Gas external circulation system applied to fluidized bed type silane deposition furnace

Abstract

The invention relates to the field of novel silicon carbon deposition equipment, in particular to a gas external circulation system applied to a fluidized bed type silane deposition furnace, which comprises a bracket, a column type fluidized bed, a three-way pipe, a bearing frame, a cooler, a pressurizer, a heater, a breather pipe, an exhaust pipe and a gas injection pipe, a column type fluidized bed is mounted on the bracket; the column type fluidized bed is communicated with a three-way pipe; the support is provided with a bearing frame. The bearing frame is sequentially provided with a cooler, a pressurizer and a heater from top to bottom; the cooler, the pressurizer and the heater are jointly communicated with a breather pipe; the breather pipe and the column type fluidized bed are jointly communicated with an exhaust pipe; and the breather pipe and the three-way pipe are jointly communicated with an air injection pipe. The process gas is filtered through the dust collection cloth capable of being flexibly adjusted, and the problems that in the prior art, filtering dust removal equipment can be cleaned only after silane deposition furnace equipment is cooled, and non-stop cleaning or replacement of the filtering dust removal equipment cannot be achieved are solved.

Description

Technical Field

[0001] The present invention relates to the field of new silicon carbide deposition equipment, and in particular to a gas external circulation system applied to a fluidized bed type silane deposition furnace. Background Art

[0002] Silicon-based anodes are regarded as the most promising next-generation lithium battery anode materials, which can greatly improve the energy density of lithium batteries. At present, the penetration rate of silicon-based anode materials is gradually increasing. There are two research and development ideas for silicon-based anodes: 1) silicon-oxygen anodes, which are composites of silicon monoxide and graphite materials; 2) silicon-carbon anodes, which combine nanosilicon and porous carbon materials. Silicon-carbon anodes can reduce the cost of pre-lithiation or magnesiumation and have the potential to significantly reduce costs compared to the silicon-oxygen route. The preparation of silicon-carbon anodes can be divided into two stages. First, a porous carbon framework structure is fabricated by high-temperature carbonization and activation etching of carbon-rich materials (preparation of porous carbon), and then a silicon-containing compound is transported into the pores of the porous carbon framework, and the gas is pyrolyzed at high temperature to deposit silicon nanoparticles (silicon deposition).

[0003] Currently, in the preparation process of silicon-carbon anodes, when using a fluidized bed to deposit and coat silicon-carbon materials, a large amount of unreacted process gas will directly be discharged from the reactor. Most fluidized bed type silane deposition furnace equipment does not utilize this part of the process gas, resulting in great waste; a small part of fluidized bed type silane deposition furnace equipment will recycle this part of the process gas. During the recycling process of the process gas, generally, it will go through steps such as filtration and dust removal - cooling - pressurization - heating, etc., and finally the process gas will be transported into the silane deposition furnace equipment; however, the method of filtering and dust removing first and then cooling will cause the filtering equipment to be in contact with high-temperature gas for a long time, resulting in a short service life of the filtering and dust removing equipment; moreover, when the filtering and dust removing equipment is blocked by particulate matter in the process gas after a long time of filtering and dust removing work, since the filtering and dust removing equipment is directly in contact with high-temperature gas, it is necessary to wait for the silane deposition furnace equipment to cool down before cleaning the filtering and dust removing equipment, and it is impossible to achieve non-stop cleaning or replacement of the filtering and dust removing equipment, which needs to be improved. Summary of the Invention

[0004] In order to overcome the disadvantages mentioned in the background, the present invention provides a gas external circulation system applied to a fluidized bed type silane deposition furnace.

[0005] Technical solution: A gas external circulation system applied to a fluidized bed type silane deposition furnace, comprising a bracket, a columnar fluidized bed, a three-way pipe, a carrier frame, a cooler, a pressurizer, a heater, a ventilation pipe, an exhaust pipe and an injection pipe; The bracket is installed with a columnar fluidized bed; The columnar fluidized bed is connected to a three-way pipe; The bracket is provided with a carrier frame; The carrier frame is successively installed with a cooler, a pressurizer and a heater from top to bottom; The cooler, the pressurizer and the heater are jointly connected to a ventilation pipe; The ventilation pipe and the columnar fluidized bed are jointly connected to an exhaust pipe; The ventilation pipe and the three-way pipe are jointly connected to an injection pipe; It also includes a cylinder, a mounting frame, a roller, a driving motor, a rotating rod, a dust-absorbing cloth, a cleaner, an annular frame and a pressing roller; The ventilation pipe is divided into upper, middle and lower sections, and a mounting frame is fixedly connected between every two adjacent sections; The middle section of the ventilation pipe is set in a "C" shape; A cylinder is arranged inside the middle section of the ventilation pipe, and there is a gap between the cylinder and the middle section of the ventilation pipe; A plurality of symmetrically distributed rollers are rotatably connected to all the mounting frames; A plurality of driving motors are installed on the upper section of the ventilation pipe, and the driving motors correspond to the rollers one by one, and the output shafts of each driving motor are fixedly connected to the corresponding side rollers; A plurality of annularly distributed rotating rods are rotatably connected to all the mounting frames; A double-layer "C"-shaped dust-absorbing cloth is jointly driven by all the rollers and the rotating rods, and the double-layer "C"-shaped dust-absorbing cloth covers the middle section of the ventilation pipe; An annular frame is fixedly connected to each mounting frame; A plurality of annularly distributed pressing rollers are rotatably connected to each annular frame, and the pressing rollers are in contact with the dust-absorbing cloth; A cleaner is jointly installed on the upper section and the lower section of the ventilation pipe, and the cleaner covers the dust-absorbing cloth.

[0006] Further explanation, it also includes an electric push rod and an arc-shaped pressing plate; A plurality of vertically arrayed electric push rods are installed on the carrier frame; The telescopic parts of all the electric push rods are jointly fixedly connected to an arc-shaped pressing plate, and the arc-shaped pressing plate is in contact with the dust-absorbing cloth; The length of the arc-shaped pressing plate is greater than that of the dust-absorbing cloth, and the parts of the arc-shaped pressing plate extending beyond the dust-absorbing cloth at both ends are respectively in contact with the upper section and the lower section of the ventilation pipe.

[0007] Further explanation, a number of fine hairs are arranged on the surface of the dust-absorbing cloth.

[0008] Further explanation, a number of vertically arrayed guiding convex strips are arranged on the dust-absorbing cloth, and the guiding convex strips are made of dust-absorbing material; The guiding convex strips have the ability of elastic deformation.

[0009] Further explanation, a number of frustum-shaped guiding rings are arranged on the cylinder, and the frustum-shaped guiding rings and the guiding convex strips are arranged in a staggered manner.

[0010] Further explanation, a fan is installed on the lower section of the ventilation pipe, and the rotating shaft of the fan is fixedly connected to the cylinder, and the cylinder is connected to the lower section of the ventilation pipe through the fan.

[0011] Further explanation: The cylinder is equipped with a crushing knife, and the crushing knife is close to the upper section of the ventilation pipe.

[0012] Further explanation: A flow dividing column is fixedly connected inside the upper section of the ventilation pipe, and there is a gap between the flow dividing column and the upper section of the ventilation pipe.

[0013] Further explanation: A funnel-shaped flow concentrating ring is fixedly connected inside the upper section of the ventilation pipe, and the flow concentrating ring is located below the flow dividing column and cooperates with the crushing knife.

[0014] The beneficial effects of the present invention are as follows: 1. The present invention uses a flexible dust-absorbing cloth to filter the process gas, solving the problem in the prior art that the cleaning of the dust filtering and removing equipment can only be carried out after the silane deposition furnace equipment cools down, and the non-stop cleaning or replacement of the dust filtering and removing equipment cannot be achieved.

[0015] 2. In the present invention, the process gas flowing from top to bottom through the middle section of the ventilation pipe will first be guided by the inclined surface of the uppermost frustum-shaped guiding ring and move towards the dust-absorbing cloth. Then, it will be further guided by the guiding protrusions and move towards the inclined surface of the next frustum-shaped guiding ring. Repeating this process multiple times, under the combined action of multiple frustum-shaped guiding rings and multiple guiding protrusions, the process gas is repeatedly deflected, further prolonging the contact time between the process gas and the dust-absorbing cloth, thereby further enhancing the adsorption and interception effect of the dust-absorbing cloth on the particulate matter carried by the process gas.

[0016] 3. In the present invention, the process gas flowing from top to bottom through the ventilation pipe will drive the fan to rotate, and thus the fan drives the cylinder and the crushing knife to rotate. The rotating crushing knife breaks up the agglomerated particulate matter, preventing the particulate matter carried by the process gas from agglomerating.

[0017] 4. The present invention uses the flow concentrating ring to concentrate the process gas and the particulate matter it carries towards the area where the crushing knife is located, enhancing the effect of the crushing knife in breaking up the agglomerated particulate matter. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram disclosed by the present invention; Figure 2 is a combined schematic structural diagram of the cooler, pressure booster, heater and ventilation pipe disclosed by the present invention; Figure 3 is a structural sectional view of the cleaner disclosed by the present invention; Figure 4 is a structural sectional view of the ventilation pipe disclosed by the present invention; Figure 5 is a combined schematic structural diagram of the crushing knife, flow dividing column and flow concentrating ring disclosed by the present invention; Figure 6Schematic diagram of the combined structure of the dust-absorbing cloth and the guiding rib disclosed by the present invention; Figure 7 Cross-sectional view of the structure of the dust-absorbing cloth disclosed by the present invention; Figure 8 Exploded view of the structure of the ventilation pipe and the mounting bracket disclosed by the present invention; Figure 9 Schematic diagram of the combined structure of the ventilation pipe, the cylinder and the dust-absorbing cloth disclosed by the present invention; Figure 10 Schematic diagram of the combined structure of the rotating roller, the rotating rod and the dust-absorbing cloth disclosed by the present invention; Figure 11 Schematic diagram of the air flow direction disclosed by the present invention.

[0019] Reference numerals in the drawings: 1 - support, 2 - columnar fluidized bed, 3 - tee pipe, 4 - carrier frame, 5 - cooler, 6 - pressurizer, 7 - heater, 8 - ventilation pipe, 9 - cylinder, 10 - mounting bracket, 11 - rotating roller, 111 - drive motor, 12 - rotating rod, 13 - dust-absorbing cloth, 14 - exhaust pipe, 15 - injection pipe, 16 - electric push rod, 17 - arc-shaped pressing plate, 18 - cleaner, 19 - annular frame, 191 - pressing roller, 20 - guiding rib, 21 - frustum-shaped guiding ring, 30 - fan, 31 - crushing knife, 40 - shunt column, 41 - converging ring. Detailed implementation manners

[0020] The present invention will be further described below in conjunction with specific embodiments. The illustrative embodiments and explanations of this invention are used to explain the present invention, but do not limit the present invention.

[0021] Embodiment 1 A gas external circulation system applied to a fluidized bed type silane deposition furnace, as Figures 1-11 shown, includes a support 1, a columnar fluidized bed 2, a tee pipe 3, a carrier frame 4, a cooler 5, a pressurizer 6, a heater 7, a ventilation pipe 8, an exhaust pipe 14 and an injection pipe 15; The support 1 is installed with a columnar fluidized bed 2; The columnar fluidized bed 2 is communicated with a tee pipe 3; The support 1 is provided with a carrier frame 4; The carrier frame 4 is successively installed with a cooler 5, a pressurizer 6 and a heater 7 from top to bottom; The cooler 5, the pressurizer 6 and the heater 7 are jointly communicated with a ventilation pipe 8; The ventilation pipe 8 and the columnar fluidized bed 2 are jointly communicated with an exhaust pipe 14; The ventilation pipe 8 and the tee pipe 3 are jointly communicated with an injection pipe 15; It further includes a cylinder 9, a mounting bracket 10, a roller 11, a driving motor 111, a rotating rod 12, a dust-absorbing cloth 13, a cleaner 18, an annular bracket 19 and a pressing roller 191; the ventilation pipe 8 is divided into upper, middle and lower sections, and a mounting bracket 10 is fixedly connected between each adjacent two sections; the middle section of the ventilation pipe 8 is arranged in a "C" shape; a cylinder 9 is arranged inside the middle section of the ventilation pipe 8, and there is a gap between the cylinder 9 and the middle section of the ventilation pipe 8; at least two symmetrically distributed rollers 11 are rotatably connected to all the mounting brackets 10 together; at least two driving motors 111 are installed on the upper section of the ventilation pipe 8, and the driving motors 111 correspond to the rollers 11 one by one, and the output shafts of each driving motor 111 are fixedly connected to the corresponding side rollers 11 respectively; at least six annularly distributed rotating rods 12 are rotatably connected to all the mounting brackets 10 together; a double-layer "C"-shaped dust-absorbing cloth 13 is driven and connected by all the rollers 11 and the rotating rods 12 together, and the double-layer "C"-shaped dust-absorbing cloth 13 covers the middle section of the ventilation pipe 8; each mounting bracket 10 is fixedly connected with an annular bracket 19; at least seven annularly distributed pressing rollers 191 are rotatably connected to each annular bracket 19, and the pressing rollers 191 are in contact with the dust-absorbing cloth 13, and the dust-absorbing cloth 13 is limited by the pressing rollers 191 to make the dust-absorbing cloth 13 fit the inner wall of the ventilation pipe 8 to prevent the dust-absorbing cloth 13 from deforming; a cleaner 18 is installed on the upper section and the lower section of the ventilation pipe 8 together, and the cleaner 18 covers the dust-absorbing cloth 13.

[0022] It further includes an electric push rod 16 and an arc-shaped pressing plate 17; at least three vertically arrayed electric push rods 16 are installed on the bearing frame 4; the telescopic parts of all the electric push rods 16 are fixedly connected with an arc-shaped pressing plate 17 together, and the arc-shaped pressing plate 17 is in contact with the dust-absorbing cloth 13; the length of the arc-shaped pressing plate 17 is greater than that of the dust-absorbing cloth 13, and the parts of the arc-shaped pressing plate 17 extending beyond the dust-absorbing cloth 13 at both ends are in contact with the upper section and the lower section of the ventilation pipe 8 respectively; the gap of the double-layer "C"-shaped dust-absorbing cloth 13 is pressed and closed by the arc-shaped pressing plate 17 to prevent the process gas from overflowing outward from the gap of the double-layer "C"-shaped dust-absorbing cloth 13.

[0023] A number of fine hairs are arranged on the surface of the dust-absorbing cloth 13 to improve the adsorption effect of the dust-absorbing cloth 13 on the particles entrained in the process gas.

[0024] The specific working process of the present invention is as follows: First, feed silicon-carbon materials into the columnar fluidized bed 2 through the feed inlet on the columnar fluidized bed 2. Then, control the external air pump to input process gas into the columnar fluidized bed 2 through the three-way pipe 3, so as to deposit and coat the silicon-carbon materials by using the columnar fluidized bed 2, thus realizing the preparation of the silicon-carbon negative electrode; among them, the unreacted process gas is transported from the columnar fluidized bed 2 to the ventilation pipe 8 through the exhaust pipe 14, so that the process gas passes through the ventilation pipe 8 from top to bottom, and the steps of cooling, filtering, pressurizing and heating are carried out in sequence, and then the heated process gas is transported into the columnar fluidized bed 2 through the injection pipe 15 and the three-way pipe 3 to realize the recycling operation of the process gas.

[0025] Specifically, in the above process, when the process gas flows through the cooler 5, the cooler 5 cools the process gas to a preset temperature to avoid damaging the dust suction cloth 13 and the pressurizer 6 during the subsequent filtering and pressurizing processes; when the process gas flows through the dust suction cloth 13, the dust suction cloth 13 intercepts and adsorbs the particulate matters entrained in the process gas to ensure the purity of the process gas; when the process gas flows through the pressurizer 6, the pressurizer 6 pressurizes the process gas after cooling and filtering, and pressurizes the cooled process gas to the preset reaction pressure; when the process gas flows through the heater 7, the heater 7 heats the pressurized gas to heat the process gas to the preset reaction temperature.

[0026] Among them, after the dust suction cloth 13 has undergone a long period of adsorption and filtration work, a large amount of particulate matter will adhere to its surface. Therefore, to ensure that the dust suction cloth 13 always has good adsorption and filtration effects, after each preparation work of the silicon-carbon negative electrode is completed, first control the telescopic part of the electric push rod 16 to drive the arc-shaped pressing plate 17 to move towards the center point of the ventilation pipe 8, so that the arc-shaped pressing plate 17 is away from the pipe wall of the ventilation pipe 8 and the dust suction cloth 13, thus no longer pressing the dust suction cloth 13, and enabling the dust suction cloth 13 to move under the rotation of the roller 11; then, control the output shaft of the drive motor 111 to drive the roller 11 to rotate clockwise from a top-down perspective, thereby driving the dust suction cloth 13 to move along the middle section of the ventilation pipe 8 through the roller 11, and assisting the movement of the dust suction cloth 13 through the rotating rod 12, so that part of the dust suction cloth 13 that was originally inside the ventilation pipe 8 and adsorbed a large amount of particulate matter gradually moves to the outside of the ventilation pipe 8, while part of the dust suction cloth 13 that was originally outside the ventilation pipe 8 and in a clean state gradually moves to the inside of the ventilation pipe 8, enabling the part of the dust suction cloth 13 inside the ventilation pipe 8 and the part of the dust suction cloth 13 outside the ventilation pipe 8 to exchange positions. At the same time, control the cleaner 18 to clean the part of the dust suction cloth 13 outside the ventilation pipe 8, and discharge the sewage through an externally connected drain pipe. In this way, the process gas is filtered by the flexibly adjustable dust suction cloth 13, solving the problem in the prior art that the cleaning of the dust filtering and removing equipment can only be carried out after the silane deposition furnace equipment cools down, and the non-stop cleaning or replacement of the dust filtering and removing equipment cannot be achieved.

[0027] Embodiment 2 On the basis of the above-mentioned Embodiment 1, as Figures 6-11 shown, the dust suction cloth 13 is provided with at least four guiding convex strips 20 distributed in a vertical array, and the guiding convex strips 20 are made of dust suction material; the guiding convex strips 20 have the ability of elastic deformation, so that the pressing roller 191 can normally press them.

[0028] As Figure 9 shown, the cylinder 9 is provided with at least four frustum-shaped guiding rings 21 distributed in a vertical array, and the frustum-shaped guiding rings 21 and the guiding convex strips 20 are distributed in an alternating manner.

[0029] The working process of the present invention is as follows: During the above filtering process, the guiding ridges 20 provided on the dust suction cloth 13 play a blocking role on the process gas flowing between the cylinder 9 and the dust suction cloth 13, slowing down the flow rate of the process gas to a certain extent, thereby increasing the contact time and contact area between the process gas and the dust suction cloth 13, and enhancing the adsorption and interception effects of the dust suction cloth 13 on the particulate matter carried by the process gas. At the same time, since the frustum-shaped guiding rings 21 and the guiding ridges 20 are staggered, the process gas flowing through the middle section of the ventilation pipe 8 from top to bottom will first be guided by the inclined surface of the uppermost frustum-shaped guiding ring 21 and move towards the dust suction cloth 13. Then, it will be guided by the guiding ridges 20 and move towards the inclined surface of the next frustum-shaped guiding ring 21. This is repeated multiple times. Under the combined action of multiple frustum-shaped guiding rings 21 and multiple guiding ridges 20, the process gas is repeatedly deflected, as shown in Figure 11 shown, further prolonging the contact time between the process gas and the dust suction cloth 13, thereby further enhancing the adsorption and interception effects of the dust suction cloth 13 on the particulate matter carried by the process gas.

[0030] Embodiment 3 Based on the above Embodiment 2, as Figures 7-9 shown, a fan 30 is installed at the lower section of the ventilation pipe 8, and the rotating shaft of the fan 30 is fixedly connected to the cylinder 9. The cylinder 9 is connected to the lower section of the ventilation pipe 8 through the fan 30.

[0031] As Figure 5 shown, a crushing knife 31 is installed on the cylinder 9, and the crushing knife 31 is close to the upper section of the ventilation pipe 8.

[0032] As Figures 4-5 shown, a flow dividing column 40 is fixedly connected inside the upper section of the ventilation pipe 8, and there is a gap between the flow dividing column 40 and the upper section of the ventilation pipe 8. The high-temperature process gas is divided by the flow dividing column 40, so that the high-temperature process gas enters the gap between the flow dividing column 40 and the upper section of the ventilation pipe 8, making the high-temperature process gas closer to the cooler 5 and enhancing the cooling effect on the high-temperature process gas.

[0033] As Figures 4-5 shown, a funnel-shaped flow concentrating ring 41 is fixedly connected inside the upper section of the ventilation pipe 8, and the flow concentrating ring 41 is located below the flow dividing column 40 and cooperates with the crushing knife 31.

[0034] The specific working process of the present invention is as follows: In the above process, the process gas flowing through the vent pipe 8 from top to bottom drives the fan 30 to rotate. Thus, the fan 30 drives the cylinder 9 and the frustum-shaped guide ring 21 to rotate. When the particulate matter contacts the cylinder 9 and the frustum-shaped guide ring 21, the rotating cylinder 9 and frustum-shaped guide ring 21 cause the particulate matter to be centrifugally thrown away, and the particulate matter entrained in the process gas is thrown towards the dust absorption cloth 13 in a dispersed state, so that the particulate matter entrained in the process gas can be evenly adsorbed on the inner side of the dust absorption cloth 13.

[0035] It should be noted that after the process gas is cooled by the cooler 5, due to the decrease in temperature, a part of the moisture originally in a saturated state in the process gas will precipitate from the air, form liquid water, and form water droplets on the inner wall of the vent pipe 8, thereby causing the moisture inside the vent pipe 8 to rise. As a result, the process gas flowing through the vent pipe 8 will entrain some moisture, and further cause the particulate matter entrained in the process gas to agglomerate. The agglomerated particulate matter is not conducive to the adsorption of the dust absorption cloth 13 due to the increase in weight and volume. Therefore, in this process, the process gas flowing through the vent pipe 8 from top to bottom drives the fan 30 to rotate. Thus, the fan 30 drives the cylinder 9 and the crushing knife 31 to rotate, and the rotating crushing knife 31 breaks up the agglomerated particulate matter to prevent the particulate matter entrained in the process gas from agglomerating.

[0036] At the same time, the process gas and the particulate matter it entrains are collected towards the area where the crushing knife 31 is located through the converging ring 41 to improve the effect of the crushing knife 31 on breaking up the agglomerated particulate matter.

[0037] Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, those skilled in the art should understand that various changes in form and detail can be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above embodiments, but should be determined not only by the appended claims but also by the equivalents of the appended claims.

Claims

1. A gas external circulation system for a fluidized bed silane deposition furnace, comprising a support (1), a column fluidized bed (2), a three-way pipe (3), a support frame (4), a cooler (5), a pressurizer (6), a heater (7), a vent pipe (8), an exhaust pipe (14) and a gas injection pipe (15); the support (1) is equipped with a column fluidized bed (2); the column fluidized bed (2) is connected to the three-way pipe (3); the support (1) is provided with a support frame (4); the support frame (4) is equipped with a cooler (5), a pressurizer (6) and a heater (7) in sequence from top to bottom; the cooler (5), the pressurizer (6) and the heater (7) are connected to a vent pipe (8); the vent pipe (8) and the column fluidized bed (2) are connected to an exhaust pipe (14); the vent pipe (8) and the three-way pipe (3) are connected to a gas injection pipe (15); the characteristics are: The device also comprises a cylinder (9), a mounting frame (10), a rotating roller (11), a driving motor (111), a rotating rod (12), a dust collecting cloth (13), a cleaning device (18), an annular frame (19) and a pressing roller (191); the ventilation pipe (8) is divided into three sections, namely, an upper section, a middle section and a lower section, and a mounting frame (10) is fixedly connected between each two adjacent sections; the middle section of the ventilation pipe (8) is arranged in a "C"-shaped structure; a cylinder (9) is arranged in the middle section of the ventilation pipe (8), and a gap exists between the cylinder (9) and the middle section of the ventilation pipe (8); all the mounting frames (10) are connected to a plurality of symmetrically distributed rotating rollers (11) for rotation; a plurality of driving motors (111) are installed in the upper section of the ventilation pipe (8), and the driving motors (111) correspond to the rotating rollers (11) one by one, and each The output shafts of the driving motors (111) are respectively fixedly connected to the rotating rollers (11) on the corresponding sides; all the mounting frames (10) are rotatably connected to a plurality of rotating rods (12) distributed in an annular shape; all the rotating rollers (11) and the rotating rods (12) are jointly transmission-connected to a double-layer "C"-shaped dust-absorbing cloth (13), and the double-layer "C"-shaped dust-absorbing cloth (13) covers the middle section of the ventilation pipe (8); each mounting frame (10) is respectively fixedly connected to an annular frame (19); each annular frame (19) is respectively rotatably connected to a plurality of pressing rollers (191) distributed in an annular shape, and the pressing rollers (191) are in contact with the dust-absorbing cloth (13); the upper section of the ventilation pipe (8) and the lower section of the ventilation pipe (8) are jointly installed with a cleaner (18), and the cleaner (18) covers the dust-absorbing cloth (13).

2. The gas external circulation system for a fluidized bed silane deposition furnace according to claim 1, characterized in that: It also includes an electric push rod (16) and an arc-shaped pressing plate (17); the support frame (4) is equipped with a plurality of electric push rods (16) distributed in a vertical array; the telescopic parts of all the electric push rods (16) are fixedly connected to an arc-shaped pressing plate (17), and the arc-shaped pressing plate (17) fits with the dust collecting cloth (13); the length of the arc-shaped pressing plate (17) is greater than the dust collecting cloth (13), and the parts of the two ends of the arc-shaped pressing plate (17) that exceed the dust collecting cloth (13) fit with the upper section of the ventilation pipe (8) and the lower section of the ventilation pipe (8) respectively.

3. A gas external circulation system for a fluidized bed silane deposition furnace according to any one of claims 1 to 2, characterized in that: The surface of the dust collecting cloth (13) is provided with a plurality of fine and dense fluffs.

4. The gas external circulation system for a fluidized bed silane deposition furnace according to claim 3, characterized in that: The dust collecting cloth (13) is provided with a plurality of guide convex strips (20) distributed in a vertical array, and the guide convex strips (20) are provided with a dust collecting material; the guide convex strips (20) have elastic deformation capability.

5. The gas external circulation system for a fluidized bed silane deposition furnace according to claim 4, characterized in that: The cylinder (9) is provided with a plurality of truncated cone-shaped guide rings (21) distributed in a vertical array, and the truncated cone-shaped guide rings (21) and the guide convex strips (20) are distributed in a staggered manner.

6. The gas external circulation system for a fluidized bed silane deposition furnace according to claim 5, characterized in that: A fan (30) is installed at the lower section of the ventilation pipe (8), and the rotating shaft of the fan (30) is fixedly connected to the cylinder (9), and the cylinder (9) is connected to the lower section of the ventilation pipe (8) through the fan (30).

7. The gas external circulation system for a fluidized bed silane deposition furnace according to claim 6, characterized in that: The cylinder (9) is equipped with a crushing knife (31), and the crushing knife (31) is close to the upper section of the ventilation pipe (8).

8. The gas external circulation system for a fluidized bed silane deposition furnace according to claim 7, characterized in that: A flow dividing column (40) is fixedly connected to the upper section of the ventilation pipe (8), and a gap exists between the flow dividing column (40) and the upper section of the ventilation pipe (8).

9. The gas external circulation system for a fluidized bed silane deposition furnace according to claim 8, characterized in that: A funnel-shaped focusing ring (41) is fixedly connected to the upper section of the ventilation pipe (8), and the focusing ring (41) is located below the diverter column (40), and the focusing ring (41) cooperates with the crushing knife (31).

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