gas is required to be introduced into a process chamber as a process gas or a shielding gas to satisfy processing requirements. At present, an L-shaped quartz tube fixed on the inner wall or the outer wall of a process chamber is generally used as an air supply tube, the quartz material is fragile and fragile, and when the L-shaped quartz tube is disassembled and assembled, the sealing tube orifice is easy to collide and crack; when the quartz tube is used, the vertical end weight of the quartz tube is fully pressed at the bending part, and the bending part is easy to break.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems in the related art to some extent. Therefore, the embodiment of the utility model provides the air inlet assembly of the vertical furnace, which has the advantages of low failure rate and convenience in assembly.

The embodiment of the utility model also provides a vertical furnace.

The air inlet assembly of the vertical furnace comprises an air inlet pipe, wherein the air inlet pipe is made of a metal material, the air inlet pipe is an elbow pipe comprising a first pipe section and a second pipe section, and one end of the first pipe section is connected with one end of the second pipe section; the gas supply pipe is made of quartz material, the inner diameter of the gas supply pipe is larger than the outer diameter of the second pipe section, and the gas supply pipe is sleeved at the other end of the second pipe section.

The air supply pipe extending along the straight line of the air supply assembly of the vertical furnace is made of quartz materials, the air supply pipe of the air supply assembly is bent and extended, and is fixed through the air supply pipe, so that the air supply pipe of the metal materials is not easy to damage when being collided in the installation process, and the air supply pipe of the metal materials can have stronger bending limit when bearing the weight of the air supply pipe, so that the buckling damage of the air supply assembly is avoided, and the vertical furnace has the advantages of being higher in reliability and convenient to install.

In some embodiments, the air inlet pipe is a right angle elbow, and the extending direction of the first pipe section and the extending direction of the second pipe section are orthogonal.

In some embodiments, the air inlet pipe further comprises a sleeve, the sleeve is sleeved on the outer peripheral side of the second pipe section, the inner diameter of the sleeve is larger than the outer diameter of the air supply pipe, and at least part of the air supply pipe is inserted between the second pipe section and the sleeve.

In some embodiments, the sleeve includes an annular portion provided at an outer circumferential side of the second pipe section and connected to an outer wall of the second pipe section, and a cylindrical portion having a lower end connected to an outer edge of the annular portion, and the air supply pipe may be fitted between the cylindrical portion and the second pipe section, and a lower end of the air supply pipe may be stopped against the annular portion.

In some embodiments, the length dimension of the barrel is less than the length dimension of the second tube segment such that at least a portion of the second tube segment protrudes from an upper side of the barrel.

In some embodiments, the air inlet assembly further includes a locking member, at least a portion of the locking member is disposed on an outer circumferential side of the sleeve, the sleeve is provided with a through hole, the air supply pipe is provided with an assembly groove, the through hole may be opposite to the assembly groove, and at least a portion of the locking member may penetrate the through hole and fit into the assembly groove, so that the air supply pipe and the air supply pipe are relatively locked.

The vertical furnace provided by the embodiment of the utility model comprises a plurality of air inlet assemblies and a furnace body, wherein the air inlet assemblies are the air inlet assemblies of the vertical furnace according to any one of the embodiments, the air inlet assemblies are uniformly arranged at intervals along the circumferential direction of the furnace body, the furnace body extends along the vertical direction, the inner cavity of the furnace body comprises an air inlet chamber and a process chamber, at least part of air supply pipes of the air inlet assemblies are arranged in the process chamber, the end parts of the air supply pipes extend to the air inlet chamber, the air inlet pipes are arranged in the air inlet chamber, and one ends of the air inlet pipes extend to the outer side of the furnace body.

In some embodiments, the furnace body comprises a partition plate, the partition plate is arranged in the inner cavity of the furnace body and extends along the radial direction of the furnace body so as to divide the inner cavity of the furnace body into an air inlet chamber and a process chamber, the air supply pipe penetrates through the partition plate along the thickness direction of the partition plate, and the air supply pipe is connected with the furnace body in a sealing way.

In some embodiments, the air inlet chamber is located at the lower side of the process chamber, the second pipe section of the air inlet pipe is connected to the lower end of the air supply pipe, and at least part of the first pipe section of the air inlet pipe extends to the outer peripheral side of the furnace body.

In some embodiments, a first fixing ring is arranged in the air inlet chamber, the first fixing ring is arranged on the inner wall of the furnace body and extends along the circumferential direction of the furnace body in a closed manner, the first fixing ring is provided with a plurality of positioning holes, the positioning holes are arranged in one-to-one correspondence with air supply pipes of the air inlet assemblies, the positioning holes penetrate through the first fixing ring along the length direction of the furnace body, and at least part of the air inlet pipes can be matched into the positioning holes to be positioned;

the air inlet device is characterized in that a second fixing ring is arranged in the air inlet chamber, the second fixing ring is arranged on the lower side of the air inlet pipe, a plurality of fasteners are arranged on the second fixing ring, the fasteners and the air inlet pipes of the air inlet assembly are arranged in one-to-one correspondence, one end of each fastener can be stopped against the air inlet pipe, and the position of each fastener relative to the second fixing ring is adjustable so as to adjust the distance between the air inlet pipe and the second fixing ring.

Drawings

Fig. 1 is a schematic structural view of a vertical furnace according to an embodiment of the present utility model.

Fig. 2 is a schematic structural view of an air intake assembly of a vertical furnace according to an embodiment of the present utility model.

Fig. 3 is a schematic cross-sectional view of a vertical furnace according to an embodiment of the present utility model.

Reference numerals:

a furnace body 1; a separator 11; a process chamber 101; an intake chamber 102; a first fixing ring 12; a second fixing ring 13; a fastener 131;

an air intake assembly 2; an intake pipe 21; a second tube segment 211; a first tube segment 212; a sleeve 213; a cylindrical portion 2131; annular portion 2132; an air supply pipe 22; a locking member 23.

Detailed Description

Reference will now be made in detail to embodiments of the present utility model, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model.

An air intake assembly 2 of a vertical furnace according to an embodiment of the present utility model will be described with reference to fig. 1, 2 and 3.

The air intake assembly 2 of the vertical furnace according to the embodiment of the present utility model includes an air intake pipe 21 and an air supply pipe 22.

The air inlet pipe 21 is made of a metal material, the air inlet pipe 21 is an elbow comprising a first pipe section 212 and a second pipe section 211, and one end of the first pipe section 212 is connected with one end of the second pipe section 211;

the air supply pipe 22, the air supply pipe 22 is made of quartz material, the inner diameter of the air supply pipe 22 is larger than the outer diameter of the second pipe section 211, and the air supply pipe 22 is sleeved at the other end of the second pipe section 211.

Specifically, the air feed pipe 22 extends in the vertical direction, and the air feed pipe 22 is cylindrical, and the air intake pipe 21 is provided at the lower end of the air feed pipe 22 and connected to the air feed pipe 22, and the air intake pipe 21 is connected to the inner wall of the furnace body 1, thereby connecting the air feed pipe 22 to the furnace body 1 through the air intake pipe 21.

Under the action of gravity applied to the air supply pipe 22, the air supply pipe 22 applies downward acting force to the air supply pipe 21, the air supply pipe 22 is supported by taking the air supply pipe 21 as a fulcrum, the acting force of the air supply pipe 22 to the air supply pipe 21 extends along the second pipe section 211, and bending moment action is generated on the air supply pipe 21 at the joint of the first pipe section 212 and the second pipe section 211, and the air supply pipe 21 is made of metal materials, so that the air supply pipe 21 has high bending strength and can bear bending moment formed by the downward acting force of the air supply pipe 22 to the air supply pipe 21.

The air inlet assembly 2 of the vertical furnace in the embodiment of the utility model has a two-stage structure, the air inlet pipe 22 is made of quartz material to normally work at a higher temperature, the air inlet pipe 21 is arranged at the lower end of the air inlet pipe 22, and the air inlet pipe 21 is made of metal material, on one hand, the air inlet pipe 21 is arranged at the lower end of the air inlet pipe 22 to bear bending moment generated by gravity of the air inlet pipe 22 on the air inlet pipe 21, so that the air inlet pipe 22 is not easy to break, on the other hand, the air inlet pipe 22 is fixed in the furnace body 1 of the vertical furnace through the air inlet pipe 21, and the air inlet pipe 21 made of metal material is not easy to damage when being installed in the furnace body 1 of the vertical furnace, so that the failure rate of the air inlet assembly 2 in the whole installation is reduced, and the air inlet assembly 2 of the vertical furnace in the embodiment of the utility model has the advantages of higher reliability and convenience in installation.

In addition, the air inlet pipe 21 made of metal materials is used as a main stress structure of the air inlet assembly 2, the bearing of the bending part of the quartz tube is limited in the related art, the diameter of the vertical end of the L-shaped quartz tube is thinner, silane can be heated and decomposed into silicon particles when flowing, the silicon particles are easy to cause the blockage of the quartz tube, and equipment is required to be stopped for replacing the quartz tube.

In some embodiments, the air inlet pipe 21 is a right angle elbow, and the extending direction of the first pipe section 212 and the extending direction of the second pipe section 211 are orthogonal.

Specifically, the air intake pipe 21 includes a second pipe section 211 and a first pipe section 212 which are perpendicular to each other, the second pipe section 211 extending in a vertical direction, one end of the first pipe section 212 being connected to a lower end of the second pipe section 211, the air supply pipe 22 being connected to the second pipe section 211 and extending in a vertical direction, and the other end of the first pipe section 212 being adapted to be fixedly connected to the furnace body 1 of the vertical furnace.

Therefore, the gas can enter the air supply pipe 22 along the first pipe section 212 and the second pipe section 211, and the gravity applied to the air supply pipe 22 extends along the axial direction of the air supply pipe 22, so that the air supply pipe 22 is prevented from being subjected to bending force, the possibility of damaging the air supply pipe 22 is reduced, and the air inlet assembly 2 of the vertical furnace has the advantages of being high in reliability and convenient to install.

In some embodiments, the air inlet pipe 21 further includes a sleeve 213, the sleeve 213 is sleeved on the outer peripheral side of the second pipe section 211, the inner diameter of the sleeve 213 is larger than the outer diameter of the air supply pipe 22, and at least part of the air supply pipe 22 is interposed between the second pipe section 211 and the sleeve 213.

Specifically, the sleeve 213 includes an annular portion 2132 and a cylindrical portion 2131, the annular portion 2132 is provided on the outer peripheral side of the second pipe section 211 and is connected to the outer wall of the second pipe section 211, the lower end of the cylindrical portion 2131 is connected to the outer edge of the annular portion 2132, the air pipe 22 may be fitted between the cylindrical portion 2131 and the second pipe section 211, and the lower end of the air pipe 22 may be stopped against the annular portion 2132.

The cylindrical portion 2131 is fitted around the outer peripheral side of the second pipe section 211, the cylindrical portion 2131 extends vertically, an annular gap is provided between the second pipe section 211 and the cylindrical portion 2131, the air pipe 22 is fitted into the annular gap from the upper side of the second pipe section 211, and the annular portion 2132 is provided at the lower end of the annular gap so that the lower end of the air pipe 22 is stopped against the upper end of the annular portion 2132.

Therefore, the air supply pipe 22 can be sleeved at the upper end of the air inlet pipe 21 from top to bottom, on one hand, the acting force of the air inlet pipe 21 on the air supply pipe 22 extends along the axial direction of the air supply pipe 22, so that the probability of bending damage of the air supply pipe 22 is reduced, and on the other hand, the air supply pipe 22 is convenient to assemble to the upper end of the air supply pipe 21, and the air supply pipe 22 made of quartz material is prevented from being damaged when the vertical furnace is installed, so that the air inlet assembly 2 of the vertical furnace has the advantages of being higher in reliability and convenient to install.

In some embodiments, the length dimension of the barrel 2131 is less than the length dimension of the second tube segment 211 such that at least a portion of the second tube segment 211 protrudes from the upper side of the barrel 2131.

Specifically, the diameter of the second pipe section 211 is smaller than the diameter of the cylindrical portion 2131, the upper end of the second pipe section 211 protrudes upward from the upper end of the cylindrical portion 2131, and when the air pipe 22 is assembled to the upper end of the air intake pipe 21, the air pipe 22 may be first fitted around the outer peripheral side of the second pipe section 211, and the air pipe 22 is moved downward between the cylindrical portion 2131 and the second pipe section 211 under the guiding action of the second pipe section 211.

Therefore, the height of the upper end of the second pipe section 211 is larger than that of the upper end of the cylindrical portion 2131, and when the air supply pipe 22 is assembled to the air inlet pipe 21, the probability of collision between the air supply pipe 22 made of quartz material and the air inlet pipe 21 is reduced, so that the air supply pipe 22 made of quartz material is prevented from being damaged when the vertical furnace is assembled, and the air inlet assembly 2 of the vertical furnace has the advantages of high reliability and convenience in installation.

In some embodiments, the air intake assembly 2 further includes a locking member 23, at least a portion of the locking member 23 is disposed at an outer circumferential side of the sleeve 213, the sleeve 213 is provided with a through hole, the air supply pipe 22 is provided with a fitting groove, the through hole may be opposite to the fitting groove, and at least a portion of the locking member 23 may penetrate the through hole and be fitted into the fitting groove, so that the air supply pipe 22 and the air supply pipe 21 are relatively locked.

Specifically, a through hole is provided at an outer circumferential side of the sleeve 213, and an assembling groove is provided at an outer circumferential side of the air feed pipe 22, and when the air feed pipe 22 is assembled to the air intake pipe 21, the through hole may correspond to the assembling groove so that the locking piece 23 is inserted into the assembling groove from an outer side of the sleeve 213 to prevent the air feed pipe 22 from moving in an up-down direction with respect to the air intake pipe 21.

A vertical furnace according to an embodiment of the present utility model will be described with reference to fig. 1 and 2.

The vertical furnace according to the embodiment of the utility model comprises a plurality of air inlet assemblies 2 and a furnace body 1, wherein the air inlet assemblies 2 are the air inlet assemblies 2 of the vertical furnace according to any embodiment, the plurality of air inlet assemblies 2 are uniformly arranged at intervals along the circumferential direction of the furnace body 1, the furnace body 1 extends along the vertical direction, the inner cavity of the furnace body 1 comprises an air inlet chamber 102 and a process chamber 101, an air supply pipe 22 of at least part of the air inlet assemblies 2 is arranged in the process chamber 101, the end part of the air supply pipe 22 extends to the air inlet chamber 102, an air inlet pipe 21 is arranged in the air inlet chamber 102, and one end of the air inlet pipe 21 extends to the outer side of the furnace body 1.

In some embodiments, the furnace body 1 includes a partition plate 11, the partition plate 11 is disposed in the inner cavity of the furnace body 1 and extends along the radial direction of the furnace body 1 to divide the inner cavity of the furnace body 1 into an air inlet chamber 102 and a process chamber 101, the air supply pipe 22 penetrates through the partition plate 11 along the thickness direction of the partition plate 11, and the air supply pipe 22 is connected with the furnace body 1 in a sealing manner.

Specifically, the furnace body 1 is in a cylindrical structure, the partition plate 11 is arranged in the inner cavity of the furnace body 1, the partition plate 11 extends along the horizontal direction to divide the inner cavity of the furnace body 1 into two chambers which are arranged up and down, the chamber at the upper end of the partition plate 11 is a process chamber 101, and when a heat treatment process such as annealing and diffusion is performed on a wafer, specific gas needs to be introduced into the process chamber 101 as process gas or shielding gas to meet the processing requirement.

The chamber at the lower end of the partition plate 11 is an air inlet chamber 102, and air enters the process chamber 101 through the air inlet chamber 102, and the air inlet chamber 102 is connected with the process chamber 101 through an air inlet assembly 2 so as to supply air into the process chamber 101 from the outer side of the furnace body 1.

In some embodiments, the air inlet chamber 102 is provided with a first fixing ring 12, the first fixing ring 12 is arranged on the inner wall of the furnace body 1 and extends along the circumferential direction of the furnace body 1 in a closed manner, the first fixing ring 12 is provided with a plurality of positioning holes, the positioning holes are arranged in one-to-one correspondence with the air supply pipes 22 of the air inlet assemblies 2, the positioning holes penetrate through the first fixing ring 12 along the length direction of the furnace body 1, and at least part of the air inlet pipes 21 can be matched into the positioning holes for positioning.

Therefore, the second pipe section 211 is assembled in the positioning hole, and the air inlet pipe 21 is assembled in the second pipe section 211, so that the position of the second pipe section 211 of the air inlet pipe 21 is limited through the positioning hole, the air inlet assembly 2 of the vertical furnace in the embodiment of the utility model is prevented from being angularly offset in the working process, the safety and the stability of equipment operation and technology are improved, and the vertical furnace in the embodiment of the utility model has the advantages of higher reliability and convenience in installation.

In some embodiments, a second fixing ring 13 is further disposed in the air inlet chamber 102, the second fixing ring 13 is disposed on the lower side of the air inlet pipe 21, the second fixing ring 13 is provided with a plurality of fasteners 131, the fasteners 131 are arranged in one-to-one correspondence with the air inlet pipes 21 of the air inlet assemblies 2, one end of each fastener 131 can be abutted against the air inlet pipe 21, and the position of each fastener 131 relative to the second fixing ring 13 is adjustable to adjust the distance between the air inlet pipe 21 and the second fixing ring 13.

Specifically, the fastening member 131 is a screw, the fastening member 131 is assembled with the second fixing ring 13 by threads, so that the height of the fastening member 131 located at the upper portion of the second fixing ring 13 is adjustable, and the upper end of the fastening member 131 can be stopped against the lower end of the first pipe section 212 by adjusting the height of the fastening member 131 located at the upper portion of the second fixing ring 13.

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", "clockwise", "counterclockwise", "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 simplifying 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, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

For purposes of this disclosure, the terms "one embodiment," "some embodiments," "example," "a particular example," or "some examples," etc., mean 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 are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While the above embodiments have been shown and described, it should be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that variations, modifications, alternatives, and variations of the above embodiments may be made by those of ordinary skill in the art without departing from the scope of the utility model.

Claims (10)

1. An air intake assembly for a vertical furnace, comprising:

the air inlet pipe is made of metal materials, is an elbow pipe comprising a first pipe section and a second pipe section, and one end of the first pipe section is connected with one end of the second pipe section;

the gas supply pipe is made of quartz material, the inner diameter of the gas supply pipe is larger than the outer diameter of the second pipe section, and the gas supply pipe is sleeved at the other end of the second pipe section.

2. The air intake assembly of a vertical furnace according to claim 1, wherein the air intake pipe is a right-angle elbow, and the extending direction of the first pipe section and the extending direction of the second pipe section are orthogonal.

3. The air intake assembly of a vertical furnace according to claim 2, wherein the air intake pipe further comprises a sleeve, the sleeve is sleeved on the outer peripheral side of the second pipe section, the inner diameter of the sleeve is larger than the outer diameter of the air supply pipe, and at least part of the air supply pipe is interposed between the second pipe section and the sleeve.

4. A vertical furnace air intake assembly according to claim 3, wherein the sleeve includes an annular portion provided on an outer peripheral side of the second pipe section and connected to an outer wall of the second pipe section, and a cylindrical portion having a lower end connected to an outer edge of the annular portion, the air supply pipe being fittable between the cylindrical portion and the second pipe section, and a lower end of the air supply pipe being fittable against the annular portion.

5. The air intake assembly of a vertical furnace of claim 4, wherein the length dimension of the barrel is less than the length dimension of the second tube segment such that at least a portion of the second tube segment extends from an end of the barrel that faces away from the first tube segment.

6. The intake assembly of a vertical furnace according to claim 4, further comprising a locking member, at least a part of the locking member being provided on an outer peripheral side of the sleeve, the sleeve being provided with a through hole, the air supply pipe being provided with an assembly groove, the through hole being opposed to the assembly groove, at least a part of the locking member being penetratable through the through hole and fitted into the assembly groove to lock the air supply pipe and the air supply pipe relatively.

7. The vertical furnace is characterized by comprising a plurality of air inlet assemblies and a furnace body, wherein the air inlet assemblies are the air inlet assemblies of the vertical furnace according to any one of claims 1-6, the air inlet assemblies are uniformly arranged at intervals along the circumferential direction of the furnace body, the furnace body extends along the vertical direction, the inner cavity of the furnace body comprises an air inlet chamber and a process chamber, an air supply pipe of at least part of the air inlet assemblies is arranged in the process chamber, the end part of the air supply pipe extends to the air inlet chamber, the air inlet pipe is arranged in the air inlet chamber, and one end of the air inlet pipe extends to the outer side of the furnace body.

8. The vertical furnace according to claim 7, wherein the furnace body comprises a partition plate which is arranged in the inner cavity of the furnace body and extends along the radial direction of the furnace body so as to divide the inner cavity of the furnace body into an air inlet chamber and a process chamber, the air supply pipe penetrates through the partition plate along the thickness direction of the partition plate, and the air supply pipe is connected with the furnace body in a sealing manner.

9. The vertical furnace according to claim 8, wherein the intake chamber is located at a lower side of the process chamber, the second pipe section of the intake pipe is connected to a lower end of the supply pipe, and at least a part of the first pipe section of the intake pipe extends to an outer peripheral side of the furnace body.

10. The vertical furnace according to claim 8, wherein a first fixing ring is arranged in the air inlet chamber, the first fixing ring is arranged on the inner wall of the furnace body and extends along the circumferential direction of the furnace body in a closed mode, the first fixing ring is provided with a plurality of positioning holes, the positioning holes are arranged in one-to-one correspondence with air supply pipes of the air inlet assemblies, the positioning holes penetrate through the first fixing ring along the length direction of the furnace body, and at least part of the air inlet pipes can be matched into the positioning holes to be positioned;

the air inlet device is characterized in that a second fixing ring is arranged in the air inlet chamber, the second fixing ring is arranged on the lower side of the air inlet pipe, a plurality of fasteners are arranged on the second fixing ring, the fasteners are arranged in one-to-one correspondence with the air inlet pipes of the air inlet assemblies, one ends of the fasteners can be stopped against the air inlet pipes, and the positions of the fasteners relative to the second fixing ring are adjustable so as to adjust the distance between the air inlet pipes and the second fixing ring.