Pneumatic material conveying device and battery black powder roasting reduction system

Abstract

The utility model relates to material conveying technical field, aims at solving the problem that the existing material conveying equipment is easy to produce dust-containing waste gas and has the hidden danger, harms personnel health and pollutes the environment in the material conveying process. For this purpose, the utility model provides a kind of airflow material conveying equipment and battery black powder roasting reduction system, the airflow material conveying equipment includes material conveying pipeline, mixed bin and negative pressure fan;Negative pressure fan is set to be able to form negative pressure in material conveying pipeline and mixed bin, so that material enters mixed bin via material conveying pipeline, and waste gas and / or dust in mixed bin can be discharged from mixed bin. The utility model can realize the dual function of material conveying and optimization mixed bin environment by setting negative pressure fan, ensure that dust-containing waste gas in mixed bin can be discharged in time, reduce dust concentration, avoid safety hazard, and reduce harm to production personnel, also will not pollute the environment.

Description

Technical Field

[0001] This utility model relates to the field of material conveying technology, specifically to an airflow material conveying device and a battery black powder roasting and reduction system. Background Technology

[0002] Material conveying equipment enables the transport of materials and has a wide range of applications, such as in the chemical and plastics industry, the mining and metallurgical processing industry, the building materials and ceramics industry, the pharmaceutical industry, the grain and food processing industry, and the manufacturing industry. In some application scenarios, material conveying equipment will generate dust during the material transport process. For example, when the material itself is fine powder and its physical characteristics are dry and have good flowability, it is very easy to generate dust.

[0003] Taking the battery black powder roasting and reduction system as an example, it needs to transport materials such as black powder through material conveying equipment. For example, lithium batteries generally need to be transported to the silo through material conveying equipment before roasting to continuously provide reaction raw materials for the roasting equipment. During the material conveying process, dust-containing waste gas will be generated. This dust-containing waste gas has safety hazards. For example, if sparks are generated due to static electricity or friction during the conveying process, and the dust-containing waste gas reaches a certain concentration, there is even a risk of explosion. In addition, if the material conveying equipment itself is not well sealed, it will also endanger the health of production personnel and easily pollute the environment.

[0004] Therefore, there is a need in the art for an airflow material conveying device and a battery black powder roasting and reduction system having the airflow material conveying device to solve the above problems. Utility Model Content

[0005] (a) Purpose of the utility model The purpose of this invention is to provide an airflow material conveying device and a battery black powder roasting and reduction system, which aims to solve the problem that existing material conveying equipment easily generates dusty exhaust gas during the material conveying process, thus posing safety hazards, endangering human health, and polluting the environment.

[0006] (II) Technical Solution To address the aforementioned problems, the first aspect of this utility model provides an airflow material conveying device, comprising a material conveying pipeline, a mixing silo, and a negative pressure fan. Both the material conveying pipeline and the negative pressure fan are connected to the mixing silo. The negative pressure fan is configured to create negative pressure in both the material conveying pipeline and the mixing silo, so that material enters the mixing silo via the material conveying pipeline. The negative pressure fan is also configured to discharge waste gas and / or dust from the mixing silo.

[0007] This setup allows for efficient material transport, utilizing the cross-section of the material conveying pipeline to its fullest extent possible without causing blockages. Simultaneously, during transport, a negative pressure fan creates negative pressure within the pipeline and mixing silo, effectively preventing dust generation from lightweight materials. More importantly, the connection between the negative pressure fan and the mixing silo not only establishes a negative pressure environment within the pipeline and silo for material transport but also directly dissipates any waste gas and / or dust generated within the silo during transport. The negative pressure fan discharges a large amount of gas from the mixing silo, thus achieving the dual functions of material conveying and optimizing the environment within the mixing silo. This ensures that waste gas and / or dust in the mixing silo can be discharged in a timely manner, greatly reducing the concentration of dust-laden waste gas in the material conveying pipeline and the mixing silo, minimizing safety risks and avoiding potential hazards. The centralized discharge of dust-laden waste gas by the negative pressure fan also facilitates the collection and centralized treatment of the dust-laden waste gas. The negative pressure fan keeps the material conveying pipeline and the mixing silo under negative pressure, preventing the gas from overflowing. In other words, it minimizes the risk of dust-laden waste gas overflowing from poorly sealed material conveying equipment or when the sealing effect decreases after prolonged use, thus avoiding harm to production personnel and preventing environmental pollution.

[0008] In some embodiments, a filter element is provided in the mixing silo, and the negative pressure fan is located downstream of the filter element along the airflow direction.

[0009] This configuration allows the filter components to filter most of the dust without affecting the exhaust gas from the negative pressure fan, thus reducing the exhaust pressure of the negative pressure fan. In other words, the filter components play the main role in filtering dust, while the negative pressure fan plays the main role in exhausting waste gas. The two components work together to avoid the fan clogging that can easily occur after prolonged use when dust needs to be discharged by the negative pressure fan. Furthermore, the filter components can block large particles in the dust, which can fall back due to their own weight, facilitating the discharge of the mixing silo.

[0010] In some embodiments, the material conveying pipeline is connected to the mixing silo through the silo inlet, the mixing silo has a silo outlet at the bottom, the negative pressure fan is connected to the mixing silo through the exhaust outlet, the silo inlet and the exhaust outlet are respectively located on both sides of the mixing silo, the exhaust outlet is located above the filter element, and the silo inlet is located below the filter element.

[0011] With this setup, the material outlet is located at the bottom of the mixing silo. After entering the mixing silo under negative pressure, the material falls to the outlet under its own gravity. The exhaust gas continues to flow to the negative pressure fan. The material inlet and exhaust outlet are located on opposite sides of the mixing silo, below and above the filter components, respectively. This allows the negative pressure airflow to flow from one side of the mixing silo to the other. Specifically, the exhaust gas flows from one side of the mixing silo below the filter components, through the filter components, to the other side of the mixing silo, and then into the exhaust outlet above the filter components. The exhaust gas is then discharged through the exhaust outlet by the negative pressure fan. This makes the exhaust gas discharge path smoother within the mixing silo, avoiding a complex airflow environment caused by tortuous exhaust gas discharge, and further promoting effective filtration of the exhaust gas.

[0012] In some embodiments, the mixing silo comprises an upper mixing chamber and a lower mixing chamber that are interconnected vertically. The material inlet and the exhaust outlet are both connected to the upper mixing chamber. The filter element is disposed within the upper mixing chamber, and the material outlet is connected to the lower mixing chamber. The lower parts of both the upper and lower mixing chambers are inverted conical in shape. A silo control switch is provided between the upper and lower mixing chambers.

[0013] This design divides the mixing silo into an upper mixing chamber and a lower mixing chamber, separated by a silo control switch. The upper mixing chamber handles feeding, filtration, and exhaust gas discharge. Material falls to the bottom of the upper mixing chamber by its own weight. The silo control switch controls the flow of material from the upper mixing chamber into the lower mixing chamber, ensuring that the material in the lower mixing chamber is under normal pressure, thus facilitating smooth material transport to subsequent equipment. Furthermore, the lower parts of both the upper and lower mixing chambers are designed with an inverted cone shape, which helps material collect at the bottom of each chamber and facilitates smooth transport to subsequent equipment. This prevents the formation of dead corners at the bottom of each chamber, which would otherwise lead to material accumulation and make cleaning and maintenance difficult.

[0014] In some embodiments, the filtration component includes multi-stage filter elements stacked together.

[0015] With this setup, multiple filter elements are installed in the mixing silo to filter dust before exhaust gas is emitted. Each filter element undertakes a different filtration task, achieving graded interception of dust, improving filtration accuracy and capacity. More importantly, during material conveying, the filter elements near the bottom are directly impacted by dust, which may cause damage and filtration failure. The multi-stage filter element setup can improve the overall structural strength of the filtration components. At the same time, even if the filter elements near the bottom are damaged, the upper filter elements can still meet the dust filtration requirements, ensuring continuous material conveying and reducing the frequency of downtime maintenance.

[0016] In some embodiments, the filtering element is a bag filter, which includes a plurality of filter bags arranged in an array.

[0017] With this setup, the filter components are arranged in an array of multiple filter bags. Multiple filter bags can expand the filtration area and improve the dust filtration effect. At the same time, the array arrangement of filter bags makes it easy to clean the attached dust and also makes it easy to replace the whole bag or part of it, thus improving maintenance efficiency.

[0018] The second aspect of this utility model provides a battery black powder roasting and reduction system, the battery black powder roasting and reduction system including a screw feeder, a rotary kiln, a post-processing device, and the aforementioned airflow material conveying device; the mixing silo is connected to the rotary kiln through the screw feeder, the negative pressure fan is connected to the post-processing device through a first exhaust gas discharge pipe, and the screw feeder is connected to the post-processing device through a second exhaust gas discharge pipe.

[0019] By applying an airflow material conveying system to the battery black powder roasting and reduction system, the airflow material conveying system draws the material into a mixing silo, which is then fed into the rotary kiln for roasting and reduction via a screw feeder. A negative pressure fan discharges the waste gas from the mixing silo through a first waste gas exhaust pipe, while the roasting waste gas from the screw feeder is discharged through a second waste gas exhaust pipe. Both gases then enter the post-processing equipment, combining the two waste gases for treatment, which saves equipment costs and improves waste gas treatment efficiency. By adjusting the feeding equipment to an airflow material conveying system, the battery black powder material enters the mixing silo at high speed. At the same time, the dust containing heavy metal elements such as nickel, cobalt, and manganese in the waste gas of the mixing silo is recovered, preventing dust from escaping and causing raw material loss, improving raw material utilization, and avoiding environmental pollution. In addition, the negative pressure fan in the airflow material conveying system can also prevent the screw feeder from introducing outside air, providing a good reduction reaction environment for the rotary kiln and preventing outside air from affecting the roasting and reduction reaction in the rotary kiln.

[0020] In some embodiments, a swing-type airflow check valve is provided on the second exhaust gas discharge pipe. The swing-type airflow check valve is configured to open when the exhaust gas discharge pressure reaches a set pressure value and close when the exhaust gas discharge pressure does not reach the set pressure value or when backflow occurs.

[0021] With this setup, a swing-type airflow check valve is installed on the second exhaust gas discharge pipe. Utilizing its one-way conduction characteristic, it opens when the exhaust gas discharge pressure reaches the set pressure value and closes when the exhaust gas discharge pressure does not reach the set pressure value or when backflow occurs. This forces the exhaust gas to flow only to the post-processing equipment, preventing exhaust gas backflow or external air backflow caused by system pressure fluctuations. This ensures the stability of the roasting and reduction conditions and product quality, while also improving system safety.

[0022] In some embodiments, the position of the screw feeder near the end of the rotary kiln is a first position, the position of the screw feeder away from the rotary kiln is a second position, the position where the screw feeder is connected to the mixing silo is a third position, and the second exhaust gas discharge pipe is connected between the first position and the third position and does not coincide with the first position or the third position.

[0023] With this setup, the material fed into the screw feeder can be used to preliminarily filter the exhaust gas generated by the rotary kiln during roasting. The dust particles in the exhaust gas are captured by the material and re-enter the rotary kiln with the screw. Taking the lithium battery black powder roasting and reduction system as an example, the dust particles contain black powder, carbon powder, and lithium carbonate and substances containing Me elements (Me elements are selected from at least one of Ni, Co, and Mn elements). Re-entering the rotary kiln not only reduces the waste of raw materials but also increases the yield of reduction products. This structure allows the screw feeder to have both material supply and roasting exhaust gas filtration functions, simplifying the structure and reducing the pressure on the post-processing equipment to treat the exhaust gas.

[0024] In some embodiments, the position of the screw feeder near the end of the rotary kiln is a first position, the position of the screw feeder away from the rotary kiln is a second position, the position where the screw feeder is connected to the mixing silo is a third position, and the second exhaust gas discharge pipe is connected between the second position and the third position and does not coincide with the second position or the third position.

[0025] With this setup, the material fed into the screw feeder can be used more fully to perform preliminary filtration of the exhaust gas generated by the rotary kiln during roasting. The entire filtration process is very long, and the material feeding process can be utilized to the maximum extent, greatly improving the filtration effect of the material on the exhaust gas and further reducing the treatment pressure of the post-treatment equipment on the exhaust gas. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the airflow material conveying equipment provided by this utility model; Figure 2This is a schematic diagram of the overall structure of the battery black powder calcination and reduction system provided by this utility model.

[0027] Figure label: 100. Pneumatic material conveying equipment; 200. Screw feeder; 300. Rotary kiln equipment; 400. Post-processing equipment; 500. First exhaust gas discharge pipe; 600. Second exhaust gas discharge pipe; 1. Material conveying pipelines; 2. Mixing silo; 2a. Silo inlet; 2b. Silo outlet; 2c. Exhaust gas outlet; 21. Upper mixing chamber; 22. Lower mixing chamber; 23. Silo control switch; 3. Negative pressure fan; 4. Filter components. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0029] The accompanying drawings show schematic diagrams of layer structures according to embodiments of the present invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0030] Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0031] In the description of this utility model, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] Based on the background art, existing material conveying equipment is prone to generating dusty exhaust gas during material conveying, which poses safety hazards, harms personnel health, and pollutes the environment. This utility model provides an airflow material conveying device, which aims to avoid safety hazards caused by high concentrations of dust exhaust gas during material conveying, reduce harm to production personnel, and prevent environmental pollution.

[0033] It should be noted that the pneumatic material conveying equipment of this utility model is not limited to specific application scenarios. It can be used in the field of new energy materials and battery recycling, such as in the lithium battery recycling process for conveying crushed battery materials, i.e., black powder; it can also be used in the chemical industry for processing various powdery and granular raw materials, such as in the manufacturing of rubber, plastics and inks for conveying common fillers such as carbon black and silica; it can also be used in the food and pharmaceutical industries for conveying raw materials such as flour, starch, and sugar powder, or for conveying or transferring pharmaceutical powders and excipients; or it can be used in the mineral processing and metallurgical industries for conveying cement raw / clinker powder, and for processing metal powders such as aluminum powder and iron powder.

[0034] It should also be noted that the pneumatic material conveying equipment of this utility model can be used for conveying a single material, conveying different materials, or mixing and conveying different materials during the pneumatic conveying process. Any technical solution that is applicable to the pneumatic material conveying equipment provided by this utility model to improve material conveying capacity and has the function of treating dusty exhaust gas is within the protection scope of this utility model.

[0035] See Figure 1 The airflow material conveying device 100 of this utility model includes a material conveying pipeline 1, a mixing silo 2, and a negative pressure fan 3. Both the material conveying pipeline 1 and the negative pressure fan 3 are connected to the mixing silo 2. The negative pressure fan 3 is configured to create negative pressure in both the material conveying pipeline 1 and the mixing silo 2 so that the material enters the mixing silo 2 through the material conveying pipeline 1. The negative pressure fan 3 is also configured to discharge the waste gas and / or dust in the mixing silo 2.

[0036] The material conveying pipeline 1 provides a directional flow path for powdery and granular materials, enabling the connection and conveying of materials from its inlet to the mixing silo 2. At the same time, the tubular structure facilitates the sealing of the negative pressure environment, preventing air leakage from affecting the conveying efficiency. The mixing silo 2 provides a buffer space for material settling and exhaust gas discharge under negative pressure conditions. The negative pressure fan 3 creates negative pressure in the material conveying pipeline 1 and the mixing silo 2 through the suction action, providing power for material flow. At the same time, the negative pressure fan 3 serves as a power source for exhausting exhaust gas and / or dust, discharging exhaust gas and / or dust out of the silo, realizing the integration of conveying and exhaust gas treatment power. During equipment operation, since the material conveying pipeline 1 is connected to the mixing silo 2, and the negative pressure fan 3 is also connected to the mixing silo 2, an airflow path can be formed. After the negative pressure fan 3 is started, it draws air to create a stable negative pressure environment in the mixing silo 2 and the material conveying pipeline 1. Under the action of negative pressure, the material is drawn into the mixing silo 2 along the material conveying pipeline 1, completing the conveying process. At the same time, the dust-containing exhaust gas generated during material conveying also enters the mixing silo 2. Under the continuous suction of the negative pressure fan 3, the dust-containing exhaust gas is discharged from the mixing silo 2. The entire process does not require additional power equipment to drive the material conveying or separate exhaust gas emission equipment. Through the dual action of the negative pressure fan 3, the separate configuration of exhaust equipment and the matching complex dust removal pipeline are eliminated. The overall structure of the equipment is simplified, saving the equipment's floor space and reducing the operating and maintenance costs. At the same time, since a large amount of dust-containing waste gas can be discharged, the concentration of dust-containing waste gas in the material conveying pipeline 1 and the mixing silo 2 is greatly reduced, minimizing safety risks and avoiding potential safety hazards. The centralized discharge of dust-containing waste gas by the negative pressure fan 3 also facilitates the collection and centralized treatment of dust-containing waste gas by other waste gas treatment equipment. The negative pressure fan 3 keeps the material conveying pipeline 1 and the mixing silo 2 under negative pressure, which also prevents the gas from overflowing. That is, it minimizes the risk of dust-containing waste gas overflowing when the airflow material conveying equipment 100 itself has poor sealing or the sealing effect decreases after long-term use, thus avoiding harm to production personnel and preventing environmental pollution.

[0037] In some preferred embodiments, a filter element 4 is provided inside the mixing silo 2. Along the airflow direction, the negative pressure fan 3 is located downstream of the filter element 4. The filter element 4 is used to intercept dust particles in the airflow, thereby achieving the filtration treatment of the exhaust gas and preventing dust from entering the negative pressure fan 3, thus protecting the negative pressure fan 3. By placing the negative pressure fan 3 downstream of the filter element 4 along the airflow direction, the airflow must be filtered before entering the negative pressure fan 3, ensuring the filtration effect and the safety of the negative pressure fan 3. When the negative pressure fan 3 is running, the airflow in the mixing silo 2 flows from upstream to downstream of the filter element 4. After the material enters the mixing silo 2, some fine dust particles flow upward with the airflow under the action of the negative pressure fan 3. When the airflow passes through the filter element 4, the dust particles are intercepted by the filter element 4. The purified exhaust gas passes through the filter element 4, enters the downstream negative pressure fan 3, and is discharged. By setting the filter element 4, large particles in the dust can be blocked. These large particles can fall back due to their own weight, facilitating the discharge of the mixing silo 2.

[0038] In some possible implementations, the material conveying pipeline 1 is connected to the mixing silo 2 through the silo inlet 2a, the mixing silo 2 is provided with a silo outlet 2b at the bottom, the negative pressure fan 3 is connected to the mixing silo 2 through the exhaust outlet 2c, the silo inlet 2a and the exhaust outlet 2c are respectively located on both sides of the mixing silo 2, the exhaust outlet 2c is located above the filter element 4, and the silo inlet 2a is located below the filter element 4. The material inlet 2a serves as the connection interface between the material conveying pipeline 1 and the mixing silo 2, guiding the material into the mixing silo 2. Its position below the filter element 4 ensures that the material settles preferentially after entering the mixing silo 2, preventing direct impact on the filter element 4 and potential damage. The material outlet 2b is located at the bottom of the mixing silo 2, discharging the material from within. The material falls to the outlet 2b under its own weight, achieving a connection between temporary storage and transfer. The exhaust outlet 2c serves as the connection interface between the negative pressure fan 3 and the mixing silo 2, located above the filter element 4. The exhaust gas outlet 2c and the feed inlet 2a of the mixing silo are located on both sides of the mixing silo 2, respectively, so that the airflow forms a longer flow path in the mixing silo 2. This path flows from one side of the mixing silo 2 to the other side, that is, below the exhaust gas filter component 4. After passing through the filter component 4, the airflow flows to the other side of the mixing silo 2 and enters the exhaust gas outlet 2c above the filter component 4. This prolongs the separation time between the airflow and the material, avoids the complex airflow environment in the mixing silo 2 caused by the tortuous discharge of exhaust gas, optimizes the airflow path, and further promotes the effective filtration and separation efficiency of the filter component 4 for dust in the exhaust gas. Alternatively, besides placing the hopper outlet 2b at the bottom of the mixing hopper 2, the hopper outlet 2b can also be located on the side of the lower part of the mixing hopper 2. This adapts to scenarios where height space is limited. In this case, an inclined plate can be installed inside the mixing hopper 2 at the hopper outlet 2b to guide the material, facilitating its entry into and discharge from the hopper outlet 2b. The exhaust gas outlet 2c can also be located at the top of the mixing hopper 2. It should be noted that those skilled in the art can flexibly set the specific locations of the inlet and outlet within the mixing hopper 2, and the specific location where the negative pressure fan 3 connects to the mixing hopper 2, in practical applications, as long as the negative pressure fan 3 can create negative pressure between the mixing hopper 2 and the material conveying pipeline 1, thereby achieving material conveying and exhaust gas discharge.

[0039] It should be noted that the specific structural form of the mixing silo 2 is not limited here. It can be an integrated silo, that is, after the material enters the mixing silo 2, it falls to the bottom of the mixing silo 2 by its own weight, and then is directly transferred to the subsequent equipment through other conveying devices. In some preferred embodiments, the mixing silo 2 has an upper mixing chamber 21 and a lower mixing chamber 22 that are interconnected. The material inlet and the exhaust outlet 2c are both connected to the upper mixing chamber 21. The filter component 4 is disposed in the upper mixing chamber 21. The upper mixing chamber 21 is used for material receiving and provides space for gas-solid separation and filtration. The material outlet is connected to the lower mixing chamber 22. The lower mixing chamber 22 is used for material temporary storage and buffering and is connected to the silo outlet 2b to avoid conveying fluctuations caused by the material in the upper mixing chamber 21 being directly conveyed to subsequent equipment. The lower part of both the upper mixing chamber 21 and the lower part of the lower mixing chamber 22 are inverted cone-shaped to guide the material to flow to the bottom and avoid material accumulation. A silo control switch 23 is provided between the upper mixing chamber 21 and the lower mixing chamber 22 to control the conveying rate and start / stop of the material from the upper layer to the lower layer, so as to achieve precise control of material conveying.

[0040] The upper mixing chamber 21 receives material from the material conveying pipe 1. Under the action of negative pressure airflow, the material settles in the upper mixing chamber 21, and the exhaust gas is discharged after passing through the filter component 4, completing gas-solid separation. The inverted cone structure at the bottom of the upper mixing chamber 21 guides the material to gather at the bottom of the chamber. When the material accumulates to a certain amount, the hopper control switch 23 is opened, and the material enters the lower mixing chamber 22. The inverted cone structure at the bottom of the lower mixing chamber 22 also guides the material to gather at the discharge port. After being temporarily stored in the lower mixing chamber 22, the material is stably discharged to the subsequent process through the hopper discharge port 2b. The separation of the upper mixing chamber 21 and the lower mixing chamber 22 ensures that the material receiving and discharging do not interfere with each other, avoiding simultaneous feeding and discharging. The material causes airflow turbulence, reducing material dust. At the same time, the temporary storage function of the lower mixing chamber 22 can buffer fluctuations in material conveying. For example, when the material conveying volume of the upper mixing chamber 21 suddenly increases, the lower mixing chamber 22 can temporarily store excess material to avoid overloading subsequent equipment. When the conveying volume of the upper mixing chamber 21 decreases, the lower mixing chamber 22 can continuously supply material to ensure production continuity. In addition, the lower part of the upper mixing chamber 21 and the lower part of the lower mixing chamber 22 are inverted conical structures, which is conducive to the material gathering at the bottom of their respective chambers and can be smoothly conveyed to subsequent equipment, avoiding the formation of structural dead corners at the bottom of each chamber, which would cause material to accumulate in the structural dead corners and be difficult to clean and maintain.

[0041] It should be noted that the specific structural form of the filter element 4 is not limited here. It can be a plate filter, in which the filter medium is made into a flat or corrugated plate module and fixed in the mixing silo 2; or it can be a rigid sintered porous material filter, in which the filter element is made of metal or ceramic powder through a high-temperature sintering process to form a tubular, plate or honeycomb rigid body with uniform micropores. In one possible scenario, the filter element 4 includes a multi-stage filter cartridge stacked together. The stacked filter cartridges achieve gradient purification. After the airflow carrying dust enters the filter element 4, it first passes through the upstream coarse filter cartridge, which intercepts large dust particles. The remaining fine dust particles are carried by the airflow into the downstream fine filter cartridge and are further intercepted. Through the multi-stage filtration, the dust particles in the exhaust gas are fully removed. The purified exhaust gas is discharged by the negative pressure fan 3. The stacked arrangement increases the filtration area of ​​the filter cartridges, improving the filtration effect. In addition, the multi-stage filter cartridge arrangement can improve the overall structural strength of the filter element 4. At the same time, even if the filter cartridge near the upstream side is damaged, the filter cartridge on the downstream side can still meet the dust filtration requirements, ensuring the continuous material conveying and reducing the frequency of downtime maintenance. Furthermore, different filter elements can be selected with different materials and pore sizes. For example, a metal mesh filter element with a larger pore size can be selected on the upstream side, while a ceramic filter element with a smaller pore size can be selected on the downstream side. Filter elements of different levels can be combined according to actual needs. For example, an activated carbon filter element layer can be added to adsorb harmful gases in the exhaust gas at the same time.

[0042] In another possible scenario, the filter element 4 is a bag filter, which includes multiple filter bags arranged in an array. The multiple filter bags are distributed in an array to increase the filtration area and improve the dust interception efficiency. Furthermore, the filter bag material is usually a flexible fiber, such as polytetrafluoroethylene or polyester, which has good filtration performance and toughness, and can also clean dust by backflushing, shaking and other methods.

[0043] Multiple filter bags are arranged in an array inside the mixing hopper 2. The airflow carries dust from the outside of the filter bags to the inside or vice versa. The dust is intercepted by the filter bag fibers and adheres to the surface of the filter bags. The purified exhaust gas is discharged from the inside of the filter bags to the negative pressure fan 3. The array arrangement ensures that the filter bags are evenly distributed and the airflow forms a uniform flow field in the hopper, avoiding filtration dead zones or excessive local filtration pressure caused by local airflow concentration. The flexible structure of the filter bags can be shaken or reversed during maintenance and cleaning to remove the attached dust, achieving rapid cleaning of the filter element.

[0044] On the other hand, this utility model also provides a battery black powder calcination and reduction system, which includes a screw feeder 200, a rotary kiln 300, a post-processing device 400, and the aforementioned pneumatic material conveying device 100; the mixing silo 2 is connected to the rotary kiln 300 through the screw feeder 200, the negative pressure fan 3 is connected to the post-processing device 400 through the first exhaust gas pipe 500, the screw feeder 200 is connected to the post-processing device 400 through the second exhaust gas pipe 600, and the screw feeder 200 connects the mixing silo 2 and the rotary kiln 300 for precise control of the material feeding rate. The material discharged from the mixing silo 2 is uniformly conveyed to the rotary kiln equipment 300 to avoid material accumulation. The rotary kiln equipment 300 is used for the roasting and reduction reaction of battery black powder. The post-treatment equipment 400 is used to treat harmful components and residual dust in the exhaust gas to ensure that the exhaust gas meets the emission standards. The first exhaust gas discharge pipe 500 is connected to the negative pressure fan 3 and the post-treatment equipment 400 to guide the exhaust gas discharged from the mixing silo 2 into the post-treatment equipment 400. The second exhaust gas discharge pipe 600 is connected to the screw feeder 200 and the post-treatment equipment 400 to guide the exhaust gas generated in the rotary kiln equipment 300 into the post-treatment equipment 400 to achieve centralized treatment of exhaust gas.

[0045] During system operation, the pneumatic material conveying device 100 transports materials to the mixing silo 2. The materials can then enter the rotary kiln 300 at a uniform speed via the screw feeder 200 for calcination and reduction reaction. Waste gas from the mixing silo 2 is extracted by the negative pressure fan 3 and enters the post-treatment device 400 through the first waste gas discharge pipe 500. The rotary kiln 300 generates calcination waste gas during the calcination and reduction process, which is also introduced into the post-treatment device 400 through the second waste gas discharge pipe 600. All waste gas is purified by the post-treatment device 400 and discharged in compliance with standards. Combining the two waste gas streams reduces the equipment footprint, saves equipment costs, and simultaneously improves efficiency. High waste gas treatment efficiency: Through the airflow material conveying equipment 100, the material can enter the mixing silo 2 quickly, conveniently and naturally. At the same time, the dust containing heavy metal elements such as nickel, cobalt and manganese in the waste gas in the mixing silo 2 can be recovered, avoiding dust emission and loss of raw materials, improving the utilization rate of raw materials, and avoiding environmental pollution. In addition, the negative pressure fan 3 keeps the mixing silo 2 in a negative pressure environment, which can prevent the screw feeder 200 from introducing outside air from the mixing silo 2, providing a good reduction reaction environment for the rotary kiln equipment 300, and preventing air from entering the rotary kiln equipment 300 and affecting the roasting and reduction reaction.

[0046] In some possible implementations, a swing-type airflow check valve is installed on the second exhaust gas discharge pipe 600. This swing-type airflow check valve is configured to open when the exhaust gas discharge pressure reaches a set pressure value and close when the exhaust gas discharge pressure does not reach the set pressure value or when backflow occurs. The swing-type airflow check valve mainly consists of a trunnion and a valve disc. When exhaust gas is discharged, the valve disc opens under pressure; when the exhaust gas discharge pressure decreases or backflow occurs, the valve disc closes under gravity. The swing-type airflow check valve effectively prevents external air from flowing back into the rotary kiln equipment 300 and affecting the roasting effect, thus enhancing the sealing effect. Utilizing the unidirectional conduction characteristic of the swing-type airflow check valve, it opens when the exhaust gas discharge pressure reaches the set pressure value and closes when the exhaust gas discharge pressure does not reach the set pressure value or when backflow occurs, forcing the exhaust gas to flow only to subsequent processing equipment, ensuring the stability of roasting and reduction conditions and product quality, while also improving system safety.

[0047] In this utility model, the position of the end of the screw feeder 200 near the rotary kiln equipment 300 is the first position, the position of the end of the screw feeder 200 away from the rotary kiln equipment 300 is the second position, and the position where the screw feeder 200 is connected to the mixing silo 2 is the third position. Those skilled in the art can flexibly set the second exhaust pipe 600 and the connection position between the mixing silo 2 and the screw feeder 300 in practical applications.

[0048] In some preferred embodiments, the second exhaust gas discharge pipe 600 is connected between the first position and the third position but does not coincide with either position. That is, material enters the screw feeder 200 from the inlet, flows through the exhaust gas inlet of the second exhaust gas discharge pipe 600, and is then conveyed to the rotary kiln 300. The exhaust gas inlet of the second exhaust gas discharge pipe 600 is located at the end of the screw feeder 200 closer to the rotary kiln 300, but does not coincide with this end. In other words, there is still a distance between the exhaust gas inlet and the discharge end of the screw feeder 200. At this time, the exhaust gas generated by the calcination in the rotary kiln 300 flows counter-currently from the rotary kiln 300 through the screw feeder 200 into the second exhaust gas discharge pipe 600, causing the exhaust gas in the screw feeder 200 located at the second exhaust gas discharge pipe to flow into the second exhaust gas discharge pipe 600. The structure between the exhaust gas inlet of the discharge pipe 600 and the feed inlet of the rotary kiln equipment 300 serves as both a feed and exhaust gas filtration function. Dust particles in the exhaust gas are captured by the material and re-enter the rotary kiln equipment 300 as the screw is propelled. At the same time, the second exhaust gas discharge pipe 600 is close to the feed inlet of the rotary kiln equipment 300, which increases the distance between the feed inlet of the screw feeder 200 and the exhaust gas inlet of the second exhaust gas discharge pipe 600. When the material enters the screw feeder 200 from the feed inlet, it ensures that the material can pass smoothly through the location of the exhaust gas inlet of the second exhaust gas discharge pipe 600. At the same time, it can effectively block oxygen that may be present in the mixing bin 2 from entering the rotary kiln equipment 300 through the screw feeder 200, ensuring the reduction environment in the rotary kiln equipment 300 and improving the quality and efficiency of black powder reduction.

[0049] In some possible implementations, the second exhaust gas duct 600 is connected between the second and third positions but does not overlap with either position. This allows the exhaust gas generated by the rotary kiln 300 to flow through the entire material feeding stroke of the screw feeder 200 when discharged through the second exhaust gas duct 600. This maximizes the filtration effect by fully utilizing the material to capture dust particles in the exhaust gas. The exhaust gas inlet of the second exhaust gas duct 600 is located near the end of the screw feeder 200, away from the rotary kiln 300, and does not overlap with that end. In other words, the exhaust gas inlet is still some distance from the end of the screw feeder 200 away from the rotary kiln 300. Because the filtration effect of the material in the screw feeder 200 is utilized more fully, the amount of dust entering the post-processing equipment 400 can be further reduced, further alleviating the pressure on the post-processing equipment 400 in handling the exhaust gas.

[0050] It should be noted that the specific structure of the after-treatment equipment 400 is not limited here. In some embodiments, the after-treatment equipment 400 includes a gas combustion assembly, a cooling tower assembly, a dust collector assembly, and a spray tower assembly connected in sequence. The second exhaust gas emission pipe 600 is connected to the gas combustion assembly, and the outlet of the first exhaust gas emission pipe 500 is connected between the cooling tower assembly and the dust collector assembly. The function of the gas combustion assembly is to remove VOCs (volatile organic compounds), CO, and other flammable substances from the exhaust gas through high-temperature combustion, and to decompose dioxins in the exhaust gas. The function of the cooling tower assembly is to rapidly cool the exhaust gas delivered from the gas combustion assembly, preventing the re-synthesis of dioxins and achieving deep removal of dioxins from the exhaust gas. The function of the dust collector assembly is to remove fine particles from the exhaust gas, and the function of the spray tower assembly is to deeply remove dust from the exhaust gas so that it ultimately meets emission standards. The specific structure of each component in the after-treatment equipment 400 is not limited here, as long as it can achieve the above functions.

[0051] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A pneumatic material conveying device, characterized in that, The airflow material conveying equipment includes a material conveying pipeline, a mixing silo, and a negative pressure fan, wherein the material conveying pipeline and the negative pressure fan are both connected to the mixing silo; The negative pressure fan is configured to create negative pressure in both the material conveying pipeline and the mixing silo, so that the material enters the mixing silo through the material conveying pipeline. The negative pressure fan is also configured to discharge the waste gas and / or dust from the mixing silo.

2. The pneumatic material conveying device according to claim 1, characterized in that, The mixing silo is equipped with a filter component, and the negative pressure fan is located downstream of the filter component along the airflow direction.

3. The pneumatic material conveying device according to claim 2, characterized in that, The material conveying pipeline is connected to the mixing silo through the silo inlet. The mixing silo has a silo outlet at its bottom. The negative pressure fan is connected to the mixing silo through the exhaust outlet. The silo inlet and the exhaust outlet are located on opposite sides of the mixing silo. The exhaust outlet is located above the filter element, and the silo inlet is located below the filter element.

4. The pneumatic material conveying device according to claim 3, characterized in that, The mixing silo has an upper mixing chamber and a lower mixing chamber that are interconnected. The material inlet and the exhaust outlet are both connected to the upper mixing chamber. The filter element is located in the upper mixing chamber, and the material outlet is connected to the lower mixing chamber. The lower part of both the upper mixing chamber and the lower part of the lower mixing chamber are inverted conical in shape, and a hopper control switch is provided between the upper mixing chamber and the lower mixing chamber.

5. The pneumatic material conveying device according to claim 2, characterized in that, The filtration component includes multi-stage filter elements stacked together.

6. The pneumatic material conveying device according to claim 2, characterized in that, The filtering component is a bag filter, which includes multiple filter bags arranged in an array.

7. A battery black powder calcination and reduction system, characterized in that, The battery black powder roasting and reduction system includes a screw feeder, a rotary kiln, a post-processing device, and an airflow material conveying device as described in any one of claims 1 to 6. The mixing silo is connected to the rotary kiln via a screw feeder, the negative pressure fan is connected to the post-processing equipment via a first exhaust gas pipe, and the screw feeder is connected to the post-processing equipment via a second exhaust gas pipe.

8. The battery black powder calcination and reduction system according to claim 7, characterized in that, The second exhaust gas discharge pipe is equipped with a swing-type airflow check valve, which is configured to open when the exhaust gas discharge pressure reaches a set pressure value and close when the exhaust gas discharge pressure does not reach the set pressure value or when backflow occurs.

9. The battery black powder calcination and reduction system according to claim 7, characterized in that, The first position is the end of the screw feeder closest to the rotary kiln equipment, the second position is the end of the screw feeder furthest from the rotary kiln equipment, and the third position is the connection point between the screw feeder and the mixing silo. The second exhaust gas pipe is connected between the first position and the third position and does not coincide with the first position or the third position.

10. The battery black powder calcination and reduction system according to claim 7, characterized in that, The first position is the end of the screw feeder closest to the rotary kiln equipment, the second position is the end of the screw feeder furthest from the rotary kiln equipment, the third position is the connection point of the screw feeder to the mixing silo, and the second exhaust gas discharge pipe is connected between the second position and the third position and does not coincide with the second position or the third position.

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