Granular continuous semi-coke rotary kiln and battery negative electrode material preparation system

Abstract

Disclosed in the present application are a granular continuous semi-coke rotary kiln and a battery negative electrode material preparation system. The granular continuous semi-coke rotary kiln comprises: an inner spiral furnace cylinder having an inner furnace chamber, a feeding end and a discharging end being respectively and rotatably connected to a feeding buffer bin and a discharging assembly; and an outer furnace cylinder, rotatably sleeved on the inner spiral furnace cylinder and spaced apart from same to form an outer furnace chamber, the outer furnace chamber being internally provided with a burner. The inner wall of the inner spiral furnace cylinder protrudes towards the inner furnace chamber in the radial direction to form a spiral blade; the spiral blade extends to the feeding end and the discharging end; and the spiral blade and the inner wall of the inner spiral furnace cylinder cooperate to form a spiral channel for guiding a raw material to move from the feeding end to the discharging end along a spiral trajectory. The spiral blade is provided with an airflow passage, the inner end of the airflow passage passes through to reach the outer surface of the spiral blade, and the outer end thereof passes through to reach an outer wall of the inner spiral furnace cylinder. In the radial direction of the inner spiral furnace cylinder, the thickness of the raw material is not greater than the distance from the inner end of the airflow passage to the inner wall of the inner spiral furnace cylinder. The present application involves high pyrolysis gas utilization efficiency, and low preparation cost for negative electrode materials.

Description

Granular continuous semi-coke rotary kiln and battery negative electrode material preparation system TECHNICAL FIELD

[0001] The present application relates to the technical field of battery negative electrode material production, and particularly relates to a granular continuous semi-coke rotary kiln and a battery negative electrode material preparation system. BACKGROUND

[0002] Semi-coke is a solid product obtained by low-temperature dry distillation of peat, lignite and high-volatile bituminous coal at 500-700 DEG C. Its main components include carbon, ash and volatile matter, and its shape is irregular, usually black powder, block, granular or honeycomb. Semi-coke has good adsorption performance and can adsorb most atmospheric pollutants. It is stable under high temperature and high pressure environment, has high calorific value and low ash content. It is widely used in industries such as calcium carbide, ferroalloy, metallurgy, power plant and carbon adsorbent.

[0003] In order to solve the problems of high cost of raw materials, complex process, high production energy consumption and semi-coke value-added utilization of sodium ion battery negative electrode material, a technology for preparing battery negative electrode material from semi-coke has emerged. This technology modifies semi-coke to prepare high-performance lithium battery negative electrode, which not only improves the economic benefit of semi-coke and reduces the environmental pollution of waste, but also reduces the cost of lithium ion battery. Current research shows that through high-temperature graphitization treatment, the negative electrode material prepared from semi-coke can reach the performance index of lithium ion battery negative electrode, with a discharge capacity of more than 300 mAh / g and no capacity decay after 300 cycles. This project has great benefits for environmental protection and resource utilization, and has certain cost advantage compared with existing lithium battery negative electrode material.

[0004] The existing semi-coke negative electrode material preparation process is as follows: semi-coke is crushed into about 1mm-10mm granular raw materials, which are dried in a drying furnace, then enter the buffer bin through the raw material bin, and then the raw materials are pushed into the inner furnace of the rotary kiln by the feeding screw device. Natural gas is introduced into the outer furnace, and the inner furnace wall is heated by the burner. Part of the pyrolysis gas generated in the inner furnace is used for drying furnace, and the remaining pyrolysis gas is dusted by the dust removal device and then enters the incinerator to generate cracking heat, and then returns to the outer furnace for high-temperature calcination, or is used as a heat source for other purposes. Finally, the collected tail gas is concentrated for treatment. The calcined raw materials are cooled by the feeding screw device and then packed.

[0005] However, the preparation steps of the existing process still have deficiencies. First, the raw materials are pushed into the inner furnace of the rotary kiln by the feeding screw device, which is easy to cause material jam, increase the maintenance cost, and may cause uneven distribution of the raw materials in the conveying process. This uneven distribution will cause uneven reaction in the rotary kiln, affecting the quality and performance of the final product.

[0006] Secondly, in the rotary kiln, the semi-coke raw materials generate pyrolysis gas through heating and pyrolysis. Part of the pyrolysis gas is used for drying the raw materials in the furnace, and the rest of the pyrolysis gas needs to be treated by a dust removal device to remove dust particles. The treated pyrolysis gas is introduced into the incinerator for further cracking to generate heat energy. In the entire process, the pyrolysis gas is treated through multiple steps and equipment, and each step causes loss of heat energy or material, thereby reducing the recycling efficiency of the pyrolysis gas. At the same time, the complex treatment equipment increases the processing time of the pyrolysis gas and increases the preparation cost of the negative electrode material. SUMMARY

[0007] The purpose of the present application is to provide a granular continuous semi-coke rotary kiln and a battery negative electrode material preparation system to solve the problems in the prior art that the feeding screw device is prone to material jamming and uneven distribution of raw materials when pushing the raw materials into the rotary kiln hearth, and the pyrolysis gas treatment steps are complex, involving many devices, resulting in low pyrolysis gas recycling efficiency and high negative electrode material preparation cost.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is:

[0009] A granular continuous semi-coke rotary kiln, comprising a support assembly, a feeding buffer bin, a discharging assembly and a rotary drive assembly, further comprising:

[0010] An inner screw furnace cylinder is rotationally arranged on the support assembly and has an inner hearth. The feeding end of the inner screw furnace cylinder is rotationally connected to the feeding buffer bin through a first dynamic sealing mechanism, and the discharging end is rotationally connected to the discharging assembly through a second dynamic sealing mechanism. The inner screw furnace cylinder is configured to rotate around an axis under the drive of the rotary drive assembly.

[0011] An outer furnace cylinder is arranged on the support assembly. The outer furnace cylinder is arranged outside the inner screw furnace cylinder and is rotationally connected to the inner screw furnace cylinder. The outer furnace cylinder and the inner screw furnace cylinder are spaced apart to form an outer hearth. A combustion nozzle is arranged in the outer hearth.

[0012] The inner wall of the inner screw furnace cylinder protrudes radially towards the inner hearth to form a screw blade. The screw blade extends along the axial direction of the inner screw furnace cylinder to the feeding end and the discharging end. The screw blade and the inner wall of the inner screw furnace cylinder cooperate to form a screw groove. The screw groove is used to guide the raw materials to move along a spiral trajectory from the feeding end to the discharging end.

[0013] An airflow channel is arranged on the screw blade. The inner end of the airflow channel penetrates to the outer surface of the screw blade, and the outer end penetrates to the outer wall of the inner screw furnace cylinder to connect the inner hearth and the outer hearth.

[0014] In the radial direction of the inner spiral furnace cylinder, the thickness of the raw material is not greater than the distance from the inner end of the airflow passage to the inner wall of the inner spiral furnace cylinder.

[0015] In some embodiments, the spiral blade is in a hollow structure, and the airflow passage is connected to the inner cavity of the spiral blade.

[0016] In some embodiments, the spiral blade comprises two side rotating walls arranged at intervals in the radial direction on the inner wall of the inner spiral furnace cylinder, and a top wall connecting the top ends of the two side rotating walls, and the inner end of the airflow passage penetrates through to the top wall.

[0017] In some embodiments, the distance between the two side rotating walls gradually decreases from the inner wall of the inner spiral furnace cylinder to the top wall.

[0018] In some embodiments, the airflow passage comprises a plurality of passage units arranged at equal intervals in the circumferential direction of the inner spiral furnace cylinder, and each passage unit comprises a plurality of through holes arranged at equal intervals in the axial direction of the inner spiral furnace cylinder.

[0019] In some embodiments, the opening of the outer end of the through hole on the outer wall of the inner spiral furnace cylinder is a waist-shaped hole, and the length direction of the waist-shaped hole is arranged along the circumferential direction of the inner spiral furnace cylinder.

[0020] In some embodiments, a plurality of air blowing units are arranged at equal intervals in the circumferential direction on the outer wall of the inner spiral furnace cylinder, and the air blowing units are arranged one by one on one side of the passage units in the circumferential direction of the inner spiral furnace cylinder.

[0021] In some embodiments, each air blowing unit comprises a plurality of air blowing fins arranged at equal intervals in the axial direction of the inner spiral furnace cylinder, and the air blowing fins are protruded outwardly in the radial direction from the outer wall of the inner spiral furnace cylinder.

[0022] In the axial direction of the inner spiral furnace cylinder, the air blowing fins gradually approach the corresponding passage units from the middle to the two ends, so that the air blowing fins are in an arc structure curved towards the corresponding passage units, and from the inner spiral furnace cylinder to the outer furnace cylinder, the two ends of the air blowing fins gradually approach the middle.

[0023] In some embodiments, an opening is formed in the middle of one end of the air blowing fin away from the inner spiral furnace cylinder.

[0024] The application also provides a battery negative electrode material preparation system, comprising:

[0025] A crushing mechanism for crushing raw materials;

[0026] A drying mechanism connected to the crushing mechanism for drying the crushed raw materials;

[0027] A raw material bin connected to the drying mechanism for storing the dried raw material;

[0028] The granular continuous semi-coke rotary kiln as described above, wherein the feeding buffer bin of the granular continuous semi-coke rotary kiln is connected to the raw material bin;

[0029] A cooling mechanism connected to the discharging assembly of the granular continuous semi-coke rotary kiln through a spiral material guiding mechanism;

[0030] A detection member for detecting the air pressure of the outer furnace chamber;

[0031] A water ring pump connected to the outer furnace chamber and the external heat using equipment and started or stopped based on the detection result of the detection member;

[0032] A furnace chamber induced draft fan connected to the outer furnace chamber and the drying mechanism;

[0033] A natural gas induced draft fan connected to the outer furnace chamber and a natural gas source;

[0034] A tail gas treatment mechanism connected to the drying mechanism, the external heat using equipment and the cooling mechanism, respectively.

[0035] Compared with the prior art, the beneficial effects of the present application are as follows:

[0036] (1) The granular continuous semi-coke rotary kiln of the present application realizes the function of shaftless feeding screw by arranging spiral blades in the inner spiral furnace cylinder, replacing the feeding screw device in the traditional process. This design simplifies the process and reduces the cost. The spiral blades extend along the axial direction to the feeding end and the discharging end, so that the raw material always advances along the spiral groove during the process of entering and discharging the inner spiral furnace cylinder, thereby effectively preventing the phenomenon of material jamming. At the same time, the structure of the spiral groove ensures the uniform distribution of the raw material in the inner furnace chamber, ensuring uniform heating of the raw material.

[0037] By arranging air flow channels on the spiral blades, the inner furnace chamber and the outer furnace chamber are connected. During high-temperature operation, semi-coke will continuously generate a large amount of pyrolysis gas, and the pressure of the inner furnace chamber will always be higher than that of the outer furnace chamber. This ensures that the hot flue gas of natural gas combustion will not enter the inner furnace chamber, and the pyrolysis gas generated in the inner furnace chamber can be discharged to the outer furnace chamber through the air flow channels. This design allows the combustion nozzle to directly use these pyrolysis gases as energy for combustion, thereby replacing the traditional incinerator. In addition, in the traditional technology, the heat generated by the incinerator needs to be transported back through the pipeline. There is a certain heat loss in this process. By directly burning the recovered pyrolysis gas in the outer furnace chamber, the present application saves the related cost of the incinerator, while improving the efficiency of heat value reuse, thereby effectively reducing the cost of gas use.

[0038] (2) The battery negative electrode material preparation system of the present application improves the utilization efficiency of pyrolysis gas and reduces the preparation cost by using a granular continuous semi-coke rotary kiln. At the same time, by setting a detection piece and a water ring pump, real-time monitoring and adjustment of the gas pressure of the outer furnace chamber are realized. When the semi-coke has not yet completely generated pyrolysis gas at the initial stage of combustion, the detection piece will monitor the pressure change of the outer furnace chamber, and the water ring pump will start vacuumizing when the pressure is detected to be rising. In this way, it can effectively prevent hot flue gas from natural gas combustion from entering the inner furnace chamber, and ensure that the pyrolysis gas can smoothly enter the outer furnace chamber, not only further improving the pyrolysis gas utilization efficiency of the system, but also enhancing the reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed to be used in the description of the specific embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0040] Fig. 1 is a cross-sectional structural schematic diagram of the granular continuous semi-coke rotary kiln of the embodiment 1 of the present application;

[0041] Fig. 2 is a structural schematic diagram of the inner spiral furnace cylinder of the granular continuous semi-coke rotary kiln of the embodiment 1 of the present application;

[0042] Fig. 3 is a cross-sectional structural schematic diagram of the inner spiral furnace cylinder shown in Fig. 2;

[0043] Fig. 4 is a structural schematic diagram of the battery negative electrode material preparation system of the embodiment 2 of the present application.

[0044] Explanation of reference signs 1-inner spiral furnace cylinder; 2-outer furnace cylinder; 3-inner furnace chamber; 4-outer furnace chamber; 5-burning nozzle; 6-spiral vane; 61-side rotating wall; 62-top wall; 63-inner cavity; 7-spiral groove; 8-through hole; 81-waist-shaped hole; 82-circular hole; 9-blast fin; 91-aperture; 10-first dynamic sealing mechanism; 20-second dynamic sealing mechanism; 30-supporting assembly; 40-feeding buffer bin; 50-discharging assembly; 100-crushing mechanism; 200-drying mechanism; 300-raw material bin; 400-spiral material guiding mechanism; 500-cooling mechanism; 600-water ring pump; 700-furnace chamber induced draft fan; 800-natural gas induced draft fan; 900-tail gas treatment mechanism; A-external heat-using equipment. DETAILED DESCRIPTION

[0045] In order to better understand the present application by those skilled in the art, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0046] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0047] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", and the like indicate the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0048] In addition, in addition to indicating the orientation or positional relationship, the above-mentioned partial terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain dependent relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the present application can be understood according to the specific circumstances.

[0049] In addition, the terms "mount", "set", "provided with", "connected", "connected", "sleeved" should be broadly understood. For example, it can be fixedly connected, detachably connected, or integrally constructed; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0050] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in the case of no conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0051] Embodiment 1

[0052] Please refer to FIG. 1 to FIG. 3, the present embodiment provides a granular continuous semi-coke rotary kiln, which comprises a supporting assembly 30, a feeding buffer bin 40, a discharging assembly 50, a rotary driving assembly, an inner spiral furnace cylinder 1 and an outer furnace cylinder 2.

[0053] The feeding buffer bin 40 is used to stably supply raw materials, so as to avoid fluctuation or interruption in the feeding process and ensure continuous and stable production process. The discharging assembly 50 is used to discharge the processed raw materials from the inner spiral furnace cylinder 1. The rotary driving assembly is used to drive the inner spiral furnace cylinder 1 to rotate around the axis, which can be an electric motor. The supporting assembly 30 is used to support the feeding buffer bin 40, the discharging assembly 50, the rotary driving assembly, the inner spiral furnace cylinder 1 and the outer furnace cylinder 2. The feeding buffer bin 40, the discharging assembly 50, the supporting assembly 30 and the rotary driving assembly are all of conventional structures, and the overall design is not changed, which will not be described here.

[0054] Specifically, the inner spiral furnace cylinder 1 is rotationally arranged on the supporting assembly 30 and has an inner furnace chamber 3. The feeding end of the inner spiral furnace cylinder 1 is rotationally connected to the feeding buffer bin 40 through a first dynamic sealing mechanism 10, and the discharging end is rotationally connected to the discharging assembly 50 through a second dynamic sealing mechanism 20.

[0055] The outer furnace cylinder 2 is arranged on the supporting assembly 30 and is sleeved outside the inner spiral furnace cylinder 1 and rotationally connected thereto. The outer furnace cylinder 2 is spaced from the inner spiral furnace cylinder 1 to form an outer furnace chamber 4, and a combustion nozzle 5 is arranged in the outer furnace chamber 4. The combustion nozzle 5 is of a conventional structure and is used to ignite fuel to generate a combustion reaction in the outer furnace chamber 4. It is of a conventional structure and will not be described here.

[0056] In some embodiments, the first dynamic sealing mechanism 10 and the second dynamic sealing mechanism 20 each comprise a graphite packing, a labyrinth sleeve packing and two layers of fish scale sealing structures which are sequentially sleeved from inside to outside, and nitrogen protection is adopted to ensure the sealing effect. It is a combination of conventional structures and will not be described here.

[0057] The inner wall of the inner spiral furnace cylinder 1 protrudes radially towards the inner furnace chamber 3 to form a spiral vane 6, which extends along the axial direction of the inner spiral furnace cylinder 1 to the feeding end and the discharging end. The spiral vane 6 and the inner wall of the inner spiral furnace cylinder 1 cooperate to form a spiral groove 7, which is used to guide the raw materials to move along a spiral trajectory from the feeding end to the discharging end.

[0058] The spiral blade 6 is provided with an airflow passage, the inner end of which penetrates to the outer surface of the spiral blade 6, and the outer end penetrates to the outer wall of the inner spiral furnace cylinder 1 to communicate the inner hearth 3 and the outer hearth 4. In the radial direction of the inner spiral furnace cylinder 1, the thickness of the raw material is not greater than the distance from the inner end of the airflow passage to the inner wall of the inner spiral furnace cylinder 1.

[0059] In some embodiments, the spiral blade 6 is hollow, and the airflow passage communicates with the inner cavity 63 of the spiral blade 6. By setting the spiral blade 6 as a hollow structure, the weight of the spiral blade 6 can be effectively reduced, while the distribution and flow efficiency of the pyrolysis gas are improved, and the resistance of the pyrolysis gas is reduced.

[0060] In detail, the spiral blade 6 includes two side rotating walls 61 arranged at intervals in the radial direction on the inner wall of the inner spiral furnace cylinder 1, and a top wall 62 connecting the top ends of the two side rotating walls 61, and the inner end of the airflow passage penetrates to the top wall 62. This layout can effectively prevent the raw material from entering the airflow passage when rolling in the inner spiral furnace cylinder 1, thereby maintaining the cleanliness of the airflow passage and the stable flow of the pyrolysis gas.

[0061] Specifically, the inner spiral furnace cylinder 1 will generate rotation and friction during operation, causing the raw material to roll in the inner spiral furnace cylinder 1 to move along a spiral trajectory. If the inner end of the airflow passage is close to the raw material rolling path, the raw material may be rolled into the airflow passage, affecting the smoothness of the pyrolysis gas and possibly causing blockage. By setting the inner end of the airflow passage on the top wall 62, the raw material must travel a longer distance to contact the airflow passage. Based on this layout, a suitable raw material filling rate is set, which increases the amount of reactable raw material while preventing the raw material from entering the airflow passage, thereby improving the production efficiency.

[0062] In some embodiments, the distance between the two side rotating walls 61 gradually decreases from the inner wall of the inner spiral furnace cylinder 1 towards the top wall 62. Such a design utilizes the inclined side rotating walls 61 to guide the raw material to concentrate towards the central area of the spiral groove 7. Specifically, the inclination angle of the side rotating wall 61 promotes the raw material to move along the inner wall of the inner spiral furnace cylinder 1 when rolling in the inner spiral furnace cylinder 1, to ensure uniform distribution of the raw material, thereby improving the reaction or treatment effect. In addition, through this design, the flow path of the raw material in the furnace cylinder becomes more smooth, effectively preventing the raw material from directly contacting the inner end of the airflow passage, further reducing the risk of blockage.

[0063] In some embodiments, the airflow passage includes a plurality of passage units arranged equidistantly along the circumference of the inner spiral furnace cylinder 1, and each passage unit includes a plurality of through holes 8 arranged equidistantly along the axial direction of the inner spiral furnace cylinder 1. This design ensures the smooth flow of pyrolysis gas from the inner hearth 3 to the outer hearth 4 by uniformly distributing the airflow, thereby optimizing the combustion efficiency and recycling efficiency. It avoids the generation of local temperature difference, ensuring the processing effect and consistency of the semi-coke.

[0064] In some embodiments, the opening of the outer end of the through hole 8 on the outer wall of the inner spiral furnace cylinder 1 is a waist-shaped hole 81, and the length direction of the waist-shaped hole 81 is arranged along the circumferential direction of the inner spiral furnace cylinder 1. And the opening of the inner end of the through hole 8 on the top wall 62 is a circular hole 82.

[0065] In detail, when the inner spiral furnace cylinder 1 rotates, the pyrolysis gas will follow the tangential rotation of the inner spiral furnace cylinder 1. By setting the opening of the outer end of the through hole 8 on the outer wall of the inner spiral furnace cylinder 1 as a waist-shaped hole 81, it is beneficial to the pyrolysis gas entering the inside of the outer furnace chamber 4. This hole shape enhances airflow guidance, reduces turbulence, and improves import efficiency, ensuring smooth flow of pyrolysis gas and reducing energy loss, thereby optimizing pyrolysis gas utilization and temperature balance, promoting a stable combustion process.

[0066] In some embodiments, the outer wall of the inner spiral furnace cylinder 1 is arranged with a plurality of air blowing units along the circumferential direction at equal intervals, and the air blowing units are arranged on one side of the channel unit in a one-to-one manner along the circumferential direction of the inner spiral furnace cylinder 1. The arrangement of the air blowing unit can effectively improve the mixing speed of the pyrolysis gas and natural gas, and make the mixed gas uniformly distributed in the outer furnace chamber 4, thereby improving the heating effect on the semi-coke. In addition, in the cooling stage, the air blowing unit can also enhance the heat dissipation effect, by promoting more uniform distribution of gas and increasing flow speed, achieving more balanced heat dissipation in the outer furnace chamber 4.

[0067] In detail, each air blowing unit includes a plurality of air blowing fins 9 arranged at equal intervals along the axial direction of the inner spiral furnace cylinder 1, and the air blowing fins 9 are formed by protruding radially outward from the outer wall of the inner spiral furnace cylinder 1.

[0068] In the axial direction of the inner spiral furnace cylinder 1, the air blowing fins 9 gradually approach the corresponding channel unit from the middle to both ends, so that the air blowing fins 9 have an arc-shaped structure curved towards the corresponding channel unit, and from the inner spiral furnace cylinder 1 to the outer furnace cylinder 2, the two ends of the air blowing fins 9 gradually approach the middle.

[0069] This design makes the structure of the air blowing fin 9 more stable. And in the process of gas flow, this design can reduce the mechanical stress caused by uneven gas flow, improve the durability and stability of the air blowing unit. The curved structure of the air blowing fin 9 can promote the gas to obtain a higher flow speed in the flow process, further improving the mixing and heat dissipation effect. This design helps to enhance the flowability of pyrolysis gas and natural gas, ensuring that the gas in the furnace chamber can effectively participate in the combustion or cooling process.

[0070] In some embodiments, the middle of the end of the air blowing fin 9 away from the inner spiral furnace cylinder 1 forms an opening 91. This can reduce the resistance of the gas flow through the air blowing fin 9, and reduce the friction loss of the gas flow through the air blowing fin 9.

[0071] Example 2

[0072] Please refer to Figure 4, the battery negative material preparation system of the embodiment includes a crushing mechanism 100 for crushing raw materials, a drying mechanism 200 connected with the crushing mechanism 100 for drying the crushed raw materials, a raw material bin 300 connected with the drying mechanism 200 for storing the dried raw materials, a granular continuous semi-coke rotary kiln connected with the raw material bin 300, a cooling mechanism 500 connected with the granular continuous semi-coke rotary kiln through a spiral material guiding mechanism 400, a detection element, a water ring pump 600, a hearth induced draft fan 700, a natural gas induced draft fan 800, and a tail gas treatment mechanism 900. Among them, the crushing mechanism 100, the drying mechanism 200, the raw material bin 300, the spiral material guiding mechanism 400, the cooling mechanism 500, the natural gas induced draft fan 800, and the tail gas treatment mechanism 900 are conventional structures, and the overall design is not changed, which will not be described here.

[0073] The structure of the granular continuous semi-coke rotary kiln in the embodiment is the same as that of the granular continuous semi-coke rotary kiln in Embodiment 1, and specific reference can be made to the foregoing Embodiment 1, which will not be described here.

[0074] In detail, the feeding buffer bin 40 of the granular continuous semi-coke rotary kiln is connected with the raw material bin 300, and the discharging assembly 50 is connected with the cooling mechanism 500 through the spiral material guiding mechanism 400. The natural gas induced draft fan 800 is connected with the outer hearth 4 and the natural gas source, and is used to introduce natural gas into the outer hearth 4. The hearth induced draft fan 700 is connected with the outer hearth 4 and the drying mechanism 200, and is used to introduce the high-temperature gas in the outer hearth 4 to the drying mechanism 200 for use.

[0075] The detection element is used to detect the air pressure of the outer hearth 4, and specifically, the detection element is a vacuum gauge. Since pyrolysis gas is not completely generated from semi-coke at the initial stage of combustion, in order to prevent the high-temperature flue gas generated by natural gas combustion from entering the inner hearth 3, a vacuum gauge is installed in the outer hearth 4 to detect the vacuum degree of the outer hearth 4, thereby avoiding the occurrence of the situation that the high-temperature flue gas flows back to the inner hearth 3, and improving the system reliability.

[0076] The water ring pump 600 is connected with the outer hearth 4 and the external heat-using equipment A, and is started or stopped based on the detection result of the detection element. Thus, when the pressure of the outer hearth 4 increases, the outer hearth 4 is vacuumized, thereby avoiding the high-temperature flue gas generated by natural gas combustion in the outer hearth 4 from entering the inner hearth 3 through the air flow passage. Due to the characteristics of the water ring pump 600, it can be normally used in harsh environments, and can remove impurities in the gas extracted from the outer hearth 4 through circulating water, so that the generated pyrolysis gas can effectively enter the outer hearth 4, and the pyrolysis gas is burned by the combustion nozzle 5 of the outer hearth 4, instead of the incinerator burning treatment in the traditional process, thereby improving the reutilization efficiency of the pyrolysis gas and simplifying the process. In addition, the high-temperature gas extracted by the water ring pump 600 can flow to the external heat-using equipment A, thereby further improving the heat energy utilization rate.

[0077] Notably, the battery negative electrode material preparation system is provided with a controller connected with the detection member and the water ring pump 600, and the controller can control the water ring pump 600 to start and stop according to the detection result of the detection member. The controller can realize signal processing and control function by using a single-chip microcomputer or a logic circuit, which is a conventional technology. Of course, the controller can also be connected with other components to realize automatic control of the system, which is prior art.

[0078] The tail gas treatment mechanism 900 is connected with the drying mechanism 200, the external heat equipment A and the cooling mechanism 500 respectively.

[0079] Compared with the prior art, the beneficial effects of the present application are as follows:

[0080] (1) The granular continuous semi-coke rotary kiln of the present application realizes the function of shaftless feeding screw by setting spiral blades in the inner spiral furnace cylinder, replacing the feeding screw device in the traditional process. This design simplifies the process and reduces the cost. The spiral blades extend to the feeding end and the discharging end along the axial direction, so that the raw materials always advance along the spiral groove during the process of entering and discharging the inner spiral furnace cylinder, thereby effectively preventing the phenomenon of material jamming. At the same time, the structure of the spiral groove ensures the uniform distribution of the raw materials in the inner furnace, ensuring uniform heating of the raw materials.

[0081] By setting the airflow channel on the spiral blade, the inner furnace and the outer furnace are connected. During high-temperature operation, semi-coke will continuously produce a large amount of pyrolysis gas, and the pressure in the inner furnace will always be higher than that in the outer furnace. This ensures that the hot flue gas produced by natural gas combustion will not enter the inner furnace, and the pyrolysis gas produced in the inner furnace can be discharged to the outer furnace through the airflow channel. This design allows the combustion nozzle to directly use the pyrolysis gas as energy for combustion, thereby replacing the traditional incinerator. In addition, in the traditional technology, the heat generated by the incinerator needs to be transported back through a pipeline, which results in a certain amount of heat loss during this process. By directly burning the recovered pyrolysis gas in the outer furnace, the present application saves the related costs of the incinerator and improves the efficiency of heat value recycling, thereby effectively reducing the cost of gas use.

[0082] (2) The battery negative electrode material preparation system of the present application improves the utilization efficiency of pyrolysis gas and reduces the preparation cost by using a granular continuous semi-coke rotary kiln. At the same time, by setting a detection member and a water ring pump, real-time monitoring and adjustment of the gas pressure in the outer furnace are realized. When the semi-coke has not yet completely produced pyrolysis gas at the initial stage of combustion, the detection member will monitor the pressure change in the outer furnace, and the water ring pump will start to perform vacuum pumping when the pressure is detected to be rising. This can effectively prevent the hot flue gas produced by natural gas combustion from entering the inner furnace, and ensure that the pyrolysis gas can smoothly enter the outer furnace, thereby further improving the utilization efficiency of pyrolysis gas of the system and enhancing the reliability of the system.

[0083] Finally, it should be noted that the above are only preferred embodiments of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent replacements can be made to some of the technical features therein, and all such modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A granular continuous semi-coke rotary kiln comprising a support assembly, a feed buffer bin, a discharge assembly and a rotary drive assembly, characterized in that, Also comprising: an inner spiral furnace barrel rotatably arranged on the support assembly and having an inner furnace chamber, a feed end of the inner spiral furnace barrel being rotatably connected to the feed buffer bin through a first dynamic sealing mechanism, and a discharge end being rotatably connected to the discharge assembly through a second dynamic sealing mechanism, the inner spiral furnace barrel being configured to rotate around an axis under the drive of the rotary drive assembly; an outer furnace barrel arranged on the support assembly, the outer furnace barrel being sleeved outside the inner spiral furnace barrel and being rotatably connected to the inner spiral furnace barrel, the outer furnace barrel being spaced from the inner spiral furnace barrel to form an outer furnace chamber, and a combustion nozzle being arranged in the outer furnace chamber; an inner wall of the inner spiral furnace barrel protruding radially towards the inner furnace chamber to form a spiral vane, the spiral vane extending along an axial direction of the inner spiral furnace barrel to a feed end and a discharge end, the spiral vane and the inner wall of the inner spiral furnace barrel cooperating to form a spiral groove for guiding the raw material to move along a spiral track from the feed end to the discharge end; an airflow passage being arranged on the spiral vane, an inner end of the airflow passage penetrating through an outer surface of the spiral vane, and an outer end of the airflow passage penetrating through an outer wall of the inner spiral furnace barrel to connect the inner furnace chamber and the outer furnace chamber; in a radial direction of the inner spiral furnace barrel, a thickness of the raw material is not greater than a distance from the inner end of the airflow passage to the inner wall of the inner spiral furnace barrel.

2. The particulate continuous semicoke rotary kiln as claimed in claim 1, wherein, the spiral vane is in a hollow structure, and the airflow passage is connected to an inner cavity of the spiral vane.

3. The particulate continuous semicoke rotary kiln as claimed in claim 2, wherein, the spiral vane includes two side rotating walls arranged at intervals in the radial direction on the inner wall of the inner spiral furnace barrel, and a top wall connecting top ends of the two side rotating walls, and the inner end of the airflow passage penetrates through the top wall.

4. The particulate continuous semicoke rotary kiln as claimed in claim 3, wherein, a distance between the two side rotating walls gradually decreases from the inner wall of the inner spiral furnace barrel towards the top wall.

5. The particulate continuous semicoke rotary kiln as claimed in claim 3, wherein, the airflow passage includes a plurality of passage units arranged at intervals in a circumferential direction of the inner spiral furnace barrel, each passage unit including a plurality of through holes arranged at intervals in an axial direction of the inner spiral furnace barrel.

6. The particulate continuous semicoke rotary kiln defined in claim 5, wherein an opening of an outer end of the through hole on the outer wall of the inner spiral furnace barrel is a waist-shaped hole, and a length direction of the waist-shaped hole is arranged along the circumferential direction of the inner spiral furnace barrel.

7. The particulate continuous semicoke rotary kiln defined in claim 5, wherein a plurality of air blowing units are arranged at intervals in the circumferential direction on the outer wall of the inner spiral furnace barrel, and each air blowing unit is arranged on one side of the passage unit in a one-to-one manner in the circumferential direction of the inner spiral furnace barrel.

8. The particulate continuous semicoke rotary kiln defined in claim 7, wherein each air blowing unit includes a plurality of air blowing fins arranged at intervals in the axial direction of the inner spiral furnace barrel, and the air blowing fins protrude radially outwards from the outer wall of the inner spiral furnace barrel; in the axial direction of the inner spiral furnace barrel, the air blowing fins gradually approach the corresponding passage unit from a middle part to both ends, so that the air blowing fins are in an arc structure curved towards the corresponding passage unit, and from the inner spiral furnace barrel to the outer furnace barrel, both ends of the air blowing fins gradually approach the middle part.

9. The particulate continuous semicoke rotary kiln defined in claim 8, wherein a middle part of one end of the air blowing fin away from the inner spiral furnace barrel forms an opening.

10. A battery anode material preparation system, characterized by, comprising: a crushing mechanism for crushing raw materials; a drying mechanism connected to the crushing mechanism for drying the crushed raw materials; a raw material bin connected to the drying mechanism for storing the dried raw materials; The granular continuous semi-coke rotary kiln according to any one of claims 1 to 9, wherein a feed buffer bin is connected to the raw material bin; a cooling mechanism connected to a discharge assembly of the granular continuous semi-coke rotary kiln through a spiral guide mechanism; a detection member for detecting the air pressure of the outer furnace; a water ring pump connected between the outer furnace and an external heat-using device and started or stopped based on the detection result of the detection member; a furnace induced draft fan connected between the outer furnace and the drying mechanism; a natural gas induced draft fan connected between the outer furnace and a natural gas source; a tail gas treatment mechanism connected to the drying mechanism, the external heat-using device, and the cooling mechanism, respectively.

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