A silicon carbide long tube sintering furnace

Abstract

The present invention relates to the technical field of sintering furnaces, and specifically relates to a silicon carbide long tube sintering furnace; a sintering mechanism is cooperatively provided with an air outlet pipe and an air inlet pipe at both ends thereof. Under the action of a negative pressure fan, a pressure difference is generated at both ends of the sintering mechanism, thereby guiding the flow of the air flow inside the sintering mechanism, enabling the air flow containing carbon monoxide to flow through the silicon carbide long tube more, improving the synthesis efficiency of silicon carbide at various parts of the silicon carbide long tube. The collection pipes and strip-shaped grooves arranged around the inner wall of the sintering mechanism cooperate to introduce the carbon monoxide gas around the sintering mechanism into the cavity and the air outlet pipe, and filter the impurity gas through a filtering component to increase the concentration of carbon monoxide, thereby further improving the synthesis efficiency of silicon carbide at various parts of the silicon carbide long tube; it solves the problem that when using a sintering furnace to sinter a silicon carbide long tube, the uneven distribution of carbon monoxide gas on the silicon carbide long tube due to the air flow inside the sintering furnace affects the overall quality of the sintered silicon carbide long tube.

Description

Technical Field

[0001] The present invention relates to the technical field of sintering furnaces, and specifically to a silicon carbide long tube sintering furnace. Background Art

[0002] During the sintering process of silicon carbide long tubes, gases such as hydrogen sulfide, sulfur dioxide, and carbon monoxide are generated. Among them, carbon monoxide will participate in the chemical reaction process of silicon carbide synthesis again, while hydrogen sulfide and sulfur dioxide are toxic gases. On the one hand, when the sintering furnace is opened after sintering, they will overflow and endanger the health of workers. On the other hand, during the sintering process, they will relatively dilute the concentration of carbon monoxide, thus affecting the synthesis efficiency of silicon carbide. And due to the relatively long length of the silicon carbide long tube, during sintering, the temperature at the central position of the sintering furnace is higher than that at the two ends and the surrounding positions. Due to the influence of the temperature gradient, the gas at the middle part expands faster, generating an air flow towards the surrounding areas with lower temperature, causing the carbon monoxide generated during the sintering process to concentrate and gather towards the surrounding areas with lower temperature, making the distribution of carbon monoxide on the silicon carbide long tube uneven, thus affecting the synthesis efficiency of silicon carbide and resulting in uneven distribution of the synthesized silicon carbide at different positions on the silicon carbide long tube, affecting the overall quality of the silicon carbide long tube. Summary of the Invention

[0003] (1) Technical Problems to be Solved

[0004] Aiming at the deficiencies of the prior art, the present invention provides a silicon carbide long tube sintering furnace, which solves the problem that when using a sintering furnace to sinter a silicon carbide long tube, the internal air flow of the sintering furnace causes uneven distribution of carbon monoxide gas on the silicon carbide long tube, thus affecting the overall quality of the sintered silicon carbide long tube.

[0005] (2) Technical Solutions

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A silicon carbide long tube sintering furnace includes a sintering mechanism for sintering a silicon carbide long tube, a cooling mechanism is provided on the sintering mechanism, and a control mechanism for guiding the air flow is provided on the sintering mechanism.

[0008] The control mechanism includes a cavity provided at one end of the sintering mechanism. A plurality of through holes are opened on the side wall of the cavity close to the sintering mechanism. A plurality of collecting pipes communicating with the cavity are evenly arranged on the inner wall of the sintering mechanism. A plurality of strip-shaped grooves are opened on the outer wall of the collecting pipe. An air outlet pipe that can be bent is communicated with the side of the cavity away from the sintering mechanism. A filtering component for removing impurity gases is communicated with the air outlet pipe. A negative pressure fan is communicated with the air outlet pipe on the side away from the cavity. A connecting pipe controlled by a solenoid valve is communicated with the air outlet pipe on the side away from the negative pressure fan. The bottom of the connecting pipe is communicated with a vacuum tank. An air inlet pipe is communicated between the other end of the air outlet pipe and the end of the sintering mechanism away from the cavity.

[0009] Preferably, the sintering mechanism includes an outer shell, an inner shell is concentrically arranged inside the outer shell, a closed cooling cavity is arranged between the outer shell and the inner shell, a hatch with an air inlet pipe in the center is hinged to one end of the outer shell away from the cavity, a heating component for sintering the silicon carbide long tube is arranged at the center of the inner shell, a guiding component for guiding the air flow to flow towards its center is arranged inside the heating component, and a plurality of support columns are fixed at the bottom of the outer shell.

[0010] Preferably, the heating component includes a fixing plate fixed on the inner shell, a heating coil is fixed on the fixing plate, a heat preservation shell with openings at both ends is arranged at the center of the heating coil, a plurality of fixing rods are fixed between the heat preservation shell and the inner shell, and a plurality of uniformly distributed material guiding rods are rotatably installed inside the heat preservation shell.

[0011] Preferably, the guiding component includes a plurality of square frame-shaped guiding plates uniformly distributed inside the heat preservation shell, and an inclined guiding surface is arranged on one side of the guiding plate facing the hatch.

[0012] Preferably, the cooling mechanism includes a cooling pipe arranged at the top of the cooling cavity, two water outlet grooves are symmetrically arranged at the bottom of the cooling pipe, a water inlet valve is communicated with the top of the cooling pipe, a water outlet valve is communicated with the bottom of the cooling cavity, and a plurality of baffles horizontally fixed and staggered are arranged inside the cooling cavity.

[0013] Preferably, a conical guiding surface is arranged on one side of the cavity away from the sintering mechanism, and the air outlet pipe is arranged at the conical tip of the guiding surface.

[0014] Preferably, the filtering component includes a filtering shell with water stored inside, a rotating rod is rotatably installed inside the filtering shell, a plurality of wire meshes arranged on the cross section of the filtering shell are fixed on the rotating rod, scraping plates fixed at the bottom of the filtering shell are slidably arranged on both sides of the wire meshes, a motor for driving the rotating rod to rotate is fixed on the filtering shell, and a water injection pipe for injecting water and draining water is communicated with the bottom of the filtering shell.

[0015] Preferably, the diameter of the air inlet pipe is smaller than the diameter of the air outlet pipe.

[0016] (III) Beneficial effects

[0017] Compared with the prior art, the present invention provides a silicon carbide long tube sintering furnace, which has the following beneficial effects:

[0018] The sintering mechanism is provided with an air outlet pipe and an air inlet pipe at both ends. Through the action of a negative pressure fan, a stable pressure difference is generated at both ends of the sintering mechanism, thereby guiding the flow of air inside the sintering mechanism, enabling the air flow containing carbon monoxide to flow through the silicon carbide long tube more, improving the synthesis efficiency of silicon carbide at various parts of the silicon carbide long tube. The collecting pipe and the strip-shaped groove arranged around the inner wall of the sintering mechanism cooperate to introduce the carbon monoxide gas flowing to the periphery of the sintering mechanism into the cavity and the air outlet pipe, improving the utilization rate of carbon monoxide. And the impurity gas is filtered through the filtering component, increasing the concentration of carbon monoxide, thereby further improving the synthesis efficiency of silicon carbide at various parts of the silicon carbide long tube and improving the overall quality of the sintered silicon carbide long tube.

[0019] The rotating rod rotatably arranged in the filter housing cooperates with the screen fixed on the rotating rod. Utilizing the surface tension of water, a water film is generated on the surface when the screen passes through the water surface, realizing the filtration of hydrogen sulfide, sulfur dioxide gas and silicon vapor mixed in the carbon monoxide air flow. And the surface of the screen is cleaned by the scraper, thereby realizing the purification of carbon monoxide gas. On the one hand, it further improves the synthesis efficiency of silicon carbide, and on the other hand, it also prevents the poisonous hydrogen sulfide and sulfur dioxide gases from harming human health after the furnace is opened. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0021] Figure 1 is a schematic diagram of the three-dimensional structure of the present invention;

[0022] Figure 2 is a schematic diagram of the sintering mechanism and the cooling mechanism of the present invention;

[0023] Figure 3 is a cross-sectional view of the sintering mechanism of the present invention;

[0024] Figure 4 is a schematic diagram of the guiding component of the present invention;

[0025] Figure 5 is a schematic diagram of the cavity and the collecting pipe of the present invention;

[0026] Figure 6 is a schematic diagram of the control mechanism of the present invention;

[0027] Figure 7 is a schematic diagram of the filtering component of the present invention.

[0028] In the figure: 1. Sintering mechanism; 11. Outer shell; 12. Inner shell; 13. Cooling chamber; 14. Hatch; 15. Heating assembly; 151. Fixed plate; 152. Heating coil; 153. Heat preservation shell; 154. Fixed rod; 155. Feeding rod; 16. Guiding assembly; 161. Guide plate; 162. Flow guiding surface; 17. Support column; 2. Cooling mechanism; 21. Cooling pipe; 22. Water outlet tank; 23. Water inlet valve; 24. Water outlet valve; 25. Baffle; 3. Control mechanism; 31. Cavity; 32. Through hole; 33. Collection pipe; 34. Strip-shaped groove; 35. Air outlet pipe; 36. Filter assembly; 361. Filter shell; 362. Rotating rod; 363. Screen; 364. Scraper; 365. Motor; 366. Water injection pipe; 37. Negative pressure fan; 38. Connecting pipe; 39. Vacuum tank; 40. Air inlet pipe; 41. Guiding surface. Specific implementation mode

[0029] The following will be combined with the drawings and embodiments to detail the implementation mode of the present application, so as to fully understand how the present application uses technical means to solve technical problems and achieve the implementation process of technical effects and implement accordingly.

[0030] Figures 1 - 7 As an embodiment of the present invention, it guides the gas flow in the sintering furnace, so as to drive the uniform flow of carbon monoxide on the surface of the silicon carbide long tube through the gas flow, make the distribution of carbon monoxide on the surface of the silicon carbide long tube more uniform, make the distribution of the synthesized silicon carbide on the surface of the silicon carbide long tube more uniform, and thus improve the overall quality of the sintered silicon carbide long tube.

[0031] A silicon carbide long tube sintering furnace includes a sintering mechanism 1 for sintering the silicon carbide long tube, a cooling mechanism 2 is arranged on the sintering mechanism 1, and a control mechanism 3 for guiding the gas flow is arranged on the sintering mechanism 1.

[0032] The control mechanism 3 includes a cavity 31 provided at one end of the sintering mechanism 1. A plurality of through holes 32 are formed in the side wall of the cavity 31 close to the sintering mechanism 1. The through holes 32 are used for the air flow in the sintering mechanism 1 to flow into the cavity 31. A plurality of collecting pipes 33 communicating with the cavity 31 are uniformly arranged on the inner wall of the sintering mechanism 1. A plurality of strip-shaped grooves 34 are formed on the outer wall of the collecting pipes 33. Through the collecting pipes 33 and the strip-shaped grooves 34, the carbon monoxide gas located around the sintering mechanism 1 flows into the cavity 31. A bendable air outlet pipe 35 is communicated with the side of the cavity 31 away from the sintering mechanism 1. A filtering assembly 36 for removing impurity gases is communicated with the air outlet pipe 35. The filtering assembly 36 is used for removing hydrogen sulfide and sulfur dioxide gases generated during the sintering process, making the concentration of carbon monoxide gas higher and the efficiency of generating silicon carbide higher. A negative pressure fan 37 is communicated with the air outlet pipe 35 on the side of the filtering assembly 36 away from the cavity 31. The negative pressure fan 37 sucks the gas at the end of the sintering mechanism 1 provided with the cavity 31 and discharges the gas to the other end of the sintering mechanism 1, so that the air pressure at one end in the sintering mechanism 1 increases and the air pressure at the other end decreases, thus enabling the air flow to continuously flow from one end of the sintering mechanism 1 to the other end, forming a stable air flow, so that the carbon monoxide in the air flow stably contacts the surface of the silicon carbide long tube to generate silicon carbide, avoiding the problem that the reaction efficiency at the middle position of the silicon carbide long tube is reduced due to the concentrated distribution of carbon monoxide gas around the sintering mechanism 1. A connecting pipe 38 controlled by an electromagnetic valve is communicated with the air outlet pipe 35 on the side of the negative pressure fan 37 away from the cavity 31. The bottom of the connecting pipe 38 is communicated with a vacuum tank 39. Since carbon monoxide gas is generated during the reaction process, when the air pressure in the sintering mechanism 1 is about 150 KPa, it is more suitable for the synthesis of silicon carbide. When the air pressure is too high, the vacuum tank 39 is opened to store part of the carbon monoxide gas, and the stored carbon monoxide gas can be sold or used as fuel. An air inlet pipe 40 is communicated between the other end of the air outlet pipe 35 and the end of the sintering mechanism 1 away from the cavity 31. The air flow in the air outlet pipe 35 enters the sintering mechanism 1 again through the air inlet pipe 40, so as to control the air pressure of the sintering mechanism 1 while forming an air pressure difference between the two ends inside the sintering mechanism 1 through the negative pressure fan 37, thus forming a stable air flow trajectory, enabling the air flow to flow on the surface of the silicon carbide long tube to be sintered, so that each position on the surface of the silicon carbide long tube can contact with carbon monoxide gas to fully react and generate silicon carbide, improving the overall quality of the silicon carbide long tube.

[0033] As a preferred technical solution of this embodiment, the sintering mechanism 1 includes an outer shell 11. An inner shell 12 is concentrically arranged inside the outer shell 11. A closed cooling cavity 13 is arranged between the outer shell 11 and the inner shell 12. When the temperature inside the sintering mechanism 1 is too high, water is injected into the cooling cavity 13 to cool the inside of the sintering mechanism 1, realizing the control of the temperature. And when there is no water in the cooling cavity 13, the static air in the cooling cavity 13 can further isolate the heat dissipation, playing a heat preservation effect. One end of the outer shell 11 away from the cavity 31 is hingedly connected with a hatch 14 with an air inlet pipe 40 in the center. A heating component 15 for sintering silicon carbide long tubes is arranged at the center of the inner shell 12. The heating component 15 is used to heat and sinter the silicon carbide long tubes inside. A guiding component 16 for guiding the air flow to flow towards its center is arranged inside the heating component 15. A plurality of support columns 17 are fixed at the bottom of the outer shell 11. Thus, the temperature inside the sintering mechanism 1 is controlled through the heating component 15 and the cooling cavity 13, making its temperature more suitable for the synthesis of silicon carbide.

[0034] As a preferred technical solution of this embodiment, the heating component 15 includes a fixing plate 151 fixed on the inner shell 12. A heating coil 152 is fixed on the fixing plate 151. After the heating coil 152 is electrified, it heats and sinters the silicon carbide long tubes. A heat preservation shell 153 with two open ends is arranged at the center of the heating coil 152. The heat preservation shell 153 is used to reduce the heat radiated to the outside, making the heat more concentrated at the silicon carbide long tubes, saving electric energy. A plurality of fixing rods 154 are fixed between the heat preservation shell 153 and the inner shell 12. A plurality of uniformly distributed guiding rods 155 are rotatably installed inside the heat preservation shell 153. When putting in the silicon carbide long tubes, through the rolling between the silicon carbide long tubes and the guiding rods 155, it is more convenient for the feeding and discharging of the silicon carbide long tubes, and it can also prevent the surface of the silicon carbide long tubes from being damaged by friction.

[0035] As a preferred technical solution of this embodiment, the guiding component 16 includes a plurality of square-ring guiding plates 161 uniformly distributed inside the heat preservation shell 153. An inclined guiding surface 162 is arranged on one side of the guiding plate 161 facing the hatch 14. When the air flow containing carbon monoxide gas flowing from the hatch 14 to the cavity 31 passes through the guiding surface 162, it will gather towards the silicon carbide long tubes located at the center of the heat preservation shell 153. Thus, the carbon monoxide concentration flowing through the silicon carbide long tubes is higher, improving the synthesis efficiency of silicon carbide.

[0036] As a preferred technical solution of this embodiment, the cooling mechanism 2 includes a cooling pipe 21 arranged at the top of the cooling chamber 13. Two water outlet grooves 22 are symmetrically arranged at the bottom of the cooling pipe 21. The top of the cooling pipe 21 is communicated with a water inlet valve 23, and the bottom of the cooling chamber 13 is communicated with a water outlet valve 24. A plurality of baffles 25 horizontally fixed and staggered are arranged in the cooling chamber 13. When cooling is required, water enters the cooling pipe 21 through the water inlet valve 23 and quickly flows out from the water outlet grooves 22 on both sides. The flowing water directly covers the surface of the cooling chamber 13, with a faster cooling speed. And when the water flow passes through the baffles 25, it flows in a staggered manner, which can further stir the air in the cooling chamber 13, accelerate heat convection, and enable the heat in the sintering mechanism 1 to be quickly taken out further, so as to achieve the purpose of rapid and timely cooling.

[0037] As a preferred technical solution of this embodiment, a conical guiding surface 41 is arranged on one side of the cavity 31 away from the sintering mechanism 1. The air outlet pipe 35 is arranged at the conical tip of the guiding surface 41. After the air flow flows into the cavity 31 through the through holes 32 and the collecting pipe 33, in order to prevent the direct air flow from directly touching the inner wall of the cavity 31 and causing the air flow to be disordered on one side of the cavity 31, the air flow is directly introduced into the air outlet pipe 35 through the guiding surface 41, so that the air flow is more stable during the flowing process, and the influence on the synthesis efficiency of silicon carbide caused by the continuous change of the flowing trajectory due to the air flow fluctuation is prevented.

[0038] As a preferred technical solution of this embodiment, the filtering component 36 includes a filtering housing 361 with water contained inside. A rotating rod 362 is rotatably installed in the filtering housing 361. A plurality of screen meshes 363 arranged on the cross-section of the filtering housing 361 are fixed on the rotating rod 362. When the screen meshes 363 pass through the water, a water film will adhere to the surface of the screen meshes 363 due to the surface tension of the water, enabling the easily water-soluble hydrogen sulfide and sulfur dioxide in the air flow to dissolve in the water when passing through the water film, while carbon monoxide is hardly soluble in water and will therefore pass through normally. Scrapers 364 fixed to the bottom of the filtering housing 361 are slidably arranged on both sides of the screen meshes 363. During the synthesis of silicon carbide, due to the too high temperature, a small amount of silicon vapor will be generated, and the silicon vapor will adhere to the water film on the surface of the screen meshes 363. In order to prevent the pores of the screen meshes 363 from being blocked, it is scraped into the water for precipitation by the scrapers 364 and discharged together after the water dissolves hydrogen sulfide and sulfur dioxide to saturation. A motor 365 for driving the rotating rod 362 to rotate is fixed on the filtering housing 361, and a water injection pipe 366 for water injection and drainage is communicated with the bottom of the filtering housing 361, so as to realize the purification of the carbon monoxide air flow and improve the efficiency of subsequent silicon carbide synthesis.

[0039] As a preferred technical solution of this embodiment, the diameter of the intake pipe 40 is smaller than that of the outlet pipe 35. Since a small amount of impurity gas in the air flow is filtered, the pressure of the air flow will decrease. By making the diameter of the intake pipe 40 smaller than that of the outlet pipe 35, the flow rate and pressure of the air flow when passing through the intake pipe 40 are greater than those of the air flow in the outlet pipe 35, so as to generate a suitable air pressure value at the nozzle of the intake pipe 40, enabling the air flow to flow stably between both ends of the sintering mechanism 1, thereby improving the efficiency of silicon carbide and making the silicon carbide synthesized on the surface of the silicon carbide long tube more uniform, and improving the overall quality of the silicon carbide long tube.

[0040] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device.

[0041] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0042] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A silicon carbide long tube sintering furnace, comprising a sintering mechanism (1) for sintering silicon carbide long tubes, and a cooling mechanism (2) is provided on the sintering mechanism (1), characterized in that: A control mechanism (3) for guiding the flow of air is provided on the sintering mechanism (1); The control mechanism (3) includes a cavity (31) provided at one end of the sintering mechanism (1). A plurality of through holes (32) are formed in the side wall of the cavity (31) close to the sintering mechanism (1). A plurality of collecting pipes (33) communicating with the cavity (31) are uniformly arranged on the inner wall of the sintering mechanism (1). A plurality of strip-shaped grooves (34) are formed on the outer wall of the collecting pipe (33). A bendable air outlet pipe (35) is communicated with the side of the cavity (31) away from the sintering mechanism (1). A filtering component (36) for removing impurity gases is communicated with the air outlet pipe (35). A negative pressure fan (37) is communicated with the air outlet pipe (35) on the side of the filtering component (36) away from the cavity (31). A connecting pipe (38) controlled by a solenoid valve is communicated with the air outlet pipe (35) on the side of the negative pressure fan (37) away from the cavity (31). The bottom of the connecting pipe (38) is communicated with a vacuum tank (39). An air inlet pipe (40) is communicated between the other end of the air outlet pipe (35) and the end of the sintering mechanism (1) away from the cavity (31); The sintering mechanism (1) includes an outer shell (11). An inner shell (12) is concentrically arranged inside the outer shell (11). A closed cooling cavity (13) is arranged between the outer shell (11) and the inner shell (12). A hatch (14) with an air inlet pipe (40) in the center is hingedly connected to the end of the outer shell (11) away from the cavity (31). A heating component (15) for sintering silicon carbide long tubes is arranged at the center of the inner shell (12). A guiding component (16) for guiding the air flow to flow towards its center is arranged inside the heating component (15). A plurality of support columns (17) are fixed at the bottom of the outer shell (11); The heating component (15) includes a fixing plate (151) fixed on the inner shell (12). A heating coil (152) is fixed on the fixing plate (151). A heat preservation shell (153) with two open ends is arranged at the center of the heating coil (152). A plurality of fixing rods (154) are fixed between the heat preservation shell (153) and the inner shell (12). A plurality of uniformly distributed material guiding rods (155) are rotatably installed inside the heat preservation shell (153); The guiding component (16) includes a plurality of square-ring-shaped guiding plates (161) uniformly distributed inside the heat preservation shell (153). An inclined guiding surface (162) is arranged on the side of the guiding plate (161) facing the hatch (14); The filtering component (36) includes a filtering shell (361) filled with water inside. A rotating rod (362) is rotatably installed inside the filtering shell (361). A plurality of wire meshes (363) arranged on the cross section of the filtering shell (361) are fixed on the rotating rod (362). Scrapers (364) fixed at the bottom of the filtering shell (361) are slidably arranged on both sides of the wire mesh (363). A motor (365) for driving the rotating rod (362) to rotate is fixed on the filtering shell (361). A water injection pipe (366) for injecting water and draining water is communicated with the bottom of the filtering shell (361).

2. The silicon carbide long tube sintering furnace according to claim 1, wherein: The cooling mechanism (2) includes a cooling pipe (21) arranged at the top of the cooling chamber (13). Two water outlet grooves (22) are symmetrically arranged at the bottom of the cooling pipe (21). The top of the cooling pipe (21) is communicated with a water inlet valve (23). The bottom of the cooling chamber (13) is communicated with a water outlet valve (24). A plurality of baffles (25) horizontally fixed and distributed in a staggered manner are arranged in the cooling chamber (13).

3. The silicon carbide long tube sintering furnace according to claim 1, characterized in that: A conical guiding surface (41) is arranged on one side of the cavity (31) away from the sintering mechanism (1). The air outlet pipe (35) is arranged at the conical tip of the guiding surface (41).

4. A silicon carbide long tube sintering furnace according to claim 1, characterized in that: The diameter of the air inlet pipe (40) is smaller than the diameter of the air outlet pipe (35).

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