Energy-saving silicon carbide composite ceramic sintering furnace

Abstract

The invention relates to the technical field of sintering furnace waste heat utilization, in particular to an energy-saving silicon carbide composite ceramic sintering furnace which comprises a furnace body, a gas storage tank, an energy storage heat exchange box and a purification box are arranged on one side of the furnace body, and the energy storage heat exchange box communicates with the furnace body and the purification box through a first connecting pipe and a second connecting pipe correspondingly. The gas storage tank is communicated with the purification box and the furnace body through a third connecting pipe and a fourth connecting pipe respectively, and a vacuum pump is arranged on the first connecting pipe. By arranging the energy storage heat exchange box and nitrogen circulation, a heat storage material in the energy storage heat exchange box can effectively absorb and store heat energy of high-temperature nitrogen, and before the next batch of ceramics is sintered, the heat storage material in the energy storage heat exchange box can release the stored heat energy to the nitrogen; and the temperature of the nitrogen is continuously increased, and the to-be-sintered ceramic in the furnace body is preheated at the same time, so that efficient recycling of waste heat is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat utilization of sintering furnaces, and particularly to an energy-saving silicon carbide composite ceramic sintering furnace. Background Art

[0002] Silicon carbide composite ceramics are widely used in fields such as aerospace and nuclear energy due to their high strength, high temperature resistance, oxidation resistance and other characteristics. They are made by high-temperature sintering in a sintering furnace. After the sintering is completed, a large amount of high-temperature oil and gas remains in the furnace body. The patent with the application publication number CN118442836A discloses a vacuum sintering furnace and a sintering method for silicon carbide products. It sets up a circulation system to continuously circulate the high-temperature oil and gas, and at the same time separates impurities in the high-temperature oil and gas in the circulation loop to reduce the pollution caused by the high-temperature oil and gas to the products sintered in the furnace body next time.

[0003] However, after the sintering of silicon carbide products is completed, the circulation system in the above patent cannot recover and utilize the waste heat of the sintering furnace. At the same time, harmful gases such as carbon monoxide and sulfur dioxide may be generated during the high-temperature sintering process, and the circulation system in the above patent cannot purify these harmful gases. Summary of the Invention

[0004] In order to overcome the above-mentioned disadvantages of the prior art, the present invention provides an energy-saving silicon carbide composite ceramic sintering furnace.

[0005] The technical solution is: an energy-saving silicon carbide composite ceramic sintering furnace, including a furnace body. On one side of the furnace body, there are a gas storage tank, an energy storage heat exchange box and a purification box. The energy storage heat exchange box is connected to the furnace body and the purification box respectively through a first connecting pipe and a second connecting pipe. The gas storage tank is connected to the purification box and the furnace body respectively through a third connecting pipe and a fourth connecting pipe. A vacuum pump is provided on the first connecting pipe. Vent pipes for communicating with the external space are provided on the pipe section of the first connecting pipe between the energy storage heat exchange box and the vacuum pump and on the fourth connecting pipe. Commutation valves are provided in the connection nodes of the first connecting pipe, the fourth connecting pipe and the corresponding vent pipes. The energy storage heat exchange box has a plurality of spaced-apart compartments, and heat storage materials are provided in each compartment. Part of the second connecting pipe extends into the energy storage heat exchange box in a serpentine shape and forms a plurality of bending sections, and each bending section is respectively embedded in a compartment. The purification box is filled with a treatment liquid for treating harmful gases. Nitrogen is stored in the gas storage tank. There is a fifth connecting pipe on the second connecting pipe that is directly connected to the gas storage tank without passing through the purification box. Electric control valves are provided on the third connecting pipe and the fifth connecting pipe.

[0006] Further, part of the second connecting pipe extends into the purification box in a serpentine shape, and a plurality of exhaust holes are opened on the pipe wall of the extended pipe section of the second connecting pipe.

[0007] Further, a dehumidification box is provided on the purification box. A moisture-absorbing material is provided inside the dehumidification box. One end of the dehumidification box is communicated with the purification box through connecting pipe six, and the other end of the dehumidification box is communicated with the gas storage tank through connecting pipe four.

[0008] Further, a filter cylinder is detachably connected to the pipe section of connecting pipe one between the furnace body and the vacuum pump. A filter cake is provided inside the filter cylinder.

[0009] Further, a fixing rod is fixedly connected to the middle inside the filter cylinder. A sleeve is rotatably connected to the outside of the fixing rod. The filter cake is fixedly connected to the first end along the gas flow direction inside connecting pipe one on the sleeve. An impeller is fixedly connected to the end of the sleeve along the gas flow direction inside connecting pipe one. A scraping bar is fixedly connected to the end of the fixing rod close to the filter cake. The scraping bar is in contact and cooperation with the filter cake.

[0010] Further, both the scraping bar and the fixing rod are of hollow structures. A dust-catching port is opened at the bottom of the end of the scraping bar away from the fixing rod. A dust-catching bag is provided inside the scraping bar. The mouth of the dust-catching bag is detachably connected to the dust-catching port. The other end of the scraping bar is communicated with the inside of the fixing rod. An exhaust port is opened at the end of the fixing rod away from the filter cake.

[0011] Further, the heat storage material is of honeycomb ceramic structure, and its material is selected from one of cordierite, alumina and silicon carbide.

[0012] Further, the material of the moisture-absorbing material is selected from one of silica gel, molecular sieve, activated carbon and calcium chloride.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By setting up the energy storage heat exchange box and nitrogen circulation, the heat storage material in the energy storage heat exchange box can effectively absorb and store the heat energy of high-temperature nitrogen. At the same time, the nitrogen is continuously cooled during the circulation process, and the cooling speed of the ceramics inside the furnace body is accelerated. Before the next batch of ceramics is sintered, the heat storage material in the energy storage heat exchange box can release the heat energy it stores to the nitrogen, so that the temperature of the nitrogen continuously rises while preheating the ceramics to be sintered inside the furnace body, thereby realizing the efficient recovery and utilization of waste heat, significantly improving the energy utilization rate, and reducing the overall energy consumption during the sintering process.

[0014] 2. The treatment liquid in the purification box can react with harmful gases such as carbon monoxide and sulfur dioxide that may be generated during the treatment process and effectively absorb them, thereby ensuring that the discharged gas is clean and harmless. This not only protects the environment but also improves the safety of the production process.

[0015] 3. Through the provided filter cartridge and the filter cake inside it, the gas discharged from the sintering furnace can be preliminarily filtered, effectively removing solid particles and impurities in the gas. The scraping bar structure inside the filter cartridge, in cooperation with the fixed rod and the impeller, realizes the automatic cleaning of the surface of the filter cake, ensures the filtering effect, reduces the need for manual cleaning, and lowers the maintenance cost. Brief Description of the Drawings

[0016] Figure 1 It is a three-dimensional structure schematic diagram of the present invention.

[0017] Figure 2 It is an installation structure schematic diagram of the vacuum pump and the energy storage heat exchange box of the present invention.

[0018] Figure 3 It is a three-dimensional structure schematic diagram of the gas storage tank and the purification box of the present invention.

[0019] Figure 4 It is a cross-sectional view of the internal structure of the energy storage heat exchange box of the present invention.

[0020] Figure 5 It is a cross-sectional view of the internal structure of the purification box of the present invention.

[0021] Figure 6 It is a cross-sectional view of the internal structure of the filter cartridge of the present invention.

[0022] Figure 7 It is an exploded three-dimensional structure diagram of the filter cake, the fixed rod and the impeller of the present invention.

[0023] Figure 8 It is a cross-sectional view of the internal structure of the fixed rod and the scraping bar of the present invention.

[0024] Names and serial numbers of components in the figure: 1 - furnace body, 2 - gas storage tank, 3 - energy storage heat exchange box, 301 - compartment, 4 - purification box, 5 - connecting pipe one, 6 - connecting pipe two, 7 - connecting pipe three, 8 - connecting pipe four, 9 - connecting pipe five, 10 - connecting pipe six, 11 - vacuum pump, 12 - ventilation pipe, 13 - dehumidification box, 14 - filter cartridge, 15 - filter cake, 16 - fixed rod, 1601 - exhaust port, 17 - sleeve, 18 - impeller, 19 - scraping bar, 1901 - dust collection port. Detailed Embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] Please refer to Figures 1-8, An energy-saving silicon carbide composite ceramic sintering furnace, comprising a furnace body 1. The furnace body 1 is used to place the silicon carbide composite ceramic material to be sintered and perform high-temperature sintering on it. On one side of the furnace body 1, there are a gas storage tank 2, an energy storage heat exchange tank 3, and a purification tank 4. The energy storage heat exchange tank 3 is connected to the furnace body 1 and the purification tank 4 through a first connecting pipe 5 and a second connecting pipe 6 respectively. The gas storage tank 2 is connected to the purification tank 4 and the furnace body 1 through a third connecting pipe 7 and a fourth connecting pipe 8 respectively. A vacuum pump 11 is provided on the first connecting pipe 5. Vent pipes 12 for communicating with the external space are provided on the pipe section of the first connecting pipe 5 between the energy storage heat exchange tank 3 and the vacuum pump 11 and on the fourth connecting pipe 8. Commutating valves are provided inside the connection nodes of the first connecting pipe 5, the fourth connecting pipe 8, and the corresponding vent pipes 12. In this embodiment, the commutating valve is selected as a pneumatic three-way valve. The energy storage heat exchange tank 3 has a plurality of spaced-apart compartments 301. Each compartment 301 is provided with a heat storage material. The heat storage material has a honeycomb ceramic structure, and its material is selected from one of cordierite, alumina, and silicon carbide. In this embodiment, the heat storage material is selected as alumina because of its good thermal stability and heat storage performance. The second connecting pipe 6 extends into the energy storage heat exchange tank 3 in a serpentine shape and forms a plurality of bending segments, and each bending segment is respectively embedded in a compartment 301. In this way, when high-temperature nitrogen enters the energy storage heat exchange tank 3 through the second connecting pipe 6, it can fully contact the heat storage material and exchange heat energy. The purification tank 4 is filled with a treatment liquid for treating harmful gases. In this embodiment, the treatment liquid is selected as sodium hydroxide solution. The sodium hydroxide solution can react with harmful gases such as carbon monoxide and sulfur dioxide that may be generated during the treatment process and effectively absorb them. The second connecting pipe 6 extends into the purification tank 4 in a serpentine shape, and a plurality of exhaust holes are opened on the tube wall of the extended tube section of the second connecting pipe 6. The gas storage tank 2 stores nitrogen used as a protective atmosphere during the sintering process. There is a fifth connecting pipe 9 on the second connecting pipe 6 that is directly connected to the gas storage tank 2 without passing through the purification tank 4. Electric control valves are provided on both the third connecting pipe 7 and the fifth connecting pipe 9.

[0027] Initially, the electromagnetic control valves of connecting pipe three 7 and connecting pipe five 9 are both in the closed state. The ceramic to be sintered is placed in the furnace body 1. First, through the switching of the reversing valve corresponding to connecting pipe one 5, the external space forms a one-way conduction with the inside of the furnace body 1 through the air pipe 12 corresponding to connecting pipe one 5, and through the switching of the reversing valve corresponding to connecting pipe four 8, the connection between the inside of the furnace body 1, the inside of the gas storage tank 2 and the external space is disconnected. Then, the air inside the furnace body 1 is pumped out by the vacuum pump 11. After the extraction is completed, through the switching of the reversing valve corresponding to connecting pipe one 5, the connection between the inside of the furnace body 1, the inside of the energy storage heat exchange box 3 and the external space is disconnected. Then, through the switching of the reversing valve corresponding to connecting pipe four 8, a one-way conduction is formed between the inside of the furnace body 1 and the inside of the gas storage tank 2. The nitrogen stored in the gas storage tank 2 is gradually discharged into the furnace body 1 due to the pressure difference, forming a protective atmosphere for the sintering of the ceramic. Then, the ceramic is heated and sintered by the sintering device inside the furnace body 1. During the sintering process, the temperature of the nitrogen inside the furnace body 1 gradually rises. After the sintering is completed, through the switching of the reversing valve corresponding to connecting pipe one 5, a one-way conduction is formed between the inside of the furnace body 1 and the energy storage heat exchange box 3. At the same time, the electromagnetic control valve on connecting pipe three 7 is opened, and the high-temperature nitrogen inside the furnace body 1 is pumped into the energy storage heat exchange box 3 by the vacuum pump 11, and then enters the gas storage tank 2 after passing through the purification box 4, and finally re-enters the furnace body 1, forming a nitrogen cycle. During this process, first, the energy storage material in the energy storage heat exchange box 3 can absorb and store the energy in the high-temperature nitrogen, and the temperature of the nitrogen gradually decreases. Then, the cooled nitrogen is discharged through the exhaust hole of connecting pipe two 6. The nitrogen floats in the treatment liquid in the purification box 4. During the floating process of the nitrogen, the harmful gases in the nitrogen can react with the treatment liquid and be absorbed and treated. Thus, the nitrogen is continuously cooled and the harmful gases in it are removed during this cycle, and at the same time, it can also accelerate the cooling of the ceramic inside the furnace body 1. After the ceramic inside the furnace body 1 is cooled, through the switching of the reversing valve corresponding to connecting pipe four 8, the connection between the inside of the furnace body 1, the inside of the gas storage tank 2 and the external space is disconnected. The nitrogen inside the furnace body 1 is all pumped into the gas storage tank 2 by the vacuum pump 11. After the extraction is completed, the electromagnetic control valve on connecting pipe three 7 is closed, so that the nitrogen is stored in the gas storage tank 2 again. Then, through the switching of the reversing valve corresponding to connecting pipe one 5, the connection between the inside of the furnace body 1, the energy storage heat exchange box 3 and the external space is disconnected. Then, through the switching of the reversing valve corresponding to connecting pipe four 8, the external space forms a one-way conduction with the inside of the furnace body 1 through the air pipe 12 corresponding to connecting pipe four 8, and the air in the external space enters the furnace body 1 due to the pressure difference. When the air pressure inside the furnace body 1 is balanced with the external space, the sintered ceramic can be taken out and the next batch of ceramics to be sintered can be placed in. After the next batch of ceramics to be sintered is placed, through the switching of the reversing valve corresponding to connecting pipe one 5, the external space and the inside of the furnace body 1 form a one-way conduction, and the air inside the furnace body 1 is pumped out by the vacuum pump 11. Then, through the switching of the reversing valve corresponding to connecting pipe one 5,A one-way conduction is formed between the interior of the furnace body 1 and the energy storage heat exchange tank 3. At the same time, through the switching of the reversing valve corresponding to the fourth connecting pipe 8, a one-way conduction is formed between the interior of the furnace body 1 and the interior of the gas storage tank 2, and the electric control valve on the fifth connecting pipe 9 is opened, thereby forming a conduction between the interior of the furnace body 1, the energy storage heat exchange tank 3 and the gas storage tank 2. At this time, through the operation of the vacuum pump 11, the nitrogen gas in the gas storage tank 2 continuously circulates between the interior of the furnace body 1, the energy storage heat exchange tank 3 and the gas storage tank 2. During this process, the heat storage material in the energy storage heat exchange tank 3 can release the stored heat energy to the nitrogen gas, causing the temperature of the nitrogen gas to continuously rise and being able to preheat the ceramic to be sintered inside the furnace body 1. In this way, the waste heat from the sintering of the previous batch of ceramics is effectively utilized. After the temperature of the nitrogen gas stabilizes, through the switching of the reversing valve corresponding to the first connecting pipe 5 and the fourth connecting pipe 8, the connection between the interior of the furnace body 1, the interior of the energy storage heat exchange tank 3 and the interior of the gas storage tank 2 is disconnected, and the electric control valve on the fifth connecting pipe 9 is closed, and the sintering work of the ceramics is restarted. In this way, by repeating this cycle, starting from the sintering of the second batch of ceramics, the waste heat from the sintering of the previous batch of ceramics can be effectively utilized.,

[0028] In order to further remove the moisture in the nitrogen gas, a dehumidification box 13 is provided on the purification box 4. A moisture absorption material is provided inside the dehumidification box 13. The material of the moisture absorption material is selected from one of silica gel, molecular sieve, activated carbon and calcium chloride. In this embodiment, the moisture absorption material is selected as silica gel because of its good moisture absorption performance. One end of the dehumidification box 13 is connected to the purification box 4 through a sixth connecting pipe 10, and the other end of the dehumidification box 13 is connected to the gas storage tank 2 through the fourth connecting pipe 8. In this way, the nitrogen gas treated by the treatment liquid in the purification box 4 can be further dehumidified by the dehumidification box 13 before entering the gas storage tank 2.,

[0029] In order to preliminarily filter the gas discharged from the furnace body 1 through the first connecting pipe 5 and remove the solid particles and impurities in the gas, a filter cylinder 14 is detachably connected to the pipe section of the first connecting pipe 5 between the furnace body 1 and the vacuum pump 11, and a filter cake 15 is provided inside the filter cylinder 14.,

[0030] A fixing rod 16 is fixedly connected to the middle inside the filter cylinder 14. A sleeve 17 is rotatably connected to the outside of the fixing rod 16. The filter cake 15 is fixedly connected to the first end of the sleeve 17 along the gas flow direction inside the first connecting pipe 5. An impeller 18 is fixedly connected to the second end of the sleeve 17 along the gas flow direction inside the first connecting pipe 5. A scraping strip 19 is fixedly connected to the end of the fixing rod 16 close to the filter cake 15, and the scraping strip 19 is in contact with the filter cake 15. When the nitrogen gas passes through the filter cylinder 14, it can drive the impeller 18 to rotate, and then drive the sleeve 17 and the filter cake 15 to rotate. In this way, while the filter cake 15 filters the gas, it can also achieve automatic cleaning through the relative movement between the scraping strip 19 and the filter cake 15, avoiding the accumulation of solid particles and impurities on the filter cake 15.,

[0031] The scraping strip 19 and the fixing rod 16 are both of hollow structures. At the bottom of one end of the scraping strip 19 away from the fixing rod 16, a dust collection port 1901 is formed. A dust collection bag (not shown in the figure) is arranged inside the scraping strip 19. The bag mouth of the dust collection bag is detachably connected to the inside of the dust collection port 1901. The other end of the scraping strip 19 is communicated with the inside of the fixing rod 16. An exhaust port 1601 is formed at one end of the fixing rod 16 away from the filter cake 15. When the dust on the filter cake 15 is swept off by the scraping strip 19, the dust floats with the air flow in the filter cylinder 14. The air flow carries the dust through the dust collection port 1901 into the inside of the scraping strip 19. Finally, the air flow passes through the dust collection bag and is discharged through the exhaust port 1601, while the dust is captured by the dust collection bag.

[0032] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An energy-saving silicon carbide composite ceramic sintering furnace, comprising a furnace body (1), characterized in that, On one side of the furnace body (1), there are a gas storage tank (2), a heat storage and heat exchange tank (3), and a purification tank (4). The heat storage and heat exchange tank (3) is connected to the furnace body (1) and the purification tank (4) respectively through a first connecting pipe (5) and a second connecting pipe (6). The gas storage tank (2) is connected to the purification tank (4) and the furnace body (1) respectively through a third connecting pipe (7) and a fourth connecting pipe (8). A vacuum pump (11) is arranged on the first connecting pipe (5). Vent pipes (12) for communicating with the external space are arranged on the pipe section of the first connecting pipe (5) between the heat storage and heat exchange tank (3) and the vacuum pump (11) and on the fourth connecting pipe (8). Commutation valves are arranged in the connection nodes of the first connecting pipe (5), the fourth connecting pipe (8) and the corresponding vent pipes (12). The heat storage and heat exchange tank (3) has a plurality of spaced-apart compartments (301). Heat storage materials are arranged in each compartment (301). Part of the second connecting pipe (6) extends into the heat storage and heat exchange tank (3) in a serpentine shape and forms a plurality of bending sections, and each bending section is respectively embedded in a compartment (301). The purification tank (4) is filled with a treatment liquid for treating harmful gases. Nitrogen is stored in the gas storage tank (2). There is a fifth connecting pipe (9) on the second connecting pipe (6) that is directly connected to the gas storage tank (2) without passing through the purification tank (4). Electric control valves are arranged on both the third connecting pipe (7) and the fifth connecting pipe (9).

2. The energy-saving silicon carbide composite ceramic sintering furnace according to claim 1, wherein Part of the second connecting pipe (6) extends into the purification tank (4) in a serpentine shape, and a plurality of exhaust holes are formed in the pipe wall of the extended pipe section of the second connecting pipe (6).

3. An energy-saving silicon carbide composite ceramic sintering furnace according to claim 2, characterized in that, A dehumidifying box (13) is arranged on the purification tank (4). A moisture-absorbing material is arranged in the dehumidifying box (13). One end of the dehumidifying box (13) is connected to the purification tank (4) through a sixth connecting pipe (10), and the other end of the dehumidifying box (13) is connected to the gas storage tank (2) through the fourth connecting pipe (8).

4. An energy-saving silicon carbide composite ceramic sintering furnace according to claim 3, characterized in that, A filter cartridge (14) is detachably connected to the pipe section of the first connecting pipe (5) between the furnace body (1) and the vacuum pump (11). A filter cake (15) is arranged in the filter cartridge (14).

5. An energy-saving silicon carbide composite ceramic sintering furnace according to claim 4, characterized in that, A fixing rod (16) is fixedly connected in the middle of the filter cartridge (14). A sleeve (17) is rotatably connected to the outside of the fixing rod (16). The filter cake (15) is fixedly connected to the first end of the sleeve (17) along the gas flow direction in the first connecting pipe (5). An impeller (18) is fixedly connected to the second end of the sleeve (17) along the gas flow direction in the first connecting pipe (5). A scraping strip (19) is fixedly connected to the end of the fixing rod (16) close to the filter cake (15). The scraping strip (19) is in contact and cooperation with the filter cake (15).

6. The energy-saving silicon carbide composite ceramic sintering furnace according to claim 5, characterized in that, Both the scraping strip (19) and the fixing rod (16) are of hollow structures. A dust collection port (1901) is formed at the bottom of the end of the scraping strip (19) away from the fixing rod (16). A dust collection bag is arranged in the scraping strip (19). The mouth of the dust collection bag is detachably connected to the dust collection port (1901). The other end of the scraping strip (19) is communicated with the inside of the fixing rod (16). An exhaust port (1601) is formed at the end of the fixing rod (16) away from the filter cake (15).

7. An energy-saving silicon carbide composite ceramic sintering furnace according to claim 6, characterized in that The heat storage material is of honeycomb ceramic structure, and its material is selected from one of cordierite, alumina and silicon carbide.

8. An energy-saving silicon carbide composite ceramic sintering furnace according to claim 7, characterized in that, The material of the moisture-absorbing material is selected from one of silica gel, molecular sieve, activated carbon, and calcium chloride.

Images