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

Abstract

The present application discloses a granular continuous semi-coke rotary kiln and a battery negative electrode material preparation system. The granular continuous semi-coke rotary kiln includes an inner spiral furnace drum, which has an inner furnace chamber, and the feed end and the discharge end are respectively connected to the feed buffer bin and the discharge assembly; an outer furnace drum, which is rotatably sleeved on the inner spiral furnace drum and spaced to form an outer furnace chamber, and a burner is arranged in the outer furnace chamber; the inner wall of the inner spiral furnace drum protrudes radially toward the inner furnace chamber to form a spiral blade, and the spiral blade extends to the feed end and the discharge end. The spiral blade and the inner wall of the inner spiral furnace drum cooperate to form a spiral groove for guiding the raw material to move from the feed end to the discharge end along a spiral trajectory; an airflow channel is provided on the spiral blade, and the inner end of the airflow channel penetrates to the outer surface of the spiral blade, and the outer end penetrates to the outer wall of the inner spiral furnace drum; in the radial direction of the inner spiral furnace drum, the raw material thickness is not greater than the distance from the inner end of the airflow channel to the inner wall of the inner spiral furnace drum. The pyrolysis gas utilization efficiency of the present application is high, and the cost of preparing negative electrode materials is low.

Description

Technical Field

[0001] The invention relates to the technical field of battery negative electrode material production, and in particular to a granular continuous semi-coke rotary kiln and a battery negative electrode material preparation system. Background Art

[0002] Semi-coke is a solid product obtained by low-temperature dry distillation of peat, lignite and high-volatile bituminous coal at 500℃ to 700℃. Its main components include carbon, ash and volatile matter. Its shape is irregular, usually black powder, block, granular or honeycomb. Semi-coke has good adsorption properties 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, ferroalloys, metallurgy, power plants and carbonaceous adsorbents.

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

[0004] The existing process flow of preparing negative electrode materials with semi-coke is as follows: the semi-coke is crushed into granular raw materials of about 1mm to 10mm, and after drying the moisture in the drying furnace, it enters the buffer bin through the raw material bin, and then the raw materials are pushed into the inner furnace of the rotary kiln using the feed screw device. Natural gas is introduced into the outer furnace, and the inner furnace wall is baked by the burner. Part of the pyrolysis gas generated in the inner furnace is used in the drying furnace, and the remaining pyrolysis gas is dedusted by the dust removal device and enters the incinerator to generate cracking heat, and then returns to the outer furnace for high-temperature calcination, or as a heat source for other purposes. Finally, the collected tail gas is centrally processed. The calcined raw materials are cooled in the cooler through the feed screw device, and the cooled products are packaged.

[0005] However, the preparation steps of the existing process still have shortcomings. First, the raw materials are pushed into the furnace of the rotary kiln by the feeding screw device, which is prone to jamming, increasing maintenance costs and may cause uneven distribution of raw materials during transportation. This uneven distribution will lead to uneven reactions in the rotary kiln, affecting the quality and performance of the final product.

[0006] Secondly, in the rotary kiln, the semi-coke raw material is heated and pyrolyzed to produce pyrolysis gas. Part of the pyrolysis gas is used to dry the raw materials in the drying furnace, and the rest of the pyrolysis gas needs to be processed by a dust removal device to remove dust particles. The treated pyrolysis gas is guided to the incinerator, where it is further cracked to generate heat energy. In the entire process, the pyrolysis gas is processed through multiple steps and equipment, and each step will result in the loss of heat energy or material, thereby reducing the reuse efficiency of the pyrolysis gas. At the same time, complex processing equipment increases the processing time of the pyrolysis gas and increases the preparation cost of the negative electrode material. Summary of the invention

[0007] The purpose of the present invention 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 feed screw device is prone to material jamming and uneven distribution of raw materials when pushing the raw materials into the rotary kiln furnace, and the pyrolysis gas treatment steps are complicated and involve many equipments, resulting in low pyrolysis gas reuse efficiency and high negative electrode material preparation cost.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] A granular continuous semi-coke rotary kiln, comprising a support assembly, a feed buffer bin, a discharge assembly and a rotary drive assembly, and also comprising:

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

[0011] An outer furnace barrel is arranged on the supporting assembly, the outer furnace barrel is sleeved on the outer side of the inner spiral furnace barrel and is rotatably connected with the inner spiral furnace barrel, the outer furnace barrel and the inner spiral furnace barrel are spaced to form an outer furnace chamber, and a burner is arranged in the outer furnace chamber;

[0012] The inner wall of the inner spiral furnace drum protrudes radially toward the inner furnace chamber to form a spiral blade, the spiral blade extends along the axial direction of the inner spiral furnace drum to the feed end and the discharge end, the spiral blade and the inner wall of the inner spiral furnace drum cooperate to form a spiral groove, and the spiral groove is used to guide the raw material to move from the feed end to the discharge end along the spiral trajectory;

[0013] The spiral blade is provided with an air flow channel, the inner end of the air flow channel penetrates to the outer surface of the spiral blade, and the outer end of the air flow channel penetrates to the outer wall of the inner spiral furnace barrel to connect the inner furnace chamber with the outer furnace chamber;

[0014] In the radial direction of the inner spiral furnace drum, the thickness of the raw material is not greater than the distance from the inner end of the air flow channel to the inner wall of the inner spiral furnace drum.

[0015] In certain embodiments, the spiral blade is a hollow structure, and the air flow channel is connected to the inner cavity of the spiral blade.

[0016] In certain embodiments, the spiral blade includes two side spiral walls radially spaced apart on the inner wall of the inner spiral furnace drum and a top wall connecting the top ends of the two side spiral walls, and the inner end of the airflow channel passes through the top wall.

[0017] In certain embodiments, the distance between the two side spiral walls gradually decreases from the inner wall of the inner spiral furnace drum toward the top wall.

[0018] In certain embodiments, the air flow channel includes a plurality of channel units equidistantly arranged along the circumference of the inner spiral furnace drum, and each of the channel units includes a plurality of through holes equidistantly arranged along the axial direction of the inner spiral furnace drum.

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

[0020] In certain embodiments, a plurality of blast units are equidistantly arranged on the outer wall of the inner spiral furnace drum in the circumferential direction, and the blast units are arranged one-to-one on one side of the channel unit in the circumferential direction of the inner spiral furnace drum.

[0021] In some embodiments, each of the blast units includes a plurality of blast fins equidistantly arranged along the axial direction of the inner spiral furnace drum, and the blast fins are formed by radially protruding outward from the outer wall of the inner spiral furnace drum;

[0022] In the axial direction of the inner spiral furnace drum, the blast fins gradually approach the corresponding channel units from the middle to both ends, so that the blast fins present an arc structure bent toward the corresponding channel units, and from the inner spiral furnace drum to the outer furnace drum, the two ends of the blast fins gradually approach the middle.

[0023] In certain embodiments, a notch is formed in the middle of one end of the blast fin away from the inner spiral furnace drum.

[0024] The present 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 material;

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

[0028] As in the above-mentioned granular continuous semi-coke rotary kiln, the feed buffer bin of the granular continuous semi-coke rotary kiln is connected to the raw material bin;

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

[0030] A detection member, used for detecting the gas pressure of the outer furnace;

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

[0032] A furnace induced draft fan, connecting the outer furnace and the drying mechanism;

[0033] A natural gas induced draft fan connecting the outer furnace with a natural gas source;

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

[0035] Due to the application of the above technical solution, the beneficial effects of the present application compared with the prior art are:

[0036] (1) The granular continuous semi-coke rotary kiln of the present application realizes the function of a shaftless feed screw by arranging spiral blades in the inner spiral furnace drum, thereby replacing the feed screw device in the traditional process. This design simplifies the process and reduces costs. The spiral blades extend axially to the feed end and the discharge end, so that the raw materials always move along the spiral groove during the process of entering and discharging from the inner spiral furnace drum, thereby effectively preventing the material from getting stuck. At the same time, the structure of the spiral groove ensures that the raw materials are evenly distributed in the inner furnace chamber, ensuring that the raw materials are evenly heated.

[0037] By setting an air flow channel on the spiral blade, the connection between the inner furnace and the outer furnace is achieved. During the high-temperature operation process, the semi-coke will continue to produce a large amount of pyrolysis gas, and the pressure of the inner furnace will always be higher than the pressure of the outer furnace. This ensures that the hot flue gas from the combustion of natural gas will not enter the inner furnace, and the pyrolysis gas produced in the inner furnace can be discharged into the outer furnace through the air flow channel. This design allows the burner to directly use these pyrolysis gases as energy for combustion, thereby replacing the traditional incinerator. In addition, in traditional technology, the heat generated by the incinerator needs to be transported and reused through pipelines, and there is a certain amount of heat loss in this process. The present application saves the relevant costs of the incinerator by directly burning the recovered pyrolysis gas in the outer furnace, while improving the reuse efficiency of the calorific value, 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 adopting a granular continuous semi-coke rotary kiln. At the same time, by setting up detection components and water ring pumps, real-time monitoring and adjustment of the gas pressure in the outer furnace can be achieved. When the semi-coke has not yet completely produced pyrolysis gas in the early stage of combustion, the detection component will monitor the pressure change in the outer furnace, and the water ring pump will start to vacuum when the pressure increase is detected. This can effectively prevent the hot flue gas from the combustion of natural gas from entering the inner furnace and ensure that the pyrolysis gas can smoothly enter the outer furnace, which not only further improves the pyrolysis gas utilization efficiency of the system, but also enhances the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0040] Figure 1 It is a schematic cross-sectional structure diagram of a granular continuous semi-coke rotary kiln according to Example 1 of the present invention;

[0041] Figure 2 It is a schematic structural diagram of the inner spiral furnace drum of the granular continuous semi-coke rotary kiln according to Example 1 of the present invention;

[0042] Figure 3 for Figure 2 The schematic cross-sectional structure diagram of the inner spiral furnace drum shown;

[0043] Figure 4 This is a schematic diagram of the structure of a battery negative electrode material preparation system according to Example 2 of the present invention.

[0044] Description of Reference Numerals

[0045] 1-inner spiral furnace drum; 2-outer furnace drum; 3-inner furnace chamber; 4-outer furnace chamber; 5-burner nozzle; 6-spiral blade; 61-side spiral wall; 62-top wall; 63-inner cavity; 7-spiral groove; 8-through hole; 81-waist-shaped hole; 82-circular hole; 9-blast fin; 91-notch; 10-first dynamic sealing mechanism; 20-second dynamic sealing mechanism; 30-support assembly; 40-feed 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 induced draft fan; 800-natural gas induced draft fan; 900-exhaust gas treatment mechanism; A-external heat equipment. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0047] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0048] 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 positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0049] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0050] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] Example 1

[0053] See also Figures 1 to 3 The present embodiment provides a granular continuous semi-coke rotary kiln including a support assembly 30, a feed buffer bin 40, a discharging assembly 50, a rotary drive assembly, an inner spiral furnace drum 1 and an outer furnace drum 2.

[0054] Among them, the feed buffer bin 40 is used to smoothly supply raw materials to avoid fluctuations or interruptions in the feeding process, thereby ensuring a continuous and stable production process. The discharge assembly 50 is used to discharge the processed raw materials out of the inner spiral furnace drum 1. The rotary drive assembly is used to drive the inner spiral furnace drum 1 to rotate around the axis, and can specifically be a motor. The support assembly 30 is used to support the feed buffer bin 40, the discharge assembly 50, the rotary drive assembly, the inner spiral furnace drum 1 and the outer furnace drum 2. The feed buffer bin 40, the discharge assembly 50, the support assembly 30, and the rotary drive assembly are all conventional structures, and the overall design has not been changed, so they are not repeated here.

[0055] Specifically, the inner spiral furnace drum 1 is rotatably set on the support assembly 30 and has an inner furnace chamber 3. The feed end of the inner spiral furnace drum 1 is rotatably connected to the feed buffer bin 40 through a first dynamic sealing mechanism 10, and the discharge end is rotatably connected to the discharge assembly 50 through a second dynamic sealing mechanism 20.

[0056] The outer furnace drum 2 is arranged on the support assembly 30, and the outer furnace drum 2 is sleeved on the outer side of the inner spiral furnace drum 1 and is rotatably connected with the inner spiral furnace drum 1. The outer furnace drum 2 and the inner spiral furnace drum 1 are spaced apart to form an outer furnace chamber 4, and a burner 5 is arranged in the outer furnace chamber 4. The burner 5 is a conventional structure, and is used to ignite fuel so as to generate a combustion reaction in the outer furnace chamber 4. It is a conventional structure and will not be described in detail here.

[0057] In some embodiments, the first dynamic sealing mechanism 10 and the second dynamic sealing mechanism 20 both include graphite packing, labyrinth sleeve packing and two-layer fish scale sealing structure sequentially arranged from the inside to the outside, and nitrogen protection is used to ensure the sealing effect. It is a combination of conventional structures and will not be described in detail here.

[0058] The inner wall of the inner spiral furnace drum 1 protrudes radially toward the inner furnace chamber 3 to form a spiral blade 6, which extends along the axial direction of the inner spiral furnace drum 1 to the feed end and the discharge end. The spiral blade 6 and the inner wall of the inner spiral furnace drum 1 cooperate to form a spiral groove 7, which is used to guide the raw material to move along the spiral trajectory from the feed end to the discharge end.

[0059] The spiral blade 6 is provided with an airflow channel, the inner end of the airflow channel penetrates to the outer surface of the spiral blade 6, and the outer end penetrates to the outer wall of the inner spiral furnace drum 1, so as to connect the inner furnace 3 with the outer furnace 4. In the radial direction of the inner spiral furnace drum 1, the thickness of the raw material is not greater than the distance from the inner end of the airflow channel to the inner wall of the inner spiral furnace drum 1.

[0060] In some embodiments, the spiral blade 6 is hollow, and the airflow channel is connected to 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 improving the distribution and flow efficiency of the pyrolysis gas and reducing the pyrolysis gas resistance.

[0061] In detail, the spiral blade 6 includes two side spiral walls 61 arranged at intervals in the radial direction on the inner wall of the inner spiral furnace drum 1 and a top wall 62 connecting the top ends of the two side spiral walls 61, and the inner end of the air flow channel passes through the top wall 62. This layout can effectively prevent the raw materials from entering the air flow channel when the inner spiral furnace drum 1 rolls, thereby maintaining the cleanliness of the air flow channel and the stable flow of the pyrolysis gas.

[0062] Specifically, the inner spiral furnace drum 1 generates rotation and friction during operation, causing the raw materials to roll inside the spiral furnace drum 1 to move along a spiral trajectory. If the inner end of the airflow channel is close to the rolling path of the raw materials, the raw materials may be drawn into the airflow channel, affecting the smoothness of the pyrolysis gas and possibly causing blockage. By setting the inner end of the airflow channel on the top wall 62, the raw materials must travel a longer distance to contact the airflow channel. Based on this layout, a suitable raw material filling rate is set to increase the amount of reactive raw materials while preventing the raw materials from entering the airflow channel, thereby improving the preparation efficiency.

[0063] In some embodiments, the distance between the two side spiral walls 61 gradually decreases from the inner wall of the inner spiral furnace drum 1 toward the top wall 62. Such a design utilizes the inclined side spiral walls 61 to guide the raw materials to concentrate in the central area of ​​the spiral groove 7. Specifically, the inclination angle of the side spiral walls 61 prompts the raw materials to move along the inner wall of the inner spiral furnace drum 1 when rolling in the inner spiral furnace drum 1, so as to ensure that the raw materials are evenly distributed, thereby improving the reaction or treatment effect. In addition, through this design, the flow path of the raw materials in the furnace drum becomes smoother, effectively avoiding direct contact between the raw materials and the inner end of the air flow channel, and further reducing the risk of blockage.

[0064] In some embodiments, the airflow channel includes a plurality of channel units equidistantly arranged along the circumference of the inner spiral furnace drum 1, and each channel unit includes a plurality of through holes 8 equidistantly arranged along the axial direction of the inner spiral furnace drum 1. This design ensures that the pyrolysis gas flows smoothly from the inner furnace 3 to the outer furnace 4 by evenly distributing the airflow, thereby optimizing the combustion efficiency and recycling efficiency. It avoids the generation of local temperature differences and ensures the treatment effect and treatment consistency of the semi-coke.

[0065] In some embodiments, the opening of the outer end of the through hole 8 on the outer wall of the inner spiral furnace drum 1 is a waist-shaped hole 81, and the length direction of the waist-shaped hole 81 is arranged along the circumference of the inner spiral furnace drum 1. And the opening of the inner end of the through hole 8 on the top wall 62 is a circular hole 82.

[0066] In detail, when the inner spiral furnace drum 1 rotates, the pyrolysis gas will follow the inner spiral furnace drum 1 to rotate in the tangential direction, and the opening of the outer end of the through hole 8 on the outer wall of the inner spiral furnace drum 1 is set as a waist-shaped hole 81, which can facilitate the pyrolysis gas to enter the outer furnace 4. This hole shape ensures the smooth flow of pyrolysis gas and reduces energy loss by enhancing airflow guidance, reducing turbulence and improving introduction efficiency, thereby optimizing the utilization of pyrolysis gas and temperature balance, and promoting a stable combustion process.

[0067] In some embodiments, a plurality of blast units are arranged equidistantly along the circumferential direction on the outer wall of the inner spiral furnace drum 1, and the blast units are arranged one-to-one on one side of the channel unit along the circumferential direction of the inner spiral furnace drum 1. The setting of the blast units can effectively increase the mixing speed of the pyrolysis gas and the natural gas, and make the mixed gas evenly distributed in the outer furnace 4, thereby improving the heating effect on the semi-coke. In addition, in the cooling stage, the blast units can also enhance the heat dissipation effect, by promoting a more even distribution of the gas and increasing the flow rate, so as to achieve a more balanced heat dissipation in the outer furnace 4.

[0068] In detail, each blast unit includes a plurality of blast fins 9 equidistantly arranged along the axial direction of the inner spiral furnace drum 1 , and the blast fins 9 are formed by protruding radially outward from the outer wall of the inner spiral furnace drum 1 .

[0069] In the axial direction of the inner spiral furnace drum 1, the blast fins 9 gradually approach the corresponding channel units from the middle to both ends, so that the blast fins 9 are in an arc structure bent toward the corresponding channel units, and from the inner spiral furnace drum 1 to the outer furnace drum 2, the two ends of the blast fins 9 gradually approach the middle.

[0070] This design makes the structure of the blast fin 9 more stable. In addition, during the gas flow process, this design can reduce the mechanical stress caused by uneven airflow and improve the durability and stability of the blast unit. The curved structure of the blast fin 9 can promote the gas to obtain a higher flow rate during the flow process, further improving the mixing and heat dissipation effects. This design helps to enhance the fluidity of pyrolysis gas and natural gas, ensuring that the gas in the furnace can effectively participate in the combustion or cooling process.

[0071] In some embodiments, a notch 91 is formed in the middle of one end of the blast fin 9 away from the inner spiral furnace drum 1. This can reduce the resistance of the airflow passing through the blast fin 9 and reduce the friction loss of the airflow passing through the blast fin 9.

[0072] Example 2

[0073] See also Figure 4 This embodiment provides a battery negative electrode material preparation system including a crushing mechanism 100 for crushing raw materials, a drying mechanism 200 connected to the crushing mechanism 100 for drying the crushed raw materials, a raw material bin 300 connected to the drying mechanism 200 for storing the dried raw materials, a granular continuous semi-coke rotary kiln connected to the raw material bin 300, a cooling mechanism 500 connected to the granular continuous semi-coke rotary kiln through a spiral material guide mechanism 400, a detection part, a water ring pump 600, a furnace induced draft fan 700, a natural gas induced draft fan 800 and an exhaust gas treatment mechanism 900. Among them, the crushing mechanism 100, the drying mechanism 200, the raw material bin 300, the spiral material guide mechanism 400, the cooling mechanism 500, the natural gas induced draft fan 800 and the exhaust gas treatment mechanism 900 are conventional structures, and the overall design has not been changed, and will not be repeated here.

[0074] The structure of the granular continuous semi-coke rotary kiln in this embodiment is the same as that of the granular continuous semi-coke rotary kiln in Embodiment 1. For details, please refer to the aforementioned Embodiment 1 and no further details will be given here.

[0075] In detail, the feed buffer bin 40 of the granular continuous semi-coke rotary kiln is connected to the raw material bin 300, and the discharging assembly 50 is connected to the cooling mechanism 500 through the spiral material guide mechanism 400. The natural gas induced draft fan 800 connects the outer furnace 4 with the natural gas source, and is used to introduce natural gas into the outer furnace 4. The furnace induced draft fan 700 connects the outer furnace 4 with the drying mechanism 200, and is used to introduce the high-temperature gas in the outer furnace 4 to the drying mechanism 200 for use.

[0076] The detection part is used to detect the air pressure of the outer furnace 4. Specifically, the detection part is a vacuum gauge. Since the semi-coke does not completely generate pyrolysis gas in the early stage of combustion, in order to prevent the high-temperature flue gas generated by the combustion of natural gas from entering the inner furnace 3, a vacuum gauge is installed in the outer furnace 4 to detect the vacuum degree of the outer furnace 4, thereby preventing the high-temperature flue gas from flowing back to the inner furnace 3 and improving the system reliability.

[0077] The water ring pump 600 connects the outer furnace 4 with the external heat-using equipment A, and starts or stops based on the detection results of the detection component. Therefore, when the pressure of the outer furnace 4 increases, the outer furnace 4 is evacuated to prevent the high-temperature flue gas generated by the combustion of natural gas in the outer furnace 4 from entering the inner furnace 3 through the air flow channel. Due to the characteristics of the water ring pump 600, it can be used normally in harsh environments, and the impurities in the gas extracted from the outer furnace 4 can be taken away by circulating water, so that the generated pyrolysis gas can effectively enter the outer furnace 4, and the pyrolysis gas is burned by the burner 5 of the outer furnace 4, replacing the incinerator combustion treatment in the traditional process, improving the reuse 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, further improving the utilization rate of thermal energy.

[0078] It is worth noting that the battery negative electrode material preparation system is provided with a controller, which is at least connected to the detection element and the water ring pump 600 signal, and the controller can control the start and stop of the water ring pump 600 according to the detection result of the detection element. The controller can use a single chip microcomputer or a logic circuit to realize signal processing and control functions, which is a conventional technology. Of course, the controller can also be connected to other components by signal to realize automatic control of the system, which is a prior art.

[0079] The exhaust gas treatment mechanism 900 is connected to the drying mechanism 200, the external heat-using device A, and the cooling mechanism 500 respectively.

[0080] Due to the application of the above technical solution, the beneficial effects of the present application compared with the prior art are:

[0081] (1) The granular continuous semi-coke rotary kiln of the present application realizes the function of a shaftless feed screw by arranging spiral blades in the inner spiral furnace drum, thereby replacing the feed screw device in the traditional process. This design simplifies the process and reduces costs. The spiral blades extend axially to the feed end and the discharge end, so that the raw materials always move along the spiral groove during the process of entering and discharging from the inner spiral furnace drum, thereby effectively preventing the material from getting stuck. At the same time, the structure of the spiral groove ensures that the raw materials are evenly distributed in the inner furnace chamber, ensuring that the raw materials are evenly heated.

[0082] By setting an air flow channel on the spiral blade, the connection between the inner furnace and the outer furnace is achieved. During the high-temperature operation process, the semi-coke will continue to produce a large amount of pyrolysis gas, and the pressure of the inner furnace will always be higher than the pressure of the outer furnace. This ensures that the hot flue gas from the combustion of natural gas will not enter the inner furnace, and the pyrolysis gas produced in the inner furnace can be discharged into the outer furnace through the air flow channel. This design allows the burner to directly use these pyrolysis gases as energy for combustion, thereby replacing the traditional incinerator. In addition, in traditional technology, the heat generated by the incinerator needs to be transported and reused through pipelines, and there is a certain amount of heat loss in this process. The present application saves the relevant costs of the incinerator by directly burning the recovered pyrolysis gas in the outer furnace, while improving the reuse efficiency of the calorific value, thereby effectively reducing the cost of gas use.

[0083] (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 adopting a granular continuous semi-coke rotary kiln. At the same time, by setting up detection components and water ring pumps, real-time monitoring and adjustment of the gas pressure in the outer furnace can be achieved. When the semi-coke has not yet completely produced pyrolysis gas in the early stage of combustion, the detection component will monitor the pressure change in the outer furnace, and the water ring pump will start to vacuum when the pressure increase is detected. This can effectively prevent the hot flue gas from the combustion of natural gas from entering the inner furnace and ensure that the pyrolysis gas can smoothly enter the outer furnace, which not only further improves the pyrolysis gas utilization efficiency of the system, but also enhances the reliability of the system.

[0084] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

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 includes: An inner spiral furnace drum is rotatably arranged on the support assembly and has an inner furnace chamber. The feeding end of the inner spiral furnace drum is rotatably connected to the feeding buffer bin through a first dynamic sealing mechanism, and the discharging end is rotatably connected to the discharging assembly through a second dynamic sealing mechanism. The inner spiral furnace drum is configured to rotate around an axis under the drive of the rotary drive assembly; An outer furnace barrel is arranged on the supporting assembly, the outer furnace barrel is sleeved on the outer side of the inner spiral furnace barrel and is rotatably connected with the inner spiral furnace barrel, the outer furnace barrel and the inner spiral furnace barrel are spaced to form an outer furnace chamber, and a burner is arranged in the outer furnace chamber; The inner wall of the inner spiral furnace drum protrudes radially toward the inner furnace chamber to form a spiral blade, the spiral blade extends along the axial direction of the inner spiral furnace drum to the feed end and the discharge end, the spiral blade and the inner wall of the inner spiral furnace drum cooperate to form a spiral groove, and the spiral groove is used to guide the raw material to move from the feed end to the discharge end along the spiral trajectory; The spiral blade is provided with an airflow channel, the inner end of the airflow channel penetrates to the outer surface of the spiral blade, and the outer end penetrates to the outer wall of the inner spiral furnace barrel to connect the inner furnace chamber with the outer furnace chamber, the spiral blade is a hollow structure, and the airflow channel is connected to the inner cavity of the spiral blade; The spiral blade comprises two side spiral walls spaced apart in radial direction on the inner wall of the inner spiral furnace drum and a top wall connecting the top ends of the two side spiral walls, the inner end of the airflow channel penetrates through the top wall, and the distance between the two side spiral walls gradually decreases from the inner wall of the inner spiral furnace drum toward the top wall; The air flow channel comprises a plurality of channel units equidistantly arranged along the circumference of the inner spiral furnace drum, and each of the channel units comprises a plurality of through holes equidistantly arranged along the axial direction of the inner spiral furnace drum; In the radial direction of the inner spiral furnace drum, the thickness of the raw material is not greater than the distance from the inner end of the air flow channel to the inner wall of the inner spiral furnace drum.

2. The granular continuous semi-coke rotary kiln according to claim 1, characterized in that: The opening of the outer end of the through hole on the outer wall of the inner spiral furnace drum is a waist-shaped hole, and the length direction of the waist-shaped hole is arranged along the circumference of the inner spiral furnace drum.

3. The granular continuous semi-coke rotary kiln according to claim 1, characterized in that: A plurality of blast units are arranged equidistantly on the outer wall of the inner spiral furnace drum along the circumferential direction, and the blast units are arranged one-to-one on one side of the channel unit in the circumferential direction of the inner spiral furnace drum.

4. The granular continuous semi-coke rotary kiln according to claim 3, characterized in that: Each of the blast units comprises a plurality of blast fins equidistantly arranged along the axial direction of the inner spiral furnace drum, wherein the blast fins protrude radially outward from the outer wall of the inner spiral furnace drum; In the axial direction of the inner spiral furnace drum, the blast fins gradually approach the corresponding channel units from the middle to both ends, so that the blast fins present an arc structure bent toward the corresponding channel units, and from the inner spiral furnace drum to the outer furnace drum, the two ends of the blast fins gradually approach the middle.

5. The granular continuous semi-coke rotary kiln according to claim 4, characterized in that: A notch is formed in the middle of one end of the blast fin away from the inner spiral furnace drum.

6. A battery negative electrode material preparation system, characterized in that: include: A crushing mechanism for crushing raw materials; A drying mechanism, connected to the crushing mechanism, for drying the crushed raw material; 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 5, wherein the feed buffer bin of the granular continuous semi-coke rotary kiln is connected to the raw material bin; A cooling mechanism is connected to a discharging assembly of the granular continuous semi-coke rotary kiln via a spiral material guiding mechanism; A detection member, used for detecting the gas pressure of the outer furnace; A water ring pump, connected to the outer furnace and external heat-using equipment, and started or stopped based on the detection result of the detection element; A furnace induced draft fan, connecting the outer furnace and the drying mechanism; A natural gas induced draft fan connecting the outer furnace with a natural gas source; The tail gas treatment mechanism is connected to the drying mechanism, the external heat-using equipment and the cooling mechanism respectively.

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