Winnowing vertical roller mill for interval particle material production

Abstract

The invention belongs to the technical field of winnowing equipment, and particularly relates to a winnowing vertical roller mill for interval particle material production, which comprises a cylinder body, a grinding device arranged in a grinding cylinder and used for crushing and grinding materials, the material dispersing device is arranged in the material dispersing barrel, is positioned above the grinding device and is used for receiving and dispersing materials; the winnowing device is arranged in the winnowing cylinder and is used for carrying out set-interval particle sorting on the rising materials; the air inlet pipe is arranged along the tangential direction of the bulk material barrel; materials to be sorted enter the feeding cylinder and fall on the material scattering device, one part of the scattered materials fall into the grinding device to be ground and then discharged, and the other part of the scattered materials are carried to the winnowing device through ascending airflow. And the winnowing device separates and collects particles in a set interval, and other particles return to the grinding device to be ground again. According to the continuous winnowing machine, material grinding can be achieved, and continuous winnowing can be conducted on particles with the particle size ranging from 20 meshes to 150 meshes.

Description

Technical Field

[0001] This invention belongs to the field of air classification equipment technology, and particularly relates to an air classification vertical roller mill for the production of inter-zone particulate materials. Background Technology

[0002] In industries such as new energy battery raw material ore processing, high-quality building material sand production, and desulfurization agent preparation for electric furnaces, large quantities of particles with a particle size concentrated between 20-150 mesh (approximately 1 mm to 0.1 mm) are typically required (also known in the industry as fine sand products). Materials in this particle size range are neither traditional powders nor coarse particles, and their production and sorting place special demands on equipment performance.

[0003] Currently, the preparation process for particles in this range mainly relies on equipment such as sand making machines, vertical roller mills (disc crushers), and double roller crushers. However, these devices generally suffer from insufficient first-pass yield, meaning the output material is a mixture of coarse sand and qualified fine sand, requiring subsequent sorting processes to extract the fine sand of the target particle size. Existing sorting methods mainly include vibrating screens and air classifiers, but neither can meet the industrial continuous production requirements for this particle size range in terms of efficiency, accuracy, and stability.

[0004] While vibrating screens offer high screening efficiency, their screen meshes (especially those with meshes finer than 20 mesh) suffer severe wear due to prolonged exposure to material erosion. In processing materials containing high-hardness components (such as silica), such as ores used in new energy battery production, screen wear is further exacerbated, leading to frequent breakage. This not only causes production interruptions and high maintenance costs but also significantly increases the labor intensity of manually replacing screens, making it difficult to ensure long-term stable system operation.

[0005] For air-based powder classification, common air-based separators such as V-type classifiers are primarily designed for separating powders with smaller particle sizes. Although fine sand can be separated by adjusting the airflow, there is still a significant drawback of low separation accuracy. Increasing the airflow can remove some fine sand, but a large amount of the target fine sand remains in the coarse sand, and the finished fine sand product also contains a lot of coarse particles, resulting in a low product qualification rate.

[0006] In existing technologies, there are attempts to use vertical roller mills to grind materials and then use a classifier on the vertical roller mill to air classify particles in the above-mentioned particle size range. However, the structural design and airflow characteristics of vertical roller mills are mainly designed for grinding processes. The air velocity inside the cylinder is generally low and the material lifts high in the vertical roller mill. Sand particles in this particle size range cannot obtain sufficient upward momentum and are prone to fall back to the grinding disc for repeated grinding, resulting in over-grinding. If the air velocity is forcibly increased to enhance the material lifting capacity, it will cause the air velocity in the classifier zone to be too high, resulting in loss of classification accuracy and inability to stably obtain products of the target particle size. Summary of the Invention

[0007] To address the technical problems existing in the prior art, this application provides a vertical roller mill for producing particles with a particle size range of 20-150 mesh, which can both grind materials and continuously classify particles with a particle size range of 20-150 mesh.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A vertical roller mill for classifying particulate materials in inter-regional production, characterized in that it comprises: The cylinder body includes an air separator, a feed cylinder, a material dispersing cylinder, and a grinding cylinder connected sequentially from top to bottom; A grinding device, installed inside the grinding cylinder, is used to crush and grind materials; A material dispersing device is installed inside the material dispersing cylinder, located above the grinding device, for receiving and dispersing materials; An air separation device is installed inside the air separation cylinder to separate particles of rising material within a set range. The air duct system includes an air inlet pipe tangentially connected to the bulk material cylinder for providing upward airflow into the cylinder; In this process, the material to be sorted enters the feed cylinder and falls onto the material distribution device. Part of the scattered material falls into the grinding device, is ground, and then discharged. The other part is carried by the rising airflow to the air separation device. The air separation device separates and collects the particles in the set range, and the remaining particles are returned to the grinding device for re-grinding.

[0009] Preferably, a material collecting cone is provided inside the grinding cylinder, and a guide grate assembly is provided on the inner wall of the material collecting cone to prevent the airflow in the material dispersing cylinder from entering the grinding cylinder outside the material collecting cone. The material scattered by the material dispersing device can fall onto the grinding device through the guide grate assembly inside the material collecting cone.

[0010] Preferably, the guide grate assembly includes grate plates arranged circumferentially along the inner wall of the collecting cone. Each grate plate is inclined relative to the inner wall of the collecting cone. The inclination direction of the grate plate is consistent with the rotation direction of the spiral airflow introduced by the air inlet pipe. The grate plates are arranged in a fish-scale stacked manner, and a material drop gap is provided between two adjacent grate plates for material to fall.

[0011] Preferably, a lower air ring is provided on the inner wall of the bulk material cylinder outside the bulk material device, and the gap between the inner wall of the lower air ring and the outer side of the bulk material device gradually decreases from bottom to top, so as to accelerate the upward movement of the rising airflow.

[0012] Preferably, an upper air ring is provided at the lower part of the feed cylinder in contact with the upper end of the lower air ring. The inner diameter of the upper air ring gradually increases from bottom to top to stabilize the accelerated upward airflow.

[0013] Preferably, the grinding device includes a lower body, a drive device I disposed on the lower body, a grinding disc disposed inside the cylinder I and driven to rotate by the drive device I, a grinding roller assembly disposed on the frame and extending into the grinding cylinder to grind the material on the grinding disc, and a feeding pipe disposed on the lower body and communicating with the cylinder I.

[0014] Preferably, the bulk material handling device includes a support assembly fixedly connected to the bulk material cylinder, a second drive device fixedly connected to the support assembly, and a bulk material disc driven to rotate by the second drive device.

[0015] Preferably, the bulk material tray includes a tray body, an inverted conical guide cylinder coaxially fixedly connected to the lower end face of the tray body, and a rotating cylinder rotatably sleeved on the support assembly and fixedly connected to the lower end face of the guide cylinder.

[0016] Preferably, the air classifier includes a drive unit three disposed on the outer side of the upper part of the air classifier cylinder and an air classifier rotor disposed inside the air classifier cylinder and driven to rotate by the drive unit three.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves efficient and precise integrated processing and sorting, solving the problem of producing fine sand of specific particle sizes: It creatively integrates grinding, centrifugal dispersion, pneumatic conveying, and dynamic classification into a single vertical system. By optimizing the internal flow field and material trajectory, especially by utilizing a spiral upward airflow at a specific wind speed, it successfully achieves high-precision and high-efficiency sorting of particles in the 20-150 mesh target range.

[0018] 2. This invention avoids the screen wear problem of traditional vibratory screening by air separating particles in the target area, greatly improves the long-term stability of equipment operation and reduces maintenance costs. It solves the industry pain point of rapid screen wear and frequent replacement caused by hard materials (such as silica), significantly reduces equipment maintenance frequency, spare parts costs and labor intensity, and ensures the continuity and stability of production.

[0019] 3. Effectively suppresses over-grinding, improving system energy efficiency and finished product quality: By setting up a collecting cone and guide grate assembly, physical isolation and optimization are formed between the material falling channel and the airflow rising channel. This structure ensures that qualified fine particles are effectively carried away by the airflow, preventing them from falling back to the grinding disc for repeated grinding, while also guiding coarse particles smoothly into the grinding zone. Furthermore, the grinding disc in this invention eliminates the traditional material blocking structure of a vertical mill, allowing the crushed material to be discharged quickly, avoiding over-grinding.

[0020] 4. High sorting accuracy and efficiency, significantly improving product qualification rate: The air classifier and the stable spiral flow field formed by tangential air intake work together to accurately classify rising materials. Compared with traditional V-type air classifiers, it can more clearly separate target fine sand from coarse sand and fine powder, thereby greatly reducing the residual amount of fine sand in coarse sand and the amount of coarse particles mixed in the finished fine sand product, ensuring that the quality of the finished product consistently meets standards.

[0021] 5. By setting up a collecting cone and a guide grate assembly, the material falling channel and the airflow rising channel are physically separated and optimized. This ingeniously utilizes the motion characteristics of the gas-solid two-phase flow, ensuring that the material falls into the grinding zone efficiently and smoothly, while effectively preventing the rising airflow from entering the grinding cylinder and interfering with the grinding process. This stabilizes the internal flow field of the system, significantly improving classification accuracy and system operational stability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of the bulk material handling device according to an embodiment of the present invention.

[0024] Figure 3 for Figure 2 A magnified structural diagram at point B.

[0025] Figure 4 This is a schematic diagram of the support component according to an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure of the material distribution tray according to an embodiment of the present invention.

[0027] Figure 6 for Figure 1 An enlarged structural diagram of point A.

[0028] Figure 7 This is a schematic diagram of the orthographic projection of the inlet pipe, feed pipe, and material distribution tray according to an embodiment of the present invention.

[0029] Figure 8 This is a schematic diagram of the material collecting cone according to an embodiment of the present invention.

[0030] Figure 9 This is a schematic diagram of the grinding device according to an embodiment of the present invention.

[0031] Figure 10 This is a schematic diagram of the structure of the grinding disc according to an embodiment of the present invention.

[0032] In the diagram: 1. Cylinder body; 11. Air separator; 111. Finished product outlet; 12. Feed cylinder; 121. Feed pipe; 13. Dispersing cylinder; 14. Grinding cylinder. 2. Grinding device; 21. Lower body; 22. Drive unit one; 221. Grinding drive motor; 222. Grinding reducer; 23. Grinding disc; 231. Rotating surface; 232. Liner; 24. Frame; 25. Grinding roller assembly; 251. Transmission arm assembly; 252. Grinding roller assembly; 253. Base; 254. Working hydraulic cylinder; 255. Rocker arm; 26. Feed pipe. 3. Bulk Material Handling Device; 31. Support Assembly; 311. Support Rod; 312. Support Cylinder; 313. Support Taper Cylinder; 314. Connecting Flange; 315. Bearing Housing; 3151. Oil Seal; 3152. Thrust Taper Roller Bearing; 3153. Spacer; 3154. Deep Groove Ball Bearing; 3155. Gland; 316. Connecting Shaft; 3161. Step One; 3162. Step Two; 3163. Step Three; 3164. Step Four. 32. Drive unit two; 321. Bulk material reducer; 322. Bulk material drive motor. 33. Material tray; 331. Tray body; 3311. Tray surface; 3312. Tray cylinder; 3313. Bushing; 3314. Reinforcing plate; 332. Flow guide tube; 333. Rotating cylinder; 334. Cover plate. 4. Air classifier; 41. Drive unit three; 42. Air classifier rotor. 5. Air duct system, 51. Air inlet duct, 6. Collecting cone; 61. Collecting cylinder; 62. Drop cylinder; 63. Grate; 64. Drop gap. 7. Downwind ring, 8. Upwind ring. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", 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 this 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 limitations on this invention. Example

[0035] See appendix Figure 1As shown, a vertical roller mill for producing inter-area granular materials includes a cylinder 1, a grinding device 2, a material dispersing device 3, an air separation device 4, an air path system 5, a collecting cone 6, a lower air ring 7, and an upper air ring 8.

[0036] The cylinder 1 includes an air separator 11, a feed cylinder 12, a bulk material cylinder 13, and a grinding cylinder 14, which are detachably and fixedly connected by bolts from top to bottom and are interconnected.

[0037] See appendix Figure 9 As shown, the grinding device 2 is installed inside the grinding cylinder 14 and is used to crush and grind materials.

[0038] Specifically, the grinding device 2 includes a lower body 21, a drive device 22, a grinding disc 23, a frame 24, a grinding roller assembly 25, and a feeding pipe 26.

[0039] The lower body 21 is fixedly installed on the ground base, and the grinding cylinder 14 is fixedly connected to the upper end face of the lower body 21. The drive device 22 includes a grinding drive motor 221 and a grinding reducer 222 connected to the output shaft of the grinding drive motor 221 via a coupling. The output shaft of the grinding reducer 222 is vertically arranged and rotatably passes through the grinding cylinder 14. A grinding disc 23 is fixedly connected to the output shaft of the grinding reducer 222 in the grinding cylinder 14. Thus, the drive device 22 can drive the grinding disc 23 to rotate horizontally.

[0040] See appendix Figure 10 As shown, the grinding disc 23 includes a rotating surface 231 and a liner 232 fixedly embedded in the rotating surface 231. The edge of the liner 232 is arc-shaped and transitions to the outer edge of the rotating surface 231.

[0041] See appendix Figure 9 As shown, the grinding roller assembly 25 is mounted on the frame 24 and extends into the grinding cylinder 14 to grind the material on the grinding disc 23.

[0042] Specifically, the grinding roller assembly 25 includes a transmission arm assembly 251 rotatably connected to the frame 24, a grinding roller assembly 252 rotatably connected to the transmission arm assembly 251, a base 253 set on the ground base, a working hydraulic cylinder 254 hinged to the base 253, and a rocker arm 255 fixedly connected to the transmission arm assembly 251. The telescopic rod of the working hydraulic cylinder 254 is hinged to the lower end of the rocker arm 255.

[0043] Multiple grinding roller assemblies 25 are provided. When the telescopic rod of the working hydraulic cylinder 254 extends, it can drive the rocker arm 255 to rotate, thereby causing the grinding roller assembly 252 to rotate away from the liner 232 on the rotating surface 231. When the telescopic rod of the working hydraulic cylinder 254 retracts, it can drive the rocker arm 255 to rotate, thereby causing the grinding roller assembly 252 to rotate toward the liner 232 on the rotating surface 231.

[0044] It should be noted that the grinding device 2 in this embodiment is similar in structure and working principle to the existing vertical roller mill. The difference is that the grinding disc 23 in this embodiment eliminates the material blocking structure of the traditional vertical mill. That is, the grinding disc 23 is provided with a rotating surface 231 and a liner 232, but no material blocking structure higher than the upper end of the rotating surface 231 is provided on the rotating surface 231, so that the crushed material can be discharged quickly and over-grinding is avoided. In addition, the lower body 21 of the grinding device 2 in this embodiment eliminates the air inlet of the traditional vertical mill and adds a feed pipe 26. The feed pipe 26 is fixedly connected to the lower body 21 and communicates with the inner cavity of the grinding cylinder 14. The material falling from the grinding disc 23 can be discharged through the feed pipe 26.

[0045] See appendix Figure 2 , 3 As shown, the bulk material device 3 is disposed inside the bulk material cylinder 13 and is located above the grinding device 2. It is used to receive the material falling from the feed cylinder 12 and to scatter the material to the outside of the bulk material device 3. The bulk material device 3 includes a support assembly 31 fixedly connected to the bulk material cylinder 13, a second drive device 32 fixedly connected to the support assembly 31, and a bulk material disc 33 driven to rotate by the second drive device 32.

[0046] See Figure 2 , 4 As shown, the support assembly 31 includes a support rod 311 horizontally fixedly welded to the inner wall of the lower opening of the bulk material cylinder 13, a support cylinder 312 with a hollow interior and cylindrical structure vertically welded to the upper end of the support rod 311, a support cone cylinder 313 with a hollow interior and conical structure welded to the upper end of the support cylinder 312, a connecting flange 314 horizontally welded to the upper end face of the support cone cylinder 313, a bearing chamber 315 fixedly connected to the upper end of the connecting flange 314 by bolts, a bearing assembly fixedly embedded in the bearing chamber 315, and a connecting shaft 316 embedded in the bearing assembly.

[0047] Specifically, the bearing assembly includes, from bottom to top, an oil seal 3151, a thrust tapered roller bearing 3152, a spacer 3153, a deep groove ball bearing 3154, and a gland 3155, which are fixedly embedded in the bearing housing 315. The gland 3155 is fixedly connected to the upper end face of the bearing housing 315 by bolts and abuts against the outer ring of the deep groove ball bearing 3154. The upper and lower end faces of the spacer 3153 abut against the deep groove ball bearing 3154 and the thrust tapered roller bearing 3152, respectively. The connecting shaft 316 has a multi-step structure from top to bottom, such as step one 3161, step two 3162, step three 3163, and step four 3164. Step two 3162, step three 3163, and step four 3164 abut against the inner ring of the deep groove ball bearing 3154, the thrust tapered roller bearing 3152, and the upper end of the oil seal 3151, respectively.

[0048] The second drive unit 32 includes a bulk material reducer 321 fixedly mounted on the lower end face of the connecting flange 314 via a flange, and a bulk material drive motor 322 fixedly mounted on the bulk material reducer 321. The output shaft of the bulk material drive motor 322 is connected to the input shaft of the bulk material reducer 321 via a coupling. The output shaft of the bulk material reducer 321 can drive through the connecting flange 314 and extend above it, and is then fixedly connected to the connecting shaft 316 via a coupling. With the above structure, the bulk material drive motor 322 can drive the connecting shaft 316 to rotate.

[0049] See Figure 5 As shown, the bulk material tray 33 includes a tray body 331, an inverted conical guide cylinder 332 coaxially fixedly connected to the lower end face of the tray body 331, and a rotating cylinder 333 welded to the lower end face of the guide cylinder 332 and rotatably sleeved on the support cylinder 312 of the support assembly 31.

[0050] To reduce the weight of the tray body 331 while ensuring its structural strength, in this embodiment, the tray body 331 includes a disc-shaped tray surface 3311, a tray cylinder 3312 vertically welded to the lower end face of the tray surface 3311, a bushing 3313 vertically welded to the center of the tray surface 3311, and multiple reinforcing plates 3314 welded at both ends to the outer circumference of the bushing 3313 and the inner wall of the tray cylinder 3312, respectively. The upper end face of the guide cylinder 332 is welded to the lower end face of the tray cylinder 3312. The tray cylinder 3312, the guide cylinder 332, and the rotating cylinder 333 are all hollow structures.

[0051] The upper end of the connecting shaft 316 passes through the bushing 3313 and is circumferentially limited by a key connection. A cover plate 334 is provided on the upper end of the bushing 3313, and fastening bolts pass through the cover plate 334 and are threaded into the connecting shaft 316. The lower end face of the bushing 3313 abuts against the upper end face of the step 3161, thereby axially limiting the material distribution disc 33. Since the rotating cylinder 333 is rotatably sleeved on the supporting cylinder 312, a rotational clearance is provided between the inner wall of the rotating cylinder 333 and the outer circumference of the supporting cylinder 312.

[0052] See Figure 1 , 7 As shown, the air duct system 5 includes an air inlet pipe 51 that is tangentially connected to the bulk material cylinder 13. The air duct system 5 is used to provide rising airflow into the cylinder 1.

[0053] Specifically, the air inlet pipe 51 is fixedly connected to the bulk material cylinder 13 along the tangential direction. Thus, the external centrifugal fan blows high-pressure airflow into the bulk material cylinder 13 through the air inlet pipe 51, and forms a spiral upward airflow in the space between the outer side of the bulk material device 3 and the inner wall of the bulk material cylinder 13.

[0054] The feed pipe 121 is fixedly welded to the feed cylinder 12 at an angle. The outlet of the feed pipe 121 is located above the disc surface 3311. The material falls onto the disc surface 3311 through the feed pipe 121. The feed pipe 121 and the air inlet pipe 51 are projected in the top view direction.

[0055] See Figure 6 As shown, in order to increase the wind speed of the spiral upward airflow entering the bulk material cylinder 13, thereby providing sufficient upward force for particles in the 20-150 mesh range to be sorted by the air classifier 4, a lower air ring 7 is provided on the inner wall of the bulk material cylinder 13 outside the bulk material device 3, and an upper air ring 8 is provided at the lower part of the feed cylinder 12 in contact with the upper end of the lower air ring 7.

[0056] The downwind ring 7 is a hollow conical structure with its inner diameter gradually decreasing from bottom to top. The upwind ring 8 is a hollow inverted conical structure with its inner diameter gradually decreasing from top to bottom. The inner diameters of the downwind ring 7 and the upwind ring 8 are the same at the joint.

[0057] The acceleration gap between the inner wall of the lower air ring 7 and the outer side of the guide tube 332 of the material distribution device 3 gradually decreases from bottom to top, reaching its minimum at the material tray cylinder 3312, which is also the point of maximum wind speed. Through the acceleration gap, the rising airflow can be accelerated upward. Since the inner diameter of the upper air ring 8 gradually increases linearly from bottom to top, it stabilizes the rising airflow that has been accelerated and enters the feed cylinder 12, thereby avoiding harmful eddies caused by a sudden increase in space.

[0058] In practical applications, the angle α between the downwind ring 7 and the bulk material cylinder 13 is 15°, which has the best acceleration and sorting effect on fine sand in the 20-150 mesh range.

[0059] See Figure 1 As shown, the air separation device 4 is installed inside the air separation cylinder 11 and is used to separate particles of the rising material within a set range.

[0060] The air classifier 4 includes a drive unit 3 41 fixedly installed on the outer side of the upper part of the air classifier cylinder 11, and an air classifier rotor 42 disposed inside the air classifier cylinder 11 and driven to rotate by the drive unit 3 41. The drive unit 3 41 can be an existing motor + reducer drive mechanism, and the air classifier rotor 42 is an existing classifier cage rotor, that is, the air classifier 4 can adopt the dynamic classifier structure used on existing vertical roller mills. There are gaps between the blades on the air classifier rotor 42. Material that meets the particle size requirements enters the inner cavity of the air classifier rotor 42 through the gaps of the rotating air classifier rotor 42, and is collected by dust collection equipment such as a pulse dust collector through one or more finished product outlets 111 provided on the air classifier cylinder 11.

[0061] See Figure 1As shown, in actual production of this air-classifying vertical roller mill, the finished product outlet 111 of the air classifier 11 is connected to the inlet of the existing pulse dust collector, the outlet of the pulse dust collector is connected to the air inlet of the centrifugal fan, and the air outlet of the centrifugal fan is connected to the air inlet pipe 51, so that the air blown out by the centrifugal fan is circulated. During this process, a negative pressure zone will be formed in the air classifier 11, and the airflow entering the bulk material cylinder 13 from the air inlet pipe 51 will be in a spiral upward state. In this embodiment, in order to further prevent the air entering the bulk material cylinder 13 from entering the grinding cylinder 14, which would cause the air pressure of the rising airflow to decrease and the material on the grinding disc 23 to be blown up, a material collecting cone 6 is provided in the grinding cylinder 14.

[0062] See Figure 8 As shown, the collecting cone 6 includes a hollow, inverted cone-shaped collecting cylinder 61 and a discharge cylinder 62 coaxially welded to the lower end of the collecting cylinder 61.

[0063] A guide grate assembly is welded to the inner wall of the collecting cylinder 61 to prevent the airflow in the bulk material cylinder 13 from entering the grinding cylinder 14 outside the collecting cone 6. The material scattered by the bulk material device 3 can fall onto the grinding disc 23 of the grinding device 2 through the guide grate assembly in the collecting cone 6.

[0064] The guide grate assembly includes grate plates 63 evenly welded circumferentially along the inner wall of the collecting cylinder 61. Each grate plate 63 is inclined relative to the inner wall of the collecting cylinder 61, and the inclination direction of the grate plate 63 is consistent with the rotation direction of the spiral airflow introduced by the air inlet pipe 51, i.e. Figure 8 As shown, when the spiral airflow entering the bulk material cylinder 13 rotates counterclockwise, the tilting direction of each grate 63 is from the upper left to the lower right, that is, the spiral airflow will blow towards the outer side of each grate 63. The grate 63 are arranged in a fish scale-like stacked manner, and a material drop gap 64 is provided between two adjacent grate 63 for the material to fall.

[0065] By setting up the flow guide grate assembly, the rotating airflow is blocked from entering the grinding cylinder 14, and the material falling from the disc surface 3311 can fall onto the grinding disc 23 through the collecting cone 6. In other embodiments, multiple sets of flow guide grate assemblies can be arranged vertically.

[0066] The working principle and process of this embodiment are as follows: The air-classifying vertical roller mill of this invention is used in conjunction with existing dust collectors, fans, and supporting pipelines. The finished product outlet 111 of the air classifier 11 is connected to the inlet of an existing dust collector (such as a pulse dust collector), the outlet of the dust collector is connected to the inlet of a centrifugal fan, and the outlet of the centrifugal fan is connected to the inlet pipe 51, thereby allowing the air blown by the centrifugal fan to circulate between the air-classifying vertical roller mill, the dust collector, and the centrifugal fan of this invention. During this process, a negative pressure zone is formed inside the air classifier 11, and the airflow entering the bulk material cylinder 13 from the inlet pipe 51 is in a spiral upward state.

[0067] When the vertical roller mill of the air classifier of the present invention is running, the third drive device 41 drives the air classifier rotor 42 to rotate, the second drive device 32 drives the material distribution disc 33 to rotate, and the first drive device 21 drives the grinding disc 23 to rotate. The air blown out by the centrifugal fan enters the bulk material cylinder 13 from the air inlet pipe 51 along the cylinder wall of the bulk material cylinder 13. Due to the presence of the collecting cone 6 and the grate plate 63, the downward path of the air is blocked. Therefore, the air entering the bulk material cylinder 13 can only go upward. In the annular channel formed by the bulk material cylinder 13 and the bulk material plate 33, it spirals through the lower air ring 7 and the upper air ring 8 and continues upward to reach the air separator 11. It then enters the finished product outlet 111 and the subsequent dust collector through the inner cavity of the air separator rotor 42. As the air passes through the lower air ring 7, the acceleration gap between the lower air ring 7 and the inner wall and the outer side of the guide tube 332 of the material distribution device 3 gradually decreases from bottom to top, which can accelerate the upward movement of the rising airflow. As the inner diameter of the upper air ring 8 gradually increases linearly from bottom to top, it stabilizes the rising airflow that has been accelerated and enters the feed tube 12, so as to avoid harmful eddies caused by the sudden increase in space. Material enters the feed cylinder 12 through the feed pipe 121 and falls onto the disc surface 3311. Under the centrifugal force of the rotating disc body 331, the material on the disc surface 3311 moves towards the edge of the disc surface 3311. After reaching the edge of the disc surface 3311 and detaching from it, the material is accelerated and blown up by the airflow accelerated by the acceleration gap. Smaller particles move upward with the wind under the action of the airflow accelerated by the lower air ring 7. Some particles within the particle size range (20-150 mesh) pass through the inner cavity of the air classifier rotor 42 and are discharged from the finished product outlet 111 and collected by the collecting equipment. Material larger than the particle size range and not within the particle size range is blocked by the air classifier rotor 42 and falls onto the disc surface 3311 or directly falls into the collecting cone 6 through the acceleration gap. Larger particles falling from the edge of the disc surface 3311 into the acceleration gap continue to fall. The material falls onto the grinding disc 23 through the collecting cylinder 61, the dropping gap 64, and the dropping cylinder 62. When the material forms a layer on the grinding disc 23, the working hydraulic cylinder 254 presses the grinding roller assembly 252, causing the grinding rollers on the grinding roller assembly 252 to press against the material layer on the grinding disc 23. Under the action of centrifugal force, the material moves to the outside of the grinding disc 23. After being crushed in the meshing area of ​​the grinding rollers and the grinding disc 23, it continues to move to the outside under the action of centrifugal force. Because the material blocking device is eliminated compared to the grinding disc of a traditional vertical mill, the material can move quickly to the edge of the grinding disc 23, avoiding over-grinding. The crushed material finally falls from the edge of the grinding disc 23 and is discharged from this air-classifying vertical roller mill through the discharge pipe 26. The discharged material can be lifted by the existing lifting device into the feed pipe 121 of this air-classifying vertical roller mill and re-enter the sorting cycle.

[0068] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vertical roller mill for air classification in the production of inter-stage granular materials, characterized in that, include: The cylinder body includes an air separator, a feed cylinder, a material dispersing cylinder, and a grinding cylinder connected sequentially from top to bottom; A grinding device, installed inside the grinding cylinder, is used to crush and grind materials; A material dispersing device is installed inside the material dispersing cylinder, located above the grinding device, for receiving and dispersing materials; An air separation device is installed inside the air separation cylinder to separate particles of rising material within a set range. The air duct system includes an air inlet pipe tangentially connected to the bulk material cylinder for providing upward airflow into the cylinder; In this process, the material to be sorted enters the feed cylinder and falls onto the material distribution device. Part of the scattered material falls into the grinding device, is ground, and then discharged. The other part is carried by the rising airflow to the air separation device. The air separation device separates and collects the particles in the set range, and the remaining particles are returned to the grinding device for re-grinding.

2. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 1, characterized in that, A material collecting cone is provided inside the grinding cylinder. A guide grate assembly is provided on the inner wall of the material collecting cone to prevent the airflow in the material dispersing cylinder from entering the grinding cylinder outside the material collecting cone. The material scattered by the material dispersing device can fall onto the grinding device through the guide grate assembly inside the material collecting cone.

3. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 2, characterized in that, The guide grate assembly includes grate plates arranged circumferentially along the inner wall of the collecting cone. Each grate plate is inclined relative to the inner wall of the collecting cone. The inclination direction of the grate plate is consistent with the rotation direction of the spiral airflow introduced by the air inlet pipe. The grate plates are arranged in a fish-scale stacked manner, and a material drop gap is provided between two adjacent grate plates for material to fall.

4. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 1, characterized in that, A lower air ring is provided on the inner wall of the bulk material cylinder outside the bulk material device. The gap between the inner wall of the lower air ring and the outer side of the bulk material device gradually decreases from bottom to top, so as to accelerate the upward movement of the rising airflow.

5. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 4, characterized in that, An upper air ring is provided at the lower part of the feed cylinder, which is in contact with the upper end of the lower air ring. The inner diameter of the upper air ring gradually increases from bottom to top to stabilize the accelerated upward airflow.

6. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 1, characterized in that, The grinding device includes a lower body, a drive device I mounted on the lower body, a grinding disc mounted inside the cylinder and driven to rotate by the drive device I, a grinding roller assembly mounted on the frame and extending into the grinding cylinder to grind the material on the grinding disc, and a feeding pipe mounted on the lower body that communicates with the cylinder I.

7. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 1, characterized in that, The bulk material handling device includes a support assembly fixedly connected to the bulk material cylinder, a second drive device fixedly connected to the support assembly, and a bulk material disc driven to rotate by the second drive device.

8. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 7, characterized in that, The material tray includes a tray body, an inverted conical guide cylinder coaxially fixedly connected to the lower end face of the tray body, and a rotating cylinder rotatably sleeved on the support assembly and fixedly connected to the lower end face of the guide cylinder.

9. The air-classifying vertical roller mill for producing intermittent granular materials according to claim 1, characterized in that, The air classifier includes a drive unit 3 installed on the upper outer side of the air classifier cylinder and an air classifier rotor installed inside the air classifier cylinder and driven to rotate by the drive unit 3.

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