A raw material final grinding system and processing method

Abstract

This invention discloses a raw material final grinding system and processing method, belonging to the field of grinding technology. The system includes a pretreatment unit comprising a batching station and a first screening device. The outlet of the batching station is connected to the inlet of the first screening device for screening and pretreatment of the mixed feed. A classifier separates the pretreated and / or ground mixture into finished material, coarse-grained material, and medium-coarse-grained material. The finished material enters the raw material homogenization system via a finished product conveying device. A grinding unit includes a grinding mill and a second screening device for grinding the coarse-grained and medium-coarse-grained materials. The ground material is then screened and returned to the classifier. This invention achieves two-stage screening and multi-stage separation while effectively controlling the particle size distribution of the material, effectively removing returned powder from the classifier, improving grinding and classification efficiency, reducing system energy consumption, and achieving high efficiency and energy saving.

Description

Technical Field

[0001] This invention belongs to the field of grinding technology, and particularly relates to a raw material final grinding system and processing method. Background Technology

[0002] Grinding systems using roller presses, vertical mills, and ball mills are widely used in industries such as cement, mining, and metallurgy. These systems primarily consist of several functional pieces of equipment, including grinding, classifying, collecting, and air supply, configured according to specific requirements. Among these, the raw material final grinding system often uses roller presses and external circulation vertical mills as grinding equipment, working in conjunction with classifying equipment to grind and classify raw materials such as limestone and sandstone into finished raw materials that meet the feeding specifications of the kiln system. Grinding systems that directly produce finished products through grinding and classification are called final grinding systems.

[0003] Among them, the powder classifier is a crucial piece of equipment in the grinding system. It primarily classifies the materials after grinding by equipment such as roller presses and vertical mills, separating materials that meet the finished product control requirements. This has a vital impact on the quality of the finished product, while the remaining unselected materials are returned to the grinding equipment for further grinding. Therefore, the characteristics of the materials fed into the powder classifier have a significant impact on its performance, and the materials that fail to be selected by the powder classifier also have a considerable impact on the performance of the grinding equipment.

[0004] Currently, the commonly used classifier in raw material roller press final grinding systems and external circulation raw material vertical mill final grinding systems is a combined classifier consisting of a V-type static classifier and a cage rotor dynamic classifier. Although this equipment can meet production needs, the following problems still exist in actual operation: 1) When the feed is biased due to the process pipeline layout, the material is unevenly distributed in the classifier, resulting in reduced classification efficiency; 2) Although the connecting pipeline between the V-type static classifier and the cage rotor dynamic classifier has been greatly shortened, a large airflow lifting force is still required to lift the material to the dynamic classification zone for accurate classification, increasing system energy consumption; 3) Field application data shows that the finished product content in the returned powder of the dynamic classifier is relatively high, generally around 75-85% of the finished product sieve residue, resulting in low classification efficiency. At the same time, a large amount of finished product returned to the grinding equipment will cause equipment vibration, reduced grinding efficiency, and other effects, thus affecting the efficiency of the entire system. Adding a de-powdering device on this basis will increase the cost and increase the resistance and energy consumption of the entire system.

[0005] In addition, raw materials such as limestone and sandstone in the system are often directly transported to the batching station after being mined and crushed by crushers. After being mixed in a certain proportion, they are directly fed into the sorting equipment of the grinding system. This often results in problems such as material blockage, wear, and reduced output caused by large feed particles. Moreover, the material after being crushed and ground by roller press and external circulation vertical mill has a large throughput and is directly transported to the elevator and subsequent classifier, which increases the equipment load power and reduces the efficiency of classification and grinding. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a raw material final grinding system and processing method that achieves two-stage screening and multi-stage sorting while effectively controlling the distribution of material particle size, effectively removing powder returned from the classifier, improving grinding efficiency and classifying efficiency, reducing system energy consumption, achieving the goal of high efficiency and energy saving, and at the same time reducing the height of civil engineering and saving costs.

[0007] This invention is implemented by providing a raw material final grinding system, comprising:

[0008] The pretreatment unit includes a batching station and a first screening device. The outlet of the batching station is connected to the inlet of the first screening device to perform screening pretreatment on the mixed feed. The classifier separates the pre-treated and / or ground mixture into finished materials, coarse-grained materials, and medium-coarse-grained materials. The finished materials are then conveyed into the raw material homogenization system. The grinding unit includes grinding equipment and a second screening device for grinding coarse and medium-coarse materials. The ground materials are then screened and returned to the classifier. The air classifier includes a housing with an inlet on its upper surface communicating with its interior. A first air classifier chamber and a second air classifier chamber are arranged from top to bottom inside the housing. A first outlet communicating with the second air classifier chamber is located at the lower end of the housing. A first air inlet channel is disposed on the housing and communicates with the first air classifier chamber, forming a spiral airflow path. An annular static grading mechanism is disposed within the first air classifier chamber and includes multiple staggered guide plates and grading plates. A first material discharge channel is formed between adjacent guide plates and grading plates. The shell of the grading mechanism at the material discharge position is connected to a coarse material outlet channel; the upper separation mechanism, located in the first powder separation chamber and within the annular static grading mechanism, includes a first cage rotor and a guide vane grid located between the first cage rotor and the annular static grading mechanism, the first cage rotor being able to rotate in the first powder separation chamber along the airflow direction; a second air inlet channel, located on the shell and connected to the second powder separation chamber, forming a spiral airflow path; a second cage rotor, located in the second powder separation chamber and being able to rotate in the airflow direction; and a cyclone separator for collecting fine-grained materials. A material guiding inner cylinder is provided between the first cage rotor and the second cage rotor, and a material guiding channel for fine-grained materials is formed between the first cage rotor, the second cage rotor and the material guiding inner cylinder. A second discharge port is provided on the material guiding inner cylinder, and the cyclone is connected to the second discharge port through a third air inlet channel.

[0009] Furthermore, an iron remover is provided between the batching station and the first screening device. The undersize outlet of the first screening device is connected to the feed inlet of the powder classifier, and the oversize outlet of the first screening device is connected to the inlet of the first elevator.

[0010] Furthermore, the grinding unit also includes a material distribution device, an external discharge bin, and a material stabilizing bin. The first discharge port and coarse material outlet channel of the classifier are connected to the inlet of the material distribution device via a first elevator. The material distribution device has two outlets, which are respectively connected to the inlets of the external discharge bin and the material stabilizing bin. The outlet of the external discharge bin is connected to the inlet of the first elevator. The outlet of the material stabilizing bin is connected to the inlet of the grinding equipment. The outlet of the grinding equipment is connected to the inlet of the second screening device. The undersize outlet of the second screening device is connected to the feed inlet of the classifier via a second elevator. The oversize outlet of the second screening device is connected to the inlet of the first elevator. A feeding control device is installed between the material stabilizing and metering bin and the grinding equipment.

[0011] Furthermore, it also includes an air supply and drying unit, which includes a kiln tail high-temperature fan, a heating device and a circulating fan, wherein the inlet of the circulating fan is connected to the air outlet of the cyclone separator in the air classifier. When the moisture content of the raw material is ≤3%, the outlet of the high-temperature blower at the kiln tail is connected to the first air inlet channel of the air classifier, the outlet of the heating device is connected to the first air inlet channel of the air classifier, and the outlet of the circulating blower is connected to the second air inlet channel of the air classifier. When the moisture content of the raw material is greater than 3%, the outlet of the high-temperature blower at the kiln tail is connected to the first air inlet channel and the second air inlet channel of the air classifier, the outlet of the heating device is connected to the first air inlet channel and the second air inlet channel of the air classifier, and the outlet of the circulating blower is connected to the first air inlet channel and the second air inlet channel of the air classifier.

[0012] Furthermore, a material spreading mechanism is provided inside the shell located between the first powder selection chamber and the feed inlet. The material spreading mechanism evenly disperses and breaks up the mixture. The material spreading mechanism includes a first spreading disc and a dispersing component disposed below the first spreading disc. The first spreading disc can rotate circumferentially, so that the mixture is scattered to form an annular material curtain. The cross-section of the dispersing component is trapezoidal, and the small diameter end of the dispersing component faces the first spreading disc. The outer surface of the dispersing component is provided with a stepped structure, and a dispersing channel is formed between the stepped structure and the inner wall of the shell. The outlet of the dispersing channel is connected to the feed inlet of the material drop channel in the annular static grading mechanism.

[0013] Furthermore, the inner guide cylinder is provided with a guide cone and a baffle. The small diameter end of the guide cone faces the air outlet of the first cage rotor, and the baffle is located at the large diameter end of the guide cone, and the baffle divides the second discharge port into upper and lower parts.

[0014] Furthermore, the shell is divided into an upper shell, a middle shell, and a lower shell from top to bottom. The feed inlet is located on the upper end face of the upper shell, and a first powder-selecting chamber is formed inside the upper shell. The middle shell includes an inner middle shell and an outer middle shell. The outer middle shell is located outside the inner middle shell, and the upper end of the inner middle shell extends into the upper shell and is connected to the lower end of the guide vane. A second material discharge channel is formed between the inner middle shell and the inner guide cylinder. The lower end of the upper shell intersects with the outer middle shell to form a coarse powder collection area, and the coarse powder outlet channel is connected to the coarse powder collection area. The lower end of the inner middle shell is connected to the lower shell, and a second powder-selecting chamber is formed inside the lower shell. The second powder-selecting chamber is connected to the second material discharge channel.

[0015] Furthermore, a speed-reducing and wear-resistant mechanism is provided in the second material discharge channel near the second powder selection chamber. The speed-reducing and wear-resistant mechanism includes multiple speed-reducing plates arranged in an alternating manner.

[0016] Furthermore, the inner shell is provided with a connecting window for connecting the coarse powder collection area and the second material discharge channel. A flap is provided on the inner shell at the location of the connecting window. The flap covers the connecting window and can be opened at a certain angle to realize the connection between the coarse powder collection area and the second material discharge channel.

[0017] Furthermore, a second material spreading disc is provided on the upper end face of the second cage rotor, so that the material is scattered to form an annular material curtain; a baffle plate is provided on the second powder separation chamber located outside the second cage rotor, and the baffle plate is correspondingly provided with the second material spreading disc.

[0018] Furthermore, the first air inlet channel is arranged tangentially or perpendicularly to the casing, and the air volume of the first air inlet channel accounts for 50-80% of the total air volume of the powder separator; The second air inlet channel is tangentially arranged with the shell, and the height of the second air inlet channel is the same as that of the second cage rotor. The air volume of the second air inlet channel accounts for 20-50% of the total air volume of the powder separator.

[0019] Furthermore, in the annular static grading mechanism, the bottom extension line of the upper-level guide plate or grading plate intersects with the lower-level grading plate or guide plate. The angle between the guide plate and the grading plate and the horizontal line is 30~65°.

[0020] On the other hand, a processing method using any of the above-described raw material final grinding systems is provided, comprising the following steps: After the raw materials are batched in a certain proportion at the batching station, they first pass through the iron remover and then enter the first screening device for screening pretreatment. The material on the screen of the first screening device enters the grinding equipment through the first elevator and the material stabilizing metering bin, and the material undersize of the first screening device enters the powder classifier. The pre-treated mixture enters the classifier through the feed inlet and falls onto the first spreading disc. After being spread by the rotation of the first spreading disc, the mixture falls into the annular static grading mechanism along the dispersion channel in the circumferential direction. The mixture moves downward along the staggered guide plates and grading plates, interacting with the horizontal airflow in the first air inlet channel. A portion of the material passes through the grading plate and moves towards the center to form a semi-finished product, while the remaining material falls into the coarse powder collection area. When the valve is open, it is finally discharged from the coarse material outlet channel. When the valve is closed, it flows into the second dropping channel through the flap action, mixes with the medium and fine powder, and falls into the deceleration and anti-wear mechanism for subsequent washing operations. Before the semi-finished product enters the guide vane grid with the airflow from the first air inlet channel, some coarse particles settle due to gravity and fall into the coarse powder collection area, where they are discharged along with the previously formed coarse powder. The remaining material flows to the first cage rotor for powder classification under the action of the guide vane grid. Under the rotational classification action of the first cage rotor, the material that passes through the first cage rotor forms finished product 1 and enters the cyclone separator from the second discharge port for collection with the airflow from the first air inlet channel and under the action of the guide cone and baffles. The material that does not pass through the first cage rotor forms medium and fine powder and falls from the second material drop channel formed between the inner shell and the inner guide cylinder to the deceleration and wear prevention area. Under the action of the deceleration and anti-wear mechanism, the material falls into the second spreading plate. The second spreading plate, through its rotating spreading action, spreads the medium and fine powder along the circumference towards the baffle plate. Through the deceleration and guiding action of the baffle plate, the medium and fine powder falls downward. Under the drag force of the horizontal rotating airflow in the second air inlet channel, it moves to the second cage rotor for powder selection. Under the rotational grading action of the second cage rotor, the material that passes through the second cage rotor forms finished product 2. With the airflow in the second air inlet channel, under the action of the guide cone and baffle, it enters the cyclone from the second outlet for collection. The material that does not pass through the second cage rotor forms medium and coarse powder and is discharged from the first outlet. The material from the first discharge port and coarse material outlet channel of the classifier is conveyed to the first elevator. The material distribution device is usually connected to the stable material metering bin, and in special cases, it is connected to the external discharge bin. Through the lifting and distribution action, the material enters the stable material metering bin. After being evenly distributed, the material enters the grinding equipment for crushing and grinding through the controlled feeding device. The crushed and ground material enters the second screening device for screening. The material on the screen of the second screening device is conveyed to the grinding equipment through the first elevator for further grinding. The material under the screen of the second screening device enters the second elevator and enters the feed port of the classifier again for sorting through the lifting action. Through the drying and multiple grading processes of the air classifier, the material exiting the finished product outlet of the air classifier's cyclone separator is conveyed by the finished product conveying device and enters the raw material homogenization system together with the dust collected by the dust collector.

[0021] The advantages and technical effects of this invention are as follows: By adopting the above technical solution, while realizing two-stage screening and multi-stage sorting, the particle size distribution of materials can be effectively controlled, the powder returned by the classifier can be effectively removed, the grinding efficiency and the powder sorting efficiency can be improved, the system energy consumption can be reduced, and the purpose of high efficiency and energy saving can be achieved. At the same time, the civil engineering height can be reduced, and the cost can be saved.

[0022] Specifically: (1) The present invention controls the overall material of the system within a stable range through two screening devices, thereby increasing the stability of the system; the first screening reduces problems such as blockage, wear and reduced output caused by large fluctuations in raw material particles; the second screening reduces the amount of material entering the classifier, thereby improving the selection efficiency; materials that do not meet the requirements of the finished product do not participate in subsequent selection, thereby reducing the circulating load and improving the efficiency of the grinding system; (2) The returned powder of the classifier of the present invention is cleaned again by the second cage rotor, which greatly reduces the finished product content in the medium and coarse powder, improves the overall selection efficiency, reduces the adverse effects of the returned powder on the grinding equipment such as vibration and reduced useful work, and improves the grinding efficiency; (3) The present invention can realize the multi-condition operation requirements under different raw material moisture levels by combining the dual action of the valve and the flap of the classifier with the adjustment of the heating device, thereby improving the grinding efficiency under multiple scenarios; (4) The classifier of the present invention integrates the functions of selection, washing and collection, effectively improving the performance of the classifier, reducing the energy consumption of the entire grinding system, and the structure is compact, reducing the civil engineering height of the entire system and saving costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the process flow of the grinding equipment provided in this embodiment of the invention, which is a roller press.

[0024] Figure 2 This is a schematic diagram of the process flow of the grinding equipment provided in this embodiment of the invention, which is an external circulation vertical mill.

[0025] Figure 3 This is a plan view of the air classifier provided in an embodiment of the present invention.

[0026] Figure 4 This is a flowchart of the powder classifier sorting process provided in an embodiment of the present invention.

[0027] Figure 5 This is a three-dimensional overall schematic diagram of the air classifier provided in an embodiment of the present invention.

[0028] Figure 6 This is a three-dimensional cross-sectional schematic diagram of the air classifier provided in an embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram of the multi-stage sorting of materials by the powder classifier provided in the embodiment of the present invention.

[0030] Figure 8 This is a schematic diagram of the tangential air intake of the first air inlet of the air classifier provided in an embodiment of the present invention.

[0031] Figure 9 This is a schematic diagram of the horizontal air intake at the first air inlet of the air classifier provided in an embodiment of the present invention.

[0032] Figure 10 This is a schematic diagram of the installation structure of the speed reduction plate provided in an embodiment of the present invention.

[0033] In the picture: 1. Batching station; 2. Iron separator; 3. First screening device; 4. Air classifier; 4-1. Feed inlet; 4-2. First spreading disc; 4-3. First transmission mechanism; 4-4. First motor; 4-5. Dispersing component; 4-6. Annular static grading mechanism; 4-7. Guide plate; 4-8. Grading plate; 4-9. First cage rotor; 4-10. Second transmission mechanism; 4-11. Second motor; 4-12. Guide vane; 4-13. Upper shell; 4-14. First air inlet channel; 4-15. Middle and outer shell; 4-16. Second discharge port; 4-17. Guide cone; 4-18. Third air inlet channel; 4- 19. Baffle; 4-20. Inner shell; 4-21. Flip plate; 4-22. Speed ​​reduction plate; 4-23. Coarse material outlet channel; 4-24. Valve; 4-25. Lower shell; 4-26. Lower shell top cover plate; 4-27. Baffle plate; 4-28. Second spreading disc; 4-29. Second cage rotor; 4-30. Third transmission mechanism; 4-31. Third motor; 4-32. Second air inlet channel; 4-33. First discharge port; 4-34. Cyclone; 4-35. Mixed finished product outlet; 4-36. Inner guide cylinder; 4-37. Guide plate; 5. Finished product conveying device; 6. First elevator; 7. Material distribution device; 8. External discharge bin; 9. Material stabilizing and metering bin; 10. Control feeding device; 11. Grinding equipment; 12. Second screening device; 13. Second elevator; 14. Kiln tail high-temperature fan; 15. Cooling device; 16. Circulating fan; 17. Dust collector; 18. External exhaust fan; 19. Chimney; 20. Heating device. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] It should be noted that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present 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. Therefore, they should not be construed as limiting the present invention.

[0036] like Figures 1 to 10 As shown, one embodiment of this application provides a raw material final grinding system, including: The pretreatment unit includes a batching station 1 and a first screening device 3. The outlet of the batching station 1 is connected to the inlet of the first screening device 3. After the raw materials are batched in a certain proportion, the mixed feed is pretreated by screening. Specifically, the first screening device 3 can be a drum screen or other screening device. The classifier 4 separates the pre-treated and / or ground mixture into finished materials, coarse materials and medium-coarse materials. The finished materials enter the raw material homogenization system through the finished product conveying device 5. The grinding unit includes a grinding mill 11 and a second screening device 12, used to grind coarse and medium-coarse materials. The ground material is then screened and returned to the classifier 4. Specifically, the second screening device 12 can be a roller screen or other screening device, and the grinding mill 11 can be a roller press, an external circulation vertical mill, or other grinding equipment 11.

[0037] The air classifier 4 includes a housing with an inlet 4-1 communicating with its interior on its upper surface. A first air classifier chamber and a second air classifier chamber are arranged from top to bottom inside the housing. A first outlet 4-33 communicating with the second air classifier chamber is provided at the lower end of the housing. A first air inlet channel 4-14 is disposed on the housing and communicates with the first air classifier chamber, forming a spiral airflow path. An annular static grading mechanism 4-6 is disposed within the first air classifier chamber and includes multiple staggered guide plates 4-7 and grading plates 4-8. A first material discharge channel is formed between adjacent guide plates 4-7 and grading plates 4-8. The housing at the material discharge position is connected to a coarse material outlet channel 4-23; the upper separation mechanism is located in the first powder separation chamber and within the annular static classification mechanism 4-6, including a first cage rotor 4-9 and a guide vane 4-12 disposed between the first cage rotor 4-9 and the annular static classification mechanism 4-6, the first cage rotor 4-9 can rotate in the airflow direction within the first powder separation chamber; the second air inlet channel 4-32 is disposed on the housing and connected to the second powder separation chamber, forming a spiral airflow path; the second cage rotor 4-29 is disposed within the second powder separation chamber and can rotate in the airflow direction; the cyclone 4-34 is used to collect fine-particle materials; A guide cylinder 4-36 is provided between the first cage rotor 4-9 and the second cage rotor 4-29 to connect the first cage rotor 4-9 and the second cage rotor 4-29. A guide channel for fine-particle material flow is formed between the first cage rotor 4-9, the second cage rotor 4-29 and the guide cylinder 4-36. A second discharge port 4-16 is provided on the guide cylinder 4-36. The cyclone 4-34 is connected to the second discharge port 4-16 through a third air inlet channel 4-18.

[0038] It should be noted that the guide vane 4-12 includes an upper support plate and a lower support plate arranged horizontally at intervals. Both the upper support plate and the lower support plate are annular plates. Multiple guide vanes are arranged between the upper support plate and the lower support plate. The multiple guide vanes are distributed at intervals along the circumference of the annular plates, and gaps are formed between adjacent guide vanes. The first air inlet channel 4-14 and the second air inlet channel 4-32 are both channels formed by an upper cover plate, a lower cover plate and two side cover plates, and the cross-section of the channel is rectangular. To facilitate the installation and fixation of the guide vanes 4-7 and the classifiers 4-8, the first and last guide vanes 4-7 are connected to the upper and lower cover plates of the first air inlet channel 4-14, respectively, and the guide vanes 4-7 are interconnected and fixed by the first reinforcing ribs. Similarly, the first and last classifiers 4-8 are connected to the upper and lower support plates of the guide vane 4-12, respectively, and the classifiers 4-8 are interconnected and fixed by the second reinforcing ribs.

[0039] When the mixture falls along the first material discharge channel, the coarse particles in the mixture fall into the coarse material outlet channel 4-23 under the action of gravity settling. The neutral and fine particles in the mixture, as well as the possible small amount of coarse particles, flow to the upper separation mechanism under the action of horizontal airflow. Some fine particles pass through the guide vane 4-12 and the first cage rotor 4-9 in sequence into the guide inner cylinder 4-36, and are collected into the cyclone 4-34 through the second discharge port 4-16 and the third air inlet channel 4-18.

[0040] The remaining medium-sized materials, some fine-sized materials, and possibly a small amount of coarse-sized materials enter the second powder-sorting chamber through the second material discharge channel, which is located between the first cage rotor 4-9 and the guide vane 4-12. The medium-sized materials or a mixture of medium-sized and coarse-sized materials fall into the first discharge port 4-33 under the rotational classification action of the second cage rotor 4-29. Some fine-sized materials enter the inner guide cylinder 4-36 through the second cage rotor 4-29 and are collected into the cyclone 4-34 through the second discharge port 4-16 and the third air inlet channel 4-18.

[0041] In some embodiments, an iron remover 2 is provided between the batching station 1 and the first screening device 3, the undersize outlet of the first screening device 3 is connected to the feed inlet 4-1 of the powder classifier 4, and the oversize outlet of the first screening device 3 is connected to the inlet of the first elevator 6.

[0042] Preferably, the equivalent diameter of the screen aperture of the first screening device 3 is less than or equal to 2 to 2.5% of the roller diameter of the grinding equipment 11.

[0043] In some embodiments, the grinding unit further includes a material distribution device 7, an external discharge bin 8, and a material stabilizing bin 9. The first discharge port 4-33 and the coarse material outlet channel 4-23 of the classifier 4 are connected to the inlet of the material distribution device 7 via a first elevator 6. The material distribution device 7 has two outlets, which are respectively connected to the inlets of the external discharge bin 8 and the material stabilizing bin 9. The outlet of the external discharge bin 8 is connected to the inlet of the first elevator 6. The outlet of the material stabilizing bin 9 is connected to the inlet of the grinding equipment 11. The outlet of the grinding equipment 11 is connected to the inlet of the second screening device 12. The undersize outlet of the second screening device 12 is connected to the feed inlet 4-1 of the classifier 4 via a second elevator 13. The oversize outlet of the second screening device 12 is connected to the inlet of the first elevator 6. A controlled feeding device 10 is provided between the material stabilizing bin 9 and the grinding equipment 11. Specifically, the controlled feeding device 10 may be a hyperbolic feeding device or other feeding control device.

[0044] Preferably, the equivalent diameter of the sieve aperture of the second screening device 12 is greater than or equal to 1 mm.

[0045] The grinding equipment 11 is a roller press or an external circulation vertical mill, and the material stabilizing and metering bin 9 is a material stabilizing bin with a uniform material distribution process. The material distributing device 7 is a three-way distributor.

[0046] In another embodiment, based on the above structure, it further includes an air supply and drying unit, which includes a kiln tail high-temperature fan 14, a heating device 20 and a circulating fan 16. The inlet of the circulating fan 16 is connected to the air outlet of the cyclone 4-34 in the classifier 4. The heating device 20 can be a hot air furnace or other heating device 20. When the moisture content of the raw material is ≤3%, the outlet of the kiln tail high temperature fan 14 is connected to the first air inlet channel 4-14 of the classifier 4, the outlet of the heating device 20 is connected to the first air inlet channel 4-14 of the classifier 4, and the outlet of the circulating fan 16 is connected to the second air inlet channel 4-32 of the classifier 4. When the moisture content of the raw material is greater than 3%, the outlet of the kiln tail high-temperature blower 14 is connected to the first air inlet channel 4-14 and the second air inlet channel 4-32 of the classifier 4, the outlet of the heating device 20 is connected to the first air inlet channel 4-14 and the second air inlet channel 4-32 of the classifier 4, and the outlet of the circulating blower 16 is connected to the first air inlet channel 4-14 and the second air inlet channel 4-32 of the classifier 4.

[0047] To achieve the treatment of kiln tail exhaust gas and raw material mill exhaust gas, some embodiments further include a cooling device 15 and a dust collector 17. The inlet of the cooling device 15 is connected to the outlet of the kiln tail high-temperature fan 14. The inlet of the dust collector 17 is connected to the outlet of the circulating fan 16 and the outlet of the cooling device 15, respectively. The outlet of the dust collector 17 is connected to the chimney 19 through an exhaust fan 18. The dust collected by the dust collector 17 enters the raw material homogenization system. The cooling device 15 may be a humidification tower or other cooling device 15.

[0048] It should be noted that the drying and sorting air of the classifier 4 mainly comes from a portion of the kiln tail exhaust gas from the high-temperature fan 14 at the kiln tail and a portion of the circulating air from the circulating fan 16. When the material moisture content is not high (raw material moisture content ≤ 3%), and the kiln tail hot air and circulating air meet the drying requirements, the heating device 20 is turned off. When the material moisture content is high (raw material moisture content > 3%), the valve 4-24 of the classifier 4 is closed, and the coarse powder enters the middle inner shell 4-20 and the guide inner cylinder 4-36 through the action of the flap 4-21 to form a second material falling channel, participating in the sorting of the second cage rotor 4-29. If the kiln tail hot air and circulating air still cannot meet the drying requirements, the heating device 20 is turned on. Part of the remaining kiln tail exhaust gas goes to the coal mill system, and the other part is cooled by the cooling device 15 and then enters the dust collector 17 together with a portion of the air from the circulating fan 16. Through the action of the tail exhaust fan, it is discharged from the system through the chimney 19.

[0049] In another embodiment, based on the above structure, a spreading mechanism is further provided inside the shell between the first powder selection chamber and the feed inlet 4-1. The spreading mechanism evenly disperses and breaks up the mixture. The spreading mechanism includes a first spreading disc 4-2 and a dispersing member 4-5 disposed below the first spreading disc 4-2. The first spreading disc 4-2 can rotate circumferentially, so that the mixture is scattered to form an annular material curtain. The cross-section of the dispersing member 4-5 is trapezoidal, and the small diameter end of the dispersing member 4-5 faces the first spreading disc 4-2. The outer surface of the dispersing member 4-5 is provided with a stepped structure, and a dispersing channel is formed between the stepped structure and the inner wall of the shell. The outlet of the dispersing channel is connected to the feed inlet 4-1 of the first material dropping channel in the annular static grading mechanism 4-6.

[0050] In another embodiment, based on the above structure, the inner guide cylinder 4-36 is further provided with a guide cone 4-17 and a baffle 4-19. The small diameter end of the guide cone 4-17 faces the air outlet of the first cage rotor 4-9. The baffle 4-19 is provided at the large diameter end of the guide cone 4-17 and divides the second discharge port 4-16 into upper and lower parts.

[0051] The projected area of ​​the guide cone 4-17 on the horizontal plane is the same as the projected area of ​​the air outlet of the first cage rotor 4-9 on the horizontal plane.

[0052] The guide cone 4-17 is arranged inside the entire inner guide cylinder 4-36 to prevent the airflow from the first cage rotor 4-9 and the second cage rotor 4-29 from clashing and to prevent the finished product sorted by the first cage rotor 4-9 from falling into the second cage rotor 4-29. The guide cone 4-17 and the baffle 4-19 divide the second discharge port 4-16 into upper and lower channels, which respectively allow the finished products from the first cage rotor 4-9 and the second cage rotor 4-29 to enter the cyclone 4-34. This achieves the zonal use of the entire equipment and the collection of finished products.

[0053] In some embodiments, the structural features of the housing are further described. The housing is divided into an upper housing 4-13, a middle housing, and a lower housing 4-25 from top to bottom. The feed inlet 4-1 is disposed on the upper end face of the upper housing 4-13, and a first powder-selecting chamber is formed inside the upper housing 4-13. The middle housing includes an inner middle housing 4-20 and an outer middle housing 4-15. The outer middle housing 4-15 is disposed outside the inner middle housing 4-20. The upper end of the inner middle housing 4-20 extends into the upper housing 4-13 and is connected to the lower end of the guide vane 4-12. A second material discharge channel is formed between the inner shell 4-20 and the inner guide cylinder 4-36; the lower end of the upper shell 4-13 intersects with the outer shell 4-15 to form a coarse powder collection area, and the coarse powder outlet channel 4-23 is connected to the coarse powder collection area. Preferably, a valve 4-24 is provided on the coarse powder outlet channel 4-23; the lower end of the inner shell 4-20 is connected to the lower shell 4-25. Specifically, the lower end of the inner shell 4-20 is connected to the upper cover plate 4-26 of the lower shell, and a second powder sorting chamber is formed inside the lower shell 4-25. The second powder sorting chamber is connected to the second material discharge channel.

[0054] In another embodiment, based on the above structure, a speed-reducing and wear-resistant mechanism is further provided in the second material discharge channel near the second powder selection chamber. The speed-reducing and wear-resistant mechanism includes a plurality of speed-reducing plates 4-22 arranged in an alternating manner. Specifically, the plurality of speed-reducing plates 4-22 are respectively arranged in an alternating manner on the outer wall of the inner guide cylinder 4-36 and the inner wall of the middle inner shell 4-20, and each speed-reducing plate 4-22 has a certain angle with the inner guide cylinder 4-36 and the middle inner shell 4-20, forming an angled area. A certain amount of material will accumulate in the angled area. When the incoming material flows through, it forms a material-on-material flow, which not only plays a certain role in speed reduction, but also reduces the scouring and wear of the material on the speed-reducing plates 4-22.

[0055] It should be noted that, as Figure 10As shown, the last deceleration plate 4-22 is set on the middle inner shell 4-20, and a guide plate 4-37 is set on the outer wall of the guide inner cylinder 4-36 relative to the installation position of the last deceleration plate 4-22. The guide plate 4-37 is set at an acute angle with the horizontal plane, and the guide plate 4-37 and the middle inner shell 4-20 form the feeding inlet of the second powder selection chamber.

[0056] In another embodiment, based on the above structure, the inner shell 4-20 is further provided with a connecting window for connecting the coarse powder collection area and the second material discharge channel. A flap 4-21 is provided on the inner shell 4-20 at the location of the connecting window. The flap 4-21 covers the connecting window and can be opened at a certain angle to connect the coarse powder collection area and the second material discharge channel. Specifically, the flap 4-21 is hinged to the inner shell 4-20. An actuating component is provided on one side of the flap 4-21 to drive the flap 4-21 to perform the opening action. The actuating component can be a cylinder, hydraulic cylinder, or electromagnetic rod, etc. Alternatively, the flap 4-21 can also be hinged to the inner shell 4-20 using a damping pivot. When coarse-grained material accumulates in the coarse powder collection area and reaches a certain pressure, the flap 4-21 is opened, and the coarse-grained material enters the second material discharge channel through the connecting window.

[0057] In another embodiment, based on the above structure, a second material spreading disc 4-28 is provided on the upper end face of the second cage rotor 4-29, so that the material is scattered to form an annular material curtain; a baffle plate 4-27 is provided on the second powder selection chamber located outside the second cage rotor 4-29, and the baffle plate 4-27 is correspondingly provided with the second material spreading disc 4-28.

[0058] In some embodiments, the air inlet of the first air inlet channel 4-14 is arranged tangentially or perpendicularly to the shell, and the air volume of the first air inlet channel 4-14 accounts for 50-80% of the total air volume of the powder selection. The vertical arrangement of the air inlet is mainly considered in the process pipeline design when the tangential arrangement cannot be carried out on site. Regardless of whether it is tangential or vertical arrangement, the airflow in the first air inlet channel 4-14 is horizontal, but the swirling flow is stronger and more widely distributed when tangentially entering.

[0059] The second air inlet channel 4-32 is tangentially arranged with the shell, and the height of the second air inlet channel 4-32 is the same as that of the second cage rotor 4-29. The air volume of the second air inlet channel 4-32 accounts for 20-50% of the total air volume of the powder separator.

[0060] In some embodiments, further, the bottom extension line of the upper-level guide plate 4-7 or the grading plate 4-8 in the annular static grading mechanism 4-6 intersects with the lower-level grading plate 4-8 or the guide plate 4-7.

[0061] The angle between the guide plate 4-7 and the grading plate 4-8 and the horizontal line is 30~65°; the guide plate 4-7 and the grading plate 4-8 are supported by the shell, the guide vane 4-12 and the stiffener.

[0062] It should be noted that, in order to achieve the rotation of the first cage rotor 4-9 and the first spreading disc 4-2, the first transmission mechanism 4-3 drives the first spreading disc 4-2 to rotate, and the second transmission mechanism 4-10 drives the first cage rotor 4-9 to rotate. The first motor 4-4 of the first transmission system and the second motor 4-11 of the second transmission mechanism 4-10 are located above the feed inlet 4-1. Specifically, the second transmission mechanism 4-10 includes the second motor 4-11 and a first transmission shaft connected to the output shaft of the second motor 4-11 via a coupling. The first transmission shaft extends into the first powder selection chamber and is connected to the first cage rotor 4-9. The first transmission system includes the first motor 4-4 and a transmission sleeve. The transmission sleeve is sleeved outside the first transmission shaft, and a bearing is provided between the transmission sleeve and the first transmission shaft. The transmission sleeve is mutually driven with the first motor 4-4 via a belt, and the transmission sleeve extends into the housing and is connected to the first spreading disc 4-2.

[0063] To achieve the rotation of the second cage rotor 4-29 and the second spreading disc 4-28, the third transmission mechanism 4-30 drives the second cage rotor 4-29 and the second spreading disc 4-28 to rotate. Specifically, the third transmission mechanism 4-30 includes a third motor 4-31 and a second transmission shaft connected to the output shaft of the third motor 4-31 via a coupling. The second transmission shaft extends into the second powder-selecting chamber and is connected to the second cage rotor 4-29 and the second spreading disc 4-28. The third motor 4-31 in the third transmission mechanism 4-30 is located in the hollow area formed between the lower cover plate of the lower housing 4-25 and the first discharge port 4-33.

[0064] By adopting the sorting machine in the above technical solution, multi-stage sorting can be achieved, and the powder returned by the four-stage classifier can be effectively de-powdered, thereby improving the sorting efficiency and grinding efficiency, reducing system energy consumption, reducing civil engineering height, and saving costs.

[0065] Specifically: 1) This invention replaces the traditional two-dimensional planar design of the V-type separator with a circular ring design, allowing semi-finished products to participate in subsequent sorting operations as quickly as possible, reducing the required airflow lifting force, lowering system resistance, and ensuring uniform material distribution in the circumferential direction, which is beneficial to improving the powder selection efficiency of the separator; 2) The returned powder of the dynamic powder separator 4 is cleaned again by the second cage rotor 4-29, significantly reducing the finished product content in the medium and coarse powder, improving the overall powder selection efficiency, reducing the adverse effects of returned powder on the grinding equipment 11 such as vibration and reduced useful work, and improving grinding efficiency; 3) Coarse powder can be adjusted under multiple working conditions through the dual action of valve 4-24 and flap 4-21, improving grinding efficiency under multiple scenarios.

[0066] On the other hand, a processing method is provided, including the following steps: After the raw materials are batched in a certain proportion by the batching station 1, they first pass through the iron remover 2 and then enter the first screening device 3 for screening pretreatment. The material on the screen of the first screening device 3 enters the grinding equipment 11 through the first elevator 6 and the material stabilizing metering bin 9, and the material undersize of the first screening device 3 enters the powder classifier 4. The pre-treated mixture enters the classifier 4 through the feed inlet 4-1 and falls onto the first spreading disc 4-2. After being spread by the rotation of the first spreading disc 4-2, the mixture falls into the annular static grading mechanism 4-6 along the dispersion channel in the circumferential direction. The mixture moves downward along the staggered guide plates 4-7 and grading plates 4-8, interacting with the horizontal airflow of the first air inlet channel 4-14. A portion of the material passes through the grading plate 4-8 and moves towards the center to form a semi-finished product. The remaining material falls into the coarse powder collection area. When the valve 4-24 is opened, it is finally discharged from the coarse material outlet channel 4-23. When the valve 4-24 is closed, it flows into the second dropping channel through the action of the flap 4-21, mixes with the medium and fine powder, and falls into the deceleration and anti-wear mechanism for subsequent washing operation. Before the semi-finished product enters the guide vane 4-12 through the airflow from the first air inlet channel 4-14, some coarse particles settle due to gravity and fall into the coarse powder collection area, where they are discharged along with the previously formed coarse powder. The remaining material flows to the first cage rotor 4-9 for powder classification by the action of the guide vane 4-12. Under the rotational classification action of the first cage rotor 4-9, the material that passes through the first cage rotor 4-9 forms finished product 1. With the airflow from the first air inlet channel 4-14 and under the action of the guide cone 4-17 and the baffle 4-19, the material enters the cyclone 4-34 from the second discharge port 4-16 for collection. The material that does not pass through the first cage rotor 4-9 forms medium and fine powder, which falls into the deceleration and anti-wear mechanism through the second material drop channel formed between the inner shell 4-20 and the inner guide cylinder 4-36. Under the action of the deceleration and anti-wear mechanism... The powder falls into the second spreading plate, which, through its rotating action, spreads the medium and fine powder circumferentially towards the baffle plate 4-27. The baffle plate 4-27 slows and guides the powder downwards. Under the pulling force of the horizontal rotating airflow in the second air inlet channel 4-32, the powder moves to the second cage rotor 4-29 for powder selection. Under the rotating classification action of the second cage rotor 4-29, the material passing through it forms finished product 2. Following the airflow in the second air inlet channel 4-32, and under the action of the guide cone 4-17 and baffle plate 4-19, the material enters the cyclone separator 4-34 from the second outlet 4-16 for collection. Finally, the mixed finished product is discharged through the mixed finished product outlet 4-35 of the cyclone separator 4-34. The material that does not pass through the second cage rotor 4-29 forms medium and coarse powder, which is discharged from the first outlet 4-33. The material from the first discharge port 4-33 and coarse material outlet channel 4-23 of the classifier 4 is conveyed to the first elevator 6. The material distribution device 7 is usually connected to the material stabilizing and metering bin 9, and in special cases, it is connected to the external discharge bin 8. Through the lifting and distribution action, the material enters the material stabilizing and metering bin 9. After being evenly distributed, the material enters the grinding equipment 11 through the control feeding device 10 for crushing and grinding. The crushed and ground material enters the second screening device 12 for screening. The material on the second screening device 12 is conveyed to the grinding equipment 11 through the first elevator 6 for further grinding. The material under the second screening device 12 enters the second elevator 13 and enters the feed port 4-1 of the classifier 4 again for sorting through the lifting action. Through the drying and multiple grading processes of the classifier 4, the material exiting the finished product outlet of the cyclone 4-34 in the classifier 4 is conveyed by the finished product conveying device 5 and enters the raw material homogenization system together with the dust collected by the dust collector 17.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A raw material final grinding system, characterized in that, include: The pretreatment unit includes a batching station and a first screening device. The outlet of the batching station is connected to the inlet of the first screening device to perform screening pretreatment on the mixed feed. The classifier separates the pre-treated and / or ground mixture into finished materials, coarse-grained materials, and medium-coarse-grained materials. The finished materials are then conveyed into the raw material homogenization system. The grinding unit includes grinding equipment and a second screening device for grinding coarse and medium-coarse materials. The ground materials are then screened and returned to the classifier. The air classifier includes a housing with an inlet on its upper surface communicating with its interior. A first air classifier chamber and a second air classifier chamber are arranged from top to bottom inside the housing. A first outlet communicating with the second air classifier chamber is provided at the lower end of the housing. A first air inlet channel is provided on the housing and communicates with the first air classifier chamber, forming a spiral airflow path. An annular static grading mechanism is provided inside the first air classifier chamber, including multiple staggered guide plates and grading plates. A first material discharge channel is formed between adjacent guide plates and grading plates. A coarse material outlet channel is provided on the housing at the material discharge position of the annular static grading mechanism. The upper separation mechanism, located in the first powder separation chamber and within the annular static classification mechanism, includes a first cage rotor and a guide vane grid disposed between the first cage rotor and the annular static classification mechanism. The first cage rotor can rotate in the first powder separation chamber along the airflow direction. A second air inlet channel is disposed on the housing and connected to the second powder separation chamber, forming a spiral airflow path. The second cage rotor is disposed in the second powder separation chamber and can rotate in the airflow direction. A cyclone is used to collect fine-particle materials. A material guiding inner cylinder is provided between the first cage rotor and the second cage rotor, and a material guiding channel for fine-grained materials is formed between the first cage rotor, the second cage rotor and the material guiding inner cylinder. A second discharge port is provided on the material guiding inner cylinder, and the cyclone is connected to the second discharge port through a third air inlet channel.

2. The raw material final grinding system according to claim 1, characterized in that, An iron remover is installed between the batching station and the first screening device. The undersize outlet of the first screening device is connected to the feed inlet of the powder classifier, and the oversize outlet of the first screening device is connected to the inlet of the first elevator.

3. The raw material final grinding system according to claim 1, characterized in that, The grinding unit also includes a material distribution device, an external discharge bin, and a material stabilizing bin. The first discharge port and coarse material outlet channel of the classifier are connected to the inlet of the material distribution device via a first elevator. The material distribution device has two outlets, which are respectively connected to the inlets of the external discharge bin and the material stabilizing bin. The outlet of the external discharge bin is connected to the inlet of the first elevator. The outlet of the material stabilizing bin is connected to the inlet of the grinding equipment. The outlet of the grinding equipment is connected to the inlet of the second screening device. The undersize outlet of the second screening device is connected to the feed inlet of the classifier via a second elevator. The oversize outlet of the second screening device is connected to the inlet of the first elevator. A feeding control device is installed between the material stabilizing and metering bin and the grinding equipment.

4. The raw material final grinding system according to claim 1, characterized in that, It also includes an air supply and drying unit, which includes a kiln tail high-temperature fan, a heating device and a circulating fan, wherein the inlet of the circulating fan is connected to the air outlet of the cyclone separator in the air classifier. When the moisture content of the raw material is ≤3%, the outlet of the high-temperature blower at the kiln tail is connected to the first air inlet channel of the air classifier, the outlet of the heating device is connected to the first air inlet channel of the air classifier, and the outlet of the circulating blower is connected to the second air inlet channel of the air classifier. When the moisture content of the raw material is greater than 3%, the outlet of the high-temperature blower at the kiln tail is connected to the first air inlet channel and the second air inlet channel of the air classifier, the outlet of the heating device is connected to the first air inlet channel and the second air inlet channel of the air classifier, and the outlet of the circulating blower is connected to the first air inlet channel and the second air inlet channel of the air classifier.

5. The raw material final grinding system according to claim 1, characterized in that, A material spreading mechanism is provided inside the shell located between the first powder selection chamber and the feed inlet. The material spreading mechanism evenly disperses and breaks up the mixture. The material spreading mechanism includes a first spreading disc and a dispersing component disposed below the first spreading disc. The first spreading disc can rotate circumferentially, so that the mixture is scattered to form an annular material curtain. The cross-section of the dispersing component is trapezoidal, and the small diameter end of the dispersing component faces the first spreading disc. The outer surface of the dispersing component is provided with a stepped structure, and a dispersing channel is formed between the stepped structure and the inner wall of the shell. The outlet of the dispersing channel is connected to the feed inlet of the material drop channel in the annular static grading mechanism.

6. The raw material final grinding system according to claim 1, characterized in that, The inner cylinder of the material guide is provided with a guide cone and a baffle. The small diameter end of the guide cone faces the air outlet of the first cage rotor. The baffle is located at the large diameter end of the guide cone and divides the second discharge port into upper and lower parts.

7. The raw material final grinding system according to claim 1, characterized in that, The shell is divided into an upper shell, a middle shell, and a lower shell from top to bottom. The feed inlet is located on the upper end face of the upper shell, and a first powder-selecting chamber is formed inside the upper shell. The middle shell includes an inner middle shell and an outer middle shell. The outer middle shell is located outside the inner middle shell. The upper end of the inner middle shell extends into the upper shell and is connected to the lower end of the guide vane. A second material discharge channel is formed between the inner middle shell and the inner guide cylinder. The lower end of the upper shell intersects with the outer middle shell to form a coarse powder collection area. The coarse powder outlet channel is connected to the coarse powder collection area. The lower end of the inner middle shell is connected to the lower shell, and a second powder-selecting chamber is formed inside the lower shell. The second powder-selecting chamber is connected to the second material discharge channel.

8. The raw material final grinding system according to claim 7, characterized in that, A speed-reducing and wear-resistant mechanism is provided in the second material discharge channel near the second powder selection chamber. The speed-reducing and wear-resistant mechanism includes multiple speed-reducing plates arranged in an alternating manner.

9. The raw material final grinding system according to claim 7 or 8, characterized in that, The inner shell is provided with a connecting window for connecting the coarse powder collection area and the second material discharge channel. A flap is provided on the inner shell at the location of the connecting window. The flap covers the connecting window and can be opened at a certain angle to realize the connection between the coarse powder collection area and the second material discharge channel.

10. The raw material final grinding system according to claim 1, characterized in that, The upper end face of the second cage rotor is provided with a second spreading disc, so that the material is thrown to form an annular material curtain; a baffle plate is provided on the second powder separation chamber located outside the second cage rotor, and the baffle plate is correspondingly provided with the second spreading disc.

11. The raw material final grinding system according to claim 1, characterized in that, The first air inlet channel is arranged tangentially or perpendicularly to the housing, and the air volume of the first air inlet channel accounts for 50-80% of the total air volume of the powder separator; The second air inlet channel is tangentially arranged with the shell, and the height of the second air inlet channel is the same as that of the second cage rotor. The air volume of the second air inlet channel accounts for 20-50% of the total air volume of the powder separator.

12. The raw material final grinding system according to claim 1, characterized in that, In the annular static grading mechanism, the bottom extension line of the upper-level guide plate or grading plate intersects with the lower-level grading plate or guide plate. The angle between the guide plate and the grading plate and the horizontal line is 30~65°.

13. A processing method using the raw material final grinding system according to any one of claims 1 to 12, characterized in that, Includes the following steps: After the raw materials are batched in a certain proportion at the batching station, they first pass through the iron remover and then enter the first screening device for screening pretreatment. The material on the screen of the first screening device enters the grinding equipment through the first elevator and the material stabilizing metering bin, and the material undersize of the first screening device enters the powder classifier. The pre-treated mixture enters the classifier through the feed inlet and falls onto the first spreading disc. After being spread by the rotation of the first spreading disc, the mixture falls into the annular static grading mechanism along the dispersion channel in the circumferential direction. The mixture moves downward along the staggered guide plates and grading plates, interacting with the horizontal airflow in the first air inlet channel. A portion of the material passes through the grading plate and moves towards the center to form a semi-finished product, while the remaining material falls into the coarse powder collection area. When the valve is open, it is finally discharged from the coarse material outlet channel. When the valve is closed, it flows into the second dropping channel through the flap action, mixes with the medium and fine powder, and falls into the deceleration and anti-wear mechanism for subsequent washing operations. Before the semi-finished product enters the guide vane grid with the airflow from the first air inlet channel, some coarse particles settle due to gravity and fall into the coarse powder collection area, where they are discharged along with the previously formed coarse powder. The remaining material flows to the first cage rotor for powder classification under the action of the guide vane grid. Under the rotational classification action of the first cage rotor, the material that passes through the first cage rotor forms finished product 1 and enters the cyclone separator from the second outlet for collection with the airflow from the first air inlet channel and under the action of the guide cone and baffles. The material that does not pass through the first cage rotor forms medium and fine powder, which is collected between the inner shell and the inner guide cylinder. The material falls through the second discharge channel to the deceleration and anti-wear mechanism. Under the action of the deceleration and anti-wear mechanism, it falls into the second spreading plate. The second spreading plate spreads the medium and fine powder along the circumference towards the baffle plate through the rotational spreading action. Through the deceleration and guiding action of the baffle plate, the medium and fine powder falls downward. Under the pulling force of the horizontal rotating airflow in the second air inlet channel, it moves to the second cage rotor for powder selection. Under the rotational grading action of the second cage rotor, the material passing through the second cage rotor forms finished product 2. With the airflow in the second air inlet channel, under the action of the guide cone and baffle, it enters the cyclone from the second discharge port for collection. Material that does not pass through the second cage rotor forms medium to coarse powder and is discharged from the first discharge port; The material from the first discharge port and coarse material outlet channel of the classifier is conveyed to the first elevator. The material distribution device is usually connected to the stable material metering bin, and in special cases, it is connected to the external discharge bin. Through the lifting and distribution action, the material enters the stable material metering bin. After being evenly distributed, the material enters the grinding equipment for crushing and grinding through the controlled feeding device. The crushed and ground material enters the second screening device for screening. The material on the screen of the second screening device is conveyed to the grinding equipment through the first elevator for further grinding. The material under the screen of the second screening device enters the second elevator and enters the feed port of the classifier again for sorting through the lifting action. Through the drying and multiple grading processes of the air classifier, the material exiting the finished product outlet of the air classifier's cyclone separator is conveyed by the finished product conveying device and enters the raw material homogenization system together with the dust collected by the dust collector.

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