Furnace interior cooling method and kiln

Abstract

The invention discloses an in-furnace cooling method and a kiln, and belongs to the technical field of lithium battery material sintering. Raising the temperature of the saggar loaded with the material in the furnace to a set temperature, and carrying out a firing reaction; s2, heat-preservation firing: after the material is heated and fired, carrying out heat preservation for a certain time, so that the material in the sagger is uniformly heated and fully reacts; s3, primary cooling; s4, sectional cooling: the materials subjected to preliminary cooling enter a first cooling section in the furnace to be rapidly cooled to be below a set value, then the box body is fed into a second cooling section behind the first cooling section, the second cooling section uses an internal circulation atmosphere mode for cooling until the temperature is reduced to be the temperature at which the materials can be taken out of the furnace, the atmosphere circulation flow can be controlled, and then the materials can be taken out of the furnace. Internal circulation is utilized to the greatest extent for cooling; and S5, discharging, wherein the sintered product is moved out of the furnace to be stored after being subjected to gas replacement, and the cooling rate is increased through segmented cooling.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery material sintering, and in particular to a furnace cooling method and a kiln. Background Art

[0002] With the development of new energy technology, lithium batteries are widely used in production and life. The positive and negative electrode materials of lithium batteries, such as the positive electrode materials of ternary lithium batteries and lithium iron phosphate batteries and the negative electrode materials of graphite batteries, need to be sintered in the kiln during production. In order to increase the output of lithium battery materials in the kiln, the following two methods are mainly used: First, increase the loading capacity of the sagger, such as increasing the loading capacity or changing the single-layer sagger to two, three or more layers; second, shorten the cooling time after sintering the material and speed up the efficiency of the refined product. The above two methods of increasing production both require a rapid cooling device in the kiln. The high-temperature atmosphere in the existing kiln is mostly cooled by finned tube water cooling, and the high-temperature atmosphere gas at the head of the cooling zone is extracted to the outside of the furnace through a sealed pipe and a fan, and then water-cooled for heat exchange. After the atmosphere temperature drops, it is re-injected into the end of the cooling zone to achieve circulating cooling of the atmosphere. However, when the atmosphere is circulated, increasing the amount of high-temperature atmosphere extracted from the cooling zone will cause a large fluctuation in the pressure in the furnace. The heat in the high-temperature zone will flow to the cooling zone under the action of pressure, making cooling difficult. At the same time, the unstable pressure during suction will reduce the consistency of the sintered product. In addition, the high-temperature atmosphere gas has high requirements on the sealing performance of the pipeline outside the furnace and the circulating fan. The air leaking from the pipeline will mix into the fan and the pipeline, causing the oxygen content in the furnace to increase, resulting in oxidation of lithium iron phosphate and graphite negative electrode materials, and oxidation of the graphite sagger loaded with materials. A kiln that can be cooled quickly is now needed to solve the above problems. Summary of the invention

[0003] One of the purposes of the present invention is to provide a furnace cooling method, which solves the problem that the suction of hot atmosphere during furnace cooling in the prior art will cause large pressure fluctuations in the furnace and low cooling efficiency.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0005] A method for cooling a furnace comprises the following steps:

[0006] S1, heating and de-coking; the sagger loaded with materials in the furnace is heated to the set temperature for sintering reaction;

[0007] S2. Heat preservation and firing: After the materials are heated and fired, they are kept warm for a certain period of time so that the materials in the sagger are heated evenly and fully reacted;

[0008] S3, preliminary cooling: the fired material is initially cooled in the furnace to evenly cool the material in the box;

[0009] S4, segmented cooling: the material after preliminary cooling enters the first cooling section in the furnace and is quickly cooled to below the set value, and then the box body is sent to the second cooling section after the first cooling section, and the second cooling section uses the internal circulation atmosphere to cool down until the temperature is reduced to the temperature that can be taken out of the furnace. The flow rate of the atmosphere circulation can be controlled to maximize the use of internal circulation for cooling;

[0010] S5. Out of the furnace: The fired product is removed from the furnace for storage after gas replacement.

[0011] Furthermore, in S4, when the sagger moves from the first cooling section to the second cooling section, it needs to pass through the ventilation section arranged between the first cooling section and the second cooling section. After the sagger enters the ventilation section, the ventilation section is in a sealed state. Inert gas is introduced into the ventilation section to replace the internal atmosphere gas. After the replacement, the sagger moves to the second cooling section. By replacing the atmosphere in the furnace to cool down and discharge the air leaked into the furnace, the product quality is improved.

[0012] Furthermore, in S4, a ventilation chamber is provided in the ventilation section, a first sealing gate is provided at the connection between the ventilation chamber and the first cooling section, a second sealing gate is provided at the connection between the ventilation chamber and the second cooling section, the first sealing gate is opened when the sagger enters the ventilation chamber from the first cooling section, and the second sealing gate is opened when the sagger enters the second cooling section from the ventilation chamber, the first sealing gate and the second sealing gate are closed before and after ventilation, separating the first cooling section and the second cooling section, so that the atmosphere temperatures between the sections will not affect each other, thereby improving the quality of the fired products.

[0013] Furthermore, in S4, after the box body enters the first cooling section, the external circulation cooling device in the first cooling section draws external cooling gas into the cooling jacket in the furnace wall, and the cooling jacket transfers the heat in the furnace to the cooling gas by heat conduction to achieve cooling, which plays a role in cooling again, controlling the atmosphere temperature in the furnace to below a certain value, which is conducive to the next step of cooling.

[0014] Furthermore, in S4, the box body enters the second cooling section, and the second cooling section is provided with an internal circulation cooling device, which extracts the hot atmosphere in the furnace for heat exchange and cooling and then returns it to the furnace for cooling, thereby improving the cooling efficiency by increasing the internal circulation flow rate.

[0015] Preferably, in S4, the internal circulation cooling device can control the flow rate circulating in the second cooling section to ensure the quality of material sintering and the efficiency of cooling.

[0016] Preferably, in S4, a first water-cooling pipe is provided in the first cooling section, and a second water-cooling pipe is provided in the second cooling section. The first water-cooling pipe and the second water-cooling pipe lead to cooling water for cooling when passing through the box body, which will not affect the material, assists in cooling and thus improves the overall cooling efficiency.

[0017] Preferably, in S4, the internal circulation cooling device includes a first temperature sensor, a second temperature sensor, a heat exchanger and a flow fan. The hot atmosphere in the second cooling section is cooled by heat exchange through the heat exchanger. The first temperature sensor and the second temperature sensor monitor the atmosphere temperature entering and exiting the heat exchanger. The flow fan is used to control the flow rate of the atmosphere and to adjust the flow rate of the atmosphere according to the atmosphere temperature in the furnace.

[0018] As a more preferred embodiment, the box body in the furnace is electrically heated during heating and heat preservation. Electric heating does not produce by-products, thereby improving the quality of the sintered product.

[0019] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0020] The second purpose of the present invention is to provide a kiln that solves the problem of low production efficiency when the existing kiln is used to burn positive and negative electrode materials of lithium batteries.

[0021] A kiln is used to implement the furnace cooling method, comprising a heating section, a heat preservation section, a slow cooling section, a first cooling section, a ventilation section, a second cooling section, an inlet displacement chamber and an outlet displacement chamber connected in sequence, the first cooling section is provided with an external circulation cooling device, the external circulation cooling device comprises an exhaust fan, a first exhaust pipe, an air intake pipe and a cooling jacket, one end of the first exhaust pipe is connected to the exhaust fan, the other end of the first exhaust pipe is connected to the cooling jacket, the air intake pipe is connected to the cooling jacket, the cooling jacket is arranged in the first cooling section, the second cooling section is provided with an internal circulation cooling device, the internal circulation cooling device comprises a second exhaust pipe and a heat exchanger, one end of the second exhaust pipe is connected to the second cooling section, and the other end of the second exhaust pipe is connected to the second cooling section, thereby improving the cooling effect of the positive and negative electrode materials of the lithium battery in the sagger, thereby achieving the purpose of increasing the output.

[0022] The beneficial effects of the present invention are:

[0023] (1) In the furnace cooling method, after the material is heated and sintered, it is initially cooled to a certain temperature and then enters the first cooling section and the second cooling section in sequence to complete the segmented cooling. The first cooling section is provided with an external circulation cooling device. The external circulation cooling device obtains cooling air from the outside and inputs it into the cooling jacket on the inner wall of the first cooling section. The cooling jacket exchanges heat with the high-temperature atmosphere in the first cooling section to complete rapid cooling. The heat conduction heat dissipation method is used to cool the atmosphere in the furnace to below 300°C, and then the material below 300°C is sent to the second cooling section. The second cooling section is provided with an internal circulation cooling device. The internal circulation cooling device extracts the hot atmosphere in the second cooling section, discharges the heat through the heat exchanger, and then inputs it into the second cooling section, realizing internal circulation heat exchange and thus cooling. Since the temperature is lower than the initial temperature and the internal circulation is used for exhaust, the pressure fluctuation in the furnace is small, and the efficiency of heat exchange can be improved by increasing the exhaust pressure. The internal circulation can also prevent external air from entering the furnace and causing oxidation of the sagger and the positive and negative electrode materials of the lithium battery. By cooling the materials in different temperature sections in stages, the cooling time of the product can be greatly shortened, thereby improving the efficiency of product sintering and playing a role in increasing unit output.

[0024] (2) When the material of the furnace cooling method is transferred between the first cooling section and the second cooling section, it passes through the ventilation section arranged between the two sections. Two sealing gates respectively connected to the two sections are arranged in the ventilation section to separate the ventilation chamber from the two sections to prevent the atmospheres of different sections from affecting each other. The first cooling section and the second cooling section are separated by the ventilation section, which can stabilize the gas atmosphere in each section and prevent the atmospheres of different temperatures on both sides from affecting each other. The ventilation section is connected to the inert gas for ventilation, which plays a certain cooling role and can also prevent the air mixed in due to sealing failure from reacting with the fired product under oxidation to reduce the product yield.

[0025] (3) The kiln cools the fired products in sections according to the temperature of the atmosphere in the kiln, which improves the cooling efficiency while reducing the requirements for pipeline sealing. The cooling efficiency in the second cooling section can be improved by increasing the flow rate of the circulating atmosphere. The pressure in the first cooling section and the second cooling section is stable, ensuring a high yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A structural diagram of the kiln provided by the present invention;

[0027] Figure 2 A structural composition diagram between the first temperature rising section and the second temperature rising section of the kiln provided by the present invention;

[0028] Figure 3 A cross-sectional structural diagram of the temperature rising section provided by the present invention;

[0029] Figure 4A schematic diagram of a sagger array provided by the present invention.

[0030] Reference numerals:

[0031] 1. Heating section; 11. Smoke exhaust device; 111. Smoke exhaust pipe; 112. Smoke exhaust fan; 2. Insulation section; 3. Slow cooling section; 4. First cooling section; 41. First water cooling pipe; 42. External circulation cooling device; 421. First exhaust pipe; 422. Exhaust fan; 423. Air intake pipe; 424. Cooling jacket; 5. Ventilation section; 51. Ventilation chamber; 52. First sealing gate; 53. Second sealing gate; 6. Second cooling section; 61. Second water cooling pipe; 62. Internal circulation cooling device; 621. Second exhaust duct; 622. Heat exchanger; 623. Flow fan; 624. First temperature sensor; 625. Valve; 626. Second temperature sensor; 627. Air supply duct; 7. Outlet displacement chamber; 8. Inlet displacement chamber; 9. Sagger array; 101. Furnace shell; 102. Insulation layer; 103. Conveying roller; 104. Sealed chamber; 105. Gas inlet; 106. Heating device; 107. Protective layer. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1

[0034] A method for cooling a furnace comprises the following steps:

[0035] S1, heating and de-coking; the sagger loaded with materials in the furnace is heated to the set temperature for sintering reaction;

[0036] S2. Heat preservation and firing: After the materials are heated and fired, they are kept warm for a certain period of time so that the materials in the sagger are heated evenly and fully reacted;

[0037] S3, preliminary cooling: the fired material is initially cooled in the furnace to evenly cool the material in the box;

[0038] S4, segmented cooling: the material after preliminary cooling enters the first cooling section 4 in the furnace and is quickly cooled to below the set value, and then the box body is sent to the second cooling section 6 after the first cooling section 4, and the second cooling section 6 uses the internal circulation atmosphere to cool down until the temperature is reduced to the temperature that can be taken out of the furnace. By cooling down in stages, different cooling methods are used in different sections to dissipate heat according to different temperatures, which can avoid the adverse effects of cooling, such as large pressure fluctuations in the furnace atmosphere and easy mixing of air;

[0039] S5. Out of the furnace: The fired products are removed from the furnace for storage after gas replacement to prevent the air outside the furnace from entering the furnace and causing excessive oxidation of the products.

[0040] Furthermore, in S4, when the sagger moves from the first cooling section 4 to the second cooling section 6, it needs to pass through the ventilation section 5 arranged between the first cooling section 4 and the second cooling section 6. After the sagger enters the ventilation section 5, the ventilation section 5 is in a sealed state to prevent the atmospheres from affecting each other and reduce the atmosphere pressure fluctuations in the sections. Inert gas is introduced into the ventilation section 5 to replace the internal atmosphere gas. After the replacement, the sagger moves to the second cooling section 6, which can play a role in cooling and removing air, thereby improving the firing efficiency and firing quality.

[0041] Furthermore, in S4, a ventilation chamber 51 is provided in the ventilation section 5, a first sealing gate 52 is provided at the connection between the ventilation chamber 51 and the first cooling section 4, a second sealing gate 53 is provided at the connection between the ventilation chamber 51 and the second cooling section 6, the first sealing gate 52 is opened when the sagger enters the ventilation chamber 51 from the first cooling section 4, and the second sealing gate 53 is opened when the sagger enters the second cooling section 6 from the ventilation chamber 51, the first sealing gate 52 and the second sealing gate 53 are closed before and after ventilation, so as to separate the first cooling section 4 and the second cooling section 6, prevent the atmosphere transfer between the two sections from affecting the sintering, and achieve the purpose of separating the atmospheres of different temperatures.

[0042] Furthermore, in S4, after the box body enters the first cooling section 4, the external circulation cooling device 42 in the first cooling section 4 draws external cooling gas into the cooling jacket 424 in the furnace wall, and the cooling jacket 424 transfers the heat in the furnace to the cooling gas by heat conduction to achieve cooling. The cooling gas circulates quickly to take away the heat and does not come into contact with the atmosphere in the furnace, thereby preventing air from oxidizing the sintered material.

[0043] Furthermore, in S4, the box body enters the second cooling section 6, and the second cooling section 6 is provided with an internal circulation cooling device 62. The internal circulation cooling device 62 extracts the hot atmosphere in the furnace for heat exchange and cooling, and then sends it back to the furnace for cooling. The internal circulation method has little effect on the atmosphere pressure in the furnace. Under the premise of controlling pressure fluctuations, the circulation flow rate of the atmosphere can be greatly improved, thereby achieving the purpose of rapid cooling out of the furnace.

[0044] Preferably, in S4, the internal circulation cooling device 62 can control the flow rate circulating in the second cooling section 6, and change the flow rate of the internal circulation by detecting the temperature change in the second cooling section 6 to ensure uniform cooling of the material in the furnace.

[0045] Preferably, in S4, a first water-cooling pipe 41 is provided in the first cooling section 4, and a second water-cooling pipe 61 is provided in the second cooling section 6. The first water-cooling pipe 41 and the second water-cooling pipe 61 are connected to the cooling water to cool down the box body when the cooling water passes through. The cooling liquid is introduced into the water-cooling pipe, and the heat is transferred by the water-cooling pipe without introducing air into the furnace. The water-cooling pipes are distributed in the cooling space of each upper integral kiln furnace, and the cooling is assisted by increasing the use density, thereby improving the cooling efficiency in the furnace.

[0046] More preferably, in S4, the internal circulation cooling device 62 includes a first temperature sensor 624, a second temperature sensor 626, a heat exchanger 622 and a flow fan 623. The hot atmosphere in the second cooling section 6 is cooled by heat exchange through the heat exchanger 622. The first temperature sensor 624 and the second temperature sensor 626 monitor the atmosphere temperature entering and exiting the heat exchanger 622. The flow fan 623 is used to control the flow rate of the atmosphere, thereby increasing the circulation flow rate of the atmosphere and accurately controlling the temperature in the furnace.

[0047] Embodiment 2

[0048] See also Figure 1-Figure 4As shown, the present embodiment discloses a kiln, comprising a heating section 1, a heat preservation section 2, a slow cooling section 3, a first cooling section 4, a ventilation section 5, a second cooling section 6, an inlet replacement chamber 8 and an outlet replacement chamber 7 which are connected in sequence. The first cooling section 4 is provided with an external circulation cooling device 42, the external circulation cooling device 42 comprises an exhaust fan 422, a first exhaust pipe 421, an air intake pipe 423 and a cooling jacket 424, one end of the first exhaust pipe 421 is connected to the exhaust fan 422, the other end of the first exhaust pipe 421 is communicated with the cooling jacket 424, the air intake pipe 423 is communicated with the cooling jacket 424, the cooling jacket 424 is arranged in the first cooling section 4, the second cooling section 6 is provided with an internal circulation cooling device 62, the internal circulation cooling device 62 comprises a second exhaust pipe 621 and a heat exchanger 622, one end of the second exhaust pipe 621 is communicated with the second cooling section 6, the other end of the second exhaust pipe 621 is communicated with the second The cooling section 6 is connected, and the external cold air enters the cooling jacket 424 through the air inlet pipe 423. The cooling air exchanges heat with the hot atmosphere in the furnace through the cooling jacket 424, absorbs the heat of the hot atmosphere and is extracted and discharged by the exhaust fan 422 through the first exhaust pipe 421, so as to achieve rapid cooling. The internal circulation cooling device 62 sucks the hot atmosphere in the furnace into the heat exchanger 622 through the second exhaust pipe 621, and the heat of the hot atmosphere is transferred by the heat exchanger 622. The cooled atmosphere is sent into the furnace again, and cooling is achieved through continuous internal circulation. While cooling, air leakage into the furnace is prevented to cause oxidation of the product and the sagger, thereby improving the product yield. The product is cooled by the first cooling section 4 and the second cooling section 6 respectively, and the two sections are separated by a sealing structure to prevent the atmospheres of different temperatures from affecting each other and to prevent the pressure fluctuation of the sucked air from affecting the product, thereby improving the product quality and yield.

[0049] Among them, the temperature of the first cooling section 4 is above 300°C, and the temperature of the second cooling section 6 is not higher than 300°C. Different cooling devices are used according to different temperatures. At a certain temperature, the cooling efficiency is greatly improved by means of pressurized internal circulation atmosphere. The cooling jacket 424 is arranged on the furnace wall or close to the inner wall of the kiln to reduce space occupancy and leave space for loading enough saggers.

[0050] Furthermore, a first water-cooling pipe 41 is provided in the first cooling section 4, and the first water-cooling pipe 41 is arranged at the upper and lower parts of the first cooling section 4. A second water-cooling pipe 61 is provided in the second cooling section 6, and the second water-cooling pipe 61 is arranged at the upper and lower parts of the second cooling section 6. The first water-cooling pipe 41 and the second water-cooling pipe 61 are both fin-type water-cooling pipes. Heat exchange and cooling are completed by cooling water to the first water-cooling pipe 41 and the second water-cooling pipe 61 and the hot atmosphere in the furnace, thereby improving the cooling efficiency in the furnace.

[0051] Preferably, the internal circulation cooling device 62 also includes a valve 625, a flow fan 623 and an air supply duct 627. The valve 625 is arranged at the air inlet end of the heat exchanger 622. One end of the flow fan 623 is connected to the heat exchanger 622, and the other end of the flow fan 623 is connected to the second cooling section 6 via the air supply duct 627. The valve 625 is an electric valve for controlling the flow of the internal circulation hot atmosphere. The flow fan 623 is used to actively control the air volume, so as to ensure the degree and efficiency of cooling. In the second cooling section 6, the internal circulation is used for exhaust heat exchange, and the entire circulation system is fully closed, which can increase the exhaust circulation volume of the atmosphere in the furnace, so as to achieve the effect of rapid cooling. The internal circulation method has small pressure fluctuations and does not inhale external air, and the cooling efficiency is extremely high.

[0052] Preferably, the internal circulation cooling device 62 also includes a first temperature sensor 624 and a second temperature sensor 626. The first temperature sensor 624 is arranged at the air inlet end of the heat exchanger 622, and the second temperature sensor 626 is arranged at the air outlet end of the heat exchanger 622, and is used to monitor the ambient temperature entering the heat exchanger 622 and the ambient temperature exiting the heat exchanger 622, respectively, to accurately control the temperature change of the second cooling section 6, to ensure that the product cooling meets the requirements, and to improve the yield and quality of the product.

[0053] More preferably, the heat exchanger 622 uses water cooling for heat exchange. A water inlet and a water outlet are provided on the heat exchanger 622. The cooling water introduced from the outside of the heat exchanger 622 takes away the heat of the hot atmosphere in the furnace. The water cooling heat exchange has high efficiency in cooling and is not easy to mix into the furnace with air.

[0054] More preferably, the flow fan 623 adopts variable frequency control, which can accurately adjust the circulation flow of the atmosphere and achieve accurate temperature control.

[0055] More preferably, the air supply duct 627 is connected to the lower part of the second cooling section 6, and the atmosphere after heat exchange is sent into the second cooling section 6 to reduce the temperature in the furnace. The atmosphere absorbs heat and is then sent into the heat exchanger 622 through the second exhaust duct 621 at the upper part for cooling. The circulation is smooth and the cooling efficiency is high.

[0056] Furthermore, it also includes a ventilation section 5, which is arranged between the first cooling section 4 and the second cooling section 6. A sealing structure is provided between the ventilation section 5 and the first cooling section 4 and the second cooling section 6, so that the first cooling section 4 and the second cooling section 6 are separated to prevent the flow of atmospheres with different temperatures and different pressures from affecting each other and reducing the quality of the product.

[0057] Preferably, a water cooling pipe is provided in the ventilation section 5 for cooling and lowering the temperature, and a water cooling pipe is provided in the overall cooling range of the kiln. The cooling water in the water cooling pipe does not directly contact the atmosphere, and the burning of the material in the furnace is not affected during cooling.

[0058] Furthermore, the ventilation section 5 includes a ventilation chamber 51, a first sealed gate 52 and a second sealed gate 53. One end of the ventilation chamber 51 is connected to the first cooling section 4, and the other end of the ventilation chamber 51 is connected to the second cooling section 6. The first sealed gate 52 is arranged between the ventilation chamber 51 and the first cooling section 4, and the second sealed gate 53 is arranged between the ventilation chamber 51 and the second cooling section 6. The ventilation chamber 51 is provided with an air inlet and an exhaust port for introducing inert gas to replace the atmosphere in the furnace, reduce the temperature and discharge possible air to prevent excessive oxidation of the product during the cooling process. The first sealed gate 52 and the second sealed gate 53 are used for separation to prevent the hot atmosphere from being transferred between different sections and affecting the rapid firing of the product.

[0059] See also Figure 4 More preferably, a roller conveyor is provided in the kiln, and the saggers are stacked on the roller conveyor, which drives the saggers forward to complete the sintering of the materials. In order to increase the processing capacity of the kiln, the saggers are stacked into a multi-layer and multi-column sagger array 9 to maximize the use of the space in the kiln and improve production efficiency.

[0060] Preferably, a heating device 106 is provided in both the temperature rising section 1 and the heat preservation section 2, and a protective layer 107 is provided on the heating device 106. The heating device 106 is an electric heating element, and the protective layer 107 is a quartz tube shell. The use of electric heating can reduce the smoke in the furnace and accurately control the sintering temperature in the furnace, thereby improving the sintering quality of the product.

[0061] Preferably, the kiln includes a furnace shell 101, an insulation layer 102 is provided on the inner wall of the furnace shell 101, a conveying roller 103 is provided in the furnace shell 101 for transporting the sagger, heating devices 106 are provided above and below the sagger for multi-directional uniform heating of the material in the sagger to improve the heating efficiency, transmission devices are provided at both ends of the conveying roller 103, the transmission device is in a sealed cavity 104, a gas inlet 105 is provided on the sealed cavity 104, inert gas is input through the gas inlet 105, the transmission device and the ends of the conveying roller 103 are protected, and external air is prevented from entering the furnace to affect the sintering quality of the positive and negative electrode materials.

[0062] Preferably, a smoke exhaust device 11 is provided at the top of the heating section 1, and the smoke exhaust device 11 includes a smoke exhaust pipe 111 and a smoke exhaust fan 112. One end of the smoke exhaust pipe 111 is connected to the smoke exhaust fan 112, and the other end is connected to the interior of the heating section 1, and is used to actively exhaust the smoke generated during the sintering of the positive and negative electrode materials to prevent the smoke from affecting the sintering quality.

[0063] Preferably, in S1, after the heating section 1 heats the material in the sagger, harmful gases such as tar generated by the material heating up are discharged to the outside or to a fume treatment device by the fume exhaust device 11 to prevent the fume from entering into subsequent processes and affecting the sintering reaction.

[0064] The working process of the kiln is as follows:

[0065] The saggers are stacked into a sagger array 9 and enter the entrance replacement chamber 8. After the air is exhausted from the entrance replacement chamber 8, they are transported by rollers to the heating section 1 for heating. After being heated to a certain degree, the sagger array 9 enters the insulation section 2 for insulation. After the insulation is completed, the sagger array 9 moves to the slow cooling section 3 for cooling, and then enters the first cooling section 4 from the slow cooling section 3. The external cooling air passes through the cooling jacket 424 and the hot atmosphere in the furnace is exchanged with heat and cooled by non-contact heat conduction. When the temperature in the furnace drops to a certain degree, the sagger array 9 enters the ventilation chamber 51 through the first sealing gate 52. After the ventilation chamber 51 is closed, nitrogen is filled in for ventilation. After the ventilation is completed, the sagger array 9 moves to the second cooling section 6 and the heat cycle in the furnace is circulated through the heat exchanger 622 for heat exchange, thereby ensuring that the pressure fluctuation in the sintering process of the positive and negative electrode materials of the lithium battery is small and the temperature drops rapidly. Then the sagger array 9 enters the outlet replacement chamber 7 and moves to the outside to complete the overall sintering process.

[0066] The kiln is used for a method of cooling the temperature in the furnace or for a process of sintering materials.

[0067] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs may also change and modify the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A method for cooling a furnace, characterized in that: The following steps are involved: S1, heating and de-coking; the sagger loaded with materials in the furnace is heated to the set temperature for sintering reaction; S2. Heat preservation and firing: After the materials are heated and fired, they are kept warm for a certain period of time so that the materials in the sagger are heated evenly and fully reacted; S3, preliminary cooling: the fired material is initially cooled in the furnace to evenly cool the material in the box; S4, segmented cooling: the material after preliminary cooling enters the first cooling section (4) in the furnace and is rapidly cooled to below the set value, and then the box is sent to the second cooling section (6) located after the first cooling section (4), and the second cooling section (6) uses an internal circulation atmosphere to cool the material until it is cooled to a temperature that can be taken out of the furnace; S5. Out of the furnace: The fired product is removed from the furnace for storage after gas replacement.

2. The furnace cooling method according to claim 1, characterized in that: In S4, when the sagger moves from the first cooling section (4) to the second cooling section (6), it needs to pass through the ventilation section (5) arranged between the first cooling section (4) and the second cooling section (6). After the sagger enters the ventilation section (5), the ventilation section (5) is in a sealed state, and inert gas is introduced into the ventilation section (5) to replace the internal atmosphere gas. After the replacement, the sagger moves to the second cooling section (6).

3. The furnace cooling method according to claim 2, characterized in that: In S4, a ventilation chamber (51) is provided in the ventilation section (5), a first sealing gate (52) is provided at the connection between the ventilation chamber (51) and the first cooling section (4), and a second sealing gate (53) is provided at the connection between the ventilation chamber (51) and the second cooling section (6). The first sealing gate (52) is opened when the sagger enters the ventilation chamber (51) from the first cooling section (4), and the second sealing gate (53) is opened when the sagger enters the second cooling section (6) from the ventilation chamber (51). The first sealing gate (52) and the second sealing gate (53) are both closed before and after ventilation, so as to separate the first cooling section (4) from the second cooling section (6).

4. The furnace cooling method according to claim 2, characterized in that: In S4, after the box body enters the first cooling section (4), the external circulation cooling device (42) in the first cooling section (4) draws external cooling gas into the cooling jacket (424) in the furnace wall, and the cooling jacket (424) transfers the heat in the furnace to the cooling gas by heat conduction to achieve cooling.

5. The furnace cooling method according to claim 4, characterized in that: In S4, the box body enters the second cooling section (6), and the second cooling section (6) is provided with an internal circulation cooling device (62). The internal circulation cooling device (62) extracts the hot atmosphere in the furnace for heat exchange and cooling, and then returns it to the furnace for cooling.

6. The method for cooling the furnace according to claim 5, characterized in that: In S4, the internal circulation cooling device (62) is capable of controlling the flow rate circulating in the second cooling section (6).

7. The method for cooling the furnace according to claim 6, characterized in that: In S4, a first water cooling pipe (41) is provided in the first cooling section (4), and a second water cooling pipe (61) is provided in the second cooling section (6). The first water cooling pipe (41) and the second water cooling pipe (61) are connected to the cooling water to cool the box body when the cooling water passes through the box body.

8. The method for cooling the furnace according to claim 7, characterized in that: In S4, the internal circulation cooling device (62) includes a first temperature sensor (624), a second temperature sensor (626), a heat exchanger (622) and a flow fan (623). The hot atmosphere in the second cooling section (6) is cooled by heat exchange through the heat exchanger (622). The first temperature sensor (624) and the second temperature sensor (626) monitor the temperature of the atmosphere entering and exiting the heat exchanger (622). The flow fan (623) is used to control the flow of the atmosphere.

9. The method for cooling a furnace according to any one of claims 1 to 8, characterized in that: The box body in the furnace adopts electric heating when heating and keeping warm.

10. A kiln, characterized in that: The method for cooling the furnace in any one of claims 1 to 9 comprises a heating section (1), a heat preservation section (2), a slow cooling section (3), a first cooling section (4), a ventilation section (5), a second cooling section (6), an inlet displacement chamber (8) and an outlet displacement chamber (7) which are connected in sequence, wherein the first cooling section (4) is provided with an external circulation cooling device (42), the external circulation cooling device (42) comprises an exhaust fan (422), a first exhaust duct (421), an air intake duct (423) and a cooling jacket (424), one end of the first exhaust duct (421) is connected to the exhaust fan (422), The other end of the first exhaust pipe (421) is in communication with the cooling jacket (424), the air intake pipe (423) is in communication with the cooling jacket (424), the cooling jacket (424) is arranged in the first cooling section (4), the second cooling section (6) is provided with an internal circulation cooling device (62), the internal circulation cooling device (62) comprises a second exhaust pipe (621) and a heat exchanger (622), one end of the second exhaust pipe (621) is in communication with the second cooling section (6), and the other end of the second exhaust pipe (621) is in communication with the second cooling section (6).

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