Sectional type kiln

Abstract

The sectional type kiln is used for recycling lithium batteries and comprises an evaporation kiln channel, a conveying assembly, a condensation assembly and a cracking furnace, the conveying assembly is arranged on the evaporation kiln channel, the evaporation kiln channel comprises a material inlet end, a material outlet end and a steam outlet end, and the conveying assembly is used for conveying materials of the evaporation kiln channel from the material inlet end to the material outlet end; the evaporation kiln channel is used for evaporating solvents in materials in the material conveying process, the steam outlet end is communicated with the condensation assembly, the condensation assembly is used for condensing steam in the evaporation kiln channel into a liquid state, the material outlet end is communicated with the cracking furnace, and the cracking furnace is used for cracking organic matter in the materials. Therefore, in the application, the electrolyte is evaporated through the evaporation kiln channel with lower temperature, so that the solvent is prevented from being carbonized or decomposed to generate gases such as HF, POF and the like, the purity of the recycled electrolyte is favorably improved, and the tail gas treatment cost is reduced; organic matters are pyrolyzed in the cracking furnace, and solid organic matter high-molecular polymers are thoroughly treated, so that residual organic matter pollution is avoided.

Description

Technical Field

[0001] This invention relates to the field of kiln technology, and more particularly to a segmented kiln. Background Technology

[0002] Currently, lithium battery recycling processes commonly use rotary kilns to dry and pyrolyze shredded battery materials. Evaporation removes the electrolyte from the shredded material, while pyrolysis removes organic matter such as battery separators and binders. Existing technologies directly pyrolyze within the same rotary kiln, completing both drying and pyrolysis processes. This approach requires less investment, occupies less land, has a shorter process flow, lower operating costs, and offers better technical and economic efficiency.

[0003] However, the boiling points of the organic solvents in the electrolyte are 90-200℃, requiring gentle heating to avoid carbonization or decomposition that could produce HF. At high temperatures (above 250℃), the electrolyte decomposes violently, releasing highly toxic gases such as HF and POF3. HF corrodes equipment, and POF3 is highly toxic, leading to a surge in exhaust gas treatment costs. Meanwhile, solid organic polymers such as diaphragms (PP / PE) and binders (PVDF) have decomposition temperatures above 400℃, requiring high-temperature decomposition to break down chains into small-molecule combustible gases (e.g., CH4, H2, CO). Low temperatures can easily result in incomplete treatment of solid organic polymers, leaving residual organic matter that contaminates the black powder that needs to be recovered. Therefore, a kiln is urgently needed to solve these problems. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a segmented kiln, which aims to solve the problems of the prior art where direct pyrolysis in the same rotary kiln leads to a surge in tail gas treatment costs or incomplete treatment of solid organic polymers.

[0005] This invention provides a segmented kiln for lithium battery recycling, comprising an evaporation kiln, a conveying assembly, a condensation assembly, and a pyrolysis furnace. The conveying assembly is installed on the evaporation kiln, which includes a material inlet, a material outlet, and a steam outlet. The conveying assembly is used to convey the material in the evaporation kiln from the material inlet to the material outlet. The evaporation kiln is used to evaporate the solvent in the material during the material conveying process. The steam outlet is connected to the condensation assembly, which is used to condense the steam in the evaporation kiln into a liquid state. The material outlet is connected to the pyrolysis furnace, which is used to pyrolyze the organic matter in the material.

[0006] According to some embodiments of the present invention, the evaporation kiln includes a kiln body and a heating layer, the heating layer being disposed on the outside of the kiln body, and the kiln body having a plurality of air inlets for connecting the internal space of the kiln body and the internal space of the heating layer.

[0007] According to some embodiments of the present invention, the conveying assembly includes a conveying motor and a spiral blade. The conveying motor is located at the end of the kiln body, and the spiral blade is located at the power output end of the conveying motor and extends into the kiln body. The conveying motor is used to drive the spiral blade to rotate in order to convey materials.

[0008] According to some embodiments of the present invention, the steam outlet end is a perforated plate provided on the kiln body, the perforated plate having a plurality of steam holes, and the condensation assembly is covered on the perforated plate.

[0009] According to some embodiments of the present invention, the condensation assembly includes a cover, an exhaust fan, and a condensation chamber. The cover is disposed on the perforated plate, and the exhaust fan is disposed on the cover. The exhaust fan is used to transport the steam entering the cover to the condensation chamber.

[0010] According to some embodiments of the present invention, a plurality of hoods, a plurality of exhaust fans and a plurality of condenser boxes are provided, the plurality of hoods are arranged sequentially along the material conveying direction, a branch pipe is connected to the exhaust fan, the plurality of branch pipes are connected to the same main pipe, the plurality of condenser boxes are connected sequentially, and the main pipe is connected to the first condenser box.

[0011] According to some embodiments of the present invention, the condenser box is provided with a plurality of condensing plates, which are spaced apart in the horizontal direction and adjacent condensing plates are staggered in the vertical direction.

[0012] According to some embodiments of the present invention, the pyrolysis furnace is provided with a conveyor chain for conveying materials.

[0013] According to some embodiments of the present invention, the pyrolysis furnace is provided with a plurality of heating components, which are spaced apart along the material conveying direction.

[0014] According to some embodiments of the present invention, the heating assembly includes a blower motor and a heating wire, both of which are disposed inside the pyrolysis furnace.

[0015] Beneficial Effects: This invention provides a segmented kiln for lithium battery recycling, comprising an evaporation kiln, a conveying assembly, a condensation assembly, and a pyrolysis furnace. The conveying assembly is installed on the evaporation kiln, which includes a material inlet, a material outlet, and a steam outlet. The conveying assembly transports the material from the material inlet to the material outlet. The evaporation kiln evaporates the solvent in the material during the conveying process. The steam outlet is connected to the condensation assembly, which condenses the steam in the evaporation kiln into a liquid state. The material outlet is connected to the pyrolysis furnace, which pyrolyzes the organic matter in the material. Therefore, in this application, the electrolyte is evaporated through a lower-temperature evaporation kiln, avoiding solvent carbonization or decomposition to produce gases such as HF and POF3, which helps improve the purity of the recovered electrolyte and reduce tail gas treatment costs. The organic matter is pyrolyzed in the pyrolysis furnace, thoroughly treating the solid organic polymers and avoiding residual organic pollution. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0017] Figure 1 This is a schematic diagram of the segmented kiln structure of the present invention; Figure 2 This is a schematic diagram of the segmented kiln of the present invention from another angle; Figure 3 This is a schematic diagram of the structure of the evaporation kiln channel of the present invention; Figure 4 This is a schematic diagram of the internal structure of the evaporation kiln of the present invention; Figure 5 This is a schematic diagram of the internal structure of several condenser boxes of the present invention; Figure 6 This is a schematic diagram of the internal structure of the pyrolysis furnace of the present invention.

[0018] In the diagram: 1. Evaporation kiln; 11. Material inlet end; 12. Material outlet end; 13. Steam outlet end; 14. Kiln body; 141. Air inlet; 15. Heating layer; 151. Vent; 2. Conveying assembly; 21. Conveying motor; 22. Spiral blades; 31. Cover; 32. Exhaust fan; 33. Branch pipe; 34. Main pipe; 35. Condensation box; 351. Condensation plate; 4. Pyrolysis furnace; 41. Conveying plate chain; 42. Heating assembly; 421. Blower motor; 422. Heating wire; 5. Lifting assembly. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Please see Figures 1 to 6 This invention provides a segmented kiln for lithium battery recycling, comprising an evaporation kiln 1, a conveying assembly 2, a condensing assembly 3, and a pyrolysis furnace 4. The conveying assembly 2 is installed on the evaporation kiln 1, which includes a material inlet end 11, a material outlet end 12, and a steam outlet end 13. The conveying assembly 2 is used to convey the material in the evaporation kiln 1 from the material inlet end 11 to the material outlet end 12. The evaporation kiln 1 is used to evaporate the solvent in the material during the material conveying process. The steam outlet end 13 is connected to the condensing assembly 3, which is used to condense the steam in the evaporation kiln 1 into a liquid state. The material outlet end 12 is connected to the pyrolysis furnace 4, which is used to pyrolyze the organic matter in the material.

[0021] Furthermore, the segmented kiln also includes a lifting assembly 5, which is used to lift the material into the evaporation kiln channel 1.

[0022] According to some embodiments of the present invention, the evaporation kiln 1 includes a kiln body 14 and a heating layer 15. The heating layer 15 is disposed on the outside of the kiln body 14. The kiln body 14 has a plurality of air inlets 141, which are used to connect the internal space of the kiln body 14 and the internal space of the heating layer 15. In this embodiment, an electric heating wire is provided inside the heating layer 15. The combustion / heating power is precisely controlled by the electric heating wire to generate clean hot air with a stable temperature of 150-200°C, avoiding contamination of the material.

[0023] According to some embodiments of the present invention, the conveying assembly 2 includes a conveying motor 21 and a spiral blade 22. The conveying motor 21 is located at the end of the kiln body 14, and the spiral blade 22 is located at the power output end of the conveying motor 21 and extends into the kiln body 14. The conveying motor 21 drives the spiral blade 22 to rotate for conveying materials. This application achieves controllable, slow, and uniform material conveying through the rotation of the spiral blade 22, while allowing hot air to penetrate the material layer. The conveying motor 21 can be driven by a variable frequency motor with a low speed, such as a few revolutions per minute or a dozen revolutions per minute, specifically calculated based on the residence time and the length of the kiln body 14. The spiral blade 22 can use a smaller pitch, which can increase the axial movement resistance of the material and extend the residence time. In conjunction with the previous embodiment, the air inlet 141 is located directly below the spiral blade 22. Under the rotation of the spiral blade 22, it slowly slides / tumbles, assisting in dispersing the material and allowing the hot air in the heating layer 15 to penetrate the material uniformly from bottom to top, greatly increasing the gas-solid contact area and efficiency, and promoting evaporation. It is worth noting that the diameter of the air inlet 141 must be much smaller than the particle size of the material to prevent material leakage, but it must also ensure that hot air can pass through smoothly. The diameter range of the air inlet 141 is generally Φ3-Φ10mm, and the specific diameter needs to be determined according to the particle size of the material.

[0024] According to some embodiments of the present invention, the steam outlet end 13 is a perforated plate disposed on the kiln body 14, the perforated plate having a plurality of steam holes, and the condensation assembly 3 covering the perforated plate. In conjunction with the previous embodiment, the cross-section of the kiln body 14 is typically U-shaped, facilitating the installation of the perforated plate and the conveying of materials by the spiral blades 22.

[0025] According to some embodiments of the present invention, the condensation assembly 3 includes a cover 31, an exhaust fan 32, and a condensation box 35. The cover 31 is disposed on the perforated plate, and the exhaust fan 32 is disposed on the cover 31. The exhaust fan 32 is used to transport the steam entering the cover 31 to the condensation box 35.

[0026] According to some embodiments of the present invention, a plurality of hoods 31, exhaust fans 32, and condenser boxes 35 are provided. A plurality of hoods 31 are arranged sequentially along the material conveying direction. Branch pipes 33 are connected to the exhaust fans 32, and a plurality of branch pipes 33 are connected to the same main pipe 34. A plurality of condenser boxes 35 are connected sequentially, and the main pipe 34 is connected to the first condenser box 35. Further, the material accumulation thickness near the material inlet end 11 is relatively thick, while the material accumulation thickness near the material outlet end 12 is relatively thin. Thicker material increases the resistance to material movement, and simultaneously reduces the gas-solid contact area and efficiency. Therefore, a vent 151 is provided on the heating layer 15 near the material outlet end 12. Since a plurality of hoods 31 are provided, external cold gas enters the heating layer 15 through the vent 151 for initial heating, and some of the lower-temperature gas is drawn away by the exhaust fans 32 near the material outlet end 12. The remaining gas that is not extracted continues to flow against the material conveying direction, further heated, until it reaches the material inlet 11 and is extracted by the exhaust fan 32. At this point, the gas is heated to a higher temperature, corresponding to the thicker material near the material inlet 11, thus promoting material evaporation through the higher temperature. It is worth noting that the power of several exhaust fans 32 decreases sequentially along the material conveying direction, ensuring that the airflow can pass through the entire heating layer 15.

[0027] According to some embodiments of the present invention, the condenser 35 is provided with a plurality of condensing plates 351, which are spaced apart in the horizontal direction and adjacent condensing plates 351 are staggered in the vertical direction. Since in the previous embodiment, the steam drawn by the plurality of exhaust fans 32 is collected on the same main pipe 34 through the branch pipe 33, and the main pipe 34 enters from the first condenser 35, in this embodiment, the staggering of adjacent condensing plates 351 in the vertical direction can also extend the steam flow path, allowing the steam to be fully condensed.

[0028] The following is the material flow process within the steam kiln: Material (including electrolyte) enters the evaporation zone inlet continuously or semi-continuously; a low-speed rotating screw propeller slowly advances the material, spreading it evenly on the bottom of the kiln body 14, where hot air at 150-200℃ is introduced. Driven by the exhaust fan 32, the material layer is forcibly penetrated from bottom to top through the air inlet 141, undergoing intense heat and mass exchange, and the solvent (electrolyte) evaporates rapidly; the hot, humid steam rich in solvent vapor is drawn from the top by the exhaust fan 32 into the condenser 35 for condensation. After 20-30 minutes of evaporation, the dried material is pushed to the material outlet by the screw blades 22, entering the next process for high-temperature pyrolysis.

[0029] According to some embodiments of the present invention, the pyrolysis furnace 4 is provided with a conveyor chain 41, which is used to convey materials.

[0030] According to some embodiments of the present invention, the pyrolysis furnace 4 is provided with a plurality of heating components 42, which are spaced apart along the material conveying direction. Since the pyrolysis of organic materials (such as diaphragm PP / PE, binder PVDF) is an endothermic chain-breaking reaction, it requires overcoming different energy barriers. In the low-temperature range (300-350℃), small molecule plasticizers and residual solvents volatilize, and the polymer softens and melts. In the medium-temperature range (350-450℃), the main chain begins to break, generating long-chain hydrocarbons. In the high-temperature range (>450℃), it undergoes deep pyrolysis into small molecule gases (CH4, H2). If the material is directly heated to 450℃, the surface of the material decomposes violently and cokes, while the interior does not react sufficiently due to heat transfer lag. Therefore, in this embodiment, the power of the plurality of heating components 42 gradually increases along the material conveying direction, so that the material gradually heats up during the conveying process (300℃→350℃→450℃).

[0031] According to some embodiments of the present invention, the heating assembly 42 includes a blower motor 421 and a heating wire 422, both of which are disposed inside the pyrolysis furnace 4.

[0032] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalent elements of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A segmented kiln for lithium battery recycling, characterized in that: The system includes an evaporation kiln (1), a conveying assembly (2), a condensing assembly (3), and a pyrolysis furnace (4). The conveying assembly (2) is installed on the evaporation kiln (1). The evaporation kiln (1) includes a material inlet end (11), a material outlet end (12), and a steam outlet end (13). The conveying assembly (2) is used to convey the material in the evaporation kiln (1) from the material inlet end (11) to the material outlet end (12). The evaporation kiln (1) is used to evaporate the solvent in the material during the material conveying process. The steam outlet end (13) is connected to the condensing assembly (3). The condensing assembly (3) is used to condense the steam in the evaporation kiln (1) into a liquid state. The material outlet end (12) is connected to the pyrolysis furnace (4). The pyrolysis furnace (4) is used to pyrolyze the organic matter in the material.

2. The segmented kiln according to claim 1, characterized in that: The evaporation kiln (1) includes a kiln body (14) and a heating layer (15). The heating layer (15) is located on the outside of the kiln body (14). The kiln body (14) has several air inlets (141) for connecting the internal space of the kiln body (14) and the internal space of the heating layer (15).

3. The segmented kiln according to claim 2, characterized in that: The conveying assembly (2) includes a conveying motor (21) and a spiral blade (22). The conveying motor (21) is located at the end of the kiln body (14), and the spiral blade (22) is located at the power output end of the conveying motor (21) and extends into the kiln body (14). The conveying motor (21) is used to drive the spiral blade (22) to rotate in order to convey the material.

4. The segmented kiln according to claim 2, characterized in that: The steam outlet end (13) is a perforated plate on the kiln body (14), and the perforated plate has a number of steam holes. The condensation component (3) is covered on the perforated plate.

5. The segmented kiln according to claim 4, characterized in that: The condensation assembly (3) includes a cover (31), an exhaust fan (32), and a condensation box (35). The cover (31) is placed on the perforated plate, and the exhaust fan (32) is placed on the cover (31). The exhaust fan (32) is used to transport the steam entering the cover (31) to the condensation box (35).

6. The segmented kiln according to claim 5, characterized in that: The cover (31), the exhaust fan (32) and the condenser (35) are provided in multiples. The multiple covers (31) are arranged sequentially along the material conveying direction. The exhaust fan (32) is connected to a branch pipe (33). The multiple branch pipes (33) are connected to the same main pipe (34). The multiple condensers (35) are connected sequentially. The main pipe (34) is connected to the first condenser (35).

7. The segmented kiln according to claim 5, characterized in that: The condenser box (35) is provided with a plurality of condensing plates (351), which are spaced apart in the horizontal direction and adjacent condensing plates (351) are staggered in the vertical direction.

8. The segmented kiln according to claim 1, characterized in that: The pyrolysis furnace (4) is equipped with a conveyor chain (41) for conveying materials.

9. The segmented kiln according to claim 8, characterized in that: The pyrolysis furnace (4) is provided with a plurality of heating components (42), which are spaced apart along the material conveying direction.

10. The segmented kiln according to claim 9, characterized in that: The heating component (42) includes a blower motor (421) and a heating wire (422), both of which are located inside the pyrolysis furnace (4).

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