Closed airflow negative pressure collision mixing system with nitrogen protection

Abstract

The application discloses a closed airflow negative pressure collision mixing system with nitrogen protection, which comprises a fan, a first raw material bin, a second raw material bin, a material bin, a plurality of mixing devices, a nitrogen buffer tank and a nitrogen gas source which are connected through a pipe network. The mixing device comprises a mixing storage bin, a collision mixing chamber and a spiral stirring assembly. The collision mixing chamber is arranged at the top of the mixing storage bin. The collision mixing chamber comprises two mixing nozzles, a collision mixing chamber shell, a first flow guide plate group, a second flow guide plate group, two reverse nozzles, a flow divider and a support rod. The two mixing nozzles are oppositely and obliquely arranged downward on the collision mixing chamber shell. The first flow guide plate group and the second flow guide plate group are fixed on the inner wall of the collision mixing chamber shell from top to bottom. The two reverse nozzles are obliquely arranged upward on the collision mixing chamber shell. The flow divider is supported by the support rod at the central position of the collision mixing chamber shell. Compared with the prior art, the application can effectively realize the efficient mixing of powder materials and realize the nitrogen atmosphere protection.

Description

Technical Field

[0001] This invention relates to the field of mixing technology, and in particular to a closed-loop negative pressure collision mixing system with nitrogen protection. Background Technology

[0002] Mixing is a crucial step in the production and mixing of cathode materials. The uniformity of the cathode material mixture directly affects the subsequent processing and the performance of the lithium battery product.

[0003] Currently, most cathode material mixing processes are dry mixing methods, using mechanical mixing equipment such as high-speed mixers and double-spiral conical mixers. However, the high-speed collisions between rotating parts and powder during mechanical mixing can lead to uneven mixing and agglomeration of the resulting cathode material. Furthermore, the cathode material powder is easily exposed to air during mixing, causing material deterioration. Additionally, in traditional mixing systems, the feeding and unloading efficiency is low for materials with poor flowability, affecting the overall efficiency of the mixing system.

[0004] In view of this, the inventors of this application, through in-depth research, have obtained a closed-loop airflow negative pressure collision mixing system with nitrogen protection. Summary of the Invention

[0005] The purpose of this invention is to provide a closed-loop negative pressure collision mixing system with nitrogen protection, which can effectively achieve efficient mixing of powder materials.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0007] A closed-loop negative pressure collision mixing system with nitrogen protection includes a fan, a first raw material silo, a second raw material silo, a silo, multiple mixing devices, a nitrogen buffer tank, and a nitrogen source. The fan, the first raw material silo, the second raw material silo, the silo, the multiple mixing devices, the nitrogen buffer tank, and the nitrogen source are connected by a pipeline network. Each mixing device includes a mixing storage silo, a collision mixing chamber, and a spiral stirring assembly. The collision mixing chamber is located at the top of the mixing storage silo and includes two mixing nozzles, a collision mixing chamber shell, a first guide plate assembly, a second guide plate assembly, two counter-current nozzles, a flow divider, and a support rod. The two mixing nozzles are inclined downwards and mounted on the collision mixing chamber shell. The first guide plate assembly and the second guide plate assembly are fixed from top to bottom to the [missing information - likely a specific component or component]. On the inner wall of the collision mixing chamber shell, the first guide plate group includes two first guide plates, and the second guide plate group includes two second guide plates. The first guide plates are arranged opposite to the mixing nozzle, and the second guide plates are arranged parallel to the mixing nozzle. The support rod is located inside the collision mixing chamber shell. The two opposing nozzles are installed obliquely upward on the collision mixing chamber shell. The fluid distribution is supported by the support rod at the center position of the collision mixing chamber shell. The bottom of the collision mixing chamber is provided with a converging collision mixing chamber outlet. The first raw material bin and the second raw material bin are respectively connected to the two mixing nozzles. The backflush nozzle is connected to the nitrogen buffer tank. The spiral stirring assembly is located in the mixing storage bin. The bin is connected to a mixing storage bin of the mixing device.

[0008] In a preferred embodiment, the fluid divider is configured as a single cone or a double cone.

[0009] In a preferred embodiment, the distributor is configured as an oval shape, and the distributor has a plurality of arc-shaped material passage holes extending from its top to its bottom. The plurality of arc-shaped material passage holes are evenly distributed around the circumference. The curvature of the inner sidewall of the arc-shaped material passage hole is smaller than the curvature of the outer sidewall of the distributor. The outer side of the arc-shaped material passage hole is provided with a plurality of mixing holes connecting the distributor.

[0010] In a preferred embodiment, the spiral mixing assembly includes a spiral mixer, a mixing motor, and a mixing drive device. The spiral mixer is located in the middle of the mixing storage silo, the mixing motor is installed on the side of the mixing storage silo, and the mixing drive device connects the mixing motor and the spiral mixer.

[0011] In a preferred embodiment, the mixing storage silo is equipped with a low-level level gauge and a silo vibrator.

[0012] In a preferred embodiment, the mixing silo is equipped with a pneumatic motor and a flow-aiding nozzle.

[0013] In a preferred embodiment, the system further includes a cyclone dust collector and a high-pressure air tank, wherein the cyclone dust collector is connected to the pipeline network and the high-pressure air tank is connected to the cyclone dust collector.

[0014] In a preferred embodiment, a temperature detector and a heater are connected to the pipeline.

[0015] In a preferred embodiment, the second guide vane assembly is provided in multiple sets.

[0016] This invention provides a closed-loop airflow negative pressure collision mixing system with nitrogen protection. It comprises multiple airflow collision mixing devices and associated nitrogen sources, valves, pipelines, and other components. During mixing, the mixing storage silo and pipelines are filled with a nitrogen atmosphere. Raw material powder is drawn from the silo into the mixing storage silo under negative pressure generated by a fan, and the high-speed flowing powder undergoes collision mixing within the mixing chamber. After the first mixing, the positive electrode material powder enters the next mixing chamber for secondary mixing under negative pressure suction. This cyclic mixing process continues until the desired mixing effect is achieved.

[0017] Compared to existing technologies, it has the following beneficial effects:

[0018] 1. The powder feeding, collision and unloading processes in the mixing system all adopt negative pressure pneumatic conveying, which avoids the problems of long mixing time and low mixing efficiency caused by poor powder flowability in traditional mixing technology;

[0019] 2. To address the issue that lithium sources, such as lithium hydroxide, are prone to deterioration when in contact with oxygen during the mixing process of cathode materials, a closed nitrogen atmosphere is introduced for protection during the airflow collision mixing process. This ensures the quality of the cathode materials during the mixing process and reduces the cost of nitrogen usage.

[0020] 3. By adopting airflow circulation collision mixing and using the developed collision mixing chamber, the mixing efficiency of cathode materials is greatly improved, solving the problems of high energy consumption, low mixing efficiency and large metal impurity contamination in traditional mixing processes. Attached Figure Description

[0021] Figure 1 This is a flowchart of a mechanical mixing process in existing technologies.

[0022] Figure 2 This invention relates to a partial process flow diagram of a closed-loop airflow negative pressure collision mixing system with nitrogen protection.

[0023] Figure 3 This invention relates to a process schematic diagram of a closed-loop airflow negative pressure collision mixing system with nitrogen protection.

[0024] Figure 4This invention relates to a schematic diagram of the collision mixing chamber of a closed-loop airflow negative pressure collision mixing system with nitrogen protection (first type of fluid splitting configuration).

[0025] Figure 5 This invention relates to a closed-loop airflow negative pressure collision mixing system with nitrogen protection. The schematic diagram of the collision mixing chamber of the closed-loop airflow negative pressure collision mixing system with nitrogen protection is shown (second type of fluid splitting configuration).

[0026] Figure 6 This is a schematic diagram of the second configuration of the fluid separator in a closed-loop negative pressure collision mixing system with nitrogen protection, which is a present invention.

[0027] Figure 7 This is a schematic diagram of the longitudinal section of the second configuration of the fluid separator in a closed-loop negative pressure collision mixing system with nitrogen protection, which is related to the present invention.

[0028] Figure 8 This invention relates to a schematic diagram of the flow-aiding nozzle of a closed-loop negative pressure collision mixing system with nitrogen protection.

[0029] In the picture

[0030] 101. First raw material bin; 102. Second raw material bin; 103. First return pneumatic ball valve; 104. First loading pneumatic ball valve; 105. Second return pneumatic ball valve; 106. Second loading pneumatic ball valve; 107. Suction pneumatic ball valve; 108. First discharge pneumatic ball valve; 109. Second discharge pneumatic ball valve; 110. Discharge negative pressure pneumatic ball valve; 111. Discharge manual butterfly valve; 112. Bin; 201. Mixing storage bin; 202. Collision mixing chamber; 2021. Mixing nozzle; 2022. Collision mixing chamber shell; 2023. First guide plate; 2024. Second guide plate; 2025. Backflush nozzle; 2026. Flow divider; 20261. Arc-shaped material passage hole; 20262 2027. Mixing orifice; 2028. Support rod; 203. Spiral agitator; 204. Low-level level gauge; 205. Silo vibrator; 206. Pneumatic motor; 207. Flow aid nozzle; 208. First pneumatic butterfly valve; 209. Mixing negative pressure pneumatic ball valve; 210. Air replenishment pneumatic ball valve; 211. Second mixing device; 212. Third mixing device; 301. High-pressure air tank; 302. Pulse angle valve; 303. Cyclone dust collector; 304. Second pneumatic butterfly valve; 401. Nitrogen buffer tank; 402. Pressure detector; 403. Safety valve; 404. Outlet pneumatic ball valve; 405. Nitrogen source; 406. Inlet pneumatic ball valve; 407. Temperature detector; 408. Heater; 409. Fan. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings.

[0032] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0033] A closed-loop negative pressure collision mixing system with nitrogen protection includes a fan, a first raw material silo, a second raw material silo, a silo, multiple mixing devices, a nitrogen buffer tank, and a nitrogen source. The fan, the first raw material silo, the second raw material silo, the silo, the multiple mixing devices, the nitrogen buffer tank, and the nitrogen source are connected by a pipeline network. Each mixing device includes a mixing storage silo, a collision mixing chamber, and a spiral stirring assembly. The collision mixing chamber is located at the top of the mixing storage silo and includes two mixing nozzles, a collision mixing chamber shell, a first guide plate assembly, a second guide plate assembly, two counter-current nozzles, a flow divider, and a support rod. The two mixing nozzles are inclined downwards and mounted on the collision mixing chamber shell. The first guide plate assembly and the second guide plate assembly are fixed from top to bottom to the [missing information - likely a specific component or component]. On the inner wall of the collision mixing chamber shell, the first guide plate group includes two first guide plates, and the second guide plate group includes two second guide plates. The first guide plates are arranged opposite to the mixing nozzle, and the second guide plates are arranged parallel to the mixing nozzle. The support rod is located inside the collision mixing chamber shell. The two opposing nozzles are installed obliquely upward on the collision mixing chamber shell. The fluid distribution is supported by the support rod at the center position of the collision mixing chamber shell. The bottom of the collision mixing chamber is provided with a converging collision mixing chamber outlet. The first raw material bin and the second raw material bin are respectively connected to the two mixing nozzles. The backflush nozzle is connected to the nitrogen buffer tank. The spiral stirring assembly is located in the mixing storage bin. The bin is connected to a mixing storage bin of the mixing device.

[0034] This embodiment presents a closed-loop airflow negative pressure collision mixing system with nitrogen protection. It comprises multiple airflow collision mixing devices and associated nitrogen sources, valves, pipelines, and other components. During mixing, the mixing storage silo and pipelines are filled with a nitrogen atmosphere. The raw material powder is drawn from the silo into the mixing storage silo under negative pressure generated by a fan, and the high-speed flowing powder undergoes collision mixing within the mixing chamber. After the first mixing, the positive electrode material powder enters the next mixing chamber for secondary mixing under negative pressure suction. This cyclic mixing process continues until the desired mixing effect is achieved.

[0035] Compared to existing technologies, it has the following beneficial effects:

[0036] In the mixing system, the powder feeding, collision and unloading processes all adopt negative pressure pneumatic conveying, which avoids the problems of long mixing time and low mixing efficiency caused by poor powder flowability in traditional mixing technology;

[0037] 2. To address the issue that lithium sources, such as lithium hydroxide, are prone to deterioration when in contact with oxygen during the mixing process of cathode materials, a closed nitrogen atmosphere is introduced for protection during the airflow collision mixing process. This ensures the quality of the cathode materials during the mixing process and reduces the cost of nitrogen usage.

[0038] 3. By adopting airflow circulation collision mixing and using the developed collision mixing chamber, the mixing efficiency of cathode materials is greatly improved, solving the problems of high energy consumption, low mixing efficiency and large metal impurity contamination in traditional mixing processes.

[0039] Specifically, the fluid separator is configured as a single cone or a double cone.

[0040] Alternatively, the distributor may be configured as an oval shape, with multiple arc-shaped material passage holes extending from its top to its bottom. The multiple arc-shaped material passage holes are evenly distributed around its circumference, and the curvature of the inner wall of the arc-shaped material passage hole is smaller than the curvature of the outer wall of the distributor. Multiple mixing holes connecting the distributor are provided on the outer side of the arc-shaped material passage holes.

[0041] Specifically, the spiral mixing assembly includes a spiral mixer, a mixing motor, and a mixing drive device. The spiral mixer is located in the middle of the mixing storage silo, the mixing motor is installed on the side of the mixing storage silo, and the mixing drive device connects the mixing motor and the spiral mixer.

[0042] Furthermore, the mixed storage silo is equipped with a low-level level gauge and a silo vibrator.

[0043] Furthermore, the mixing storage bin is equipped with a pneumatic motor and a flow-aiding nozzle.

[0044] The closed-loop negative pressure collision mixing system with nitrogen protection in this embodiment also includes a cyclone dust collector and a high-pressure air tank. The cyclone dust collector is connected to the pipeline network, and the high-pressure air tank is connected to the cyclone dust collector.

[0045] Furthermore, a temperature detector and a heater are connected to the pipeline.

[0046] Furthermore, the second guide vane assembly is provided in multiple sets.

[0047] In summary, the closed-loop negative pressure collision mixing system with nitrogen protection in this embodiment is a closed system with nitrogen protection. During the mixing process, the system is filled with nitrogen and there is no direct gas exchange with air. If nitrogen is lost due to leakage within the system, it is replenished by an external nitrogen source to ensure normal system operation. This protects the quality of the positive electrode material during mixing and reduces the cost of using nitrogen protection.

[0048] The mixing system adopts airflow negative pressure circulation collision mixing technology. A negative pressure environment is created in the mixing storage silo by a fan, and the material in the raw material silo or the previous mixing storage silo is sucked into the mixing chamber for pneumatic circulation collision mixing. This solves the problems of poor efficiency and low mixing uniformity of mechanical mixing.

[0049] The mixing process mainly consists of a preparation stage, a feeding stage, a mixing stage, and a discharging stage, which are carried out sequentially in the mixing equipment.

[0050] During the preparation phase, nitrogen is introduced into the collision mixing storage silo, cyclone dust collector, and other equipment and pipelines through a pre-stored nitrogen buffer tank, filling the system with nitrogen and ensuring good airtightness of the equipment during the mixing process to prevent air from entering the system.

[0051] During the material suction stage, the mixing fan and related pneumatic ball valves are opened sequentially. Under the suction of the fan, a negative pressure environment of -0.02 to -0.05 MPa is generated in the cyclone dust collector and mixing storage silo, drawing the cathode material raw material out of the mixing storage silo. The solid-to-gas ratio is approximately 8-15, and under the action of negative pressure, the material undergoes high-speed collisions at a speed of 12-20 m / s within the mixing storage silo, resulting in the first pneumatic collision mixing. The powder after the collision settles within the mixing storage silo.

[0052] During the mixing stage, the mixing fan creates negative pressure in the next stage mixing unit. The positive electrode material powder, which has been mixed in the previous stage, enters the next stage mixing and storage silo through a pneumatic butterfly valve and pipeline for collision mixing. The mixing cylinder is equipped with a low-level gauge and flow-aiding nozzles. When the material level is low, the low-level gauge alarms and the mixing action is terminated through program control. The flow-aiding nozzles have an arch-breaking function and open periodically to prevent material from accumulating and caking in the mixing and storage silo.

[0053] During the discharge stage, the pneumatic butterfly valve at the bottom of the mixing storage silo is opened, and the mixing fan and discharge valve are opened in sequence, forming a negative pressure in the storage silo, dust collector and corresponding pipelines. The positive electrode material powder enters the storage silo through the pneumatic butterfly valve, and nitrogen is introduced through the flow-aiding air cushion to assist the discharge.

[0054] The entire pneumatic circulation collision mixing system can fulfill all process requirements through a preset control program. Under normal circumstances, no manual intervention is required.

[0055] The collision mixing chamber is the core component of the equipment, consisting of a chamber shell, mixing nozzles, guide vanes, backflush nozzles, and a flow divider. The upper part of the chamber shell is cylindrical, with the outer shell initially expanding and then contracting at the outlet. The ratio of the widest diameter of the mixing chamber to the outlet diameter is 1.4-2. The mixing nozzles are installed at an angle on the upper part of the chamber, with the nozzle outlets pointing downwards at an angle of 50-70° to the chamber axis. The center-to-center distance between the nozzle outlets is 1D-3D, where D is the inner diameter of the nozzle outlet. Guide vanes are installed below the mixing nozzles, and multiple sets are typically provided, usually two or more. The uppermost set of guide vanes faces the mixing nozzles, while the lower sets face the same direction, at an angle of 30-60° to the mixing axis. Several pairs of backflush nozzles are installed below the guide vanes, with their outlets pointing upwards at an angle of 60-80° to the chamber axis, pointing towards the guide vanes. The inlets of the backflush nozzles are connected to a nitrogen buffer tank. The fluid distributor is installed near the outlet of the collision mixing chamber and is mounted on the shell of the collision mixing chamber via a mounting rod. The ratio of the width of the fluid distributor to the outlet diameter is 0.2-0.7.

[0056] The separator can be a single cone or a double cone, designed to prevent cathode material powder from accumulating and clogging at the outlet of the collision mixing chamber. Alternatively, the separator can be shaped like an olive, with multiple arc-shaped feed holes extending from its top to its bottom. These arc-shaped feed holes are evenly distributed around the circumference, and the curvature of the inner wall of each hole is smaller than that of the outer wall of the separator. Multiple mixing holes connecting to the separator are located on the outer side of each arc-shaped feed hole. In this configuration, some of the cathode material powder enters the arc-shaped feed hole during its descent. In the feed hole, part of the material flows through the outer wall of the distributor. Because the curvature of the inner wall of the arc-shaped feed hole is smaller than that of the outer wall of the distributor, the flow velocity and pressure of the positive electrode material powder flowing through the outer wall of the distributor are high, while the flow velocity and pressure of the positive electrode material powder flowing through the arc-shaped feed hole are low. As a result, the positive electrode material powder flowing through the arc-shaped feed hole flows through the mixing hole to the outer wall of the distributor and collides with the positive electrode material powder flowing through the outer wall of the distributor, thus achieving re-mixing. This achieves a better mixing effect while performing the flow separation operation.

[0057] When the cathode material powder enters the collision mixing chamber under negative pressure, it is ejected through the mixing nozzle for the first collision mixing. The collision nozzle is installed at an angle in the collision mixing chamber to ensure that the mixed powder does not accumulate at the top of the nozzle. Part of the mixed cathode material powder flows into the lower mixing chamber under the guidance of the guide plate, increasing the mixing intensity between different powders. During mixing, the backflushing nozzle is opened periodically to spray, causing some of the powder after the first collision mixing to re-enter the impact area below the mixing nozzle for secondary mixing, increasing the mixing uniformity. After mixing, the powder is diverted by a separator and enters the mixing storage bin, reducing the falling velocity of the mixed powder and preventing the re-separation of the cathode material powder and the generation of a large amount of dust.

[0058] A spiral agitator is installed at the center axis of the outlet of the mixing storage silo. Driven by a motor installed on the outer shell of the mixing storage silo, the material powder that has been mixed in the mixing chamber is further mixed under the stirring action of the spiral agitator. The speed is 20-80 rpm, and a lower value should be used to ensure the uniformity of powder mixing and the integrity of particle morphology.

[0059] A rotatable flow-aiding nozzle is installed at the discharge port of the mixing storage silo, and the nozzle is directly connected to a nitrogen gas source. The flow-aiding nozzle is driven by an electric motor or a pneumatic motor, and the nozzle outlet is at an acute angle to the nozzle axis. When the mixing storage silo is unloading, nitrogen gas is sprayed out from the nozzle, and the motor drives the nozzle to rotate, so that the nitrogen gas can fully contact the material powder deposited on the wall surface, increasing the unloading speed and uniformity of the material.

[0060] To further explain the specific structure and working principle of a closed-loop airflow negative pressure collision mixing system with nitrogen protection according to this embodiment, the following description is provided in conjunction with the accompanying drawings:

[0061] Combination Figure 1 , Figure 2 Explanation: In traditional mechanical mixing processes for cathode materials, lithium sources and precursors, prepared by an automated or manual batching system, are fed into mechanical mixing equipment, such as a high-speed mixer, via manual or automated feeding methods, such as pneumatic or screw feeding. After the raw materials enter, the mixer begins a pre-set mixing time, using a stirring shaft or stirring balls to mix the cathode material powder. In a high-speed mixer, the rotation speed is typically 500-700 rpm, and the mixing time is 20-40 minutes. After mixing, the material is discharged through a discharge valve or other means and transported to a silo.

[0062] The process of the nitrogen-protected closed-loop negative pressure collision mixing section of the present invention is as follows: Figure 2As shown. After automatic weighing and batching, the lithium source and precursor are vacuum-fed via negative pressure pumping and enter the first mixing unit for pneumatic collision mixing. After mixing, the material settles in the mixing chamber while a spiral agitator starts stirring and mixing the raw materials. The cathode material powder, having completed this process, is then vacuum-conveyed into the second mixing unit for pneumatic collision mixing and spiral stirring, before returning to the first mixing unit for the same mixing process, ending the mixing stage. The uniformity of the mixed cathode material powder is tested. If the uniformity meets the requirements, it is vacuum-conveyed to the silo; if the uniformity does not meet the requirements, the unloaded cathode material powder is re-entered into the pneumatic mixing equipment under negative pressure pumping for a second mixing. The entire vacuum conveying and mixing process operates under a nitrogen atmosphere. This process has, but is not shown in, [the following text is incomplete and likely refers to a separate process:] Figure 2 The following aspects are reflected in the mixing process: The entire mixing system is a closed system, with no direct airflow exchange with the outside air. Nitrogen lost during the mixing process is replenished from the nitrogen source through a nitrogen buffer tank. The uniformity of mixing can be detected and judged after any mixing step of the mixing device is completed.

[0063] Combination Figure 1 , 2 3. Explanation. The first raw material bin 101 and the second raw material bin 102 are respectively connected to the mixing nozzles 2021 on both sides of the collision mixing chamber 202 via the first feeding pneumatic ball valve 104 and the second feeding pneumatic ball valve 106.

[0064] The main body of the mixing device includes a mixing storage silo 201, a collision mixing chamber 202, a spiral agitator 203, a low-level level gauge 204, a silo vibrator 205, a pneumatic motor 206, a flow-aiding nozzle 207, a first pneumatic butterfly valve 208, a stirring motor, and a stirring drive device. The collision mixing chamber 202 is installed at the top of the mixing storage silo 201. The stirring motor is installed on the outer shell of the mixing storage silo 201 and is connected to and drives the spiral agitator 203 via the stirring drive device. The spiral agitator 203 is installed in the middle of the mixing storage silo 201, and the collision mixing chamber 202, spiral agitator 203, and mixing storage silo 201 are coaxially mounted. The silo vibrator 205, low-level level gauge 204, and flow-aiding nozzle 207 are installed sequentially from top to bottom on the lower wall of the mixing storage silo 201. The pneumatic butterfly valve 208 is installed at the outlet position of the bottom silo 201.

[0065] The mixing nozzle 2021 is obliquely mounted on the collision mixing chamber housing 2022; the first guide plate 2023 and the second guide plate 2024 are fixed on the collision mixing chamber housing 2022 from top to bottom; the backflush nozzle 2025 is installed on the upper part of the contraction section of the collision mixing chamber 202, and the nozzle outlet points to the second guide plate 2024, and the nozzle inlet is connected to the nitrogen buffer tank 401 through a pipe; the flow divider 2026 is installed in front of the outlet of the collision mixing chamber 202 through the support rod 2027. The flow aid nozzle 207 is fixed on the mixing storage silo 201 through the nozzle support block 2072, and the pneumatic motor 206 is connected to the rotating nozzle 2071 and installed outside the mixing storage silo 201.

[0066] The high-pressure air manifold 301 is connected to the cyclone dust collector 303 via a pulse angle valve 302. The cyclone dust collector 303 is connected to the fan 409 and three mixing devices via a suction pneumatic ball valve 107, a mixing negative pressure pneumatic ball valve 209, and a discharge negative pressure pneumatic ball valve 110. The second pneumatic butterfly valve 304 is installed at the lower outlet of the cyclone dust collector 303.

[0067] The first discharge pneumatic ball valve 108 and the second discharge pneumatic ball valve 109 are connected to the third mixing device 212, and together with the second mixing device 211 and its pneumatic ball valve, they are connected to the first pneumatic butterfly valve 208 and the second pneumatic butterfly valve 304. Additionally, the third mixing device 212 is connected to the hopper 112 via a manual butterfly valve 111; the second mixing device 211 is connected to the first feeding pneumatic ball valve 104 and the second feeding pneumatic ball valve 106 via the first return pneumatic ball valve 103 and the second return pneumatic ball valve 105.

[0068] The fan 409, nitrogen buffer tank 401, temperature detector 407, heater 408, gas supply pneumatic ball valve 210, and gas supply nozzle are connected in sequence. The pressure detector 402 and safety valve 403 are installed on the side of the nitrogen buffer tank 401. The nitrogen source 405 is connected to the nitrogen buffer tank 401 through the inlet pneumatic ball valve 406 and the outlet pneumatic ball valve 404.

[0069] During operation, the first feeding pneumatic ball valve 104, the second feeding pneumatic ball valve 106, the mixing negative pressure pneumatic ball valve 209, and the extraction pneumatic ball valve 107 are opened, and the blower 409 starts working, generating negative pressure in the mixing storage silo 201. Under the action of negative pressure, the powder material in the first raw material silo 101 and the second raw material silo 102 enters the collision mixing chamber 202. After the powder passes through the mixing nozzle 2021 and undergoes collision mixing, some of the powder falls onto the first guide plate 2023 and the second guide plate 2024 before falling down. The backflush nozzle 2025 is connected to the nitrogen buffer tank 401 through a pipeline and is opened periodically during the collision mixing process. The falling powder returns to the area above the collision mixing chamber for secondary mixing under the action of the backflush nozzle 2025. The mixed powder enters the lower part of the mixing storage silo 201 through the distributor 2026 for deposition, while the spiral agitator 203 works to assist in mixing. When the material in the mixing storage bin 201 accumulates to a certain height, 208 opens and 209 closes, the corresponding valve in the second mixing device 211 opens, and the blower 409 creates a vacuum environment in the second mixing device 211, allowing the material to enter the second mixing device 211 through 208. At this time, the bin vibrator 205, the pneumatic motor 206 and the flow-aiding nozzle 207 start working to assist in unloading, and the material undergoes a second collision and mixing in the second mixing device 211.

[0070] The separator 2026 can be configured as a single cone or a double cone, its function being to prevent the cathode material powder from accumulating and clogging at the outlet of the collision mixing chamber; alternatively, the separator 2026 can be configured as an oval shape, with multiple arc-shaped feed holes 20261 extending from its top to its bottom. These arc-shaped feed holes 20261 are evenly distributed around their circumference, and the curvature of the inner wall of each arc-shaped feed hole 20261 is smaller than the curvature of the outer wall of the separator 2026. Multiple mixing holes 20262 connecting the separator 2026 are located on the outer side of each arc-shaped feed hole 20261. With this configuration, some of the cathode material powder enters the arc-shaped feed hole during its descent. In the arc-shaped feed hole 20261, part of the material flows through the outer wall of the distributor 2026. Because the curvature of the inner wall of the arc-shaped feed hole 20261 is smaller than that of the outer wall of the distributor 2026, the flow velocity and pressure of the positive electrode material powder flowing through the outer wall of the distributor 2026 are high, while the flow velocity and pressure of the positive electrode material powder flowing through the arc-shaped feed hole 20261 are low. As a result, the positive electrode material powder flowing through the arc-shaped feed hole 20261 flows through the mixing hole 20262 to the outer wall of the distributor 2026, colliding with the positive electrode material powder flowing through the outer wall of the distributor 2026, thus achieving re-mixing. This achieves a better mixing effect while performing the flow separation operation.

[0071] When a certain amount of dust accumulates in the cyclone dust collector 303, the pulse angle valve 302 opens, and the high-pressure gas in the high-pressure air tank 301 cleans the cyclone dust collector 303. The second pneumatic butterfly valve 304 opens, sending the material dust into the second mixing device 211. A pressure detector 402 is installed on the nitrogen buffer tank. When the pressure is too high, the safety pneumatic ball valve 403 is opened to vent the gas. When nitrogen leakage causes losses, nitrogen is replenished from an external nitrogen source 405 through the nitrogen buffer tank 401. The heater 408 heats the nitrogen according to the temperature detected by the temperature detector 407.

[0072] After the material mixing uniformity meets the requirements, the third mixing device 212 generates negative pressure in the same way to suck in the mixed material. After the material accumulates to a certain height, the manual butterfly valve 111 is opened to let the material fall into the hopper 112.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element. Additionally, in this document, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number.

[0074] The above description of the embodiments is provided to facilitate understanding and use of the present invention by those skilled in the art. It is obvious to those skilled in the art that various modifications can be easily made to the embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A closed-loop airflow negative pressure collision mixing system with nitrogen protection, characterized in that, The system includes a blower, a first raw material silo, a second raw material silo, a silo, multiple mixing devices, a nitrogen buffer tank, and a nitrogen source. The blower, first raw material silo, second raw material silo, silo, multiple mixing devices, nitrogen buffer tank, and nitrogen source are connected via a pipeline network. Each mixing device includes a mixing storage silo, a collision mixing chamber, and a spiral stirring assembly. The collision mixing chamber is located at the top of the mixing storage silo and includes two mixing nozzles, a collision mixing chamber shell, a first guide plate assembly, a second guide plate assembly, two opposing nozzles, a flow divider, and a support rod. The two mixing nozzles are inclined downwards and mounted on the collision mixing chamber shell. The first guide plate assembly and the second guide plate assembly are fixed from top to bottom to the inner wall of the collision mixing chamber shell. The first guide plate assembly includes two first guide plates, and the second guide plate assembly includes two second guide plates. The first guide plates are positioned opposite the mixing nozzles. The second guide plate is arranged parallel to the mixing nozzle. The support rod is located inside the collision mixing chamber housing. The two opposing nozzles are installed obliquely upward on the collision mixing chamber housing. The distributor is supported by the support rod at the center of the collision mixing chamber housing. The bottom of the collision mixing chamber has a converging collision mixing chamber outlet. The first raw material silo and the second raw material silo are respectively connected to the two mixing nozzles. The backflush nozzle is connected to the nitrogen buffer tank. The spiral stirring assembly is located in the mixing storage silo. The silo is connected to the mixing storage silo of the mixing device. The distributor is shaped like an olive. The distributor has multiple arc-shaped material passage holes extending from its top to its bottom. The multiple arc-shaped material passage holes are evenly distributed around its circumference. The curvature of the inner sidewall of the arc-shaped material passage hole is smaller than the curvature of the outer sidewall of the distributor. Multiple mixing holes connecting the distributor are located on the outer side of the arc-shaped material passage hole.

2. The closed-loop airflow negative pressure collision mixing system with nitrogen protection according to claim 1, characterized in that, The fluid separator is configured as a single cone or a double cone.

3. The closed-loop negative pressure collision mixing system with nitrogen protection according to claim 1, characterized in that, The spiral mixing assembly includes a spiral mixer, a mixing motor, and a mixing drive device. The spiral mixer is located in the middle of the mixing storage silo, the mixing motor is installed on the side of the mixing storage silo, and the mixing drive device connects the mixing motor and the spiral mixer.

4. The closed-loop negative pressure collision mixing system with nitrogen protection according to claim 1, characterized in that, The mixed storage silo is equipped with a low-level level gauge and a silo vibrator.

5. The closed-loop negative pressure collision mixing system with nitrogen protection according to claim 1, characterized in that, The mixing storage bin is equipped with a pneumatic motor and a flow-aiding nozzle.

6. The closed-loop airflow negative pressure collision mixing system with nitrogen protection according to claim 1, characterized in that, It also includes a cyclone dust collector and a high-pressure air tank, wherein the cyclone dust collector is connected to the pipeline network and the high-pressure air tank is connected to the cyclone dust collector.

7. The closed-loop airflow negative pressure collision mixing system with nitrogen protection according to claim 1, characterized in that, Temperature detectors and heaters are connected to the pipeline network.

8. The closed-loop negative pressure collision mixing system with nitrogen protection according to claim 1, characterized in that, The second guide vane assembly has multiple sets.

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