Silicon carbide vacuum multi-chamber continuous sintering furnace and sintering method thereof

Abstract

The present application relates to the technical field of silicon carbide sintering equipment, and discloses a silicon carbide vacuum multi-chamber continuous sintering furnace and a sintering method thereof. The continuous sintering furnace comprises a preparation chamber, a plurality of heating chambers connected in sequence, wherein the first heating chamber is connected with the preparation chamber, a plurality of cooling chambers connected in sequence, wherein the first cooling chamber is connected with the last heating chamber, a cooling chamber connected with the last cooling chamber, and a heat preservation tray provided with a product to be treated and sequentially passing through the preparation chamber, the plurality of heating chambers, the plurality of cooling chambers and the cooling chamber. Gradual temperature rise of the product to be treated can reduce internal thermal stress and prevent micro-crack propagation or failure caused by excessive temperature difference. Gradual cooling treatment through the plurality of cooling chambers can prevent product fragmentation caused by excessive cooling speed, improve product quality, separate temperature rise and temperature drop, avoid energy loss, and reduce production cost.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide sintering equipment technology, and in particular to a silicon carbide vacuum multi-chamber continuous sintering furnace and its sintering method. Background Technology

[0002] Silicon carbide sintering is the process of treating silicon carbide powder at high temperatures to transform it into a dense and robust ceramic material. Currently, silicon carbide sintering involves simultaneous heating and cooling in a single-chamber furnace. In this single-chamber furnace, the temperature is raised first and then lowered within the same chamber, resulting in a long production cycle, low capacity, and significant energy loss due to the simultaneous heating and cooling, leading to energy waste and increased production costs. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] In view of this, the present invention provides a silicon carbide vacuum multi-chamber continuous sintering furnace and its sintering method. The continuous sintering furnace gradually heats the product to 1800°C through a preparation chamber and multiple heating chambers. Gradual heating of the product to be processed can reduce internal thermal stress and prevent the propagation of microcracks or failure caused by excessive temperature difference. Gradual cooling is carried out through multiple cooling chambers to prevent product breakage caused by excessive cooling rate, improve product quality, separate heating and cooling to avoid energy loss and reduce production costs.

[0005] Specifically, the following technical solutions are included: An embodiment of the first aspect of the present invention provides a silicon carbide vacuum multi-chamber continuous sintering furnace, the continuous sintering furnace comprising: Preparation room; Multiple heating chambers are connected in sequence, wherein the first heating chamber is connected to the preparation chamber; Multiple cooling chambers are connected in sequence, wherein the first cooling chamber is connected to the last heating chamber; The cooling chamber is connected to the last of the aforementioned cooling chambers; An insulated tray, on which the product to be processed is placed, passes sequentially through the preparation chamber, multiple heating chambers, multiple cooling chambers, and the cooling chamber.

[0006] Optionally, the continuous sintering furnace further includes: The feeding trolley is located at the end of the preparation chamber away from the first heating chamber; The discharge trolley is located at the end of the cooling chamber furthest from the last cooling chamber. The insulated pallet enters the preparation chamber via the feeding trolley and leaves the cooling chamber via the discharging trolley.

[0007] Optionally, the preparation chamber, the heating chamber, and the cooling chamber have the same structure, each including: A cavity, wherein a receiving chamber is provided within the cavity, and at least a portion of the insulated tray is located within the receiving chamber; A transmission system is located within the cavity and is disposed below the receiving chamber. The transmission system is configured to move the insulated tray. A heating system is provided in the accommodating chamber, and the heating system is configured to heat the accommodating chamber; A temperature measuring system is installed in the containment chamber, and the temperature measuring system is configured to measure the temperature of the containment chamber. A cooling system is provided outside the cavity and is configured to provide cooling protection for the continuous sintering furnace. A positioning signal system is installed on both sides of the cavity. When the insulated tray is located between the positioning signal systems, the transmission system stops working. The control system is electrically connected to the transmission system, the positioning signal system, the heating system, the temperature measuring system, and the cooling system, respectively. The containment chamber is either a heat preservation chamber or a heat reduction chamber.

[0008] Optionally, the transmission system includes: The drive roller is connected to the motor via a belt; Multiple driven rollers are arranged in the same plane as the driving roller, and the multiple driven rollers are connected to the driving roller through a transmission component; A support frame is configured to support the drive roller and a plurality of driven rollers, the drive roller and the driven rollers being rotatably connected to the support frame respectively.

[0009] Optionally, the cavity is fixedly connected to the end of the receiving chamber away from the transmission system. The receiving chamber has an opening on the side facing the transmission system. The heat-insulating tray includes a first horizontal plate, a second horizontal plate, and a connecting plate connecting the first horizontal plate and the second horizontal plate. The first horizontal plate, the second horizontal plate, and the connecting plate form an I-shape. Notches are formed on both sides of the connecting plate. The notches match the bottom walls of the receiving chamber on both sides of the opening.

[0010] Optionally, the cooling chamber includes: Receiving cavity; An inflation system, connected to the receiving cavity, is configured to introduce an inert gas into the receiving cavity; An air-cooled heat exchange system is connected to the receiving cavity, and the air-cooled heat exchange system is configured to cool the receiving cavity.

[0011] Optionally, the continuous sintering furnace further includes a slide gate valve, which includes a first slide gate valve, a second slide gate valve, a third slide gate valve, a fourth slide gate valve, and a fifth slide gate valve. The first slide gate valve is located at the end of the preparation chamber away from the first heating chamber. The second slide gate valve is located between the preparation chamber and the first heating chamber. The third slide gate valve is located between the first heating chamber and the second heating chamber. The fourth slide gate valve is located between the last two cooling chambers. The fifth slide gate valve is located between the last cooling chamber and the cooling chamber. The end of the cooling chamber away from the last cooling chamber is provided with a cooling chamber door. A heat insulation valve assembly is provided between the remaining two adjacent heating chambers, between the remaining two adjacent cooling chambers, and between the last heating chamber and the first cooling chamber.

[0012] Optionally, the continuous sintering furnace further includes a vacuum system, with multiple vacuum systems respectively connected to the preparation chamber, the first heating chamber, the last cooling chamber and the cooling chamber, and the remaining heating chambers connected to at least one vacuum system, and the remaining cooling chambers connected to at least one vacuum system.

[0013] A second aspect of the present invention provides a sintering method for a silicon carbide vacuum multi-chamber continuous sintering furnace, wherein the sintering method utilizes the continuous sintering furnace described in any of the preceding claims, and the sintering method includes the following steps: The product to be processed enters the preparation chamber and is preheated. The preheated product to be processed enters multiple heating chambers in sequence for progressively increasing temperature. The product to be processed after being heated in stages enters multiple cooling chambers in sequence for cooling in stages. The product to be processed, after being subjected to a step-by-step cooling process, enters a cooling chamber for further cooling.

[0014] Optionally, the preparation chamber, the plurality of heating chambers, the plurality of cooling chambers, and the cooling chamber each include a set of the products to be processed.

[0015] The silicon carbide vacuum multi-chamber continuous sintering furnace and its sintering method provided in this invention include a preparation chamber, multiple heating chambers, multiple cooling chambers, and a cooling chamber connected in sequence. Insulated trays hold the products to be processed. The products sequentially pass through the preparation chamber, multiple heating chambers, multiple cooling chambers, and the cooling chamber, undergoing step-by-step heating and cooling processes. The step-by-step heating process using the preparation chamber and multiple heating chambers reduces internal thermal stress and prevents microcrack propagation or failure caused by excessive temperature differences. The step-by-step cooling process using the multiple cooling chambers prevents product breakage caused by excessively rapid cooling, improving product quality. Simultaneously, the heating and cooling processes are not performed in the same space, allowing for temperature retention for the next incoming product, reducing energy loss and improving production economy. Furthermore, the sequential entry into the next space, with each product operating simultaneously during heating or cooling, enhances production efficiency.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a continuous sintering furnace according to an embodiment of the present invention; Figure 2 This is a top view schematic diagram of a continuous sintering furnace according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a preparation room, heating room, or cooling room according to an embodiment of the present invention; Figure 4 This is a schematic diagram of an insulated tray according to an embodiment of the present invention.

[0019] in, Figures 1 to 4 The correspondence between the reference numerals and component names in the attached drawings is as follows: 1. Preparation chamber; 2. First heating chamber; 3. Second heating chamber; 4. Third heating chamber; 5. Fourth heating chamber; 6. Fifth heating chamber; 7. First cooling chamber; 8. Second cooling chamber; 9. Third cooling chamber; 10. Fourth cooling chamber; 11. Fifth cooling chamber; 12. Cooling chamber; 13. First gate valve; 14. Second gate valve; 15. Third gate valve; 16. Fourth gate valve; 17. Fifth gate valve; 18. Cooling chamber door; 19. Insulation valve assembly; 20. Feeding trolley; 21. Discharge trolley; 22. Transmission system; 23. Vacuum system; 24. Heating power supply; 25. Control system; 26. Heating system; 27. Temperature measurement system; 28. Cooling system; 29. ​​Insulated tray; 2901. First horizontal plate; 2902. Second horizontal plate; 2903. Connecting plate; 30. Inflation system; 31. Air-cooled heat exchange system; 32. Reception chamber; 33. Position signal system; 34. Cavity. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Before providing a further detailed description of the embodiments of the present invention, the directional terms used in the embodiments of the present invention, such as "upper part", "lower part" and "side part", are not intended to limit the scope of protection of the present invention.

[0022] To make the technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0023] like Figures 1 to 3 As shown, one embodiment of the present invention provides a silicon carbide vacuum multi-chamber continuous sintering furnace, the continuous sintering furnace comprising: Preparation Room 1; Multiple heating chambers are connected in sequence, with the first heating chamber connected to preparation chamber 1; Multiple cooling chambers are connected in sequence, with the first cooling chamber connected to the last heating chamber; Cooling chamber 12 is connected to the last cooling chamber; The insulated tray 29 has products to be processed on it. The insulated tray 29 passes through the preparation chamber 1, multiple heating chambers, multiple cooling chambers and cooling chamber 12 in sequence.

[0024] Among them, such as Figure 1As shown, the continuous sintering furnace includes a preparation chamber 1, multiple heating chambers, multiple cooling chambers, and a cooling chamber 12 connected in sequence. Insulated trays 29 hold the products to be processed. The products sequentially pass through the preparation chamber 1, multiple heating chambers, multiple cooling chambers, and cooling chamber 12, undergoing step-by-step heating and cooling processes. The step-by-step heating process using the preparation chamber 1 and multiple heating chambers reduces internal thermal stress and prevents the propagation of microcracks or failure caused by excessive temperature differences. The step-by-step cooling process using the multiple cooling chambers 12 prevents product breakage caused by excessively rapid cooling, thus improving product quality. Simultaneously, the heating and cooling processes are not performed in the same space, allowing the temperature to be maintained for the next incoming product, reducing energy loss and improving production economy. Furthermore, the sequential entry into the next space, with each product operating simultaneously during heating or cooling, enhances production efficiency.

[0025] It should be noted that this embodiment is provided with five heating chambers, namely the first heating chamber 2, the second heating chamber 3, the third heating chamber 4, the fourth heating chamber 5 and the fifth heating chamber 6, and five cooling chambers, namely the first cooling chamber 7, the second cooling chamber 8, the third cooling chamber 9, the fourth cooling chamber 10 and the fifth cooling chamber 11.

[0026] Furthermore, when the first set of insulated trays 29 carrying products to be processed enters the first heating chamber 2 from the preparation chamber 1, the second set of insulated trays 29 carrying products to be processed enters the preparation chamber 1; when the first set of insulated trays 29 carrying products to be processed enters the second heating chamber 3 from the first heating chamber 2, the second set of insulated trays 29 carrying products to be processed enters the first heating chamber 2, while the third set of insulated trays 29 carrying products to be processed enters the preparation chamber 1, and so on, without wasting the energy in the preparation chamber 1, heating chamber, cooling chamber 12, and cooling state of the previous set continues to supply the energy to the next set, which can make efficient use of energy and avoid energy waste. At the same time, processing products to be processed one after another can also improve processing efficiency and reduce the labor intensity of workers.

[0027] This application divides the heating and cooling process into multiple stages, enabling the heating chamber to heat only and the cooling chamber to cool only, thus solving the problem of large energy loss caused by simultaneous heating and cooling. Through the staged heating and cooling process, the processing time can be shortened, and the capacity of a single continuous sintering furnace can be increased during continuous production.

[0028] In one feasible implementation, the continuous sintering furnace further includes: The feeding trolley 20 is located at the end of the preparation room 1 away from the first heating chamber; The discharge trolley 21 is located at the end of the cooling chamber 12 away from the last cooling chamber. Among them, the insulated pallet 29 enters the preparation chamber 1 through the feeding trolley 20, and the insulated pallet 29 leaves the cooling chamber 12 through the discharging trolley 21.

[0029] The system features an automated movement of the insulated pallet 29, containing the product to be processed, placed on the insulated pallet 29 by staff. The insulated pallet 29 is then fed into the preparation chamber 1 by the insulated pallet 20. The transmission system 22 within the continuous sintering furnace moves the insulated pallet 29 between the preparation chamber 1, multiple heating chambers, multiple cooling chambers, and the cooling chamber 12. After processing, the pallet 29 exits from the cooling chamber 12 and is then removed from the continuous sintering furnace by the discharge trolley 21. This automated movement of the insulated pallet 29 reduces the labor intensity of staff and improves production efficiency.

[0030] It should be noted that the feeding trolley 20 and the discharging trolley 21 can be roller conveyors.

[0031] In one feasible implementation, such as Figure 3 As shown, the preparation chamber 1, heating chamber, and cooling chamber have the same structure and all include: The cavity 34 has a receiving chamber 32 inside, and at least part of the insulated tray 29 is located in the receiving chamber 32; The transmission system 22 is located inside the cavity 34 and is positioned below the receiving chamber 32. The transmission system 22 is configured to move the insulated tray 29. A heating system 26 is disposed within the receiving chamber 32, and the heating system 26 is configured to heat the receiving chamber 32; Temperature measuring system 27 is installed inside the containment chamber 32 and is configured to measure the temperature of the containment chamber 32. Cooling system 28 is located outside cavity 34 and is configured to provide cooling protection for continuous sintering furnace. The positioning signal system 33 is located on both sides of the cavity 34. When the insulated tray 29 is located between the positioning signal systems 33, the transmission system 22 stops working. The control system 25 is electrically connected to the transmission system 22, the positioning signal system 33, the heating system 26, the temperature measuring system 27, and the cooling system 28, respectively. Among them, the containment room 32 is a heat preservation room or a heat reduction room.

[0032] It should be noted that the cavity 34 of the preparation chamber 1 and the heating chamber contains a receiving chamber 32, the receiving chamber 32 in the cooling chamber is a cooling chamber, and the receiving chamber 32 in the heating chamber is a heat preservation chamber. The cooling chamber and the heat preservation chamber have the same structural shape. All cavities 34 require a cooling system 28 to prevent high temperatures from being conducted to the outside of the cavities 34 after heating, which could cause high-temperature damage to the structure of the continuous sintering furnace. This is mainly achieved through cooling water cooling, providing a safety protection for the continuous sintering furnace. Industrially available water cooling is used to reduce production costs while ensuring safety and reliability.

[0033] The preparation chamber 1, heating chamber, and cooling chamber have identical structures, each including a cavity 34, a transmission system 22, a heating system 26, a temperature measuring system 27, a cooling system 28, a positioning signal system 33, and a control system 25. A receiving chamber 32 (insulation or cooling chamber) is fixedly installed inside the cavity 34. The receiving chamber 32 and the insulated tray 29 entering the cavity are connected with a clearance fit under the support of the transmission system 22. The transmission system 22 drives the insulated tray 29 to move within the cavity 34. When the insulated tray 29 moves between the positioning signal system 33, the transmission system 22 stops operating. Typically, the positioning signal system 33 can be an infrared transmitter and receiver. When the insulated tray 29 reaches between the infrared transmitter and receiver, the infrared signal is cut off and sent to the transmission system 22, causing the transmission system 22 to stop operating, and the insulated tray 29 to be stably positioned on the transmission system 22 and no longer move. At this point, heating or cooling processes begin. Typically, the insulated tray 29, carrying the product to be processed, remains in each chamber 34 for 2 hours. This 2-hour period includes the time for valve (slide valve, heat insulation valve group 19, and cooling chamber door 18) lifting and the transmission system 22, constituting one production cycle, thus achieving the heating or cooling process for the product. Taking preparation chamber 1 as an example, the heating process in preparation chamber 1 involves raising the temperature from room temperature to 200℃ according to a time-temperature curve, for example, increasing the temperature by 2℃ per minute. This is regulated by a temperature controller. If the temperature rises too slowly, the power supply of the heating system 26 is increased to accelerate the rise; if the temperature rises too quickly, the power supply of the heating system 26 is decreased to slow the rise, until the temperature reaches 200℃. Maintaining a specific power level ensures a dynamic balance between heating and heat dissipation, stabilizing the temperature at 200℃. Cooling process of the cooling chamber: For example, if the temperature is set to drop by 3°C per minute, the high-temperature product will automatically and slowly cool down without activating the heating system 26. If the temperature drops too quickly, the heating system 26 will be activated to assist in cooling the product more slowly.

[0034] It should be noted that since the working time in each cavity 34 is slightly less than 2 hours, and each containment chamber 32 is guaranteed to have a set of insulated trays 29 with products to be processed, once the first set of insulated trays 29 with products to be processed leaves the cooling chamber 12, the processing of products to be processed will be completed every 2 hours (including the time for opening and closing the gate valve and the heat insulation valve group 19), thus improving the processing efficiency.

[0035] It is understood that the temperature measurement system 27 can be a temperature sensor; the heating system 26 can be a heating resistance wire connected to the heating power supply 24, and the heating system 26 can be started and stopped by controlling the switch of the heating power supply 24 through the control system 25; the cooling system 28 includes a main water inlet pipe and a main water return pipe, which supplies cooling water to the main water inlet pipe through a water pump. The main water inlet pipe has multiple branch water pipes, which cool and protect the cavity and other parts through cooling water, and then all of them are collected in the main water return pipe and flow back to the water tank; the control system 25 is an automatic control system, which is implemented through programming. The specific programming program is existing technology and will not be described in detail.

[0036] In one feasible implementation, the transmission system 22 includes: The drive roller is connected to the motor via a belt; Multiple driven rollers are arranged in the same plane as the driving roller, and the multiple driven rollers are connected to the driving roller through a transmission component; A support frame is configured to support a drive roller and multiple driven rollers, with the drive roller and driven rollers rotatably connected to the support frame.

[0037] In this system, the rotation of the 22 rollers in the conventional system moves the insulation tray 29 on it. The drive roller is connected to a motor via a belt; the motor's rotation, under the action of friction, drives the belt, which in turn drives the drive roller connected to the belt. Multiple driven rollers are connected to the drive roller via a transmission mechanism. The drive roller and the driven rollers are supported by a support frame, ensuring that the drive roller and the multiple driven rollers are in the same plane. The drive roller and the multiple driven rollers are connected by a transmission component. This transmission component can be a belt, chain, or gear, to transmit the rotational force of the drive roller, enabling the simultaneous rotation of the drive roller and the multiple driven rollers, thereby moving the insulation tray 29 on it.

[0038] It is understood that the transmission system 22 is communicatively connected to the control system 25 and the positioning signal system 33. After receiving the signal from the positioning signal system 33, the control system 25 controls the transmission system 22 to stop working. When the working time of each cavity 34 is reached, the gate valve or heat insulation valve group 19 between the cavities 34 opens, and the control system 25 controls the transmission system 22 to continue working, carrying the heat-insulated tray 29 into the receiving chamber 32 of the next cavity 34. The gate valves or heat insulation valve groups 19 between the cavities 34 do not start simultaneously, but open one by one. For example, when the product to be processed in the fifth cooling chamber 11 is transferred to the empty cooling chamber 12, the fifth gate valve 17 is opened first. After the product to be processed enters the cooling chamber 12, the fifth gate valve 17 closes, and the fifth cooling chamber 11 is empty. The fourth gate valve 16 opens, and the product to be processed in the fourth cooling chamber 10 enters the fifth cooling chamber 11 through the transmission system 22. The fourth gate valve 16 is then closed, and so on, until all the products to be processed have entered the next cavity 34.

[0039] It should be noted that the transmission system 22 of this application is completely located outside the housing chamber 32. Compared with the existing cases where at least part of the transmission system 22 is located inside the housing chamber 32, the cooperation between the housing chamber 32 and the heat preservation tray 29 can prevent heat from being conducted outward through the transmission system 22, further avoiding energy loss and the cost of manufacturing the high-temperature resistant transmission system 22, reducing production costs and improving production economy; at the same time, it reduces the manufacturing difficulty of the transmission system 22.

[0040] In one feasible implementation, the cavity 34 is fixedly connected to the end of the receiving chamber 32 away from the transmission system 22. The receiving chamber 32 has an opening on the side facing the transmission system 22. The heat preservation tray 29 includes a first horizontal plate 2901, a second horizontal plate 2902, and a connecting plate 2903 connecting the first horizontal plate 2901 and the second horizontal plate 2902. The first horizontal plate 2901, the second horizontal plate 2902, and the connecting plate 2903 form an I-shape. Notches are formed on both sides of the connecting plate 2903, and the notches match the bottom walls of the receiving chamber 32 on both sides of the opening.

[0041] Among them, such as Figure 4 As shown, by setting the shape of the insulation tray 29 to an I-shape, with notches on both sides, and an opening in the bottom wall of the receiving chamber 32, a labyrinthine insulation structure is formed, with a section of bottom wall on both sides of the opening that fits into the notch. This further reduces heat loss. When entering the receiving chamber 32 of the next cavity 34, another insulation tray 29 will simultaneously enter, closing the opening again. Short-term heat loss is negligible. The transmission system 22 drives the insulation tray 29 to move within the receiving chambers 32 of adjacent cavities 34.

[0042] Furthermore, the continuous sintering furnace housing 32 of this application has an opening at the bottom. The transmission system is located inside the cavity 34 but below the housing 32. The second horizontal plate 2902 of the insulation tray 29 includes a metal plate and an insulation plate. The first horizontal plate 2901 and the connecting plate 2903 are both insulation plates. During operation, the insulation plate portion of the insulation tray 29 and the lower opening of the housing 32 form a labyrinth-like sealing structure to prevent heat radiation (in a vacuum state, heat transfer is mainly through thermal radiation) to the outside of the housing 32.

[0043] In one feasible implementation, such as Figure 2 As shown, the cooling chamber 12 includes: Receiving cavity; An inflation system 30 is connected to the receiving cavity and is configured to introduce inert gas into the receiving cavity; The air-cooled heat exchange system 31 is connected to the housing cavity and is configured to cool the housing cavity.

[0044] When the insulated tray 29 enters the final cooling chamber 12, the inflation system 30 fills the cooling chamber 12 with inert argon gas until the pressure inside the cooling chamber 12 reaches 90 kPa. Inflation then stops, increasing the pressure in the cooling chamber 12 while preventing the gas from reacting with the product to be processed. After the inflation system 30 stops, the air-cooled heat exchange system 31 starts to cool the product to be processed, reducing its temperature to below 200°C. The air-cooled heat exchange system 31 then stops, the vacuum in the cooling chamber 12 is broken to atmospheric pressure, the cooling chamber 12 is opened, and the insulated tray 29, carrying the cooled product to be processed, is delivered to the unloading trolley 21. Once unloading is complete, the cooling chamber 12 is closed.

[0045] Furthermore, the vacuum system 23 evacuates the cooling chamber 12 to 10 Pa. After the set time is reached, the subsequent products to be processed and the insulated tray 29 are sequentially sent into the next chamber 34 for the next stage of production. After the products to be processed leave the cooling chamber 12, oxygen has now entered the cooling chamber 12, and the fifth cooling chamber 11 is under vacuum. To transfer the products to be processed to the cooling chamber 12 without oxidation, the cooling chamber 12 must be evacuated again. The cooling time in the cooling chamber 12 is slightly less than 2 hours. The total 2 hours include the cooling time, the time for opening and closing valves (slide valve and insulation valve group 19), the time for transferring the products to be processed, and the evacuation time. The set time here refers to the time when the cooling process in the fifth cooling chamber 11 is completed and the products are about to be transferred into the cooling chamber 12.

[0046] It is understandable that a temperature measuring system 27 is also installed inside the cooling chamber 12. The temperature measuring system 27 is connected to the control system 25 to provide timely feedback on the temperature inside the cooling chamber 12, so as to control the opening and closing of the cooling chamber door 18. At the same time, a position signal system 33 is also installed outside the cavity to facilitate the start and stop of the transmission system 22. The working principle is the same as described above and will not be repeated.

[0047] In one feasible embodiment, the continuous sintering furnace further includes a gate valve, which includes a first gate valve 13, a second gate valve 14, a third gate valve 15, a fourth gate valve 16, and a fifth gate valve 17. The first gate valve 13 is located at the end of the preparation chamber 1 away from the first heating chamber. The second gate valve 14 is located between the preparation chamber 1 and the first heating chamber. The third gate valve 15 is located between the first heating chamber and the second heating chamber. The fourth gate valve 16 is located between the last two cooling chambers. The fifth gate valve 17 is located between the last cooling chamber and the cooling chamber 12. The end of the cooling chamber 12 away from the last cooling chamber is provided with a cooling chamber door 18. Insulation valve assembly 19 is provided between the remaining two adjacent heating chambers, between the remaining two adjacent cooling chambers, and between the last heating chamber and the first cooling chamber.

[0048] Each cavity 34 is separated by a gate valve or a heat insulation valve assembly 19. In this embodiment, a first gate valve 13 is provided at the inlet end of the preparation chamber 1; a second gate valve 14 is provided between the preparation chamber 1 and the first heating chamber 2; a third gate valve 15 is provided between the first heating chamber 2 and the second heating chamber 3; a heat insulation valve assembly 19 is provided between the second heating chamber 3 and the third heating chamber 4; a heat insulation valve assembly 19 is provided between the third heating chamber 4 and the fourth heating chamber 5; and a heat insulation valve assembly 19 is provided between the fourth heating chamber 5 and the fifth heating chamber 6. A heat insulation valve assembly 19 is installed between the fifth heating chamber 6 and the first cooling chamber 7; a heat insulation valve assembly 19 is installed between the first cooling chamber 7 and the second cooling chamber 8; a heat insulation valve assembly 19 is installed between the second cooling chamber 8 and the third cooling chamber 9; a heat insulation valve assembly 19 is installed between the third cooling chamber 9 and the fourth cooling chamber 10; a fourth gate valve 16 is installed between the fourth cooling chamber 10 and the fifth cooling chamber 11; a fifth gate valve 17 is installed between the fifth cooling chamber 11 and the cooling chamber 12; and a cooling chamber door 18 is installed at the outlet end of the cooling chamber 12.

[0049] It should be noted that the slide gate valve has both heat insulation and air isolation functions, while the heat insulation valve assembly 19 only has a heat insulation function. The heat insulation valve assembly 19 has a simpler structure and lower cost. Both the preparation chamber 1 and the cooling chamber 12 need to feed and discharge materials and will frequently come into contact with air, so they must be separately airtightly isolated. To prevent air leakage caused by damage to the isolation between the first heating chamber 2 and the fifth cooling chamber 11, a second slide gate valve 14 is installed between the preparation chamber 1 and the first heating chamber 2, a third slide gate valve 15 is installed between the first heating chamber 2 and the second heating chamber 3, a fourth slide gate valve 16 is installed between the fourth cooling chamber 10 and the fifth cooling chamber 11, and a fifth slide gate valve 17 is installed between the fifth cooling chamber 11 and the cooling chamber 12. The slide gate valves are mainly used to prevent the chambers 34 from the second heating chamber 3 to the fourth cooling chamber 10 from coming into contact with air.

[0050] In one feasible embodiment, the continuous sintering furnace further includes a vacuum system 23, which is connected to a preparation chamber 1, a first heating chamber, a last cooling chamber and a cooling chamber 12 respectively. The remaining heating chambers are connected to at least one vacuum system 23, and the remaining cooling chambers are connected to at least one vacuum system 23.

[0051] Among them, such as Figure 2 As shown, the preparation chamber 1, the first heating chamber 2, the fifth cooling chamber 11, and the cooling chamber 12 are independent airtight chambers, therefore each is equipped with a separate vacuum system 23. The second heating chamber 3 to the fourth cooling chamber 10 form a single airtight chamber, which in principle would only require one vacuum system 23. However, due to the long length, a vacuum system 23 is installed at each interval of chamber 34 to ensure the stability and reliability of the vacuuming. That is, the second heating chamber 3, the fourth heating chamber 5, the first cooling chamber 7, and the third cooling chamber 9 are each equipped with a vacuum system 23, or the third heating chamber 4, the fifth heating chamber 6, the second cooling chamber 8, and the fourth cooling chamber 10 are each equipped with a vacuum system 23.

[0052] It should be noted that vacuuming refers to evacuating the cavities 34 of the preparation chamber 1, the heating chamber, and the cooling chamber 12, as well as the receiving chamber 32 (the insulation chamber and the cooling chamber) located within the cavity 34. The cooling chamber is entirely in a vacuum environment. Vacuuming removes air from a certain space to prevent oxidation of the product to be processed and high-temperature components during heating. Since the receiving chambers 32 (insulation chamber and cooling chamber) and the insulation tray 29 are all located within the cavity 34, vacuuming the cavity 34 ensures that the insulation tray 29, the product to be processed, and all components within the cavity 34 are in a vacuum environment, preventing oxidation. After the first gate valve 13 is opened, the preparation chamber 1 comes into contact with air and is no longer in a vacuum state. After the first gate valve 13 is closed, the preparation chamber 1 needs to be vacuumed again. The same applies to the cooling chamber 12 and the cooling chamber door 18. When the remaining gate valves and the insulation valve assembly 19 are open, both cavities 34 are in a vacuum state, which does not affect the vacuum status.

[0053] Another embodiment of the present invention provides a sintering method for a silicon carbide vacuum multi-chamber continuous sintering furnace. The sintering method using the above-mentioned continuous sintering furnace includes the following steps: The products to be processed enter the preparation room and are preheated. The preheated products to be processed enter multiple heating chambers in sequence for gradual heating. The products to be processed after being heated in stages enter multiple cooling chambers in sequence for cooling in stages. The products to be processed after being cooled in stages enter the cooling chamber for further cooling.

[0054] The preparation room, multiple heating rooms, multiple cooling rooms, and cooling chamber each contain a set of products to be processed.

[0055] Specifically, the first gate valve 13 is opened, and the transmission system 22 sends the product to be processed and the insulation tray 29 into the preparation chamber 1. After the positioning signal system 33 is triggered, the transmission system 22 stops working and the first gate valve 13 is closed. The vacuum system 23 evacuates each chamber 34 of the continuous sintering furnace to a vacuum level of 10 Pa. The preparation chamber 1 is then heated by the heating system 26, which is powered by the heating power supply 24. The temperature measuring system 27 measures the temperature of each containment chamber 32 and feeds it back to the control system 25, so that the control system 25 can make judgments on the process. For example, the preparation chamber 1 is heated from room temperature to 200°C at a rate of 2°C per minute. The temperature measuring system 27 transmits the real-time temperature to the control system 25, which then judges the relationship between temperature and time and adjusts the power supply of the heating system 26 to meet the set temperature requirements. The cooling system 28 provides cooling protection for the continuous sintering furnace to prevent damage to its components.

[0056] Furthermore, in preparation chamber 1, the temperature is raised to 200°C according to the heating curve (e.g., set to increase the temperature by 2°C per minute, requiring a total of 100 minutes) and held at that temperature. After reaching the set time (the time after the process is completed in the current chamber 34 and the material is about to be transferred to the next chamber 34), the cycle begins from this moment. The process of opening the door, driving the transmission, closing the door, heating to the predetermined temperature, and holding at that temperature is completed. This is one cycle of 2 hours. Preparation chamber 1 also includes vacuuming time. Cooling chamber 12 is not heated, but it includes cooling and vacuuming time. After reaching the set time, the second slide valve 14 is opened, and the heat-insulating tray 29 and the product to be processed are sent to the first heating chamber 2. The second slide valve 14 is then closed. This process takes 2 hours, which is the production cycle of the continuous sintering furnace. The first heating chamber 2 is heated to 600℃ according to the heating curve and held at that temperature. Simultaneously, the vacuuming of the preparation chamber 1 is stopped, and the vacuum in the preparation chamber 1 is broken down to atmospheric pressure. The first gate valve 13 is opened, and the second insulated tray 29, prepared on the feeding trolley 20, and the product to be processed are transferred into the preparation chamber 1. The first gate valve 13 is closed, and the preparation chamber 1 is evacuated to 10Pa. The temperature is then raised to 200℃ according to the heating curve and held at that temperature. At this time, the heating of the preparation chamber 1 and the first heating chamber 2 occurs simultaneously. After the set time is reached, the third gate valve 15 is opened, and the insulated tray 29 and the product to be processed in the first heating chamber 2 are transferred to the second heating chamber 3. The third gate valve 15 is then closed. The second heating chamber 3 is heated to 1000℃ according to the heating curve and held at that temperature. Meanwhile, the preparation chamber 1 continues to receive new insulated trays 29 and products to be processed following the same steps. The insulated trays 29 in the preparation chamber 1 then enter the first heating chamber 2. The steps are as described above and will not be repeated. Once the set temperature is reached, the heat insulation valve assembly 19 between the second heating chamber 3 and the third heating chamber 4 is opened, and the insulated tray 29 and the product to be processed in the second heating chamber 3 are sent to the third heating chamber 4. The heat insulation valve assembly 19 between the second heating chamber 3 and the third heating chamber 4 is then closed. Since the production atmosphere is the same at this time (i.e., the second heating chamber 3 to the fourth cooling chamber 10 are all under vacuum, and the required vacuum level is the same), the heat insulation valve assembly 19 only serves as insulation, ensuring thermal isolation within each chamber 34, and does not require an airtight isolation structure, thus saving costs and improving production efficiency. The third heating chamber 4 is heated to 1380℃ according to the heating curve and held at that temperature. Simultaneously, the product to be processed and the insulated tray 29 are sequentially sent to the next chamber 34 for the next stage of the production process. Upon reaching the set time, the thermal insulation valve group 19 between the third heating chamber 4 and the fourth heating chamber 5 is opened, allowing the insulated tray 29 and the product to be processed in the third heating chamber 4 to be transferred into the fourth heating chamber 5. The thermal insulation valve group 19 between the third heating chamber 4 and the fourth heating chamber 5 is then closed. The fourth heating chamber 5 is heated to 1550℃ according to the heating range and maintained at that temperature. Simultaneously, the product to be processed and the insulated tray 29 are sequentially transferred into the next chamber 34 for the next stage of the production process.After the set time is reached, the insulation valve group 19 between the fourth heating chamber 5 and the fifth heating chamber 6 is opened, allowing the product to be processed and the insulated tray 29 in the fourth heating chamber 5 to be transferred into the fifth heating chamber 6. The insulation valve group 19 between the fourth heating chamber 5 and the fifth heating chamber 6 is then closed. The fifth heating chamber 6 heats up to 1800℃ according to the heating curve and maintains that temperature. Simultaneously, the product to be processed and the insulated tray 29 are sequentially transferred into the next chamber 34 for the next stage of the production process. After the set time is reached, the insulation valve group 19 between the fifth heating chamber 6 and the first cooling chamber 7 is opened, allowing the insulated tray 29 and the product to be processed in the fifth heating chamber 6 to be transferred into the first cooling chamber 7. The insulation valve group 19 between the fifth heating chamber 6 and the first cooling chamber 7 is then closed.

[0057] Furthermore, the first cooling chamber 7, following a cooling curve (a curve defining the rate of temperature drop per minute and the required cooling time), uses the heating system 26 to provide auxiliary heating (to prevent the product from cracking due to rapid cooling) to lower the temperature from 1800℃ to 1400℃, thus preventing excessively rapid cooling and cracking of the product to be processed. Simultaneously, the product to be processed and the insulated tray 29 sequentially enter the next chamber 34 for the next stage of the production process. Upon reaching the set time, the insulation valve group 19 between the first and second cooling chambers 7 and 8 is opened, transferring the insulated tray 29 and the product to be processed from the first cooling chamber 7 into the second cooling chamber 8. The insulation valve group 19 is then closed. The second cooling chamber 8, following the cooling curve, uses auxiliary heating to lower the temperature from 1400℃ to 1150℃, preventing excessively rapid cooling and cracking of the product. Upon reaching the set time, the insulation valve assembly 19 between the second cooling chamber 8 and the third cooling chamber 9 is opened, transferring the insulated tray 29 and the product to be processed from the second cooling chamber 8 to the third cooling chamber 9. The insulation valve assembly between the second and third cooling chambers 8 and 9 is then closed. The third cooling chamber 9, following the cooling curve, uses auxiliary heating to cool the temperature from 1150℃ to 950℃ to prevent excessively rapid cooling and product cracking. Upon reaching the set temperature, the insulation valve assembly 19 between the third and fourth cooling chambers 9 and 10 is opened, transferring the insulated tray 29 and the product to be processed from the third cooling chamber 9 to the fourth cooling chamber 10. The insulation valve assembly 19 between the third and fourth cooling chambers 9 and 10 is then closed. The fourth cooling chamber 10, following the cooling curve, uses auxiliary heating to lower the temperature from 950℃ to 750℃ to prevent excessively rapid cooling and product cracking. After the set time is reached, the fourth gate valve 16 is opened to transfer the insulated tray 29 and the product to be processed from the fourth cooling chamber 10 to the fifth cooling chamber 11, and then the fourth gate valve 16 is closed. The fifth cooling chamber 11, following the cooling curve, uses auxiliary heating to lower the temperature from 750℃ to 600℃ to prevent excessively rapid cooling and product cracking. After the set time is reached, the fifth gate valve 17 is opened to transfer the insulated tray 29 and the product to be processed from the fifth cooling chamber 11 to the cooling chamber 12, and then the fifth gate valve 17 is closed. The gas filling system 30 in the cooling chamber 12 is activated to fill it with inert argon gas. Gas filling stops when the pressure reaches 90 kPa. The air-cooled heat exchange system 31 is activated to cool the product to be processed. When the temperature of the product drops below 200°C, the air-cooled heat exchange system 31 is shut off, the vacuum in the cooling chamber 12 is broken down to atmospheric pressure, the cooling chamber door 18 is opened, and the insulated tray 29 and the product to be processed are sent to the unloading trolley 21. After unloading, the product to be processed on the insulated tray 29 is removed, and the cooling chamber door 18 is closed. The vacuum control system 23 evacuates the cooling chamber 12 to 10 Pa. After a set time, the product to be processed and the insulated tray 29 are sequentially sent to the next chamber 34 for the next stage of the production process.

[0058] Understandably, the doors of each chamber 34 (slide valve, insulation valve assembly 19, and cooling chamber door 18) will not open simultaneously. The opening-transfer-closing operation of the previous chamber will be completed before the opening-transfer-closing operation of the next chamber is performed. Each chamber 34 will be evacuated to remove air from the high-temperature zone, preventing oxidation of the product and its components at high temperatures. The cooling chamber 12 does not require a heating system. When the product to be processed is below 650°C, it can be cooled rapidly, eliminating the need for the slow cooling operation in the cooling chamber and preventing cracking of the product. It also improves cooling efficiency.

[0059] By maintaining the above process, continuous production of silicon carbide sintering can be achieved, with a production cycle of 2 hours. That is, after the first insulated tray 29 and the product to be processed come out of the cooling chamber 12, a batch of products to be processed will be produced every 2 hours thereafter. This increases the capacity of a single sintering furnace, reduces the energy consumption per unit of product production, has a high degree of automation, and reduces the labor intensity of operators.

[0060] It should be noted that the heating curve represents the relationship between temperature and time. Specifically, it shows how many degrees Celsius rise per minute and how long it takes. The temperature is fed back to the control system 25 in real time via the temperature measurement system 27, which then adjusts the power supply to the heating system 26 to control the rate of heating and ensure it meets the set requirements. The cooling curve follows the same principle and will not be elaborated further.

[0061] It is understandable that when the first insulated tray 29 and the product to be processed enter the next cavity 34, the subsequent insulated trays 29 and the products to be processed enter the next cavity 34 in sequence for the next stage of the production process. This ensures that each cavity 34 contains insulated trays 29 and products to be processed, improving product processing efficiency and saving energy. Therefore, the steps described above are not detailed in detail.

[0062] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "a plurality" refers to two or more unless otherwise expressly defined.

[0063] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A silicon carbide vacuum multi-chamber continuous sintering furnace, characterized in that, The continuous sintering furnace includes: Preparation room; Multiple heating chambers are connected in sequence, wherein the first heating chamber is connected to the preparation chamber; Multiple cooling chambers are connected in sequence, wherein the first cooling chamber is connected to the last heating chamber; The cooling chamber is connected to the last of the aforementioned cooling chambers; An insulated tray, on which the product to be processed is placed, passes sequentially through the preparation chamber, multiple heating chambers, multiple cooling chambers, and the cooling chamber.

2. The silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 1, characterized in that, The continuous sintering furnace also includes: The feeding trolley is located at the end of the preparation chamber away from the first heating chamber; The discharge trolley is located at the end of the cooling chamber furthest from the last cooling chamber. The insulated pallet enters the preparation chamber via the feeding trolley and leaves the cooling chamber via the discharging trolley.

3. The silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 1, characterized in that, The preparation chamber, the heating chamber, and the cooling chamber have the same structure, each including: A cavity, wherein a receiving chamber is provided within the cavity, and at least a portion of the insulated tray is located within the receiving chamber; A transmission system is located within the cavity and is disposed below the receiving chamber. The transmission system is configured to move the insulated tray. A heating system is provided in the accommodating chamber, and the heating system is configured to heat the accommodating chamber; A temperature measuring system is installed in the containment chamber, and the temperature measuring system is configured to measure the temperature inside the containment chamber; A cooling system is provided outside the cavity and is configured to provide cooling protection for the continuous sintering furnace. A positioning signal system is installed on both sides of the cavity. When the insulated tray is located between the positioning signal systems, the transmission system stops working. The control system is electrically connected to the transmission system, the positioning signal system, the heating system, the temperature measuring system, and the cooling system, respectively. The containment chamber is either a heat preservation chamber or a heat reduction chamber.

4. The silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 3, characterized in that, The transmission system includes: The drive roller is connected to the motor via a belt; Multiple driven rollers are arranged in the same plane as the driving roller, and the multiple driven rollers are connected to the driving roller through a transmission component; A support frame is configured to support the drive roller and a plurality of driven rollers, the drive roller and the driven rollers being rotatably connected to the support frame respectively.

5. The silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 3, characterized in that, The cavity is fixedly connected to the end of the receiving chamber away from the transmission system. The receiving chamber has an opening on the side facing the transmission system. The heat preservation tray includes a first horizontal plate, a second horizontal plate, and a connecting plate connecting the first horizontal plate and the second horizontal plate. The first horizontal plate, the second horizontal plate, and the connecting plate form an I-shape. Notches are formed on both sides of the connecting plate. The notches match the bottom walls of the receiving chamber on both sides of the opening.

6. The silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 1, characterized in that, The cooling chamber includes: Receiving cavity; An inflation system, connected to the receiving cavity, is configured to introduce an inert gas into the receiving cavity; An air-cooled heat exchange system is connected to the receiving cavity, and the air-cooled heat exchange system is configured to cool the receiving cavity.

7. The silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 1, characterized in that, The continuous sintering furnace also includes a slide gate valve, which includes a first slide gate valve, a second slide gate valve, a third slide gate valve, a fourth slide gate valve, and a fifth slide gate valve. The first slide gate valve is located at the end of the preparation chamber away from the first heating chamber. The second slide gate valve is located between the preparation chamber and the first heating chamber. The third slide gate valve is located between the first heating chamber and the second heating chamber. The fourth slide gate valve is located between the last two cooling chambers. The fifth slide gate valve is located between the last cooling chamber and the cooling chamber. The end of the cooling chamber away from the last cooling chamber is provided with a cooling chamber door. A heat insulation valve assembly is provided between the remaining two adjacent heating chambers, between the remaining two adjacent cooling chambers, and between the last heating chamber and the first cooling chamber.

8. The silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 1, characterized in that, The continuous sintering furnace also includes a vacuum system, and multiple vacuum systems are respectively connected to the preparation chamber, the first heating chamber, the last cooling chamber and the cooling chamber. The remaining heating chambers are connected to at least one vacuum system, and the remaining cooling chambers are connected to at least one vacuum system.

9. A sintering method for a silicon carbide vacuum multi-chamber continuous sintering furnace, utilizing the continuous sintering furnace according to any one of claims 1 to 8, characterized in that, The sintering method Includes the following steps; The product to be processed enters the preparation chamber and is preheated. The preheated product to be processed enters multiple heating chambers in sequence for progressively increasing temperature. The product to be processed after being heated in stages enters multiple cooling chambers in sequence for cooling in stages. The product to be processed, after being subjected to a step-by-step cooling process, enters a cooling chamber for further cooling.

10. The sintering method of the silicon carbide vacuum multi-chamber continuous sintering furnace according to claim 9, characterized in that, The preparation chamber, the plurality of heating chambers, the plurality of cooling chambers, and the cooling chamber each contain a set of the products to be processed.

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