In-mill straight-return material guide structure for materials of vertical mill

Abstract

The invention relates to the technical field of vertical mills, in particular to a vertical mill material in-mill straight return material guide structure which comprises a material guide support and a material guide assembly. The snakelike material guide groove is in a spiral rising shape and lifts materials thrown out by the millstone to a certain height from the edge of the millstone, and the material guide assembly is used for providing centripetal force for the materials, overcoming gravitational potential energy and guiding the thrown large-particle-size materials to return to the millstone again; kinetic energy generated when large-particle-size materials are thrown out of the millstone is recycled, the kinetic energy is converted into potential energy through the snakelike material guiding groove, the materials are lifted to a certain height, then the materials return to the millstone under the gravity effect and the guiding of the material returning groove, and the falling point distribution and the material distribution form of the materials on the millstone are accurately controlled through the arrangement of the multiple sets of material guiding assemblies. And in cooperation with the rotating millstone, it is ensured that the materials are still located in the millstone grinding belt H before being thrown out of the millstone again, zero energy consumption of short-distance circulation in the mill of the large-particle-size materials is achieved through the targeted feeding mode, and the grinding efficiency of the vertical mill device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vertical mills, and more specifically, to a direct return material guiding structure inside the mill for materials used in a vertical mill. Background Art

[0002] A vertical mill is an energy-saving grinding equipment. Its working principle is that a grinding structure composed of grinding rollers and a grinding table applies pressure to the materials on the table to crush the materials and produce products with the target particle size. When the vertical mill is working, after the materials are fed into the vertical mill, they fall onto the grinding table. The grinding table rotates and throws the materials towards the edge. When the materials reach the crushing area, they are crushed under high pressure. The crushed materials are thrown out from the edge of the grinding table and are transported out of the vertical mill. They are lifted by an external circulation elevator to a sorting or screening device. Qualified products are selected, and the unqualified part (materials with large particle sizes) is fed back into the vertical mill to continue crushing. This process repeats.

[0003] An air extraction device provided in the vertical mill grinding system forms an upward air flow inside the vertical mill, making the finely ground particle materials suspended and transported to the classifier. Since the grinding of the vertical mill belongs to unrestricted grinding, when the materials pass through the grinding roller crushing area, not all materials can be crushed, and the crushed materials cannot all meet the requirements of the product particle size at one time. Therefore, there are a large number (at least more than 50%) of non-product materials with large particle sizes in the materials thrown out by the grinding table of the vertical mill. The existing common technology for returning this part of the materials to the grinding table of the vertical mill is to transport them back through an elevator outside the vertical mill. However, when dealing with a large amount of materials, the motor power requirement of the elevator increases significantly, resulting in a relatively high overall energy consumption. In addition, in the external circulation device, the unqualified materials slide into the bottom discharge port under the action of gravity. The materials discharged from the mill are transported through a conveyor in the horizontal conveying section and through an elevator in the vertical lifting section to the top of the mill, and finally the materials are sent back to the feeding system again. This process includes a material discharge stage, a mechanical conveying stage, and a classification return stage. The path that the materials pass through in the whole process is relatively long, so the required time is relatively long, which may affect the grinding efficiency. Secondly, the materials collide with the equipment during the conveying process, which will accelerate the wear of the shell, generate relatively large noise, and have an adverse impact on the working environment. At the same time, the stability of the external circulation device is greatly affected by the material characteristics. When the material particle size is too large or the moisture content is too high, it is easy to cause blockage in the elevator or conveying pipeline.

[0004] Therefore, the present invention provides a direct return material guiding structure inside the mill for materials that can realize the circulation of large particle size materials inside the vertical mill. This device does not require additional power configuration and belongs to a power-free and zero-energy consumption vertical mill grinding material circulation technology. Summary of the Invention

[0005] In view of the problems of high energy consumption and low grinding efficiency of the material circulation device of the vertical mill in the prior art, the present invention provides a direct return material guiding structure inside the mill for a vertical mill.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a direct return material guiding structure inside the mill for a vertical mill, including a material guiding support and a material guiding component; the material guiding component includes a serpentine material guiding groove and a return material groove. The serpentine material guiding groove is in a spiral rising shape, lifting the material thrown by the grinding table from the edge of the grinding table to a certain height. The center line of the serpentine material guiding groove is a cylindrical helix, and its projection on the horizontal plane is an arc. The diameter of the arc is larger than the diameter of the grinding table. The bending design reduces the requirement for the inner diameter size of the vertical mill housing. The bottom of the serpentine material guiding groove is a groove bottom plate inclined towards the center of the grinding table of the vertical mill device. The inclination angle of the middle section of the groove bottom plate towards the center of the vertical mill becomes smaller as the height of the serpentine material guiding groove increases, reducing the acceleration of the lateral movement of the material during the upward decelerating spiral movement and reducing the wear on the serpentine material guiding groove. The material guiding component is used to provide centripetal force for the material and overcome the gravitational potential energy, guiding the large particle size material thrown out to return to the grinding table again.

[0007] Preferably, multiple groups of the material guiding components are arranged on the periphery of the grinding table of the vertical mill device, and the height of each material guiding component is the same. The spiral lift angle of each serpentine material guiding groove is different. The closer it is to the next grinding roller, the larger its spiral lift angle and the shorter the length of the serpentine material guiding groove. The material guiding support corresponds to the material guiding component.

[0008] Preferably, the material guiding component further includes a connecting plate. The connecting plate is integrally annular and is located below the serpentine material guiding groove. There are transition plates with smooth transitions between the connecting plate and multiple serpentine material guiding grooves.

[0009] Preferably, the side of the connecting plate close to the edge of the grinding table is smoothly arranged and the connecting plate is not connected to the grinding table.

[0010] Preferably, the return material groove includes an upper groove and a lower groove. The upper end of the serpentine material guiding groove is fixedly connected to the upper groove, and one end of the upper groove far from the serpentine material guiding groove is rotatably connected to the lower groove. The lower groove is inclined downward towards the grinding table.

[0011] Preferably, the serpentine material guiding groove further includes a groove bottom plate and a baffle fixedly connected to the side of the groove bottom plate far from the grinding table.

[0012] Preferably, the connecting plate is alternately provided with material leakage holes and material leakage grooves. The material leakage holes are located below the transition plate, and the material leakage grooves are located outside the grinding rollers, and the number of material leakage grooves is the same as the number of grinding rollers.

[0013] Preferably, the connecting plate is provided with a material leakage groove, and there is a serrated connection port at its edge connected to a transition plate. The transition plate is provided with material leakage holes. The material leakage grooves are located outside the grinding rollers, and the number of material leakage grooves is the same as the number of grinding rollers. The serpentine material guiding groove further includes a groove bottom plate and a baffle fixedly connected to the bottom side of the groove bottom plate.

[0014] Preferably, the material guiding bracket includes a supporting component and an adjusting component. One end of each of the supporting component and the adjusting component is fixedly connected to the inner wall of the housing, and the other end of each is corresponding to the material guiding component. The end of the supporting component away from the inner wall of the housing is fixedly connected to the lower end of the material guiding component, and the end of the adjusting component away from the inner wall of the housing is movably connected to the material return chute. The adjusting component is located at the bottom of the supporting component.

[0015] Preferably, diversion holes are respectively formed on both sides of the trough bottom plate.

[0016] Advantages of the present invention: (1) For the in-mill direct return material guiding structure for a vertical mill described in the present invention, the kinetic energy when large particle size materials are thrown out from the grinding table is recycled. The kinetic energy is converted into potential energy through the serpentine material guiding groove to lift the materials to a certain height. Then, under the action of gravity and the guiding of the material return chute, the materials return to the grinding table. The arrangement of multiple groups of material guiding components precisely controls the landing distribution and the feeding pattern of the materials on the grinding table. Cooperating with the rotating grinding table, it ensures that the materials can reach the grinding belt of the grinding table before being thrown out of the grinding table again. The zero-energy consumption of the short-distance in-mill circulation of large particle size materials is achieved by the targeted feeding method, improving the grinding efficiency of the vertical mill device.

[0017] (2) For the in-mill direct return material guiding structure for a vertical mill described in the present invention, the arrangement of the diversion holes, in cooperation with the upward airflow inside the vertical mill device, can provide auxiliary force for the large particle size materials to a certain extent to assist the large particle size materials to move upward along the serpentine material guiding groove.

[0018] (3) For the in-mill direct return material guiding structure for a vertical mill described in the present invention, the large particle size materials thrown out of the grinding table are directly returned inside the device, reducing the external circulation amount of the materials, reducing the specifications and power consumption of the external circulation lifting device, and reducing the investment cost and operation cost of the external circulation of the vertical mill materials.

[0019] (4) For the in-mill direct return material guiding structure for a vertical mill described in the present invention, the impact and erosion of the materials on the mill housing after being thrown out by the grinding table are reduced, and the wear of the mill housing is reduced. Description of the Drawings

[0020] The present invention will be further described below with reference to the drawings and embodiments.

[0021] Figure 1 It is the overall structure schematic diagram provided by the present invention; Figure 2 It is the connection schematic diagram of the material guiding bracket and the material guiding component provided by the present invention; Figure 3 It is the connection schematic diagram of the material guiding component and the grinding table provided by the present invention; Figure 4Schematic diagram of the connection between the snake-shaped material guiding trough and the return material trough provided by the present invention; Figure 5 Schematic diagram of the material movement trajectory provided by the present invention; Figure 6 Top view schematic diagram of the return material trough provided by the present invention; Figure 7 Schematic diagram of the connection between the adjusting component and the return material trough provided by the present invention; Figure 8 Schematic diagram of the changing trend of the inclination angle of the trough bottom plate towards the center of the vertical mill when the trough bottom plate changes from low to high provided by the present invention; Figure 9 Schematic diagram of the first perspective of the straightened state of the trough bottom plate provided by the present invention; Figure 10 Schematic diagram of the second perspective of the straightened state of the trough bottom plate provided by the present invention; Figure 11 Schematic diagram of the connecting plate provided by the present invention; Figure 12 Schematic diagram of the connection between the connecting plate in another form and the return material trough provided by the present invention; Figure 13 Schematic diagram of the structure of the snake-shaped material guiding trough in another form provided by the present invention.

[0022] In the figure: 1. Material guiding support; 11. Support component; 12. Adjusting component; 2. Material guiding component; 21. Snake-shaped material guiding trough; 211. Trough bottom plate; 212. Baffle; 22. Return material trough; 221. Upper trough; 222. Lower trough; 23. Transition plate; 24. Connecting plate; 25. Leakage hole; 26. Diversion hole; 27. Leakage trough; 3. Material width-to-thickness ratio adjusting component. Detailed implementation manners

[0023] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific implementation manners.

[0024] Example 1: As Figures 1 - 11As shown in the figure, a direct return material guiding structure inside a vertical mill according to the present invention includes a material guiding support 1 and a material guiding assembly 2; the material guiding assembly 2 includes a serpentine material guiding groove 21 and a return material groove 22. The serpentine material guiding groove 21 is in a spiral ascending shape, which lifts the material thrown out by the grinding table from the edge of the grinding table to a certain height. The center line of the serpentine material guiding groove 21 is a cylindrical helix, and its projection on the horizontal plane is an arc, and the diameter of the arc is larger than the diameter of the grinding table. The bending design reduces the requirement for the inner diameter size of the vertical mill housing. The bottom of the serpentine material guiding groove 21 is a groove bottom plate 211 inclined towards the center of the grinding table of the vertical mill device. The inclination angle of the middle section of the groove bottom plate 211 towards the center of the vertical mill becomes smaller as the height of the serpentine material guiding groove 21 increases, reducing the lateral movement acceleration of the material during the upward decelerating spiral movement and reducing the wear on the serpentine material guiding groove 21. The material guiding assembly 2 is used to provide centripetal force for the material and overcome the gravitational potential energy, guiding the thrown large-particle-size material back to the grinding table again.

[0025] In this embodiment, the material enters the device housing from the top of the vertical mill device and drops onto the grinding table. The grinding table is driven by a motor at the bottom of the grinding table to rotate, and a fixed set of grinding rollers cooperate to grind the material. The fine-particle material is discharged and collected outside the vertical mill device under the action of the air extraction device above the grinding table. When the grinding table rotates, the material on the grinding table moves outward under the action of centrifugal force. Part of the material slides out from the edge of the grinding table onto the connecting plate 24, and the smaller-particle-size material leaks out through the leakage holes 25 on the connecting plate 24. This part of the material is discharged from the lower discharge port of the mill and re-fed into the mill from the top of the vertical mill device under the action of the external circulation device. The large-particle-size material cannot pass through the leakage holes 25 and moves upward under the guiding action of the transition plate 23 and the serpentine material guiding groove 21. Each upper end of the serpentine material guiding groove 21 is connected to a return material groove 22. When reaching the highest point of the serpentine material guiding groove 21, it returns to the grinding table again under the action of gravity and the guidance of the return material groove 22, realizing the circulation of the large-particle-size material inside the vertical mill device and reducing the external circulation volume. The lengths of the serpentine material guiding grooves 21 of each material guiding assembly 2 are different to adapt to the distance change between the material guiding assembly 2 and the grinding roller. The closer the serpentine material guiding groove 21 is to the next grinding roller, the shorter its length. Since the height of the serpentine material guiding groove 21 remains unchanged, it means that its inclination angle is larger, so that the material can return to the grinding table under the guidance of each group of material guiding assemblies 2 and can be targeted and fed into the grinding belt H of the grinding table.

[0026] As Figures 1 - 5As shown, multiple sets of material guiding components 2 are arranged on the periphery of the grinding table of the vertical mill device, and the height of each material guiding component 2 is the same. The spiral lift angles of each serpentine material guiding groove 21 are different, and the closer it is to the next grinding roller, the larger its spiral lift angle and the shorter the length of the serpentine material guiding groove 21. The material guiding bracket 1 corresponds to the material guiding component 2; the serpentine material guiding groove 21 further includes a groove bottom plate 211 and a baffle 212 fixedly connected to the side of the groove bottom plate 211 away from the grinding table; the material guiding component 2 further includes a connecting plate 24. The connecting plate 24 is integrally annular and is located below the serpentine material guiding groove 21. There are transition plates 23 with smooth transitions between the connecting plate 24 and multiple serpentine material guiding grooves 21; the return material groove 22 includes an upper groove 221 and a lower groove 222. The upper end of the serpentine material guiding groove 21 is fixedly connected to the upper groove 221, and one end of the upper groove 221 away from the serpentine material guiding groove 21 is rotatably connected to the lower groove 222. The lower groove 222 is inclined downward toward the grinding table; the side of the connecting plate 24 close to the edge of the grinding table is smoothly arranged and the connecting plate 24 is not connected to the grinding table.

[0027] In this embodiment, after the material enters the serpentine guide chute 21 through screening, material diversion is achieved as the material slides along the serpentine guide chute 21. When the vertical mill device operates, fine particle material rises with the airflow under the action of the air extraction device in the mill and is discharged outside the vertical mill device for collection. The inclination angle of the bottom plate 211 of the serpentine guide chute 21 towards the center of the vertical mill matches the initial kinetic energy of the grinding table. When the grinding table rotates, the guide component 2 is not affected by the rotation of the grinding table. The rotating grinding table throws the material out. There is a leakage groove 27 at the connecting plate 24 outside the two grinding rollers. The material thrown to this place is either ground by the grinding rollers or directly falls outside the mill through the leakage groove 27 and enters the external circulation device. The material thrown onto the connecting plate 24 is screened through the leakage holes 25. Large particle size material that cannot pass through the leakage holes 25 starts to move upward along the serpentine guide chute 21. The return chute 22 connected to the higher end of the serpentine guide chute 21 bends and inclines towards the grinding table. The return chute 22 includes an upper chute 221 and a lower chute 222. The upper chute 221 is fixedly connected to the upper end of the serpentine guide chute 21, and the lower chute 222 is movably connected to the end of the upper chute 221 away from the serpentine guide chute 21. The side wall of the lower chute 222 is provided with a sliding groove, so that the lower chute 222 has an adjustment space when pulled by the electric telescopic rod. The height of the lower end of the lower chute 222 can be adjusted slightly under the action of the adjustment component 12. When the height of the lower end of the lower chute 222 is adjusted, its upper end is always in a connected state with the upper chute 221. When the large particle size material separates from the guide component 2, it falls onto the grinding table. If there is no return chute 22 facing the grinding table at the end, the large particle size material may not be able to return to the grinding table or may not fall within the grinding belt H on the grinding table when separating from the guide component 2. The distance between each guide component 2 and the next grinding roller is different, and the length of the serpentine guide chute 21 of each guide component 2 is adapted to the distance between each guide component 2 and the next grinding roller. The closer it is to the next grinding roller, the shorter the length of the serpentine guide chute 21 of this guide component 2, avoiding deviation of the material falling point P2 so that the material cannot reach the grinding belt H on the grinding table. The inclination angle of the bottom plate 211 at the lower end of each serpentine guide chute 21 towards the center of the vertical mill is the same, and the inclination angle of the lower end of the serpentine guide chute 21 towards the center of the vertical mill is greater than the inclination angle of the middle section towards the center of the vertical mill, and the inclination angle of the middle section towards the center of the vertical mill is greater than the inclination angle of the upper end towards the center of the vertical mill. When the height of each group of guide components 2 is the same, the landing positions of each group of guide components 2 on the grinding table are different, that is, the distance between the landing position of each guide component 2 and the next grinding roller is different. The falling point P2 is set within the area of the grinding belt H on the grinding table, so that the material directly enters under the grinding rollers with the rotation of the grinding table for grinding, improving the grinding efficiency after material return and reducing the situation where the material cannot enter the grinding belt on the grinding table after return. When the thrown material returns to the grinding table again through the guide component 2, it will also move towards the outside of the grinding table under the action of the centrifugal force generated by the rotating grinding table. The setting of different landing positions enables the material to still be within the grinding belt H on the grinding table before being thrown out of the grinding table again and be bitten by the grinding rollers for grinding.Materials at different landing positions reach the same grinding roller along different paths and with different path lengths. The function of multiple sets of material guiding components 2 is to make the ejected materials return to the grinding table again through targeted feeding, and ensure that the materials returning to the grinding table can be within the grinding belt H of the grinding table, avoiding ineffective internal circulation and reducing the external circulation volume.

[0028] In this embodiment, as Figure 5 shown, where the highest point of the material is P1, the feeding point is P2, the grinding belt of the grinding table is H, and the material moves on the serpentine material guiding groove 21. After reaching the highest point P1 of the material, it enters the return material groove 22, and through the guiding of the return material groove 22, the material returns to the grinding table. The feeding points P2 of different material guiding components 2 are different, and all the feeding points P2 are within the area of the grinding belt H of the grinding table. The rotation of the grinding table can drive the material closer to the grinding roller, facilitating the grinding roller to bite the material.

[0029] As Figures 2 - 4 shown, the connecting plate 24 is alternately provided with material leakage holes 25 and leakage grooves 27. The material leakage holes 25 are located below the transition plate 23, the leakage grooves 27 are located outside the grinding roller, and the number of leakage grooves 27 is the same as that of the grinding rollers; diversion holes 26 are respectively provided on both sides of the bottom plate 211 of the groove; the material guiding support 1 includes a support component 11 and an adjustment component 12. One ends of the support component 11 and the adjustment component 12 are both fixedly connected to the inner wall of the housing, and the other ends are both corresponding to the material guiding component 2. The end of the support component 11 away from the inner wall of the housing is fixedly connected to the lower end of the material guiding component 2, and the end of the adjustment component 12 away from the inner wall of the housing is movably connected to the return material groove 22.

[0030] In this embodiment, materials with a particle diameter smaller than the size of the material leakage hole 25 enter the external circulation lifting device through screening, and under the action of the external circulation lifting device, this part of the materials is re-fed from the top of the vertical mill device. Large-particle-size materials with a size larger than the material leakage hole 25 are more likely to overcome air resistance and move along a stable trajectory due to their large mass and inertia. During this process, the air extraction device is always in a working state. While separating fine-particle materials from coarse-particle materials, the diversion holes 26 on both sides of the trough bottom plate 211 can also provide certain assistance for the upward movement of large-particle-size materials. The aperture of the diversion hole 26 is smaller than that of the material leakage hole 25. The diversion holes 26 on the side of the trough bottom plate 211 close to the grinding table are inclined towards the middle of the trough bottom plate 211 to assist the movement of large-particle-size materials on the serpentine guide trough 21. The guide support 1 provides support for the guide component 2, enabling the guide component 2 to remain stable when the grinding table rotates and not being affected by the grinding table. Both the support component 11 and the adjustment component 12 are provided with arc-shaped plates fixedly connected to the inner wall of the shell. A plurality of support plates are fixedly connected to the arc-shaped plate of the support component 11, and each support plate corresponds to a guide component 2. The end of the support plate away from the arc-shaped plate is fixedly connected to the lower end of the guide component 2. A plurality of adjustment plates are fixedly connected to the arc-shaped plate of the adjustment component 12, and each adjustment plate also corresponds to a guide component 2. The end of the adjustment plate away from the arc-shaped plate is fixedly connected to the bottom of the return chute 22. One end of the support component 11 is fixedly connected to the shell of the vertical mill device, and the other end is fixedly connected to the lower end of the guide component 2. One end of the bracket of the adjustment component 12 is fixedly connected to the shell of the vertical mill device, and the other end is fixedly connected to the upper end of the serpentine guide trough 21. One implementation of the adjustment component 12 is that the end of the adjustment plate away from the arc-shaped plate is connected to an electric telescopic rod. The electric telescopic rod is arranged at the bottom of the upper chute 221, and its telescopic end is movably connected to the bottom of the lower chute 222. When the electric telescopic rod expands and contracts, the inclination angle of the lower chute 222 of the return chute 22 can be changed to control the small-angle rotation of the return chute 22, thereby adjusting the return angle. When the electric telescopic rod shortens, it pulls the lower chute 222, causing the lower end of the lower chute 222 to be pulled down and getting closer to the grinding table. On the contrary, when the electric telescopic rod extends, the lower end of the lower chute 222 moves away from the grinding table. There is an overlapping part between the upper chute 221 and the lower chute 222 of the return chute 22, and the bottom plate of the lower chute 222 is located below the bottom plate of the upper chute 221. When the materials are separated from the upper end of the serpentine guide trough 21, they enter the upper chute 221 of the return chute 22 and then fall onto the grinding table through the lower chute 222. The return angle of the return chute 22 is adjusted by controlling the electric telescopic rod according to the actual use situation.

[0031] In this embodiment, as Figure 6As shown, a material width-to-thickness ratio adjustment component 3 can also be set in the lower trough 222 of the return trough 22, including another electric telescopic rod fixedly connected to the inner walls on both sides of the lower trough 222 of the return trough 22, and the telescopic end of the other electric telescopic rod is fixedly connected to a sliding plate that can slide on the bottom plate of the lower trough 222. By controlling the other electric telescopic rod to move the sliding plate, the width of the slot of the lower trough 222 before the material enters the grinding disc is adjusted.

[0032] Example 2: Similar to Example 1, except that Figure 12 and Figure 13 As shown, the connecting plate 24 is provided with a leakage groove 27, and a serrated connection port on its edge is connected to the transition plate 23, the transition plate 23 is provided with a leakage hole 25, the leakage groove 27 is located on the outside of the grinding roller, and the number of the leakage grooves 27 is the same as the grinding roller, the serpentine guide trough 21 also includes a trough bottom plate 211 and a baffle 212 fixedly connected to the bottom side of the trough bottom plate 211.

[0033] In this embodiment, baffles 212 are provided on both sides of the serpentine guide trough 21, and the leakage hole 25 is opened on the transition plate 23. The transition plate 23 is fixedly connected to the serpentine guide trough 21 at the serrated interface of the connecting plate 24. The end of the transition plate 23 away from the connecting plate 24 is fixedly connected to the serpentine guide trough 21, and the side plate of the transition plate 23 and the inner baffle 212 of the serpentine guide trough 21 are smoothly transitioned. When the grinding disc rotates, the connecting plate 24 and each serpentine guide trough 21 do not rotate with the grinding disc. The guide assembly 2 is fixed to the inner wall of the shell through the guide bracket 1. When the material on the grinding disc is thrown out, it first reaches the connecting plate 24, and then climbs up the serpentine guide trough 21 through the transition plate 23. During this period, the material is screened by the leakage holes 25 on the transition plate 23, and the smaller particle size material enters the external circulation lifting device through the leakage holes 25. The large particle size material that cannot pass through the leakage holes 25 is guided upward by the combined action of the inner side plate and the bottom plate of the transition plate 23 when passing through the transition plate 23. After the large particle size material reaches the serpentine guide trough 21, since the trough bottom plate 211 of the serpentine guide trough 21 is in the shape of a cylindrical spiral rise, the material needs centripetal force to move in a circle, and the supporting force guiding the material to climb upward is only provided by the trough bottom plate 211 of the serpentine guide trough 21. After the material leaves the return trough 22, it returns to the grinding disc and is ground by the grinding roller.

[0034] Working principle: When the vertical mill device is working, materials are fed onto the grinding table from the top of the housing of the vertical mill device. The rotating grinding table throws some materials outward from the grinding table. The materials that are not thrown out come to the grinding area of the grinding roller and are ground and crushed. The fine particle materials are discharged outside the vertical mill device along with the airflow formed by the air extraction device arranged in the vertical mill grinding system and are collected and screened. The materials that are thrown out are screened by the leakage holes 25. The materials with smaller particle sizes pass through the leakage holes 25 and enter the external circulation lifting device. The large particle materials that cannot pass through the leakage holes 25 move in a spiral upward manner under the guidance of the transition plate 23 and the serpentine guide chute 21. The guide component 2 provides centripetal force for the large particle materials and overcomes the gravitational potential energy, guiding the large particle materials to move in the serpentine guide chute 21 and falling onto the grinding table after leaving the return chute 22. When the materials come into contact with the guide component 2, during the process of sliding upward along the cylindrical helix, they are affected by three forces: gravity, the supporting force of the guide component 2 on the materials, and the frictional force of the guide component 2 on the materials. The kinetic energy when the materials are thrown out from the periphery of the grinding table is converted into the increased potential energy of the materials rising through the guiding action of the guide component 2, and at the same time, it provides energy for the materials to overcome the frictional force when sliding to the highest point of the guide component 2. The lengths of the serpentine guide chutes 21 of each group of guide components 2 are different, and in cooperation with the return chute 22, the landing positions of the materials are different, controlling the landing distribution and the feeding pattern of the materials on the grinding table. The landing position that is farther away from the next grinding roller has a longer moving trajectory of the materials following the grinding table compared to the landing position that is closer to the next grinding roller when the materials approach the grinding roller. The different landing positions enable the materials that return to the rotating grinding table to accurately reach the grinding belt H of the grinding table with the assistance of centrifugal force. All the feeding points P2 are within the grinding belt H of the grinding table. The leakage holes 25 of the guide component 2 screen the materials with different sizes that are thrown out of the grinding table, and through the targeted feeding method, the large particle materials are circulated inside the mill. All the required energy comes from the recovery of the kinetic energy of the materials, achieving zero energy consumption for the internal circulation of some large particle materials. The smaller particle materials are easily affected by disturbances and their trajectories are changed, so they are circulated through the external circulation lifting device, reducing the energy consumption of the external circulation lifting device and greatly reducing the operating cost.

[0035] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A material internal direct-return feeding structure for a vertical mill, characterized in that: It includes a material guiding support (1) and a material guiding component (2); The material guiding component (2) includes a serpentine material guiding groove (21) and a return material groove (22). The serpentine material guiding groove (21) is in a spiral rising shape, which lifts the materials thrown out by the grinding disc from the edge of the grinding disc to a certain height. The center line of the serpentine material guiding groove (21) is a cylindrical helix, and its projection on the horizontal plane is an arc. The diameter of the arc is larger than the diameter of the grinding disc. The bending design reduces the requirement for the inner diameter size of the vertical mill housing. The bottom of the serpentine material guiding groove (21) is a groove bottom plate (211) inclined towards the center of the grinding disc of the vertical mill device. The inclination angle of the middle section of the groove bottom plate (211) towards the center of the vertical mill becomes smaller as the height of the serpentine material guiding groove (21) increases, reducing the lateral movement acceleration of the materials during the upward decelerating spiral movement and reducing the wear on the serpentine material guiding groove (21). The material guiding component (2) is used to provide centripetal force for the materials and overcome the gravitational potential energy, guiding the large particle size materials thrown out to return to the grinding disc again.

2. The internal direct-return material guiding structure for a vertical mill according to claim 1, characterized in that: Multiple groups of the material guiding component (2) are arranged around the grinding disc of the vertical mill device, and the height of each material guiding component (2) is the same. The spiral lift angles of each serpentine material guiding groove (21) are different. The closer it is to the next grinding roller, the larger its spiral lift angle and the shorter the length of the serpentine material guiding groove (21). The material guiding support (1) corresponds to the material guiding component (2).

3. The internal direct-return material guiding structure for vertical mill according to claim 2, characterized in that: The material guiding component (2) further includes a connecting plate (24). The connecting plate (24) is integrally annular and is located below the serpentine material guiding groove (21). There are transition plates (23) with smooth transitions between the connecting plate (24) and multiple serpentine material guiding grooves (21).

4. A material in-mill direct return feeding structure for a vertical mill according to claim 3, characterized in that: One side of the connecting plate (24) close to the edge of the grinding disc is smoothly arranged and the connecting plate (24) is not connected to the grinding disc.

5. A material internal direct return feeding structure for a vertical mill according to claim 4, characterized in that: The return material groove (22) includes an upper groove (221) and a lower groove (222). The upper end of the serpentine material guiding groove (21) is fixedly connected to the upper groove (221). One end of the upper groove (221) far from the serpentine material guiding groove (21) is rotatably connected to the lower groove (222), and the lower groove (222) is inclined downward towards the grinding disc.

6. The internal direct-return material guiding structure for a vertical mill according to claim 5, characterized in that: The serpentine material guiding groove (21) further includes a groove bottom plate (211) and a baffle (212) fixedly connected to the side of the groove bottom plate (211) far from the grinding disc.

7. The material in-mill direct return and guiding structure for vertical mill according to claim 6, characterized in that: The connecting plate (24) is alternately provided with material leakage holes (25) and leakage grooves (27). The material leakage holes (25) are located below the transition plates (23), and the leakage grooves (27) are located outside the grinding rollers, and the number of the leakage grooves (27) is the same as that of the grinding rollers.

8. A material internal direct return feeding structure for a vertical mill according to claim 5, characterized in that: [[ID= 9. The material in-mill direct return feeding structure for a vertical mill according to claim 7 or 8, characterized in that: The material guiding bracket (1) includes a supporting component (11) and an adjusting component (12). One ends of the supporting component (11) and the adjusting component (12) are both fixedly connected to the inner wall of the shell, and the other ends are both corresponding to the material guiding component (2). The end of the supporting component (11) away from the inner wall of the shell is fixedly connected to the lower end of the material guiding component (2), and the end of the adjusting component (12) away from the inner wall of the shell is movably connected to the material return groove (22).

10. A material internal direct return feeding structure for a vertical mill according to claim 9, characterized in that: Flow guiding holes (26) are respectively formed on both sides of the bottom plate (211) of the groove.

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