A closed loop lapping and sorting system

Abstract

The present application relates to a kind of closed loop grinding sorting systems, belong to powder processing equipment technical field, the closed loop grinding sorting system includes the air path pipe being equipped with venturi, air path power unit, sorting unit, is equipped with fine material outlet and coarse material outlet, air path power unit is communicated with fine material outlet;Grinding unit, is equipped with feed inlet and discharge port, feed inlet is communicated with coarse material outlet;Return material pipe, one end is communicated with discharge port and the other end is communicated with the throat pipe of venturi, so set, utilize the gas flow kinetic energy of air path power unit cooperate with the negative pressure suction force of venturi to realize the function of driving material and automatic return material simultaneously, need not be additionally configured power equipment drive for return material, reduce energy consumption, improve efficiency, whole-process closed loop is continuously completed on-line sorting and circulating grinding, ensure that only qualified fine particulate material can be as finished product discharge, unqualified coarse particulate material returns system and carries out circulating grinding and sorting, to obtain narrow, high uniformity product of granularity distribution.

Description

Technical Field

[0001] This invention belongs to the technical field of powder processing equipment, and specifically relates to a closed-loop grinding and sorting system. Background Technology

[0002] The preparation of ultrafine powders is a key technology in new materials, pharmaceuticals, and other fields. Traditional powder processing technologies mostly adopt an open-loop model, where materials are ground and then transported to external screening equipment for sorting, with unqualified coarse materials returning to the grinding equipment for further processing. This model suffers from drawbacks such as discontinuous processes, the need to transfer materials between different devices, high system energy consumption, and difficulty in achieving continuous production. While connecting the grinding and classification processes into a closed-loop system can solve the above problems, the return process usually relies on gravity or additional mechanical conveying devices, such as screw conveyors and bucket elevators, to return coarse materials. This not only increases the overall complexity of the system structure, potential points of failure, and cost, but also introduces additional energy consumption.

[0003] Therefore, a closed-loop grinding and sorting system with a simpler structure, more reliable operation, and lower energy consumption is urgently needed. Summary of the Invention

[0004] This invention provides a closed-loop grinding and sorting system to solve the technical problems of complex system structure, high energy consumption, many failure points and high maintenance costs caused by the reliance on mechanical conveying devices in the coarse material return process in the prior art.

[0005] This invention is achieved through the following technical solution: a closed-loop grinding and sorting system, comprising... An air passage is used for inputting materials, and a venturi tube is provided on the air passage; A pneumatic power unit is used to drive the directional flow of air in the pneumatic pipe to transport materials. The sorting unit is provided with a fine material outlet for separating and discharging qualified fine particulate material and a coarse material outlet for separating and discharging coarse particulate material, and the pneumatic power unit is connected to the fine material outlet. A grinding unit, wherein the grinding unit is provided with a feed inlet and a discharge outlet, and the feed inlet is connected to the coarse material outlet; The return pipe has one end connected to the outlet and the other end connected to the throat of the venturi tube.

[0006] To better realize the present invention, further optimizations are made to the above structure. The sorting unit is a centrifugal classifier, a cyclone classifier, or a turbine classifier. The coarse material outlet is located at the bottom of the sorting unit, and the fine material outlet is located at the top of the sorting unit.

[0007] To better realize the present invention, further optimizations are made to the above structure. The grinding unit is a vertical grinding mill, a dry horizontal sand mill, a drum ball mill, or a vibratory mill. The feed inlet is located at the top of the grinding unit, and the discharge outlet is located at the bottom of the grinding unit.

[0008] To better realize the present invention, the above structure is further optimized, and the air path power unit is an induced draft fan.

[0009] To better realize the present invention, the above structure is further optimized by including a material collector, which is disposed between the pneumatic power unit and the sorting unit. The bottom of the material collector is provided with a discharge port, and the two sides of the material collector are provided with an air inlet and an air outlet. The air inlet is connected to the fine material outlet, and the air outlet is connected to the pneumatic power unit.

[0010] To better realize the present invention, the above structure is further optimized by including a receiving box, wherein the inlet of the receiving box is provided with a receiving hopper, and the receiving hopper is connected to the discharge port.

[0011] To better realize the present invention, the above structure is further optimized by providing a discharge valve on the receiving hopper.

[0012] To better realize the present invention, the above structure is further optimized by including a feeder for conveying materials to the air passage pipe. The feeder's inlet end is connected to a raw material bin, and the feeder's outlet end is provided with a feed pipe, which is connected to the air passage pipe or a venturi pipe.

[0013] A closed-loop grinding and sorting method, employing a closed-loop grinding and sorting system, including... Step 1: Input the material into the air passage pipe, and establish a directional airflow in the air passage pipe through the air passage power unit, which serves as a carrier for transporting the material; Step 2: The material is transported to the sorting unit by directional airflow for sorting, so that the material is sorted into qualified fine particles and unqualified coarse particles. Step 3: Discharge the qualified fine particles from the fine material outlet, and discharge the unqualified coarse particles from the coarse material outlet to the grinding unit for grinding; Step 4: Using the negative pressure generated by the Venturi tube, the material processed by the grinding unit is drawn into the air passage through the return pipe, so that the material returns to step 2 for further sorting.

[0014] Compared with the prior art, the present invention has the following advantages: The closed-loop grinding and sorting system provided by this invention includes an air passage pipe for inputting materials, with a Venturi tube installed on the air passage pipe; an air power unit for driving the directional flow of air within the air passage pipe to transport materials; a sorting unit with a fine material outlet for separating and discharging qualified fine particles and a coarse material outlet for separating and discharging coarse particles, the air power unit being connected to the fine material outlet; a grinding unit with an inlet and an outlet, the inlet being connected to the coarse material outlet; and a return pipe, one end of which is connected to the outlet and the other end to the throat of the Venturi tube. This configuration utilizes the kinetic energy of the airflow from the air power unit in conjunction with the negative pressure suction of the Venturi tube to simultaneously drive the materials and automatically return them. No additional power equipment is needed for the return process, reducing energy consumption and improving efficiency. The entire closed-loop process continuously completes online sorting and cyclic grinding, ensuring that only qualified fine particles are discharged as finished products, while unqualified coarse particles return to the system for cyclic grinding and sorting, thereby obtaining products with narrow particle size distribution and high uniformity. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the closed-loop grinding and sorting system in this invention; Figure 2 This is a schematic diagram of the closed-loop grinding and sorting method in this invention.

[0017] In the picture: 1-Air passage pipe; 2-Air passage power unit; 3-Sorting unit; 4-Grinding unit; 5-Return pipe; 6-Venturi tube; 7-Fine material outlet; 8-Coarse material outlet; 9-Inlet; 10-Outlet; 11-Collector; 12-Discharge port; 13-Air inlet; 14-Air outlet; 15-Receiving box; 16-Feeder; 17-Raw material bin; 18-Feeding pipe. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] Example 1: In this embodiment, a closed-loop grinding and sorting system, such as Figure 1 As shown, the system includes an air passage 1 for inputting materials, with a Venturi tube 6 on the air passage 1; an air power unit 2 for driving the directional flow of air within the air passage 1 to transport materials; a sorting unit 3, which has a fine material outlet 7 for separating and discharging qualified fine particles and a coarse material outlet 8 for separating and discharging coarse particles, with the air power unit 2 connected to the fine material outlet 7; a grinding unit 4, which has an inlet 9 and an outlet 10, with the inlet 9 connected to the coarse material outlet 8; and a return pipe 5, one end of which is connected to the outlet 10 and the other end is connected to the throat of the Venturi tube 6, for returning unqualified coarse particles back to the air passage 1 for re-sorting and re-grinding.

[0022] This configuration utilizes the pneumatic kinetic energy of the aforementioned pneumatic power unit 2 in conjunction with the negative pressure suction of the aforementioned venturi tube 6 to simultaneously achieve the functions of driving materials and automatic material return. There is no need to configure additional power equipment for material return, which reduces energy consumption and improves efficiency. The entire process is a closed loop that continuously completes online sorting and circulating grinding, ensuring that only qualified fine particles can be discharged as finished products, while unqualified coarse particles return to the system for circulating grinding and sorting, thereby obtaining products with narrow particle size distribution and high uniformity.

[0023] In this embodiment, as Figure 1As shown, the air passage pipe 1, sorting unit 3, grinding unit 4, and return pipe 5 together form a closed-loop circulation path. Driven by the air passage power unit 2, qualified fine particles are discharged from the closed-loop circulation path. Under the negative pressure drive of the venturi tube 6, unqualified coarse particles are circulated within the closed-loop circulation path for re-sorting and re-grinding. No additional mechanical conveying equipment is required, simplifying the mechanical structure and reducing energy consumption. The air passage power unit 2 is an induced draft fan, located at the end of the system. It is connected to the fine material outlet 7 of the sorting unit 3 through a pipeline, continuously drawing air to direct the airflow within the closed-loop circulation path, thereby conveying the material in the air passage pipe 1 to the sorting unit 3.

[0024] In this embodiment, the Venturi tube 6 is a pipe designed based on Bernoulli's principle of fluid mechanics, including a contraction section, a throat, and a diffusion section. A side opening is provided on one side of the throat to communicate with the return pipe 5. When the airflow driven by the pneumatic power unit 2 passes through the Venturi tube 6, the flow velocity reaches its maximum in the throat with the smallest cross-sectional area, thereby forming a significant negative pressure area at the side opening, which is the power source for the automatic return of unqualified coarse particles through the return pipe 5.

[0025] In this embodiment, the sorting unit 3 is a centrifugal classifier, a cyclone classifier, or a turbine classifier. The coarse material outlet 8 is located at the bottom of the sorting unit 3, and the fine material outlet 7 is located at the top of the sorting unit 3. The sorting unit 3 is used to separate materials according to particle size. In one embodiment, the sorting unit 3 is preferably a centrifugal classifier, which is equipped with a high-speed rotating impeller. After the material particles enter the classification zone with the airflow, they are subjected to centrifugal force and air drag. Coarse particles have high inertia and are thrown against the inner wall and discharged from the coarse material outlet 8 at the bottom. Fine particles have low inertia and pass through the impeller gap with the airflow and are discharged from the fine material outlet 7 at the top. In another embodiment, the sorting unit 3 is preferably a cyclone classifier. The material enters the cyclone with the airflow. After the cyclone classifier is activated, a rotating flow field is formed. Coarse particles are thrown against the wall due to their greater inertial force and fall down the wall to the coarse material outlet 8 at the bottom. Fine particles, on the other hand, move upward with the rotating airflow and are discharged from the fine material outlet 7 at the top. By adjusting the airflow and velocity of the main air path entering the cyclone classifier, the cutting point can be effectively changed, thereby controlling the final particle size of the product. In addition, the sorting unit 3 can also be a turbine classifier. After the material enters, the high-speed rotating turbine impeller generates a strong shear airflow, forming a classifying vortex field. Through the "screening effect" of the impeller blade gap, fine particles pass through the blade gap and are discharged from the fine material outlet 7 at the top with the airflow. Coarse particles are impacted by the blades and fall to the coarse material outlet 8 at the bottom for discharge.

[0026] In this embodiment, the grinding unit 4 is a vertical stirred mill, a dry sand mill, a drum ball mill, or a vibratory mill. The feed inlet 9 is located at the top of the grinding unit 4, and the discharge outlet 10 is located at the bottom of the grinding unit 4. Unqualified coarse particles are sorted out and then enter the grinding unit 4. After grinding, they are discharged from the discharge outlet 10 and enter the return pipe 5. By controlling the size of the discharge outlet 10, it is ensured that only materials within a certain particle size range can pass through the discharge outlet 10, guaranteeing that all coarse particles receive sufficient grinding processing within the grinding unit 4. In one embodiment, the grinding unit 4 is a vertical stirred mill, filled with high-hardness, high-density grinding media, such as zirconia beads or ceramic balls, and ground by an internal stirring arm. The high-speed rotation of the grinding media drives violent, irregular motion, effectively pulverizing coarse particles under the intense impact, shearing, compression, and grinding action of these moving media. In one embodiment, the grinding unit 4 is a vibratory mill, which drives the grinding media and materials inside the cylinder to generate relative motion through high-frequency vibration to achieve efficient grinding, suitable for different production conditions and factory layouts. In another embodiment, the grinding unit 4 is a drum ball mill, which drives the internal steel or ceramic balls to impact and grind the materials through the rotation of the cylinder, suitable for large-scale, high-intensity grinding tasks. In yet another embodiment, the grinding unit 4 is a dry sand mill, which utilizes the high-speed moving grinding media to collide and shear the materials, achieving ultrafine pulverization of the materials in a dry airflow environment.

[0027] In this embodiment, the coarse particles discharged from the coarse material outlet 8 of the sorting unit 3 enter the grinding unit 4 for efficient grinding. The ground material is then discharged from the discharge outlet 10 and immediately drawn back into the air passage pipe 1 by the negative pressure generated by the venturi tube 6 through the return pipe 5. Thus, it re-enters the sorting unit 3 for further sorting with the airflow. Qualified fine particles are discharged from the fine material outlet 7 with the airflow, while unqualified coarse particles re-enter the grinding unit 4 for further grinding, thereby forming a closed-loop circulation system that does not require additional mechanical power. Depending on the properties of the material to be processed, the particle size of the target product, investment costs, maintenance requirements, and other factors, different types and specifications of equipment suitable for the sorting unit 3 and grinding unit 4 can be flexibly selected to achieve the same technical effect, making it widely applicable.

[0028] In this embodiment, a collector 11 is also included. The collector 11 is disposed between the pneumatic power unit 2 and the sorting unit 3. The bottom of the collector 11 is provided with a discharge port 12. The two sides of the collector 11 are provided with an air inlet 13 and an air outlet 14. The air inlet 13 is connected to the fine material outlet 7, and the air outlet 14 is connected to the pneumatic power unit 2. The qualified fine particles separated by the sorting unit 3 enter the collector 11 along with the airflow through the fine material outlet 7 and are collected. The collector 11 is preferably a bag collector 11. The airflow passes through the filter bag and is discharged through the air outlet 14, while the fine particles are intercepted by the filter bag and retained in the collector 11, thereby completing the gas-solid separation. The air filtered by the collector 11 is finally extracted by the induced draft fan.

[0029] As an optimization, a receiving box 15 is also included. The inlet of the receiving box 15 is provided with a receiving hopper, which is connected to the discharge port 12. The receiving hopper is provided with a discharge valve. The receiving box 15 is used to collect and store finished products, and the discharge valve is used to close the discharge port 12 during system operation.

[0030] It is worth noting that the mechanical connections between the components in the above-mentioned closed-loop grinding and sorting system are all made using flange sealing connections, thereby ensuring the normal operation of the system and ensuring that the airflow generated by the above-mentioned pneumatic power unit 2 has sufficient kinetic energy to complete the material conveying and circulation within the system. The above-mentioned pneumatic power unit 2 draws air from the inside of the system, creating a low pressure inside the system. The negative pressure area formed at the throat of the venturi tube 6 causes the air inside the system to form a directional circulation. That is, the main airflow, under the suction of the induced draft fan, flows through the above-mentioned pneumatic pipe 1 in sequence through the sorting unit 3 and the collector 11, and is finally discharged by the above-mentioned induced draft fan. The circulating airflow, under the negative pressure of the above-mentioned venturi tube 6, flows through the return pipe 5 in sequence through the pneumatic pipe 1, the sorting unit 3, and the grinding unit 4 before returning to the return pipe 5.

[0031] In this embodiment, as Figure 1 As shown, it also includes a feeder 16 for conveying materials to the air passage pipe 1, preferably a screw feeder 16. The feed end of the feeder 16 is connected to a raw material bin 17, and the discharge end of the feeder 16 is provided with a feed pipe 18. The feed pipe 18 is bypassed to the air passage pipe 1 or the venturi pipe 6. The feed pipe 18 is bypassed at the throat of the venturi pipe 6. The feed pipe 18 and the return pipe 5 are respectively bypassed on the upper and lower sides of the throat. The feed pipe 18 can also be bypassed in the diffuser section of the venturi pipe 6 and is axially offset from the return pipe 5.

[0032] The aforementioned closed-loop grinding and sorting system realizes continuous production through the Internet of Things. It enriches the sorting unit 3 from a single material separator to a material particle size judge in the cyclic process. Together with the grinding unit 4 and the venturi tube 6, it forms a closed-loop system with real-time feedback and adjustment functions. No additional power equipment is required to drive it, eliminating the energy consumption and time loss of material transfer and equipment start-up and shutdown. Since coarse particles are cyclically ground and sorted, it ensures that every particle must meet the requirements before it can be discharged, thereby achieving ultra-high product uniformity.

[0033] The above-mentioned closed-loop grinding and sorting system includes the following steps when in use. Step 1: Input the material into the air passage pipe 1, and establish a directional airflow in the air passage pipe 1 through the air passage power unit 2, which is used as a carrier for conveying the material; Step 2: The material is transported to the sorting unit 3 by directional airflow for sorting, so that the material is sorted into qualified fine particles and unqualified coarse particles. Step 3: The qualified fine particles are discharged from the fine material outlet 7, and the unqualified coarse particles are discharged from the coarse material outlet 8 to the grinding unit 4 for grinding. Step 4: Using the negative pressure generated by the Venturi tube 6, the material processed by the grinding unit 4 is sucked into the air passage pipe 1 through the return pipe 5, so that the material is returned to step 2 for further sorting.

[0034] This method enables the continuous and automatic cycle of material sorting, grinding, negative pressure return, and sorting. It ensures that only fine particles that meet the preset particle size standard can leave the system as finished products, while any unqualified coarse particles are automatically sent back to sorting unit 3 and grinding unit 4 for reprocessing. The closed-loop design guarantees that the final product has an extremely narrow particle size distribution and high uniformity. Compared with traditional processes, the total power and operating energy consumption of the system are significantly reduced due to the elimination of the independent mechanical return device and its drive motor. The continuous operation of the entire process also greatly improves production efficiency.

[0035] Taking the processing of silica powder to achieve a final product particle size of less than 1μm as an example, at the initial stage of system operation, the operator starts the induced draft fan to establish a stable high-speed negative pressure airflow field throughout the system. Subsequently, the silica is fed into the air passage pipe 1 at a preset rate through the feeder 16. After entering, the material is immediately dispersed and carried by the high-speed airflow, forming a material-containing gas. This material-containing gas flows through the air passage pipe 1 and enters the sorting unit 3. According to the target product particle size requirements, the impeller speed of the sorting unit 3 is set to a precise value through the frequency converter. Particle size sorting is performed inside the sorting unit 3. Qualified fine particles with a particle size of less than 1μm are dragged by the airflow force sufficient to overcome centrifugal force and pass through the impeller with the airflow. They are then discharged from the fine material outlet 7 and intercepted and collected by the subsequent collector 11 as the final product. Conversely, for unqualified coarse particles with a particle size greater than or equal to 1 μm, the centrifugal force dominates, causing them to be thrown against the wall of the classifier impeller. Under the action of gravity, the coarse particles are discharged from the coarse material outlet 8 and fall directly into the grinding unit 4 below. The coarse particles are repeatedly impacted and ground by the high-speed grinding media, and their particle size is effectively reduced. The ground material, containing a large amount of material with a smaller particle size, is discharged from the discharge port 10 at the bottom of the grinding unit 4. Since the discharge port 10 is connected to the throat of the venturi tube 6 through the return pipe 5, the strong negative pressure immediately causes these materials to be sucked up and sent back to the air passage pipe 1 through the return pipe 5. After the returned material is mixed with the newly fed raw material, it re-enters the sorting unit 3 for sorting. This cycle is repeated to obtain a silica product with an extremely narrow particle size distribution and high uniformity.

[0036] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A closed-loop grinding and sorting system, characterized in that: include Air pipe (1) is used to input materials, and a venturi tube (6) is provided on the air pipe (1). The pneumatic power unit (2) is used to drive the directional flow of air in the pneumatic pipe (1) to transport materials; The sorting unit (3) is provided with a fine material outlet (7) for separating and discharging qualified fine particles and a coarse material outlet (8) for separating and discharging coarse particles. The pneumatic power unit (2) is connected to the fine material outlet (7). The grinding unit (4) is provided with a feed inlet (9) and a discharge outlet (10), and the feed inlet (9) is connected to the coarse material outlet (8); The return pipe (5) is connected at one end to the outlet (10) and at the other end to the throat of the venturi tube (6).

2. The closed-loop grinding and sorting system according to claim 1, characterized in that: The sorting unit (3) is a centrifugal classifier, a cyclone classifier, or a turbine classifier. The coarse material outlet (8) is located at the bottom of the sorting unit (3), and the fine material outlet (7) is located at the top of the sorting unit (3).

3. The closed-loop grinding and sorting system according to claim 2, characterized in that: The grinding unit (4) is a vertical stirring mill, a dry sand mill, a drum ball mill, or a vibratory mill. The feed inlet (9) is located at the top of the grinding unit (4), and the discharge outlet (10) is located at the bottom of the grinding unit (4).

4. The closed-loop grinding and sorting system according to claim 1, characterized in that: The pneumatic power unit (2) is an induced draft fan.

5. A closed-loop grinding and sorting system according to claim 4, characterized in that: It also includes a collector (11), which is located between the pneumatic power unit (2) and the sorting unit (3). The bottom of the collector (11) is provided with a discharge port (12), and the two sides of the collector (11) are provided with an air inlet (13) and an air outlet (14). The air inlet (13) is connected to the fine material outlet (7), and the air outlet (14) is connected to the pneumatic power unit (2).

6. A closed-loop grinding and sorting system according to claim 5, characterized in that: It also includes a receiving box (15), the inlet of which is provided with a receiving hopper, and the receiving hopper is connected to the discharge port (12).

7. A closed-loop grinding and sorting system according to claim 6, characterized in that: The receiving hopper is equipped with a discharge valve.

8. The closed-loop grinding and sorting system according to claim 1, characterized in that: It also includes a feeder (16) for conveying materials to the air pipe (1). The feeder (16) has a raw material bin (17) connected to its feed end and a feed pipe (18) provided at its discharge end. The feed pipe (18) is connected to the air pipe (1) or the venturi pipe (6).

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