Furnace tube

Abstract

Disclosed in the present invention is a furnace tube, comprising an outer furnace tube, an inner furnace tube, an upper furnace cover, and a lower furnace door. The upper furnace cover is mounted at the upper end of the outer furnace tube; the upper end of the inner furnace tube is hoisted on the upper furnace cover; an opening is formed at the lower end of the inner furnace tube, and a support table is provided at the opening, so that the inner furnace tube can be upward inserted into the outer furnace tube from the bottom of the outer furnace tube for mounting; the lower furnace door is mounted at the lower ends of the outer furnace tube and the inner furnace tube; a center hole is formed in the middle of the lower furnace door, used for allowing a support base of the inner furnace tube to pass through; and an axially-perforating magnetic fluid sealing assembly is sealedly mounted between the lower furnace door and the lower end of the inner furnace tube. According to the present invention, by forming an opening at the lower end of an inner furnace tube, providing a connecting member on the upper end of the inner furnace tube, and mounting a support base at the lower end of the inner furnace tube, the inner furnace tube can be inserted from the bottom of a vertical furnace for mounting, and the upper end of the inner furnace tube is directly hoisted on and connected to an upper furnace cover, thereby facilitating sealing between the upper furnace cover and the outer furnace tube, realizing a more convenient mounting mode, and reducing the sealing requirements.

Description

A furnace tube TECHNICAL FIELD

[0001] The present application relates to the technical field of solar energy, in particular to a furnace tube. BACKGROUND

[0002] The current diffusion of the photovoltaic industry, oxidation, annealing, doping, PECVD, LPCVD and other processes produce two types of vertical furnace and horizontal furnace. The structure of these two types needs to load the silicon wafer into a specific carrier and transfer it into the reaction cavity for process. Through the specific reaction gas, the specific film coating, diffusion, oxidation and thin film deposition process of the silicon wafer are realized. In the existing two-layer furnace tube design, the bottom and top wall are used to seal the two ends of the double-layer furnace tube to form a straight-through cavity. The wafer to be processed is placed in the straight-through cavity, and the heating layer on the double-layer furnace tube is used to heat the straight-through cavity or the furnace body is set as an inner and outer furnace body, and the inner furnace cavity is in a closed form.

[0003] When installing the inner and outer furnace tubes in the prior art, due to the structural limitations of the inner furnace tube, for example, the existing patent CN116499251B has an open top and a closed bottom, and a heating element is installed. In order to avoid damaging the heating element, the inner furnace tube can only be lifted from the top and inserted into the outer furnace tube from the top. If the height space of the existing processing site is limited, the lifting difficulty during the installation of the inner furnace tube is increased or the normal installation cannot be performed, which greatly increases the assembly difficulty. SUMMARY

[0004] The present application is to solve the technical problem of the prior art that the inner furnace tube can only be lifted from the top of the outer furnace tube. A furnace tube is provided.

[0005] The technical scheme adopted by the present application is:

[0006] The present application provides a furnace tube, which comprises an outer furnace tube, an inner furnace tube, an upper furnace cover, a lower furnace door and a rotating device.

[0007] The upper furnace cover is installed at the upper end of the outer furnace tube, the inner furnace tube is installed in the outer furnace tube, the upper end of the inner furnace tube is lifted on the upper furnace cover, and the lower end of the inner furnace tube is open and provided with a support table to allow the inner furnace tube to be inserted into the outer furnace tube from the bottom of the outer furnace tube and installed and supported upward.

[0008] The lower furnace door is installed at the lower end of the outer furnace tube and the inner furnace tube, the middle part of the lower furnace door is provided with a center hole for passing through the support base of the inner furnace tube, the lower furnace door and the lower end of the inner furnace tube are axially connected through a magnetic fluid sealing assembly, the upper and lower ends of the containing space between the inner furnace tube and the outer furnace tube form a closed chamber, the inner furnace tube and the outer furnace tube are provided with a heating source for heating the closed chamber, the rotating device is provided with a plurality of carrier placement positions which can be adjusted in position and angle corresponding to the closed chamber, and the transmission part for driving the carrier to rotate in the closed chamber is connected with the transmission shaft of the magnetic fluid sealing assembly.

[0009] In the first embodiment, the inner furnace tube is open at the upper end, and the inner wall is provided with a supporting flange.

[0010] In the second embodiment, the inner furnace tube is closed at the upper end and is provided with a hemispherical top cover which is protruded upward, the outer wall of the top cover is provided with an annular connecting seat which is arranged upward, the inner wall of the connecting seat is provided with a supporting flange, and the supporting flange is connected with the upper furnace cover by hoisting.

[0011] Preferably, the lower end face of the inner furnace tube is flush with the lower end face of the outer furnace tube, or the lower end face of the inner furnace tube exceeds the lower end face of the outer furnace tube, or the lower end face of the outer furnace tube exceeds the lower end face of the inner furnace tube.

[0012] Further, the inner wall of the inner furnace tube at the opening of the lower end is protruded with an annular step or is provided with a supporting flange to form the supporting platform.

[0013] Preferably, a hanging seat is connected between the upper end of the inner furnace tube and the upper furnace cover.

[0014] Further, the outer wall of the upper end of the outer furnace tube is provided with an outer sealing flange, the upper furnace cover covers the upper end faces of the outer furnace tube and the inner furnace tube, the outer edge of the upper furnace cover is sealingly connected with the outer sealing flange, the outer edge of the lower furnace door is sealingly connected with the step of the lower end of the outer furnace tube, and the inner edge of the lower furnace door is sealingly connected with the magnetic fluid sealing assembly.

[0015] Further, the outer end faces of the upper furnace cover and the lower furnace door which are away from the containing space are protruded outward to form a spherical protrusion, the inner part of the upper furnace cover is provided with a cavity, and a plurality of reinforcing ribs are arranged in the cavity and connected between the upper and lower inner walls of the cavity.

[0016] The rotating device comprises: a boat support base provided in the closed chamber of the furnace tube and provided with a plurality of carrier placement positions, the boat support base is connected with the transmission shaft of the magnetic fluid sealing assembly; and a rotating power source which is located outside the closed chamber and connected with the transmission shaft to drive the boat support base to rotate.

[0017] In the first embodiment, the boat support base comprises:

[0018] A rotating base is arranged at the bottom of the sealed chamber and connected with the transmission shaft.

[0019] A hanging plate is arranged vertically on the rotating base, and a plurality of carrier placing positions for hanging the carriers are arranged on the hanging plate.

[0020] In the second embodiment, the boat base comprises:

[0021] The rotating base has a plurality of carrier placing positions for the carriers to pass through or be placed on, and is connected with the transmission shaft.

[0022] A plurality of pairs of bearing members are arranged on both sides of each carrier placing position and are foldably arranged on the rotating base.

[0023] When the bearing members are switched to the folded state, the carriers can pass through the corresponding carrier placing positions from the bottom; and when the bearing members are switched to the unfolded state, the carriers can be placed on the bearing members.

[0024] The magnetic fluid sealing assembly is annular, has a corresponding central hole in the middle, and is divided into an inner ring portion, an outer ring portion, and a transmission shaft annularly arranged between the inner ring portion and the outer ring portion; the inner ring portion is sealingly connected with the support base at the bottom of the inner furnace tube, the outer ring portion is sealingly connected with the inner edge of the lower furnace door, and the inner ring portion and the outer ring portion are rotationally sealed with the transmission shaft.

[0025] Further, a plurality of furnace openings are formed in the lower furnace door, the size and shape of the furnace openings match the size and shape of the side surface of the carrier, each furnace opening is provided with a furnace cover, the furnace cover is connected with a driving structure, and the driving structure is used to drive the furnace cover to open or close relative to the furnace opening.

[0026] Further, an inner heating source is arranged on the inner side of the inner furnace tube, and an outer heating source is arranged on the outer side of the outer furnace tube, the inner heating source is divided into a plurality of independent heating sections, and the outer heating source and the periphery of the inner heating source are provided with a heat dissipation device.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] 1. By arranging an opening at the lower end of the inner furnace tube and a connecting piece at the upper end of the inner furnace tube, the lower end of the inner furnace tube can be installed with a support base, so that the inner furnace tube can be inserted from the bottom of the vertical furnace to complete the installation, and the upper end of the inner furnace tube is directly connected with the upper furnace cover for hoisting, which facilitates the sealing of the upper furnace cover and the outer furnace tube, and the installation method is more convenient, and the sealing requirement is reduced.

[0029] 2. The carrier in the furnace tube is placed on the rotatable boat support base, so that the carrier can be adjusted in position and angle in the furnace, so that when the reaction gas is introduced into the closed chamber or the temperature difference is raised, the gas field and the thermal field inside the closed chamber are uniform, and the overall process yield is improved.

[0030] 3. The lower furnace door and the upper furnace cover are designed as outwardly convex drum surfaces, which have better pressure bearing capacity and are not easy to deform.

[0031] 4. The bottom is sealed by a magnetic fluid sealing assembly, which can be external to the driving part of the boat support base, while ensuring that the closed chamber through which the reaction gas passes remains sealed.

[0032] 5. The lower furnace door is provided with a plurality of small furnace doors, which can be opened individually when the carrier is loaded or unloaded, thereby avoiding the loss of heat in the furnace and affecting the processing efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Fig. 1 is a front view of an embodiment of the present application;

[0035] Fig. 2 is an A-A sectional view of an embodiment of the present application;

[0036] Fig. 3 is a sectional view of the furnace tube part of an embodiment of the present application;

[0037] Fig. 4 is a sectional view of the furnace tube part of an embodiment of the present application;

[0038] Fig. 5 is a sectional view of the furnace tube part of an embodiment of the present application;

[0039] Fig. 6 is an enlarged view of the lower part of Fig. 2 of the present application;

[0040] Fig. 7 is a position relationship diagram of the furnace tube heating source and the heat dissipation device in the horizontal sectional view of the present application;

[0041] Fig. 8 is a front view of the first embodiment of the boat support base of the present application;

[0042] Fig. 9 is a structural diagram of the second embodiment of the boat support base of the present application;

[0043] Fig. 10 is a perspective structural diagram of the second embodiment of the boat support base of the present application;

[0044] Fig. 11 is a perspective structural diagram of the bottom view of the present application;

[0045] Fig. 12 is a perspective view of the lower furnace door in an embodiment of the present application;

[0046] Fig. 13 is a structural view of the lower furnace door and the driving structure in an embodiment of the present application;

[0047] Fig. 14 is a perspective view of the driving structure cooperating with the furnace cover in an embodiment of the present application;

[0048] Fig. 15 is a structural view of the driving structure cooperating with the furnace cover in an embodiment of the present application;

[0049] Fig. 16 is a structural view of the driving structure cooperating with the furnace tube in an embodiment of the present application;

[0050] 1. furnace tube;

[0051] 11. outer furnace tube; 111. support flange; 112. outer sealing flange; 12. inner furnace tube; 121. support flange; 122. annular step; 123. annular heat insulation pad; 125. top cover; 126. connecting seat; 13. sealed chamber;

[0052] 2. upper furnace cover;

[0053] 21. reinforcing rib; 22. lower layer plate; 23. inner layer plate; 24. outer layer plate;

[0054] 3. lower furnace door;

[0055] 31. furnace opening; 311. first protrusion; 312. annular cavity;

[0056] 32. furnace cover; 321. second protrusion; 322. mounting plate; 323. first guide column; 324. weight-reducing hole;

[0057] 33. driving structure; 331. rotary driving device; 332. shaft coupling; 333. rotary shaft; 334. rotary plate; 335. push-pull driving device; 336. mounting area; 337. second guide column; 338. first electrical interface; 339. second electrical interface; 340. connecting plate; 341. first partition plate; 342. second partition plate; 343. third partition plate; 344. first containing space; 345. second containing space;

[0058] 5. boat support base; 50. carrier; 591. gear;

[0059] 51. rotary base; 52. fixing ring; 53. hanging plate; 54. hook hole;

[0060] 501. carrier placement position; 55. carrier; 551. carrier fixed part; 552. carrier movable part; 553. rotary shaft;

[0061] 6. magnetic fluid sealing assembly;

[0062] 61, outer ring part; 62, inner ring part; 59, transmission shaft;

[0063] 71, external heating source; 72, internal heating source; 73, heat dissipation device; 74, water cooling interface. DETAILED DESCRIPTION

[0064] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0065] The principles and structures of the present application will be described in detail below in combination with the drawings and examples.

[0066] The existing vertical furnace generally has inner and outer double-layer furnace pipes. When the inner and outer furnace pipes are installed, due to the structural limitation of the inner furnace pipe, for example, the existing patent CN116499251B has an open top and a closed bottom, and a heating element is installed at the bottom, so that the inner furnace pipe can only be hoisted at the top opening and inserted from the top of the outer furnace pipe. If the height space of the existing processing site is limited, the hoisting difficulty during the installation of the inner furnace pipe is increased or the normal installation cannot be performed, which greatly increases the assembly difficulty.

[0067] To this end, as shown in FIGS. 1, 2, 7, and 7, the present application proposes a furnace pipe 1, which includes an outer furnace pipe 11, an inner furnace pipe 12, an upper furnace cover 2, a lower furnace door 3, and a rotating device;

[0068] Both the inner and outer furnace pipes are in a circular pipe shape, wherein the upper and lower ends of the outer furnace pipe 11 are open, and the inner furnace pipe 12 is installed inside. After installation, a containing space is formed between the outer wall of the inner furnace pipe 12 and the inner wall of the outer furnace pipe;

[0069] The lower end of the inner furnace pipe 12 is open, the inner side of the inner furnace pipe 12 is provided with an internal heating source 72, the upper end is provided with a connecting piece for hoisting connection with the upper furnace cover 2, and a support table is arranged at the lower end opening. The support table can install a support base, so that the inner furnace pipe 12 can be inserted into the outer furnace pipe 11 from the bottom of the outer furnace pipe 11 for installation;

[0070] The upper furnace cover 2 and the lower furnace door 3 are installed at the upper end and the lower end of the outer furnace pipe 11 and the inner furnace pipe 12, respectively, for sealing the upper end and the lower end of the containing space between the inner furnace pipe 12 and the outer furnace pipe 11 to form a sealed chamber 13 (which needs to be matched with a sealing assembly) to meet the process requirement of vacuumizing. The inner side of the inner furnace pipe 12 is provided with an internal heating source 72, and the outer side of the outer furnace pipe 11 is provided with an external heating source 71. The internal and external heating sources can heat the sealed chamber 13 of the furnace pipe 1 through the pipe walls of the inner and outer furnace pipes;

[0071] The rotating device is provided with a plurality of carrier placing positions corresponding to the closed chamber, and the rotating device drives the carrier on the carrier placing position to adjust the position and angle in the closed chamber when the rotating device rotates, so that the silicon wafer on the carrier is uniformly heated.

[0072] The inner furnace tube is provided with an opening at the lower end, and the upper end of the inner furnace tube is provided with a connecting piece, the opening at the lower end is provided with a support table to install a support base, so that the installation of the inner furnace tube can be completed by inserting from the bottom of the vertical furnace, and the upper end of the inner furnace tube is directly connected with the upper furnace cover for hoisting, which facilitates the sealing of the upper furnace cover and the outer furnace tube, and the installation mode is more convenient, the sealing requirement is reduced, and the carrier in the furnace tube is placed on the rotating device which can rotate, so that the carrier can adjust the position and angle in the furnace, the gas field and the thermal field in the closed chamber are uniform when the reaction gas is introduced or the temperature difference is increased, and the overall process yield is improved.

[0073] The upper end structure of the inner furnace tube has various embodiments, and two embodiments are specifically proposed as follows:

[0074] The upper end of the inner furnace tube 12 is opened, that is, the inner furnace tube is an axially penetrating furnace tube, and the inner wall at the upper end opening of the inner furnace tube 12 is provided with a circle of support flanges 121, which are connecting pieces, so that the inner furnace tube can be directly connected with a hanging seat (not shown in the figure) or a connector (not shown in the figure) on the support flanges 121. The connector can be used for hoisting the inner furnace tube during installation, and after hoisting is completed, the connector can be detached and the hanging seat is installed to be directly connected with the inner side of the upper furnace cover 2, so that the upper end of the inner furnace tube 12 is hung on the upper furnace cover 2 (or the connector is directly connected with the upper furnace cover).

[0075] It should be noted that although the connection relationship between the inner furnace tube 12 and the upper furnace cover 2 is not directly shown in the figure, the support connected by screws and flanges can be easily implemented by those skilled in the art. The present application mainly indicates that the upper furnace cover 2 is directly sealed and connected with the outer furnace tube 11, and the inner furnace tube 12 is located on the inner side of the upper furnace cover, so as to reduce the number of components required for sealing and connecting at the upper end of the furnace tube and reduce the installation difficulty.

[0076] Specifically, the connector or the hanging seat for hanging is installed on the support flange by screw connection, and the hanging seat is directly fixed to the inner side of the upper furnace cover 2 by screws, so as to ensure that the entire inner furnace tube 12 is stably hung during use.

[0077] The second embodiment is shown in Fig. 3, the upper end of the inner furnace tube 12 is closed, and a hemispherical top cover 125 protrudes upward, the outer wall surface of the top cover 125 is provided with a ring-shaped connecting seat 126 protruding upward, the inner wall of the connecting seat 126 is provided with a circle of support flanges (not shown in the figure), and the support flanges are connected with the upper furnace cover for hoisting.

[0078] Specifically, as shown in FIG. 1 and FIG. 2, the outer wall of the outer furnace tube 11 is provided with a support flange 111 near the lower end surface, which can be used to install a bottom support (not shown in the figure). The bottom support can be used to assist in fixing the peripheral components of the furnace tube, such as water cooling pipes, etc., and can also be used to support the entire furnace tube during installation.

[0079] In specific embodiments, the support platform at the lower end of the inner furnace tube 12 also has various configurations. Two specific embodiments are described below.

[0080] In the first embodiment, as shown in FIG. 6, the inner wall of the inner furnace tube 12 at the lower end is provided with a ring-shaped step 122. The lower surface of the ring-shaped step 122 can be used as a support platform to install or connect a support base that can stabilize the bottom of the inner furnace tube.

[0081] In the second embodiment, a ring-shaped support flange (not shown in the figure) is installed on the inner wall of the inner furnace tube 12 near the lower end. The support flange is used to connect a support base to support the bottom of the inner furnace tube.

[0082] In further embodiments of the above two embodiments, as shown in FIG. 2, the ring-shaped step or the support flange can be provided with a ring-shaped heat insulation pad 123. The ring-shaped heat insulation pad 123 can be used as a support base, and the lower end of the ring-shaped heat insulation pad 123 can extend beyond the lower end of the inner furnace tube 12, thereby providing both support and heat insulation.

[0083] Specifically, the ring-shaped heat insulation pad 123 is connected and fixed to the ring-shaped step or the support flange of the inner furnace tube 12 in a sealed manner, i.e., the connection between the ring-shaped heat insulation pad 123 and the inner furnace tube is in a sealed state.

[0084] In specific embodiments, as shown in FIG. 3, FIG. 4, FIG. 5, FIG. 6, and FIG. 11, the central hole of the lower furnace door 3 can extend through the lower end of the inner furnace tube 12. The lower end surface of the inner furnace tube can be flush with the lower end surface of the outer furnace tube, or the lower end surface of the inner furnace tube can extend beyond the lower end surface of the outer furnace tube, or the lower end surface of the outer furnace tube can extend beyond the lower end surface of the inner furnace tube, all of which are within the scope of the present application.

[0085] Specifically, as shown in FIG. 2, the structure and sealed connection of the upper furnace cover 2 are as follows:

[0086] The outer end surface of the upper furnace cover 2 is outwardly convex to form a spherical protrusion. Since the sealed chamber 13 needs to be vacuumed, the outwardly convex spherical protrusion of the outer end surface of the upper furnace cover can withstand greater pressure and prevent the internal vacuum from being deformed.

[0087] The inner part of the upper furnace cover 2 is further provided with a lower layer plate 22, an outer layer plate 24 and an inner layer plate 23 which cooperate with the inner side of the outer end face to form a cavity, all of which are annular, forming an annular cavity on the inner side of the outer end face of the upper furnace cover 2, and a plurality of reinforcing ribs 21 are arranged in the annular cavity, specifically between the upper and lower inner walls of the cavity, the reinforcing ribs 21 are plate-shaped and have a plurality of through holes on the plate surface, and the reinforcing ribs 21 are arranged in an annular manner in the annular cavity.

[0088] Preferably, the lower layer plate 22, the outer layer plate 24 and the inner layer plate 23 are hollow layer plates, and the inside of the hollow layer plates can be used as a water cooling channel or a water cooling component such as a water cooling pipe is installed, etc., to avoid heat dissipation from the upper furnace cover affecting the processing.

[0089] As shown in FIG. 2, the sealing method of the top of the furnace tube is specifically implemented as follows:

[0090] The outer wall of the upper end of the outer furnace tube 11 is provided with an outer sealing flange 112 (the outer sealing flange is located above the support flange), the upper furnace cover 2 is circular as a whole, the upper furnace cover 2 covers the upper end face of the outer furnace tube and the inner furnace tube, the outer edge thereof is buckled to the upper end face of the outer furnace tube 11 and is sealingly connected with the outer sealing flange 112 of the outer furnace tube 11, so that the upper end face of the entire furnace tube is directly sealed.

[0091] The sealing connection method of the specific sealing flange and the upper furnace cover is a conventional sealing means in the prior art, for example, screws, gaskets, sealing rings, etc. are also needed, and those skilled in the art can completely reproduce it, and no repeated description is made in the present application.

[0092] As shown in FIGS. 6 and 11, in a specific embodiment, a magnetic fluid sealing assembly is sealingly connected at the central hole of the lower furnace door for rotary sealing of the rotating device. The magnetic fluid sealing assembly is vertically axially hollow, so that the support base of the inner furnace tube can be supported by passing through the external support of the magnetic fluid sealing assembly, so that the overall structure is stable and reliable.

[0093] Further, the rotating device specifically comprises a boat support base and a rotary power source. The boat support base is arranged in the sealed chamber of the furnace tube and has a plurality of carrier placing positions, the inner edge of the bottom of the boat support base is protruded downward by a circle and is connected with the transmission shaft of the magnetic fluid sealing assembly, so that the boat support base follows the rotation of the rotating shaft when the rotating shaft rotates; the rotary power source is directly connected with the transmission shaft of the magnetic fluid sealing assembly at the lower end outside the sealed chamber of the furnace tube, so as to provide a power source outside the furnace tube, avoiding the influence of high temperature in the furnace on the normal operation of the rotary power source, that is, because the temperature in the furnace tube is about 500° or above, the motor as the rotary power source cannot work normally at this temperature, and the external placement of the rotary power source can ensure the normal operation of the rotating device.

[0094] By setting the rotatable boat holder base 5, the position and angle of the carrier can be adjusted, so that when the reaction gas is introduced into the closed chamber or the temperature difference is increased, the gas field and the heat field inside the closed chamber are uniform, and the overall process yield is improved.

[0095] Specifically, as shown in FIG. 2, the magnetic fluid sealing assembly 6 is located at the bottom of the furnace tube 1, and specifically includes an annular outer ring portion 61, an inner ring portion 62, and a transmission shaft 59. The top surface of the outer ring portion 61 is sealingly connected with the edge of the central hole of the lower furnace door 3, and a first sealing ring 611 can be seen in the figure. The top surface of the inner ring portion 62 is sealingly connected with the lower end surface of the annular heat insulation pad 123 at the bottom of the inner furnace tube 12, and a second sealing ring 621 can be seen in the figure. The gap between the inner ring portion 62 and the outer ring portion 61 of the magnetic fluid sealing assembly 6 is a rotating sealing space in the form of an annulus, and the transmission shaft 59 penetrates the rotating sealing space of the magnetic fluid sealing assembly 6.

[0096] The inside of the boat holder base 5 surrounds the inner furnace tube 12 and has a plurality of carrier placement positions 501. The rotating base 51 at the bottom is annular and penetrates the central hole of the lower furnace door. The rotating base 51 is connected with the annular transmission shaft 59 below. The upper end of the transmission shaft 59 is connected with the bottom of the rotating base 51 and penetrates the rotating sealing space of the magnetic fluid sealing assembly 6. The lower end of the transmission shaft 59 is located outside the furnace tube and is rotatably connected with the rotating power source by a gear or a belt pulley. Thus, the rotating power source drives the entire boat holder base 5 to rotate around the inner furnace tube 12 through the transmission shaft 59.

[0097] The gap between the inner wall surface of the transmission shaft 59 and the outer wall surface of the inner ring portion 62 of the magnetic fluid sealing assembly is provided with magnetic fluid (not shown in the figure). Specifically, a plurality of annular grooves can be provided on the inner wall surface of the transmission shaft 59 or on the outer wall surface of the inner ring portion of the magnetic fluid sealing assembly to place the magnetic fluid, thereby forming a plurality of sealing rings in the gap between the inner wall surface of the transmission shaft 59 and the outer wall surface of the inner ring portion 62 of the magnetic fluid sealing assembly 6.

[0098] The outer wall surface of the transmission shaft and the inner wall surface of the outer ring portion of the magnetic fluid sealing assembly are also provided with magnetic fluid in the same way. Permanent magnets are arranged inside the outer ring portion 61 and the inner ring portion 62, and the magnetic poles serve as the inner wall of the rotating sealing space, so that the magnetic fluid can surround the transmission shaft 59, thereby forming a plurality of sealing rings in the gap between the outer wall surface of the transmission shaft and the inner wall surface of the outer ring portion of the magnetic fluid sealing assembly.

[0099] Specifically, the outer edge of the lower furnace door 3 is sealingly connected with the step of the bottom end of the outer furnace tube 11, and the inner edge of the lower furnace door 3 is sealingly connected with the outer ring part 61 of the magnetic fluid sealing assembly 6, that is, the annular heat insulation pad (supporting base) at the bottom of the inner furnace tube, the inner edge of the lower furnace door, and the transmission shaft (in the form of a tube and also called a transmission tube) passing through the magnetic fluid sealing assembly are directly sealingly connected, thereby sealing the lower end of the closed chamber 13 in the furnace tube 1.

[0100] In a specific embodiment, the transmission shaft 59 is provided with a ring of gears 591 on the outer wall surface of the rotating sealing space of the magnetic fluid sealing assembly 6, and the rotating power source drives the internal boat support base in the form of external motor gear transmission.

[0101] In other embodiments, a belt pulley can also be provided on the outer wall surface of the rotating sealing space of the magnetic fluid sealing assembly through which the transmission shaft passes, and the rotating power source drives the transmission shaft in the form of belt pulley transmission.

[0102] As shown in FIG. 8, the first embodiment of the boat support base is as follows:

[0103] The boat support base comprises a rotating base 51, a fixed ring 52, and a hanging plate 53.

[0104] The rotating base 51 is in the form of a disc, and a plurality of hanging plates are vertically and spacedly arranged along the annular edge of the upper surface of the base. The fixed ring 52 is connected to the top of the hanging plate 53 to fix the top of the hanging plate 53, so that the hanging plate 53 is in a stable vertical state. The outer side surface of the hanging plate 53 is provided with a plurality of hanging and taking places (i.e., carrier placing positions) along the length direction, which are used for suspending the carriers, that is, the hanging plate 53 can hang a plurality of carriers 50 along the height direction. Specifically, the carriers 50 can be hung at different heights of the boat support base, so that the carriers can be hung in multiple layers along the height direction of the entire boat support base.

[0105] The annular transmission shaft 59 is connected to a ring along the inner edge of the rotating base 51, which can support the rotating base 51 and drive the rotating base 51 to rotate around the central axis. When the rotating base 51 rotates, the carriers 50 located on the outer side surface of the hanging plate 53 rotate around the central axis of the base center, so that the position and angle of the carriers can be changed during the processing.

[0106] In a specific embodiment, the hanging and taking place of the hanging plate 53 is provided with a hook hole 54 for hanging the carriers. The upper part of the hook hole 54 is wider, and the lower part is narrower, which facilitates the hanging of the carriers.

[0107] The carrier 50 is a vertical quartz boat, which is provided with a hook that can be downwardly clamped into the hook hole. The hook of the vertical quartz boat is clamped into the hook hole, so that the vertical quartz boat is hung in the hanging and taking place.

[0108] Specifically, the side surface of each vertical quartz boat is provided with two hooks in the height direction, and each two hook holes on the hanging plate correspond to hanging one vertical quartz boat. In a specific embodiment, each hanging plate 53 can hang two vertical quartz boats in the height direction, so that the quartz boats can be arranged in two circles around the boat holder base, thereby allowing multiple vertical quartz boats hung on the boat holder base to be heated in various forms such as layered heating, local heating, and overall heating.

[0109] As shown in FIGS. 9 and 10, the second embodiment of the boat holder base is:

[0110] The boat holder base comprises a rotating base 51 and a plurality of pairs of bearing members 55. The rotating base 51 has a plurality of carrier placement positions 501 for the carriers to pass through or be placed. Each pair of bearing members 55 is located at the two side edges of a carrier placement position 501 and is foldably arranged on the rotating base 51. Meanwhile, each pair of bearing members 55 has a folded state and an unfolded state. If a carrier 50 is to be placed, each pair of bearing members 55 is switched to the folded state, so that the carrier 50 can pass through the carrier placement position 501 from the bottom upwards. When the bottom of the carrier 50 moves above the horizontal plane of the carrier placement position 501, each pair of bearing members 55 is switched to the unfolded state, so that the carrier 50 is placed on the bearing members. Subsequently, if the carrier 50 is to be taken out, each pair of bearing members 55 is switched to the folded state, so that the carrier 50 can pass through the carrier placement position 501 and be taken out from the furnace door, thereby realizing the taking and placing of the carrier boat.

[0111] In each pair of bearing members 55, each bearing member 55 comprises a bearing fixed part 551 and a bearing movable part 552. The bearing fixed part 551 is fixedly arranged on the rotating base 51, and the bearing movable part 552 is rotatably arranged on the bearing fixed part 551. In each bearing member 55, the bearing fixed part is provided with a rotating shaft 553, and the bearing movable part 552 comprises two opposite first bearing rods and a second bearing rod connected with the two first bearing rods. The two bearing rods are sleeved on the two ends of the rotating shaft away from the second bearing rod. It can be understood that the rotating base further comprises a driving member (not shown in the figure), which is used to drive the rotating shaft to rotate. The driving member can be a motor. In addition, the rotating base further comprises a self-locking support structure (not shown in the figure), which is used to limit the rotation angle of the bearing movable part.

[0112] When each pair of bearing members 55 is in the folded state, the bearing movable part 552 in each bearing member 55 is arranged away from the carrier placement position 501. When each pair of bearing members 55 is in the unfolded state, the bearing movable part 552 in each bearing member 55 is arranged towards the carrier placement position and abuts against the carrier.

[0113] In the case that the rotation angle of the bearing active part in each bearing part 55 is 90 degrees, each pair of bearing parts 55 is in the folded state, and the bearing active part 552 in each bearing part 55 is in the vertical state, the bearing active part 552 in each bearing part 55 does not interfere with the carrier placement position 501 of the rotating base 51, and thus does not interfere with the up-and-down movement of the carrier boat. In the case that each pair of bearing parts is in the unfolded state, and the bearing active part in each bearing part is in the horizontal state, the bearing active part in each bearing part extends into the carrier placement position of the rotating base, and thus can bear the carrier boat.

[0114] In the embodiment, in any two adjacent pairs of bearing parts, one bearing fixed part belonging to one pair of bearing parts is connected to one bearing fixed part belonging to another pair of bearing parts. In actual application, in any two adjacent pairs of bearing parts, the two bearing fixed parts connected to each other can be integrally formed. Such design can reduce the number of parts and save installation time.

[0115] In the embodiment, the carrier placement position 501 is a notch arranged on the rotating base 51. The shape and size of the carrier placement position 501 are matched with the shape and size of the carrier boat, so that the carrier boat can smoothly pass through the carrier placement position. It can be understood that in other embodiments, the carrier placement position can be a through hole arranged on the rotating base.

[0116] [Corrected according to Rule 91 on 26.03.2025] As shown in FIG. 10, the carriers can be stacked in the height direction, that is, multiple carriers can be placed on one carrier placement position, and in order to avoid the carriers from falling, a circle of vertical guardrails can be arranged along the outer edge of the rotating base. Since the inner edge of the rotating base is close to the outer wall of the inner furnace tube, the outer wall of the inner furnace tube and the guardrails can ensure that the stacked carriers will not fall.

[0117] Specifically, as shown in FIGS. 12 to 16, the lower furnace door structure is specifically implemented as follows:

[0118] In the first embodiment, the lower furnace door 3 is an integral whole, and a central hole is arranged in the middle part. When the lower furnace door is opened, the entire lower furnace door is directly opened.

[0119] Further, the lower furnace door 3 is protruded downward to form a drum surface, that is, a spherical protruding structure is arranged. Like the upper furnace cover, the lower furnace door can bear greater pressure.

[0120] In the second embodiment, the middle part of the lower furnace door 3 is provided with a center hole, and a plurality of small furnace doors, i.e. furnace openings 31, and furnace covers 32 corresponding to each small furnace door are arranged on the lower furnace door. The size and shape of the furnace openings 31 match the size and shape of the carrier side surface, and specifically, the shape of the furnace openings 31 can be consistent with the shape of the carrier side surface, and the size is slightly larger than the size of the carrier side surface, so that the carrier can just pass through the furnace openings 31. The furnace covers 32 are connected with driving structures 33, which are used to drive the furnace covers 32 to open or close relative to the furnace openings 31, so that the small furnace doors can be opened individually, reducing the heat loss in the furnace tube.

[0121] In the present embodiment, the lower furnace door 3 and the furnace cover 32 are preferably downwardly convex spherical convex structures. The lower furnace door and the furnace cover can withstand greater pressure, so that the lower furnace door and the furnace cover are not sucked flat when the sealed space in the furnace tube is vacuumized, causing damage to the lower furnace door.

[0122] In order to make the furnace cover 32 better fit the corresponding furnace opening 31, improve the sealing performance, and reduce the heat loss in the furnace tube, the side of the furnace opening 31 facing the furnace cover 32 is provided with a first protrusion 311, which forms an annular cavity 312 around the circumference of the furnace opening 31, and the furnace opening 31 is completely located in the annular cavity 312.

[0123] The furnace cover 32 matched with the furnace opening 31 is provided with a second protrusion 321 on the side facing the furnace opening 31, which can be matched and inserted into the annular cavity 312. In order to further improve the sealing performance between the furnace cover 132 and the corresponding furnace opening 31, a high-temperature-resistant sealing strip can also be arranged around the second protrusion 321.

[0124] Specifically, the driving structure 33 includes a rotating driving device 331, a shaft coupling 332, a rotating shaft 333, a rotating plate 334, a push-pull driving device 335, and a connecting plate 340.

[0125] Among them, the rotating driving device 331 is preferably a rotating motor, and the push-pull driving device 335 is preferably a push-pull motor.

[0126] The lower furnace door 3 is provided with a rotating driving device 331 on one side corresponding to each of the furnace openings 31. The rotating end of the rotating driving device 331 is connected with the rotating shaft 333 through the coupling 332. The end of the rotating shaft 333 is connected with a rotatable rotating plate 334. The rotating plate 334 is located in front of the furnace opening 31. The coupling 332 can firmly connect the rotating end of the rotating driving device 331 and the rotating shaft 333. The rotating end of the rotating driving device 331 and the rotating shaft 333 rotate together and transmit torque and motion. The relative position between the rotating end of the rotating driving device 331 and the rotating shaft 333 remains unchanged during the transmission of motion and power, so as to realize reliable transmission. The coupling 332 can also compensate for the deviation of the rotating end of the rotating driving device 331 and the rotating shaft 333, so as to ensure the continuity and stability of the transmission. The coupling 332 can also absorb impact and vibration, reduce the wear and failure risk of the rotating end of the rotating driving device 331 and the rotating shaft 333, and improve the stability and reliability of the driving structure 33.

[0127] The middle part of the rotating plate 334 is bolted with a push-pull driving device 335. The push-pull end of the push-pull driving device 335 penetrates the rotating plate 334 and is connected with the furnace cover 32.

[0128] Specifically, the driving structure 33 further comprises a first partition plate 341 and a second partition plate 342 arranged at one end of a connecting plate 340, and a third partition plate 343 arranged at the other end of the connecting plate 340; a first accommodating space 344 is formed between the first partition plate 341, the second partition plate 342 and the corresponding part of the connecting plate 340; a second accommodating space 345 is formed between the second partition plate 342, the third partition plate 343 and the corresponding part of the connecting plate 340; and a through hole (not shown, the same below) is arranged at the same position of the first partition plate 341, the second partition plate 342 and the third partition plate 343. The rotating driving device 331 is fixed on the side of the third partition plate 343 away from the second partition plate 342, and then the rotating end of the rotating driving device 331 is connected with the coupling 332 through the through hole of the third partition plate 343, and the coupling 332 is located in the second accommodating space 345; one end of the rotating shaft 333 is rotatably connected in the through hole of the first partition plate 341, and the other end of the rotating shaft 333 is connected with the coupling 332 through the through hole of the second partition plate 342, and the rotating plate 334 is sleeved on the rotating shaft 333 located in the first accommodating space 344. In this way, the first accommodating space 344 and the second accommodating space 345 can effectively isolate the space between the coupling 332 and the rotating shaft 333 sleeved with the rotating plate 334, can prevent accidental contact due to mechanical failure or improper operation, reduce the potential risk of injury, and protect the safety of workers and equipment; and the first accommodating space 344 and the second accommodating space 345 can reduce the mutual influence between the coupling 332 and the rotating shaft 333 sleeved with the rotating plate 334, prevent the vibration and force generated when the rotating driving device 331 works from being transmitted between the coupling 332 and the rotating shaft 333 sleeved with the rotating plate 334, and improve the stability of the entire driving structure 33.

[0129] The lower furnace door further comprises a control unit, the rotating driving device 331 is provided with a first electrical interface 338, the push-pull driving device 335 is provided with a second electrical interface 139, and the first electrical interface 338 and the second electrical interface 339 are both used for electrically connecting with the control unit for controlling the furnace door structure.

[0130] In this way, when the furnace cover 32 needs to be opened relative to the furnace port 31, the worker clicks start on the operation panel corresponding to the control unit, and when the control unit receives the opening signal sent by the operation panel, the push-pull driving device 335 is first started to control the furnace cover 32 to move away from the corresponding furnace port 31, and when the furnace cover 32 is not in contact with the corresponding furnace port 31, the control center closes the push-pull driving device 335, and at the same time, the rotating driving device 331 is started, at this time, the rotating driving device 331 controls the rotating plate 334 and the furnace cover 32 located on the rotating plate 334 to move to the outside away from the center of the furnace cover 32, so that the corresponding furnace port 31 is completely exposed, the control unit closes the rotating driving device 331, and then the worker places the carrier with the wafer to be processed into the furnace port 31 and then places it in the furnace tube 1, and then the process is performed, that is, the specific reaction gas is introduced into the furnace tube 1, so as to realize the specific film coating, diffusion, oxidation and thin film deposition process on the wafer to be processed.

[0131] When the furnace cover 32 needs to be closed relative to the furnace port 31, the worker clicks close on the operation panel corresponding to the control unit, and when the control unit receives the closing signal sent by the operation panel, the control unit first starts the rotating driving device 331 to control the rotating plate 334 and the furnace cover 32 located on the rotating plate 334 to move to the inside away from the center of the furnace cover 32 for resetting, and then the control center closes the rotating driving device 331, and at the same time, the push-pull driving device 335 is started to control the furnace cover 32 to move close to the corresponding furnace port 31, until the second protrusion 321 of the furnace cover 32 matches the insertion into the annular cavity 312 of the corresponding furnace port 31, so that the furnace cover 32 completely covers the corresponding furnace port 31, and then the control unit closes the push-pull driving device 335.

[0132] The side of the furnace cover 32 facing the rotating plate 334 is further provided with a rectangular mounting plate 322, the push-pull end of the push-pull driving device 335 is connected with the middle part of the mounting plate 322, and the mounting plate 322 is connected with the furnace cover 32 through the first guide column 323 around. The mounting plate 322 can share part of the weight and load between the furnace cover 32 and the push-pull driving device 335, enhance the stability and reliability of the overall structure; and the mounting plate 322 can also absorb the vibration and impact force generated when the furnace cover 32 rotates, so as to reduce the damage to the furnace cover 32 and the push-pull driving device 335, and prolong the service life thereof; and the mounting plate 322 can be connected with the furnace cover 32 through the first guide column 323, so that the relative position between the furnace cover 32 and the push-pull driving device 335 can be better adjusted, and the accuracy and stability of the rotation of the furnace cover 32 can be ensured.

[0133] And the mounting plate 322 is also provided with a plurality of lightening holes 324, which can reduce the weight of the mounting plate 322, and make the rotary drive device 331 and the push-pull drive device 335 better control the movement of the furnace cover 32.

[0134] Wherein, the middle part of the rotating plate 334 is provided with a rectangular mounting area 336, and the middle part of the mounting area 336 is provided with a push-pull drive device 335, and the mounting area 336 is connected with the mounting plate 322 through the second guide column 337 around.

[0135] The second guide column 337 in the embodiment is taken as an example of being mounted at the four corners of the mounting area 336.

[0136] The second guide column 337 can ensure that the relative position between the mounting plate 322 and the furnace cover 32 is accurately aligned, so that in the rotating process of the furnace cover 32, the second guide column 337 can guide the mounting plate 322 and the furnace cover 32 to move along the predetermined path, prevent it from deviating from the correct position or offset, which helps to maintain the stability and accuracy of the rotation of the furnace cover 32.

[0137] In a specific embodiment, the outer heating source and the inner heating source are an integral whole, that is, directly wrapped around the inner and outer furnace pipes in the form of an electric heating wire, directly heating the closed cavity.

[0138] As shown in Figure 7, in a preferred embodiment, the outer heating source 71 and the inner heating source 72 are both arranged in a ring shape and arranged along the height direction of the inner and outer furnace pipes. Specifically, it can be divided into multiple independent heating sections along the height direction of the furnace pipe, and the boat support base can also be correspondingly layered and hung to place the carrier along the height direction, so as to achieve layered corresponding heating and improve the overall heating efficiency.

[0139] Alternatively, the outer heating source and the inner heating source are divided into multiple independent heating sections, and the multiple heating sections are arranged around the inner and outer furnace pipes.

[0140] The inner and outer heating sources can specifically adopt resistance wire heating furnace pipe, infrared heating, electromagnetic induction heating, etc.

[0141] In a further embodiment, as shown in Figure 7, a heat dissipation device 73 is arranged around the outer heating source 71 and the inner heating source 72 to quickly and stably adjust the temperature of the reaction furnace pipe. The heat dissipation device can be independent or integrated with the heating device. The heat dissipation device can be manually controlled or automatically controlled by collecting temperature signals, pressure signals, etc. Any automatic control method is included in this range. The heat dissipation device 73 can adopt air cooling structure or water cooling structure. But not limited to the above structure, any mechanism with heat exchange and heat dissipation function is included in this range.

[0142] Specifically, the outer furnace tube 11 and the end surface positions of the upper furnace cover and the lower furnace door 3 in Figure 6 are provided with water cooling joints 74 for supplying water to the heat dissipation devices arranged inside.

[0143] As shown in the figure, the bottom of the furnace tube is provided with a water sliding ring at the position inside the bottom support for supplying water to the water cooling pipeline (not shown in the figure).

[0144] In a specific embodiment, the inner and outer furnace tubes are specifically quartz tubes or silicon nitride tubes. The furnace tube proposed in the present application adopts a through design for the inner furnace tube, which can be hoisted from the top or supported from the bottom and inserted upward for installation, so as to diversify the installation mode of the inner furnace tube.

[0145] The carrier in the furnace tube is placed on a rotatable boat support base, so that the carrier can be adjusted in position and angle in the furnace, so that the gas field and thermal field inside the sealed chamber are uniform when the reaction gas is introduced or the temperature difference is raised, and the overall process yield is improved.

[0146] The lower furnace door and the upper furnace cover are designed to have outwardly convex drum surfaces, which have better pressure bearing capacity and are not easy to deform.

[0147] The bottom is sealed by a magnetic fluid sealing assembly, which can be external to the driving components of the boat support base, while ensuring that the sealed chamber through which the reaction gas passes remains sealed.

[0148] Moreover, the lower furnace door is provided with a plurality of small furnace doors, which can be opened when the carrier is loaded or unloaded, so as to avoid the loss of heat in the furnace affecting the processing efficiency.

[0149] It should be noted that the terms used above are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that, when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0150] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims, along with full equivalents thereof.

[0151] In the description of the present application, it is to be understood that the orientation or positional relationships indicated by terms such as "front", "back", "up", "down", "left", "right", "lateral", "vertical", "horizontal", "top", "bottom", and the like are generally based on the orientation or positional relationships shown in the drawings, and are merely intended to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the scope of protection of the present application. The orientation terms "inner", "outer" refer to the inner and outer relative to the contour of the components themselves.

[0152] For the convenience of description, spatial relative terms such as "above", "upper", "top", "up", "lower", "bottom", and the like can be used herein to describe the spatial position relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device as described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0153] In addition, it should be noted that the use of the terms "first", "second", and the like do not have a special meaning, and therefore should not be construed as limiting the scope of protection of the present application, unless otherwise stated.

[0154] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A furnace tube characterized by, The furnace comprises an outer furnace tube, an inner furnace tube, an upper furnace cover, a lower furnace door and a rotating device. The upper furnace cover is installed on the upper end of the outer furnace tube, the inner furnace tube is installed in the outer furnace tube, the upper end of the inner furnace tube is hung on the upper furnace cover, the lower end of the inner furnace tube is open and a support table is arranged at the opening, so that the inner furnace tube can be inserted into the outer furnace tube from the bottom of the outer furnace tube. The lower furnace door is installed on the lower end of the outer furnace tube and the inner furnace tube, the center of the lower furnace door is provided with a center hole for passing through the support base of the inner furnace tube, the lower furnace door and the lower end of the inner furnace tube are sealingly installed with an axial through magnetic fluid sealing assembly, the upper and lower ends of the containing space between the inner furnace tube and the outer furnace tube are sealingly formed into a closed chamber, the inner furnace tube and the outer furnace tube are provided with a heating source for heating the closed chamber, the rotating device is provided with a plurality of carrier placing positions with adjustable positions and angles corresponding to the closed chamber, and the transmission part of the rotating device located in the closed chamber is connected with the transmission shaft of the magnetic fluid sealing assembly.

2. The furnace tube of claim 1, wherein The upper end of the inner furnace tube is open, and an inner wall is provided with a ring of support flanges, the support flanges are hung and connected with the upper furnace cover.

3. The furnace tube of claim 1 wherein, The upper end of the inner furnace tube is closed and protrudes upward to form a hemispherical top cover, an outer wall of the top cover is provided with an annular connecting seat facing upward, an inner wall of the connecting seat is provided with a ring of support flanges, and the support flanges are hung and connected with the upper furnace cover.

4. The furnace tube of claim 1 wherein, The lower end face of the inner furnace tube is flush with the lower end face of the outer furnace tube, or the lower end face of the inner furnace tube exceeds the lower end face of the outer furnace tube, or the lower end face of the outer furnace tube exceeds the lower end face of the inner furnace tube.

5. The furnace tube of claim 1 wherein, An inner wall at the opening of the lower end of the inner furnace tube protrudes a ring of annular steps or is provided with support flanges to form the support table.

6. The furnace tube of claim 1 wherein, A hanging seat is connected between the upper end of the inner furnace tube and the upper furnace cover.

7. The furnace tube of claim 1 wherein, An outer sealing flange is arranged on the outer wall of the upper end of the outer furnace tube, the upper furnace cover covers the upper end faces of the outer furnace tube and the inner furnace tube, the outer edge of the upper furnace cover is sealingly connected with the outer sealing flange, the outer edge of the lower furnace door is sealingly connected with the step of the lower end of the outer furnace tube, and the inner edge of the lower furnace door is sealingly connected with the magnetic fluid sealing assembly.

8. The fire tube as claimed in claim 1, wherein, The outer end faces of the upper furnace cover and the lower furnace door away from the containing space protrude outward to form spherical protrusions, the inner part of the upper furnace cover is provided with a cavity, and a plurality of reinforcing ribs are arranged between the upper and lower inner walls of the cavity.

9. The fire tube as claimed in claim 1, wherein, The rotating device comprises a boat support base provided in the closed chamber of the furnace tube and provided with a plurality of carrier placing positions, and the boat support base is connected with the transmission shaft of the magnetic fluid sealing assembly; and a rotating power source located outside the closed chamber and connected with the transmission shaft to drive the boat support base to rotate.

10. The furnace tube of claim 9, wherein The boat support base comprises: a rotating base located at the bottom of the closed chamber and connected with the transmission shaft; a hanging plate vertically arranged on the rotating base and provided with a plurality of carrier placing positions for hanging the carriers.

11. The furnace tube of claim 9 wherein, The boat support base comprises: a rotating base provided with a plurality of carrier placing positions for passing or placing the carriers and connected with the transmission shaft. A plurality of pairs of carriers, each pair of carriers is located at both side edges of a carrier placement position and is foldably arranged on the rotating base; When the carrier switches to the folded state, the carrier can pass through the carrier placement position corresponding to the carrier from the bottom to the top; when the carrier switches to the unfolded state, the carrier can be placed on the carrier.

12. The fire tube as claimed in claim 1, wherein, The magnetic fluid sealing assembly is annular, has a corresponding central hole in the middle part, and is divided into an inner ring part, an outer ring part, and a transmission shaft in the form of a ring between the inner ring part and the outer ring part; the inner ring part is sealingly connected with the support base at the bottom of the inner furnace tube, the outer ring part is sealingly connected with the inner edge of the lower furnace door, and the inner ring part and the outer ring part are rotationally sealed with the transmission shaft.

13. The fire tube as claimed in claim 1, wherein, The lower furnace door is provided with a plurality of furnace openings penetrating the lower furnace door, the size and shape of the furnace openings match the size and shape of the side surface of the carrier, each furnace opening is provided with a furnace cover, and the furnace cover is connected with a driving structure for driving the furnace cover to open or close relative to the furnace opening.

14. The fire tube as claimed in claim 1, wherein, The inner side of the inner furnace tube is provided with an inner heating source, the outer side of the outer furnace tube is provided with an outer heating source, the inner heating source is divided into a plurality of independent heating sections, and the outer heating source and the periphery of the inner heating source are provided with a heat dissipation device.

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