A multi-particle size classification device with a centrally mounted coupling cage and a classification method thereof

Abstract

The present invention discloses a multi-particle size classification device with a central coupling cage and a classification method thereof. The multi-particle size classification device includes a pre-separation device located in a lower pre-separation zone, a central coupling cage located in a central coupling zone, and a fine classification device located in an upper fine separation zone. The three are connected in sequence to form a bottom-up structure. The pre-separation device is used to break up bulk materials and separate coarse particles in one step. The central coupling cage is used to rectify the airflow field and material flow field introduced by the pre-separation device, and at the same time realize secondary sorting to produce coarse powder, and to guide and export the medium-coarse powder produced by the fine classification device and the coarse powder produced by self-classification. The fine classification device is used for tertiary fine sorting to produce fine powder and medium-coarse powder. The present invention integrates the pre-separation zone and the fine separation zone through the coupling zone, so that the airflow and material flow are effectively controlled, and multi-particle size classification of coarse particles, coarse powder, medium-coarse powder and fine powder is realized with low resistance and high precision.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, in particular to a multi-particle size classification device with a centrally placed coupling rotating cage and a classification method thereof. Background Art

[0002] In the mineral crushing and classification process, since the particle size of materials produced by various crushing, coarse grinding and fine grinding equipment is different from the particle size suitable for grinding, it is necessary to use a classification device to complete the sorting in order to obtain the appropriate particle size that meets the requirements of the corresponding industrial finished products and the grinding equipment.

[0003] At present, whether it is a roughing device implemented by a V-type classifier, a fine separation device implemented by a dynamic eddy current classifier, or a combined classifier with a built-in cyclone dust collector, they all operate independently and cannot meet the requirements of multi-grade separation.

[0004] In addition, after analyzing and testing the existing multi-cage classifiers, it was found that regardless of single, double, or triple cages, since they are all arranged inside the dynamic eddy current classifier, there are obvious defects in flow field control and material flow control, such as unevenness and material backmixing, and it is impossible to form an effective coupling operation mechanism, which leads to fine particles mixed in the sorted coarse particles and coarse particles mixed in the fine particles, which cannot meet the requirements of high-precision multi-particle sorting.

[0005] Therefore, it is urgent to design and develop a multi-particle size classification device to solve the above-mentioned problem of being unable to complete multi-particle size sorting or unable to complete multi-particle size sorting requirements with high precision. Summary of the Invention

[0006] In response to the problems existing in the prior art, the present invention provides a multi-particle size classification device with a centrally placed coupling cage and a classification method thereof, which can achieve low-resistance, high-efficiency, multi-particle size and high-precision sorting operations.

[0007] The present invention is achieved by providing a multi-particle size classification device with a central coupling cage, comprising a pre-separation device located in a lower pre-separation zone, a central coupling cage located in a central coupling zone, and a fine classification device located in an upper fine separation zone, wherein the pre-separation device, the central coupling cage, and the fine classification device are sequentially connected to form a bottom-up through-structure.

[0008] The pre-separation device is used to break up the bulk material and separate the coarse particles in one step; the central coupling cage is used to rectify the air flow field and material flow field introduced by the pre-separation device, and at the same time realize secondary sorting to produce coarse powder, and drain the medium coarse powder produced by the fine classification device and the coarse powder produced by self-classification to the device; the fine classification device is used for tertiary fine sorting to produce fine powder and medium coarse powder;

[0009] The central coupling rotating cage includes a central cage, a shaft system, a transmission device, a diverter cone, a half-volute, a medium-coarse powder return pipe and a coarse powder drainage pipe. A hollow cone is provided inside the central cage. The shaft system is connected to the central cage through the hollow cone. The transmission device is connected to the shaft system. The diverter cone cooperates with the outer edge of the bottom end of the central cage and is coaxially located below the central cage. The outer edge of the top end of the central cage cooperates with the fine classification machine housing of the fine classification device; the upper end of the hollow cone cooperates with the medium-coarse powder discharge cone hopper of the fine classification device, and the lower end of the hollow cone cooperates with the diverter cone. The medium-coarse powder discharge cone hopper, the hollow cone, and the diverter cone are combined. A through channel is formed to guide the medium and coarse powder sorted by the fine grading device into the diverter cone; a medium and coarse powder return pipe is provided at the lower part of the diverter cone; the outer side of the central cage is evenly distributed around the half-volute, so that an annular airflow channel is formed between the half-volute and the central cage, and the air inlet of the half-volute is connected to the air outlet of the pre-separation device, and a coarse powder drainage pipe is provided at the end of each half-volute, and the coarse powder drainage pipe is located in the low wind speed area of ​​this annular airflow channel, and a coarse powder drainage plate matching the coarse powder drainage pipe is provided immediately behind each coarse powder drainage pipe, and the coarse powder drainage plate is installed on the inner wall of the half-volute, and there is a certain gap between the coarse powder drainage plate and the outer edge of the central cage.

[0010] Preferably, each of the coarse powder guide plates is provided with a guide plate regulating valve for rotating and adjusting the rotation angle of the coarse powder guide plate.

[0011] Preferably, the central cage includes an upper ring plate, a lower ring plate, a middle partition plate, and secondary grading blades, wherein the upper ring plate is located at the upper part of the central cage, the middle partition plate is located in the middle part of the central cage, and the lower ring plate is located at the lower part of the central cage. The upper ring plate, the lower ring plate, and the middle partition plate are concentric and connected by supporting steel pipes to form a cage frame. The secondary grading blades are evenly distributed around the periphery of the central cage along the axis of the central cage and fixed to the cage frame.

[0012] The upper part of the hollow cone is connected to the upper ring plate and the middle partition plate respectively through two layers of staggered driving steel pipes, the bottom of the hollow cone is directly connected to the lower ring plate, and the hollow cone is connected to the shaft system through driving round steel.

[0013] Further preferably, an air outlet seal is provided around the outer edge of the top end of the upper ring plate, a medium-coarse powder lower seal is provided around the outer edge of the bottom end of the lower ring plate, and a medium-coarse powder upper seal is provided around the outer edge of the upper end of the hollow cone.

[0014] Preferably, the transmission device 1 is located below or above the shaft system 1.

[0015] Preferably, the central cage is a hollow inverted truncated cone cage or a hollow cylindrical cage, and the diverter cone is an inverted conical cavity.

[0016] Preferably, the shaft system includes a lower solid shaft section, a middle hollow shaft section and an upper solid shaft section, and the lower solid shaft section, the middle hollow shaft section and the upper solid shaft section are connected in sequence through matching flanges to form a coaxial whole; the lower solid shaft section is supported by a lower bearing assembly, the lower bearing assembly is located in an inverted lower bearing seat, and the inverted lower bearing seat is connected to the lower bearing seat support beam; the middle hollow shaft section is composed of a circular steel pipe and spokes uniformly distributed around the circular steel pipe in the circumferential direction, the spokes are staggered with driving round steels, and the driving round steels are connected to the hollow cone; the upper end of the upper solid shaft section is supported by an upper bearing assembly, the upper bearing assembly is located in the upper bearing seat, and the upper bearing seat is connected to the upper bearing seat support beam.

[0017] Preferably, the pre-separation device is a static classifier, which includes a feed inlet, a coarse particle outlet, a static classifier air inlet, a static classifier air outlet, a scattering plate, a grading plate, a multi-flow control air duct, and a static classifier housing. The feed inlet is located at the top of the static classifier housing, and the coarse particle outlet is located at the bottom of the static classifier housing. The static classifier air inlet and the static classifier air outlet are respectively located on both sides of the scattering plate and the grading plate. The scattering plate and the grading plate are located between the feed inlet and the coarse particle outlet in the static classifier housing, and a scattering and grading channel is formed correspondingly between the scattering plate and the grading plate. The scattering plate is located on the air inlet side of the static classifier and is directly below the feed inlet. The grading plate is located on the air outlet side of the static classifier and corresponds to the scattering plate. The scattering plate and the grading plate are respectively in a stepped structure stacked at a certain interval. The scattering plate and the grading plate constitute a V-shaped structure and are inclined to the air inlet side of the static classifier as a whole.

[0018] Further preferably, an air inlet regulating valve is provided on the air inlet of the static classifier; a plurality of multi-flow control air ducts are provided in the lower middle part of the air inlet of the static classifier, and each of the multi-flow control air ducts is provided with an air control duct regulating valve.

[0019] Further preferably, the static classifier is arranged in a "W"-shaped symmetrical arrangement, or a "W"-shaped tangential arrangement, or a single "V"-shaped arrangement, or a multiple "V"-shaped arrangement.

[0020] Preferably, the fine classifying device includes a second transmission device, a second shaft system, stationary blades, a cylindrical cage, a fine classifier housing and a medium and coarse powder discharge cone hopper. The second transmission device is connected to the second shaft system, and the second shaft system is connected to the cylindrical cage. The stationary blades and the cylindrical cage are both located inside the middle section of the fine classifier housing. The stationary blades are at the same height as the cylindrical cage and are concentrically distributed around the cylindrical cage. A fine powder outlet is provided at the top of the fine classifier housing, and the top of the medium and coarse powder discharge cone hopper is connected to the bottom end of the stationary blades.

[0021] A classification method for a multi-size particle classification device with a centrally mounted coupling cage, wherein the ground material is fed into a pre-separation device, the material is separated by a separation airflow, the separated coarse particles are discharged from the bottom of the pre-separation device, and the powdered material is carried into the upper coupling zone to complete the pre-separation;

[0022] The dust-laden airflow entering the coupling zone directly reaches the diverter cone, which guides the dust-laden airflow and then enters the annular area formed by the central cage and the half-volute from the air inlet of the half-volute. At the same time, the transmission device drives the shaft system to drive the central cage to rotate, forming an annular forced vortex airflow in this area, completing the second sorting of the material. The sorted coarse powder is guided by the coarse powder guide plate and discharged from the coarse powder drainage pipe. The dust-laden airflow passes through the central cage and rotates upward to enter the fine separation area.

[0023] The dust-laden airflow flows upward in the fine separation area and is sorted by the fine classification device. The sorted medium and coarse powder falls into the medium and coarse powder discharge cone hopper, and then falls into the hollow cone of the central cage from the medium and coarse powder discharge cone hopper, and is then introduced into the diversion cone and discharged from the medium and coarse powder return pipe. The fine powder passes through the cylindrical cage and is collected as an industrial finished product.

[0024] The advantages and positive effects of the present invention are:

[0025] 1. The present invention effectively couples the pre-separation device by arranging a central coupling cage. The dust-laden airflow passing through the pre-separation device does not require an excessive air duct, and can be rectified into an annular forced eddy flow field around the central coupling cage, thereby avoiding the occurrence of biased flow. At the same time, a uniformly distributed stable flow field is provided for the fine classification device, thereby reducing the content of coarse powder brought into the fine classification device, reducing the height of the fine classification device, reducing resistance, improving classification accuracy, and improving efficiency. Through the integration of the pre-separation zone and the fine separation zone in the coupling zone, the airflow and material flow are effectively controlled, thereby realizing multi-particle size classification of coarse particles, coarse powder, medium-coarse powder, and fine powder with low resistance and high precision.

[0026] 2. The centrally-mounted coupling cage of the present invention adopts a hollow design. The medium-coarse powder discharge cone bucket of the fine classification device is connected through the internal hollow cone to realize the discharge of medium-coarse powder. At the same time, the coarse powder drainage is realized through the coarse powder drainage pipe to avoid the influence of coarse powder back-mixing on classification.

[0027] 3. The centrally-mounted coupling rotating cage of the present invention can realize the second classification of materials. At the same time, it has a transmission device with variable frequency speed regulation, which can produce coarse powder with a specific particle size required by the grinding equipment.

[0028] 4. The pre-separation device of the present invention adopts a symmetrical air inlet form and multi-flow control air ducts, and respectively sets regulating valves on the air inlet of the static classifier and each multi-flow control air duct, ensuring that the pre-separation air flow field is evenly distributed up and down and left and right, providing stable separation conditions for pre-separation.

[0029] 5. The present invention effectively improves the sorting accuracy through the three-stage sorting of pre-separation device, middle coupling cage and fine classification device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the specific embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the specific embodiments. Obviously, the drawings described below are some specific embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a diagram showing the partitioning, airflow, and material flow directions of a multi-particle size classification device provided by an embodiment of the present invention;

[0032] Figure 2 Schematic diagram of the internal structure of the multi-particle classification device provided by an embodiment of the present invention;

[0033] Figure 3 1 is a schematic structural diagram of a central coupling cage provided by an embodiment of the present invention;

[0034] Figure 4 A schematic diagram of the arrangement structure of the half volute and the coarse powder drainage pipe provided in an embodiment of the present invention;

[0035] Figure 5 A schematic structural diagram of a pre-separation device provided in an embodiment of the present invention;

[0036] Figure 6 A schematic diagram of an arrangement of air inlets for a static classifier provided in an embodiment of the present invention;

[0037] Figure 7 A schematic diagram of another arrangement of the air inlet of a static classifier provided in an embodiment of the present invention.

[0038] Among them: 1. Fine separation zone; 2. Coupling zone; 3. Pre-separation zone; 4. Transmission device 2; 5. Shaft system 2; 6. Cylindrical cage; 7. Stationary blades; 8. Fine classifier housing; 9. Shaft system 1; 10. Center cage; 11. Diverter cone; 12. Transmission device 1; 13. Medium and coarse powder return pipe; 14. Feed inlet; 15. Static classifier air outlet; 16. Classification plate; 17. Breaking plate; 18. Static classifier air inlet; 19. Multi-flow control air duct; 20. Coarse particle outlet; 21. Upper bearing seat; 22. Upper bearing seat support beam; 23. Upper solid shaft section; 24. Upper matching flange; 25. Air outlet seal; 26. Upper ring plate ; 27. Secondary grading blades; 28. Middle partition; 29. ​​Driving steel pipe; 30. Lower ring plate; 31. Medium and coarse powder lower seal; 32. Lower bearing seat support beam; 33. Middle hollow shaft section; 34. Spoke plate; 35. Medium and coarse powder upper seal; 36. Support steel pipe; 37. Hollow cone; 38. Driving round steel; 39. Lower matching flange; 40. Dust cover; 41. Lower solid shaft section; 42. Inverted lower bearing seat; 43. Air inlet of half volute; 44. Half volute; 45. Coarse powder drainage pipe; 46. Coarse powder drainage plate; 47. Drainage plate regulating valve; 48. Air inlet regulating valve; 49. Air control pipe regulating valve; 50. Integral support.

[0039] The hollow arrows represent gas flow, the solid arrows represent material flow, and the particle-filled arrows represent dust-laden air flow. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships 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 direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0042] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0043] Example

[0044] The multi-size particle classification device of the present invention is functionally divided into a pre-separation zone 3, primarily composed of a static classifier; a coupling zone 2 (circled in the figure), primarily composed of a centrally mounted coupling cage; and a fine separation zone 1, primarily composed of a fine classifier. The coupling zone 2 also serves as a secondary separation zone, connecting the pre-separation zone 3 and the fine separation zone 1, forming a bottom-up flow. By controlling the airflow and material flow in these three zones, high-precision classification of coarse particles, coarse powder, medium-coarse powder, and fine powder is achieved.

[0045] The multi-particle size classification device with a centrally-mounted coupling cage provided by the present invention is described in detail below.

[0046] See also Figures 1 to 5 The multi-particle size classification device with a central coupling cage provided in an embodiment of the present invention includes a pre-separation device located in the lower pre-separation zone 3, a central coupling cage located in the central coupling zone 2, and a fine classification device located in the upper fine separation zone 1. The pre-separation device, the central coupling cage and the fine classification device are connected in sequence to form a structure that is connected from bottom to top.

[0047] The pre-separation device is located at the bottom, and is used to break up the bulk material and separate the coarse particles once; the central coupling cage connects the pre-separation device and the fine classification device, and is used to rectify the airflow field and material flow field introduced by the pre-separation device, to ensure that the airflow field is more uniform and is conducive to subsequent fine classification. At the same time, it can itself realize secondary sorting to produce coarse powder, and drain the medium-coarse powder produced by the fine classification device and the coarse powder produced by its own classification to avoid back mixing and affecting the sorting efficiency; the fine classification device is located at the top, and is used for tertiary fine sorting to produce fine powder (industrial finished product) and medium-coarse powder.

[0048] The pre-separation device is a static classifier, and the static classifier includes a feed port 14, a coarse particle outlet 20, a static classifier air inlet 18, a static classifier air outlet 15, a scattering plate 17, a grading plate 16, a multi-flow control air duct 19, and a static classifier housing. The feed port 14 is located at the top of the static classifier housing, the coarse particle outlet 20 is located at the bottom of the static classifier housing, the static classifier air inlet 18 and the static classifier air outlet 15 are respectively located on both sides of the scattering plate 17 and the grading plate 16, and the scattering plate 17 and the grading plate 16 are respectively located at the bottom of the static classifier housing. Between the feed port 14 and the coarse particle outlet 20 in the static classifier casing, a scattering and grading channel is formed between the scattering plate 17 and the grading plate 16. The scattering plate 17 is located on the side of the static classifier air inlet 18 and is directly below the feed port 14. The grading plate 16 is located on the side of the static classifier air outlet 15 and corresponds to the scattering plate 17. The scattering plate 17 and the grading plate 16 are respectively in a stepped structure stacked at a certain distance. The scattering plate 17 and the grading plate 16 constitute a V-shaped structure and are tilted toward the side of the static classifier air inlet 18 as a whole.

[0049] A plurality of multi-flow control air ducts 19 are provided in the lower middle part of the static classifier air inlet 18. The number of the multi-flow control air ducts 19 is set according to the size of the device, thereby improving the uniformity of the airflow entering. An air inlet regulating valve 48 is provided on the static classifier air inlet 18, and each of the multi-flow control air ducts 19 is provided with an air control duct regulating valve 49. By adjusting the air control duct regulating valve 49, the uniformity of the sorting airflow is achieved.

[0050] The static classifier is arranged in a symmetrical "W" shape, a tangential "W" shape, a single "V" shape, or a multiple "V" shape. This embodiment is a flat multi-flow control air W-shaped static classifier, and the static classifier air inlet 18, static classifier air outlet 15, feed port 14, coarse particle outlet 20, scattering plate 17, grading plate 16 and multi-flow control air duct 19 are all symmetrically distributed.

[0051] The air inlet of the static classifier can be tangential, direct or other insertion forms. Figure 6 The figure shows a layout of the static classifier air inlet 18. The center lines of the static classifier air inlet 18 are parallel, and the distance between the two center lines is D. The size of the distance D determines the airflow entry form of the left and right parts. Figure 7 Another arrangement of the static classifier air inlet 18 is shown, where D is 0 and the two center lines completely coincide, that is, the airflows on the left and right sides enter completely vertically.

[0052] The central coupling cage includes a central cage 10, a shaft system 9, a transmission device 12, a diverter cone 11, a half-volute 44, a medium-coarse powder return pipe 13, and a coarse powder drainage pipe 45. A hollow cone 37 is provided within the central cage 10. The shaft system 9 is connected to the central cage 10 via the hollow cone 37. The transmission device 12 is connected to the shaft system 9, and the transmission device 12 drives the shaft system 9 to rotate the central cage 10. The diverter cone 11 mates with the bottom outer edge of the central cage 10 and is coaxially located below the central cage 10. The top outer edge of the central cage 10 mates with the fine classifier housing 8 of the fine classifier. The upper end of the hollow cone 37 cooperates with the medium-coarse powder discharge cone hopper of the fine classification device, and the lower end of the hollow cone 37 cooperates with the diverter cone 11. The medium-coarse powder discharge cone hopper, the hollow cone 37, and the diverter cone 11 form a through channel, so that the medium-coarse powder sorted by the fine classification device is introduced into the diverter cone 11; a medium-coarse powder return pipe 13 is provided at the lower part of the diverter cone 11 to realize the discharge of the medium-coarse powder.

[0053] The outer side of the central cage 10 is evenly distributed around the half-volute 44, so that an annular airflow channel is formed between the half-volute 44 and the central cage 10. The air inlet 43 of the half-volute is connected to the air outlet of the pre-separation device. A coarse powder drainage pipe 45 is provided at the end of each half-volute 44. The coarse powder drainage pipe 45 is located in the low wind speed area of ​​this annular airflow channel. A coarse powder drainage plate 46 matching the coarse powder drainage pipe 45 is provided immediately behind each coarse powder drainage pipe 45. The coarse powder drainage plate 46 is installed on the inner wall of the half-volute 44. There is a certain gap between the coarse powder drainage plate 46 and the outer edge of the central cage 10. The coarse powder drainage is achieved by setting the coarse powder drainage plate 46 to avoid back mixing of the material flow.

[0054] Each of the coarse powder guide plates 46 is provided with a guide plate regulating valve 47 , which is used to rotate and adjust the angle of the coarse powder guide plate 46 to change the gap between the coarse powder guide plate 46 and the central cage 10 , thereby adjusting the coarse powder drainage amount.

[0055] The central cage 10 includes an upper ring plate 26, a lower ring plate 30, a middle partition 28, and secondary grading blades 27. The upper ring plate 26 is located at the upper part of the central cage 10, the middle partition 28 is located in the middle of the central cage 10, and the lower ring plate 30 is located at the lower part of the central cage 10. The upper ring plate 26, the lower ring plate 30 and the middle partition 28 are concentric and connected by a supporting steel pipe 36 to form a cage frame. The secondary grading blades 27 are evenly distributed around the periphery of the central cage 10 along the axis of the central cage 10 and are fixed to the cage frame; the upper part of the hollow cone 37 is connected to the upper ring plate 26 and the middle partition 28 respectively through two layers of staggered driving steel pipes 29, the bottom of the hollow cone 37 is directly connected to the lower ring plate 30, and the hollow cone 37 is connected to the shaft system 9 through a driving round steel 38.

[0056] An air outlet seal 25 is provided around the outer edge of the top end of the upper ring plate 26, and the air outlet seal 25 prevents the coarse powder from directly passing through the middle cage 10; a medium-coarse powder lower seal 31 is provided around the outer edge of the bottom end of the lower ring plate 30, and a medium-coarse powder upper seal 35 is provided around the outer edge of the upper end of the hollow cone 37. The combination of the medium-coarse powder lower seal 31 and the medium-coarse powder upper seal 35 prevents the medium-coarse powder after sorting from being mixed back into the sorting area.

[0057] The transmission device 12 is located below or above the shaft system 9. The transmission device 12 can be installed below or above the shaft system 9. This embodiment adopts the below-installed transmission method. The transmission device 12 is arranged within the diverter cone 11. The transmission device 12 can be driven by a pulley, a speed reducer, a variable frequency motor, a permanent magnet motor, or the like.

[0058] The central cage 10 is a hollow, inverted frustum-shaped cage, but can also be designed as a hollow cylindrical cage depending on the gas flow direction. The diverter cone 11 is an inverted conical cavity, used to guide the dust-laden airflow from the pre-separation device and isolate dust at the lower transmission device 12. The angle of the diverter cone 11 depends on the speed and direction of the material-lifting airflow. In this embodiment, the central cage 10 is a hollow, inverted frustum-shaped cage, so that the diverter cone 11 and the central cage 10 form an inverted cone.

[0059] The shaft system 9 includes a lower solid shaft section 41, a middle hollow shaft section 33 and an upper solid shaft section 23. The lower solid shaft section 41, the middle hollow shaft section 33 and the upper solid shaft section 23 are sequentially connected to form a coaxial whole through matching flanges. Specifically, the lower solid shaft section 41 and the middle hollow shaft section 33 are connected by a lower matching flange 39, and the middle hollow shaft section 33 and the upper solid shaft section 23 are connected by an upper matching flange 24; the lower solid shaft section 41 is supported by a lower bearing assembly, and the lower bearing assembly is located in an inverted lower bearing seat 42, and the inverted lower bearing seat 42 is connected to the lower bearing seat support beam 32. The inverted lower bearing seat 42 transmits the force to the equipment foundation through the lower bearing seat support beam 32, and a dust cover 40 is provided on the lower solid shaft section 41; the middle hollow shaft section 33 is composed of a circular steel pipe and spokes 34 uniformly distributed around the circular steel pipe in the circumferential direction, and the spokes 34 serve as reinforcing ribs and connections. The driving round steel 38 is staggeredly distributed on the spoke plate 34, and the driving round steel 38 is connected to the hollow cone 37. The driving round steel 38 is divided into two layers, the upper and lower layers, which connect the middle hollow shaft section 33 and the hollow cone 37 into a whole, and then connect the entire central coupling cage into an axial concentric body; the upper end of the upper solid shaft section 23 is supported by the upper bearing assembly, and the upper bearing assembly is located in the upper bearing seat 21. The upper solid shaft section 23 is aligned and aligned by the upper bearing assembly, and the upper bearing seat 21 is connected to the upper bearing seat support beam 22. The upper bearing seat 21 is supported and fixed by the upper bearing seat support beam 22, and the centrifugal force of the rotation is transmitted to the integral support.

[0060] The fine classifying device is a planar eddy current fine classifier, including a transmission device 24, a shaft system 25, a stationary blade 7, a cylindrical cage 6, a fine classifier housing 8 and a medium and coarse powder discharge cone bucket. The transmission device 24 is connected to the shaft system 25, and the shaft system 25 is connected to the cylindrical cage 6. The transmission device 24 drives the shaft system 25 to drive the cylindrical cage 6 to rotate. The transmission device 24 in this embodiment adopts an upper transmission, the upper end of the shaft system 25 is connected to the transmission device 24, and the lower part of the shaft system 25 is connected to the cylindrical cage 6 through a flange; the shaft system 25 is composed of a solid shaft and a sleeve, and the sleeve has a built-in bearing assembly to support the solid shaft. The static blades 7 and the cylindrical cage 6 are both located inside the middle section of the fine classifier housing 8. The static blades 7 are at the same height as the cylindrical cage 6 and are concentrically distributed around the cylindrical cage 6. A circle of static blades 7 is evenly distributed around the concentric periphery of the cylindrical cage 6. The cylindrical cage 6 has a slightly smaller diameter and is arranged inside the static blades 7. A fine powder outlet is provided at the top of the fine classifier housing 8. The upper platform of the fine classifier housing 8 at the fine powder outlet supports the shaft system 2 5. Below the static blades 7 is a medium and coarse powder discharge cone hopper. The top of the medium and coarse powder discharge cone hopper is connected to the bottom end of the static blades 7.

[0061] An integral support 50 for supporting the fine classifying device is provided at the bottom of the fine classifying device. The integral support 50 also bears the centrifugal force of the middle cage 10 transmitted by the upper bearing seat support beam 22 of the shaft system 9.

[0062] The classification method of the multi-particle size classification device with a centrally mounted coupling cage is specifically as follows:

[0063] During operation, the ground material is fed into the pre-separation device through the feed port 14. Due to the action of gravity, the material falls onto the first layer of scattering plate 17, and then rebounds from the scattering plate 17 to the first layer of grading plate 16. The material is loosened by the reciprocating impact layer by layer. The sorting airflow enters from the static classifier air inlet 18, passes through the scattering plate 17, and then enters the grading plate 16 to complete the classification of the loose material. The coarse particles cannot be carried away by the sorting airflow due to gravity and inertia and fall to the coarse particle outlet 20 for discharge. During the falling process, the sorting airflow is introduced from the multi-flow control air duct 19 to clean the powdery materials adhered to the coarse particles. By adjusting the air inlet regulating valve 48 and the air control duct regulating valve 49, the air flow field is ensured to be uniform up and down. A symmetrical air inlet is adopted to ensure that the air flow field is uniform left and right, thereby efficiently bringing the powdery materials from the static classifier outlet 15 into the upper coupling area 2 to complete the pre-separation.

[0064] The dust-laden airflow entering coupling zone 2 reaches diverter cone 11 directly, eliminating the need for intermediate ducting. This provides a short path and low resistance. Diverter cone 11 guides the dust-laden airflow, which then enters the annular area formed by central cage 10 and semi-volute 44 through the air inlet 43 of the semi-volute. Transmission device 12 drives shaft system 19, rotating central cage 10, thereby forming an annular forced vortex airflow in this area, effectively eliminating the phenomenon of free flow deviation. Simultaneously, transmission device 12 is driven by a variable frequency motor, enabling adjustable speed of central cage 10. This completes the secondary classification of the material, producing coarse powder of the specific particle size required by the grinding equipment. This coarse powder is then discharged from coarse powder drainage pipe 45 under the guidance of coarse powder drainage plate 46. The angle of coarse powder drainage plate 46 is adjusted by drainage plate regulating valve 47, preventing coarse powder back-mixing from affecting classification. The dust-laden airflow, after passing through central cage 10, rotates upward and enters fine separation zone 1.

[0065] The dust-laden airflow flows upward in the fine separation zone 1 and enters the stationary blades 7 for guidance, and the guidance angle of the stationary blades 7 is adjustable; the dust-laden airflow after guidance enters the annular sorting zone composed of the stationary blades 7 and the cylindrical cage 6, and the transmission device 2 4 drives the shaft system 2 5 to drive the cylindrical cage 6 to rotate, thereby forming a sorting airflow in the annular sorting zone, and the medium and coarse powder loses kinetic energy after colliding with the stationary blades 7 under the action of centrifugation, falls into the medium and coarse powder discharge cone hopper, and then falls into the hollow cone 37 of the coupling zone 2 from the medium and coarse powder discharge cone hopper, and then is introduced into the diversion cone 11 and discharged from the medium and coarse powder return pipe 13; the fine powder passes through the cylindrical cage 6 because the air drag is greater than the centrifugal force and is collected as a finished product.

[0066] The high-precision sorting principle of the present invention is: when conventional parameters remain unchanged, the sorting efficiency is inversely proportional to the circulation load, and the sorting efficiency can be expressed as: E = f / (1+C)a; where E is the sorting efficiency, f is the throughput of fine powder of a specific particle size, a is the throughput of feed material of a specific particle size, and C is the circulation load; the greater the circulation load, the higher the concentration. By reducing the single sorting circulation load and concentration through multi-stage classification, not only the multi-particle size classification requirements are met, but also the overall sorting efficiency is correspondingly improved.

[0067] Taking the sorting of PO42.5 cement as an example, if the 45μm fine powder throughput f = 94%, the 45μm feed material throughput a = 60%, and the circulating load C = 100%, the sorting efficiency E = 78.3%. The secondary classification of the center-coupled rotor removes some coarse powder, reducing the concentration in subsequent sorting. Assuming the circulating load is reduced to C = 80%, the overall sorting efficiency is increased to E = 87%. However, in a closed-circuit grinding system, due to the limitations of grinding capacity and sorting principles, the circulating load C cannot be reduced indefinitely. Furthermore, as the circulating load C decreases, the feed material throughput a also changes. Therefore, the center-coupled rotor is set to variable frequency speed regulation to meet the requirements of different particle size classifications and effectively improve the overall sorting efficiency.

[0068] The present invention integrates the pre-separation zone 3 and the fine separation zone 1 through the coupling zone 2, so that the air flow and material flow are effectively controlled, and multi-particle size classification of coarse particles, coarse powder, medium coarse powder and fine powder is achieved with low resistance and high precision.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-particle size classification device with a centrally mounted coupling cage, characterized in that: It includes a pre-separation device located in the lower pre-separation area, a middle coupling cage located in the middle coupling area, and a fine classification device located in the upper fine separation area. The pre-separation device, the middle coupling cage and the fine classification device are sequentially connected to form a bottom-up through-structure. The pre-separation device is used to break up the bulk material and separate the coarse particles in one step; the central coupling cage is used to rectify the air flow field and material flow field introduced by the pre-separation device, and at the same time realize secondary sorting to produce coarse powder, and drain the medium coarse powder produced by the fine classification device and the coarse powder produced by self-classification to the device; the fine classification device is used for tertiary fine sorting to produce fine powder and medium coarse powder; The central coupling rotating cage includes a central cage, a shaft system, a transmission device, a diverter cone, a semi-volute, a medium-coarse powder return pipe and a coarse powder drainage pipe. A hollow cone is arranged inside the central cage, the shaft system is connected to the central cage through the hollow cone, the transmission device is connected to the shaft system, the diverter cone cooperates with the outer edge of the bottom end of the central cage and is coaxially located below the central cage, and the outer edge of the top end of the central cage cooperates with the fine classification machine housing of the fine classification device; the upper end of the hollow cone cooperates with the medium-coarse powder discharge cone hopper of the fine classification device, and the lower end of the hollow cone cooperates with the diverter cone, and the medium-coarse powder discharge cone hopper, the hollow cone and the diverter cone form a through channel, so that the medium-coarse powder sorted by the fine classification device is introduced into the diverter Cone; a medium and coarse powder return pipe is provided at the lower part of the diversion cone; the outer side of the central cage is evenly distributed around the half-volute, so that an annular airflow channel is formed between the half-volute and the central cage, and the air inlet of the half-volute is connected to the air outlet of the pre-separation device, and a coarse powder drainage pipe is provided at the end of each half-volute, which is located in the low wind speed area of ​​this annular airflow channel, and a coarse powder drainage plate matching the coarse powder drainage pipe is provided immediately behind each coarse powder drainage pipe, and the coarse powder drainage plate is installed on the inner wall of the half-volute, and there is a certain gap between the coarse powder drainage plate and the outer edge of the central cage; so that the dust-laden airflow passing through the pre-separation device can be rectified into an annular forced vortex field around the central coupling cage, providing a uniformly distributed stable flow field for the fine classification device.

2. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 1, characterized in that: Each of the coarse powder guide plates is provided with a guide plate regulating valve for rotating and adjusting the rotation angle of the coarse powder guide plate.

3. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 1, characterized in that: The central cage includes an upper ring plate, a lower ring plate, a middle partition plate, and secondary grading blades. The upper ring plate is located at the upper part of the central cage, the middle partition plate is located in the middle part of the central cage, and the lower ring plate is located at the lower part of the central cage. The upper ring plate, the lower ring plate, and the middle partition plate are concentric and connected by supporting steel pipes to form a cage frame. The secondary grading blades are evenly distributed around the periphery of the central cage along the axis of the central cage and fixed to the cage frame. The upper part of the hollow cone is connected to the upper ring plate and the middle partition plate respectively through two layers of staggered driving steel pipes, the bottom of the hollow cone is directly connected to the lower ring plate, and the hollow cone is connected to the shaft system through driving round steel.

4. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 3, characterized in that: An air outlet seal is provided around the outer edge of the top end of the upper ring plate, a medium-coarse powder lower seal is provided around the outer edge of the bottom end of the lower ring plate, and a medium-coarse powder upper seal is provided around the outer edge of the upper end of the hollow cone.

5. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 1, characterized in that: The transmission device 1 is located below or above the shaft system 1.

6. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 1, characterized in that: The central cage is a hollow inverted truncated cone cage or a hollow cylindrical cage, and the diverter cone is an inverted conical cavity.

7. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 1, characterized in that: The shaft system includes a lower solid shaft section, a middle hollow shaft section and an upper solid shaft section, and the lower solid shaft section, the middle hollow shaft section and the upper solid shaft section are connected in sequence through matching flanges to form a coaxial whole; the lower solid shaft section is supported by a lower bearing assembly, and the lower bearing assembly is located in an inverted lower bearing seat, and the inverted lower bearing seat is connected to the lower bearing seat support beam; the middle hollow shaft section is composed of a circular steel pipe and spokes uniformly distributed around the circular steel pipe in the circumferential direction, and driving round steels are staggered on the spokes, and the driving round steels are connected to the hollow cone; the upper end of the upper solid shaft section is supported by an upper bearing assembly, and the upper bearing assembly is located in the upper bearing seat, and the upper bearing seat is connected to the upper bearing seat support beam.

8. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 1, characterized in that: The pre-separation device is a static classifier, and the static classifier includes a feed inlet, a coarse particle outlet, a static classifier air inlet, a static classifier air outlet, a scattering plate, a grading plate, a multi-flow control air duct, and a static classifier housing. The feed inlet is located at the top of the static classifier housing, and the coarse particle outlet is located at the bottom of the static classifier housing. The static classifier air inlet and the static classifier air outlet are respectively located on both sides of the scattering plate and the grading plate. The scattering plate and the grading plate are located between the feed inlet and the coarse particle outlet in the static classifier housing, and a scattering and grading channel is formed correspondingly between the scattering plate and the grading plate. The scattering plate is located on the air inlet side of the static classifier and is directly below the feed inlet. The grading plate is located on the air outlet side of the static classifier and corresponds to the scattering plate. The scattering plate and the grading plate are respectively in a stepped structure stacked at a certain interval. The scattering plate and the grading plate constitute a V-shaped structure and are inclined as a whole to the air inlet side of the static classifier.

9. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 8, characterized in that: An air inlet regulating valve is provided on the air inlet of the static classifier; a plurality of multi-flow control air ducts are provided in the middle and lower part of the air inlet of the static classifier, and each of the multi-flow control air ducts is provided with an air control duct regulating valve.

10. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 8, characterized in that: The static classifier is arranged in a "W"-shaped symmetrical arrangement, a "W"-shaped tangential arrangement, a single "V"-shaped arrangement, or a multiple "V"-shaped arrangement.

11. The multi-particle size classification device with a centrally-mounted coupling cage according to claim 1, characterized in that: The fine classifying device includes a second transmission device, a second shaft system, a stationary blade, a cylindrical cage, a fine classifier housing and a medium and coarse powder discharge cone hopper. The second transmission device is connected to the second shaft system, and the second shaft system is connected to the cylindrical cage. The stationary blade and the cylindrical cage are both located inside the middle section of the fine classifier housing. The stationary blade and the cylindrical cage are at the same height and are concentrically distributed around the cylindrical cage. A fine powder outlet is provided at the top of the fine classifier housing, and the top of the medium and coarse powder discharge cone hopper is connected to the bottom end of the stationary blade.

12. A classification method based on the multi-size classification device with a centrally-mounted coupling cage according to any one of claims 1 to 11, characterized in that: The classification method is to feed the ground material into the pre-separation device, sort the material through the sorting airflow, and the sorted coarse particles are discharged from the bottom of the pre-separation device, and the powdered material is brought into the upper coupling area to complete the pre-separation; The dust-laden airflow entering the coupling zone directly reaches the diverter cone, which guides the dust-laden airflow and then enters the annular area formed by the central cage and the half-volute from the air inlet of the half-volute. At the same time, the transmission device drives the shaft system to drive the central cage to rotate, forming an annular forced vortex airflow in this area, completing the second sorting of the material. The sorted coarse powder is guided by the coarse powder guide plate and discharged from the coarse powder drainage pipe. The dust-laden airflow passes through the central cage and rotates upward to enter the fine separation area. The dust-laden airflow flows upward in the fine separation area and is sorted by the fine classification device. The sorted medium and coarse powder falls into the medium and coarse powder discharge cone hopper, and then falls into the hollow cone of the central cage from the medium and coarse powder discharge cone hopper, and is then introduced into the diversion cone and discharged from the medium and coarse powder return pipe. The fine powder passes through the cylindrical cage and is collected as an industrial finished product.

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