Dual-fan combined dynamic powder concentrator and its process system

Abstract

The invention discloses a dual-fan combined dynamic powder selector and a process system thereof. The dual-fan combined dynamic powder selector comprises a combined powder selector, a cyclone and two fans. The combined powder selector comprises a feed port, a dynamic scattering plate, an inner cone, a static scattering plate, a fluidized bed and an outer shell; the dynamic scattering plate is located below the feed port, the static scattering plate is connected to the outlet at the bottom of the inner cone, and the fluidized bed is located below the static scattering plate; a coarse powder outlet is arranged at the bottom of the outer shell, two air inlets are arranged at the lower sides, and a fine powder outlet is arranged at the upper side; cyclones are symmetrically arranged on both sides of the combined powder selector, two fans are located on both sides of the combined powder selector, the fine powder outlet is connected to the corresponding cyclone feed port, the cyclone outlet is connected to the corresponding side fan inlet, and the two fan outlets are connected to the corresponding side outer shell inlet. The invention solves the problems of uneven flow field distribution, high pressure loss, low powder selection efficiency, and serious dust accumulation in the air duct existing in the single-fan powder selector and the system.

Description

Technical Field

[0001] The invention belongs to the technical field of material sorting, and in particular relates to a double-fan combined dynamic powder separator and a process system thereof. Background Art

[0002] In the mineral crushing and sorting process, the main fan of the powder material classifier matched with the grinding equipment (tube mill) adopts a single fan. The most common ones are the side air intake form represented by the "O-Sepa classifier" and the lower side air intake form represented by the "internal circulation classifier". The air supply of a single main fan will lead to:

[0003] (1) The "O-Sepa powder classifier" adopts the side air inlet form. The primary and secondary air directly enter the powder classifier guide vane from the side along the volute. Due to the short path and uneven primary and secondary air, the flow field entering the guide vane is uneven, resulting in low powder selection efficiency;

[0004] (2) The "internal circulation powder classifier" with lower air intake extends the air intake path by moving the air inlet downward. However, due to the single fan and single inlet design, the air volume is too concentrated and the pressure loss is high. The flow field unevenness problem of the above-mentioned "O-Sepa powder classifier" also exists. At the same time, the horizontal air duct between the cyclone outlet and the fan and the horizontal section of the circulation air duct are too long, and dust is seriously accumulated, further increasing the system resistance.

[0005] (3) Both the "O-sepa powder classifier" and the "internal circulation powder classifier" use tertiary air ducts to re-classify the fine powder entrained in the coarse powder. Since the wind speed of the tertiary air duct and the coarse powder flow are too concentrated, the re-classification effect is poor and the sorting efficiency is low.

[0006] Chinese patent publication number CN105170463A, patent name "A powder classifier for mining"; Chinese patent publication number CN207952006U, patent name "Multi-point air distribution and material distribution powder classifier"; and Chinese patent publication number CN104984911A, patent name "A rotor type powder classifier" are all single-fan machines, and the above problems have not been solved.

[0007] Therefore, it is urgent to solve the problems existing in the above-mentioned single-fan powder classifier and system, such as uneven flow field distribution, high pressure loss, low powder selection efficiency, and serious dust accumulation in the air duct. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a dual-fan combined dynamic powder classifier and a process system thereof, which solves the problems of uneven flow field distribution, high pressure loss, low powder selection efficiency, severe dust accumulation in the air duct, etc. existing in the single-fan powder classifier and system.

[0009] The present invention is implemented as follows: a dual-fan combined dynamic powder classifier comprises a combined powder classifier, a cyclone and two fans; the combined powder classifier comprises a feed port, a dynamic material spreading plate, a rotating cage assembly, a driving device, a flow guiding device, an inner cone, a static material spreading plate, a fluidized bed and an outer shell; the feed port and the dynamic material spreading plate are located above the rotating cage assembly or below the inner cone, the dynamic material spreading plate is located below the feed port, the rotating cage assembly is connected to the driving device, the flow guiding device is distributed along the circumference of the rotating cage assembly, the inner cone is connected to the flow guiding device and is located below the flow guiding device, and the The static spreading plate is connected to the bottom outlet of the inner cone, and the fluidized bed is located below the static spreading plate; a coarse powder outlet is arranged at the bottom of the outer shell, two air inlets are arranged on the lower sides, and a fine powder outlet is arranged on the upper side; the coarse powder outlet is located below the fluidized bed, and cyclones are symmetrically arranged on both sides of the combined powder classifier, and two fans are located on both sides of the combined powder classifier according to the direction of the air inlet, the fine powder outlet is connected to the corresponding cyclone feed inlet, and the cyclone outlets on both sides are connected to the air inlet of the corresponding side fan through air ducts, and the two fan outlets are connected to the corresponding side outer shell air inlet through circulating air ducts.

[0010] In the above technical solution, preferably, when the feed port and the dynamic feed spreading plate are located above the rotating cage assembly, the dynamic feed spreading plate is installed on the outer edge of the upper plane of the rotating cage assembly, and a plurality of feed ports evenly arranged along the circumference are provided on the surface of the outer shell body directly above the dynamic feed spreading plate, and a buffer plate is provided on the upper part between the outer side surface of the rotating cage assembly and the inner side surface of the guide device, and the buffer plate is installed on the outer shell body.

[0011] In the above technical solution, preferably, when the feed port and the dynamic material spreading plate are located below the inner cone, the dynamic material spreading plate is located at the lower part of the inner cone. At this time, the dynamic material spreading plate is controlled by a separate frequency conversion drive, and the feed port extends from the outer shell to above the dynamic material spreading plate.

[0012] In the above technical solution, preferably, the two air inlets are volute-type air inlets, and the air inlets form a rotating volute along the outer shell, and there is an eccentric distance E between the center of the volute and the center of the outer shell, E=0.1~0.8R, and R is the radius of the outer shell.

[0013] In the above technical solution, preferably, the two air inlets are tangential air inlets, and the air inlets enter tangentially along the outer edge of the housing.

[0014] In the above technical solution, preferably, the two air inlets are direct-entry air inlets, and the center line of the air inlet coincides with the center line of the outer shell.

[0015] In the above technical solution, preferably, the static material spreading tray is a single-layer type, and the single-layer static material spreading tray includes a layer of material spreading plate, and the material spreading plate is a blind plate.

[0016] In the above technical scheme, preferably, the static spreading plate is stacked, and each layer of the stacked static spreading plate is provided with a connecting rib plate and a spreading plate. The first layer of the spreading plate is connected to the bottom of the inner cone through the connecting rib plate, and each layer of the spreading plates is connected by the connecting rib plate. The angle α formed by the outer edge of the first layer of the spreading plate and the center line of the coarse powder outlet at the bottom of the inner cone is 10 to 80°, and the angle formed by the outer edge of the second layer of the spreading plate to the lowest layer of the spreading plate and the center line of the bottom of the upper layer of the spreading plate adjacent to it is 10 to 80°. Through holes are provided in the middle of the first layer of the spreading plate to the second to last layer of the spreading plate, and the lowest layer of the spreading plate is a blind plate. The diameter of the central through hole of the first layer of the spreading plate is (0.1 to 0.9) times the diameter of the coarse powder outlet at the bottom of the inner cone, and the diameter of the central through hole of the second layer of the spreading plate to the second to last layer of the spreading plate is (0.1 to 0.9) times the diameter of the central through hole of the upper layer of the spreading plate adjacent to it.

[0017] In the above technical solution, preferably, a plurality of horizontal holes, V-shaped holes or nozzles are evenly distributed on the fluidized bed.

[0018] A dual-fan combined dynamic powder classifier process system comprises grinding equipment, a dust collector I, a conveying equipment, a dual-fan combined dynamic powder classifier, a dust collector II and a venting fan, wherein the air outlet of the grinding equipment is connected to the dust collector I, the material outlet of the grinding equipment is connected to the material inlet of the conveying equipment, the material outlet of the conveying equipment is connected to the material inlet of the combined powder classifier, the coarse powder outlet of the combined powder classifier is connected to the material inlet of the grinding equipment, the air outlets of the two fans are also connected to the air inlet of the dust collector II; the air outlet of the dust collector II is connected to the air inlet of the venting fan.

[0019] The present invention has the following advantages and beneficial effects:

[0020] The present invention pre-disperses the materials ground by the grinding equipment through the dynamic spreading plate. According to the working conditions, the dynamic spreading plate can be located above the rotary cage assembly or below the inner cone, thereby improving the pre-dispersion effect of different materials; the double air inlet solves the problem of wind deviation existing in the single air inlet, and the flow field distribution in the selection area between the flow guide device and the rotary cage assembly is more uniform and stable, the powder selection efficiency is high, and the cutting particle size is clear; the double fans are arranged on both sides to solve the problems of low dust collection efficiency caused by uneven air volume of each cyclone and local resistance loss caused by too many air duct elbows existing in the single fan arrangement on one side. The loss is large, the air duct is too long, resulting in large resistance loss along the way, and dust accumulation in the straight section of the air duct leads to blocked air path; the higher dust collection efficiency also reduces the amount of dust circulating in the air duct, reducing the wear and vibration of the fan impeller; the laminated static spreading disc under the inner cone has good distribution and dispersion effects, and the coarse powder after the first sorting is scattered on the boiling air flow layer formed by the fluidized bed under its action to complete the second sorting, and further reduce the content of fine powder in the coarse powder; the content of fine powder in the coarse powder is reduced, and the over-grinding phenomenon in the grinding equipment is controlled, which is conducive to increasing the system output. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the dual-fan combined dynamic powder classifier in the present invention;

[0022] Figure 2a It is a schematic diagram of the arrangement of the two sides of the double fans supporting the combined powder classifier in the present invention;

[0023] Figure 2b This is a schematic diagram of the single-fan single-side arrangement of a traditional internal circulation powder classifier;

[0024] Figure 3 It is a schematic diagram of the process system of the present invention;

[0025] Figure 4a It is a schematic diagram of one arrangement form of the dynamic spreading plate of the combined powder selecting machine in the present invention;

[0026] Figure 4b It is a schematic diagram of the second arrangement of the dynamic spreading plate of the combined powder selecting machine in the present invention;

[0027] Figure 5a It is a schematic diagram of the volute type air inlet structure of the combined powder classifier in the present invention;

[0028] Figure 5b It is a schematic diagram of the tangential air inlet structure of the combined powder classifier in the present invention;

[0029] Figure 5c It is a schematic diagram of the direct-entry air inlet structure of the combined powder classifier in the present invention;

[0030] Figure 6a It is a schematic diagram of the stacked static spreading disc of the combined powder selecting machine in the present invention;

[0031] Figure 6b for Figure 6a Sectional view along the centerline;

[0032] Figure 7a A schematic diagram of a fluidized bed structure of a combined powder classifier in the present invention;

[0033] Figure 7b The second schematic diagram of the fluidized bed structure of the combined powder classifier of the present invention;

[0034] Figure 7c Schematic diagram of the fluidized bed structure of the combined powder classifier of the present invention.

[0035] In the figure: 1. Grinding equipment; 2. Dust collector I; 3. Conveying equipment; 4. Combined powder classifier; 5. Cyclone; 6. Fan; 7. Dust collector II; 8. Vent fan; 9. Feed inlet; 10. Dynamic scattering plate; 11. Driving device; 12. Rotating cage assembly; 13. Outer shell; 14. Inner cone; 15. Guide device; 16. Air inlet; 17. Circulating air duct; 18. Static scattering plate; 19. Fluidized bed; 20. Vent; 21. Buffer plate; 22. Frequency conversion drive; 23. Horizontal air duct; 24. Internal circulation powder classifier; 25. Single fan; 26. Connecting rib plate; 27. Spreading plate I; 28. Spreading plate II; 29. ​​Spreading plate III; 30. Nozzle;

[0036] The solid line with arrows is material flow, and the dotted line with arrows is air flow. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal", etc. indicate orientations or positional relationships based on the orientations 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 orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Example

[0041] See also Figure 1The dual-fan combined dynamic powder classifier provided in the embodiment of the present invention comprises a combined powder classifier 4, a cyclone 5 and two fans 6. The combined powder classifier 4 comprises a feed port 9, a dynamic material spreading plate 10, a rotating cage assembly 12, a driving device 11, a flow guiding device 15, an inner cone 14, a static material spreading plate 18, a fluidized bed 19 and an outer shell 13; the dynamic material spreading plate 10 is located below the feed port 9, the rotating cage assembly 12 is connected to the driving device 11, the flow guiding device 15 is distributed along the circumference of the rotating cage assembly 12, the inner cone 14 is connected to the flow guiding device 15 and is located at the flow guiding device 19. Below the device 15, the static material spreading disc 18 is connected to the bottom outlet of the inner cone 14, and the fluidized bed 19 is located below the static material spreading disc 18; a coarse powder outlet is arranged at the bottom of the outer shell 13, two air inlets 16 are arranged on the lower sides, and a fine powder outlet is arranged on the upper side; the coarse powder outlet is located below the fluidized bed 19, and cyclones 5 are symmetrically arranged on both sides of the combined powder selector 4, and one or more cyclones can be arranged on each side. Two fans 6 are located on both sides of the combined powder selector 4 according to the direction of the air inlet 16, so that the fans on the corresponding sides form a one-to-one or one-to-many connection with the cyclones. The fine powder outlet is connected to the corresponding cyclone 5 feed port, and the cyclone 5 outlets on both sides are connected to the air inlet of the corresponding side fan 6 through air ducts, and the two fan 6 outlets are connected to the corresponding side outer shell 13 air inlet through the circulating air duct 17.

[0042] The conveying device 3 feeds the ground material into the feed port 9, and the material falls on the dynamic spreading plate 10 through the feed port 9, and the dynamic spreading plate 10 rotates to complete the pre-dispersion of the fed material; on the other hand, the matching double fan 6 draws air from the cyclone 5 under the drive of the motor, and at the same time, the circulating air is evenly introduced into the area between the outer shell 13 and the inner cone 14 along the double air inlet 16 of the combined powder classifier 4, which is the air flow converging area; the height H of the center line of the double air inlet 16 from the lower edge of the cage assembly 12 is proportional to the cage diameter D: H / D=0.3~5, so as to facilitate the uniform distribution of the sorting air flow; the way of air intake on both sides ensures that the wind is gradually mixed and uniformly mixed during the rising process, and when it reaches the guide device 15, it is evenly distributed in the 360° circumferential direction, the flow field vector is consistent, and the evenly distributed air flow generates a stable and balanced air drag to carry the material pre-dispersed by the above-mentioned dynamic spreading plate 10, and the powder selection operation is completed under the comprehensive action of the centrifugal field formed by the high-speed rotation of the cage assembly 12 driven by the driving device 11. The fine powder passes through the rotating cage assembly 12 because the air drag force is greater than the centrifugal force, and is collected by the subsequent cyclone 5 as a finished product. The gas purified by the cyclone 5 returns to the fan 6 from the air ducts on both sides. Since the double fans 6 are respectively located on both sides of the combined powder selector 4, the length of the air duct is effectively shortened, and the dust accumulation caused by the horizontal section is eliminated. The circulating air duct 17 between the fan 6 and the air inlet 16 is also shortened accordingly; the coarse powder is thrown outward to the inner side of the guide device 15 because the air drag force is less than the centrifugal force, and loses kinetic energy by collision. It falls into the inner cone 14 under the action of gravity, and further falls to the static spreading plate. 18, the static scattering plate 18 disperses and distributes the coarse powder again, so that it is evenly scattered on the fluidized bed 19 below. The fluidized bed 19 is blown by positive pressure from a separate fan, and a stable and uniform boiling air flow layer is formed between the static scattering plate 18 and the fluidized bed 19. The air flow layer can lift the fine powder entrained in the coarse powder to the ascending flow field again, and the air flow entering through the double air inlet 16 is brought into the sorting area between the guide device 15 and the rotating cage assembly 12 to complete the secondary powder selection, thereby ensuring that the fine powder entering the grinding equipment 1 is further reduced, thereby improving the powder selection efficiency of the combined powder selector 4 and reducing the over-grinding phenomenon in the grinding equipment 1. The dual-fan combined dynamic powder classifier is provided with a vent 20 on the circulating air duct 17 between the fan and the corresponding side air inlet of the combined powder classifier 4. When the temperature and moisture content of the sorted material are too high, air is released through the vent 20, thereby reducing the temperature and moisture content of the sorted fine powder, reducing the vibration of the dual fans 6 and the crusting of the inner wall of the circulating air duct 17.

[0043] like Figure 2a As shown, the double fans 6 are arranged on both sides of the combined powder classifier 4. The double fans 6 are respectively located on both sides of the combined powder classifier 4. The air outlet side of the double fans 6 is connected to the double air inlet 16 of the combined powder classifier 4 through the circulating air duct 17. Figure 2bThe conventional arrangement of a single fan on one side and the arrangement of air intake on both sides of the dual fans solves the problem of uneven distribution of airflow in the circumferential direction inside the inner circulation powder selector 24 caused by the arrangement of air intake on one side of the single fan. At the same time, under the same system air volume, the air volume passing through the circulating air duct 17 in the arrangement of the dual fans on both sides is half of the air volume passing through the circulating air duct 17 in the arrangement of the single fan on one side. Therefore, the length and diameter of the circulating air duct 17 are smaller than those of the single fan on one side, that is, the straight section of the circulating air duct 17 is shorter, and the possibility of dust accumulation is lower. In addition, the cyclone 5 arranged on both sides of the dual fans can form a one-to-one or one-to-many connection with the dual fans 6 near the two sides of the combined powder selector 4, respectively, completely eliminating the straight dust accumulation section caused by the excessive length of the horizontal air duct 23 arranged on one side of the conventional single fan. Therefore, compared with the conventional arrangement of a single fan on one side, the separation flow field of the dual fans arranged on both sides is more uniform and has lower resistance loss.

[0044] See also Figure 3 The embodiment of the present invention provides a dual-fan combined dynamic powder classifier process system, including a grinding device 1, a dust collector I 2, a conveying device 3, the above-mentioned dual-fan combined dynamic powder classifier (including a combined powder classifier 4, a cyclone 5 and two fans 6), a dust collector II 7 and a vent fan 8.

[0045] The connection mode of each of the above-mentioned equipment is that the air outlet of the grinding equipment 1 is connected with the air inlet of the dust collector Ⅰ2, the material outlet of the grinding equipment 1 is connected with the material inlet of the conveying equipment 3, and the material outlet of the conveying equipment 3 is connected with the material inlet of the combined powder selector 4; the coarse powder outlet of the combined powder selector 4 is connected with the material inlet of the grinding equipment 1, and the fine powder outlet of the combined powder selector 4 is connected with the material inlet of the corresponding cyclone 5; the air outlet of the cyclone 5 is connected with the air inlet of the corresponding fan 6, and the air outlets of the two fans 6 are connected with the air inlet of the combined powder selector 4 and the air inlet of the dust collector Ⅱ7; the air outlet of the dust collector Ⅱ7 is connected with the air inlet of the vent fan 8. The grinding equipment of this embodiment is a tube mill, and the above only describes the process flow related to the combined powder selector, and the known pre-grinding part is not repeated here.

[0046] During operation, new materials are ground by the grinding equipment 1 and then enter the conveying equipment 3, and the dust collector Ⅰ2 ventilates and removes dust for the grinding equipment 1; the conveying equipment 3 feeds the ground materials into the combined powder classifier 4, and the selected coarse powder returns to the grinding equipment 1 for further grinding, and the fine powder enters the cyclone 5 under the negative pressure of the dual fan 6 to be collected; part of the fine dust-containing air discharged from the cyclone 5 passes through the dual fan 6, the dust collector Ⅱ 7, and the venting fan 8 to be vented.

[0047] The difference between the process system of the present invention and the traditional process flow is that in the traditional process flow, the internal circulation powder classifier has only a single air inlet and is only equipped with a single fan, and the flow field distribution is uneven and unstable; in the process system of the present invention, a fan is arranged on each side of the combined powder classifier 4 to form a dual-fan system, and the two fans 6 are respectively connected to the cyclones 5 for fine powder collection on both sides of the combined powder classifier 4 to form a one-to-one or one-to-many connection nearby, so the air path is smoother and more stable, and the internal flow field of the combined powder classifier 4 is more uniform, which effectively improves the powder selection efficiency of the combined powder classifier 4 and the dust collection efficiency of the cyclone 5.

[0048] Preferably, the feed inlet 9 and the dynamic spreading plate 10 of the combined powder classifier 4 are located above the rotating cage assembly 12 or below the inner cone 14 .

[0049] When the feed port 9 and the dynamic spreading plate 10 are located above the rotating cage assembly 12, refer to Figure 4a The dynamic spreading disc 10 is installed on the outer edge of the upper plane of the rotating cage assembly 12. The surface of the outer shell body directly above the dynamic spreading disc 10 is provided with multiple feed ports 9 evenly arranged along the circumference. A buffer plate 21 is provided on the upper part between the outer side surface of the rotating cage assembly 12 and the inner side surface of the guide device 15. The buffer plate 21 is installed on the outer shell body 13. This position is suitable for working conditions with finer materials. The ground material is fed into the feed port 9 and is scattered between the guide device 15 and the rotating cage assembly 12 under the combined action of the rotating scattering of the dynamic spreading disc 10 and the static buffering of the buffer plate 21 to complete pre-dispersion.

[0050] When the feed port 9 and the dynamic spreading plate 10 are located at the lower part of the inner cone, refer to Figure 4b The dynamic spreading plate 10 is located at the lower part of the inner cone 14. At this time, the dynamic spreading plate is controlled by an attached separate frequency conversion drive 22. The rotation speed can be adjusted according to the working conditions to achieve the best pre-dispersion and pre-sorting effects. The feed port 9 passes through the outer shell 13 and extends to the top of the dynamic spreading plate 10. This position is suitable for working conditions with coarse materials. The ground material is fed through the feed port 9. Under the rotation and scattering action of the dynamic spreading plate 10, the coarse particles lose kinetic energy due to the large centrifugal force and collide with the outer shell 13, and then fall down to complete a sorting. The finer particles mixed with fine powder are pre-dispersed under the action of the rotating rising airflow.

[0051] The above-mentioned dynamic spreading plate 10 can be a single-layer or multi-layer structure to improve the material pre-dispersion effect.

[0052] Preferably, the two air inlets are volute-type air inlets, tangential air inlets or direct air inlets.

[0053] See also Figure 5aIt is a volute type air inlet. The air inlet 16 forms a rotating volute along the outer shell 13. There is an eccentric distance E between the center of the volute and the center of the outer shell 13. E=(0.1~0.8)R, R is the radius of the outer shell 13. The structure of the volute is conducive to the mixing and uniform distribution of the incoming airflow.

[0054] See also Figure 5b It is a tangential air inlet. The air inlet 16 enters tangentially along the outer edge of the outer shell 13. The meshing of the air inlet 16 and the outer edge of the outer shell 13 forms a smaller volute form with the radius R of the outer shell 13 as its radius. This form reduces the radius of the vortex trajectory of the rotating airflow, which is beneficial for the airflow to carry the material to rise quickly and reduce the local resistance loss caused by the vortex.

[0055] See also Figure 5c It is a straight-in air inlet, the center line of the air inlet 16 coincides with the center line of the outer shell 13, and the air flow enters the outer shell 13 vertically along the air inlet 16. The counter-flow has a deagglomeration effect on the materials that are bonded together, which is beneficial to the pre-dispersion of the materials. At the same time, the shorter air flow path minimizes the resistance along the way.

[0056] The common feature of the above three structural forms is that the lower double air inlet 16 is used to replace the traditional lower single side air inlet form, so that the internal flow field of the combined powder classifier 4 is more stable and uniform, which is conducive to material pre-dispersion and subsequent sorting operations.

[0057] Preferably, the static spreading disc 18 is of a single-layer or stacked type to extend the residence time of the material, increase the spreading range, and facilitate the separation of fine powder from coarse powder.

[0058] The single-layer static spreading plate includes a layer of spreading plate, and the spreading plate is a blind plate.

[0059] Each layer of the stacked static spreading plate is provided with a connecting rib plate and a spreading plate. The first layer of spreading plates is connected to the bottom of the inner cone through the connecting rib plate, and each layer of spreading plates is connected through the connecting rib plate. The angle α formed by the outer edge of the first layer of spreading plates and the center line of the coarse powder outlet at the bottom of the inner cone 14 is 10 to 80°, and the angle formed by the outer edge of the second layer of spreading plates to the lowest layer of spreading plates and the center line of the bottom of the upper layer of spreading plates adjacent to it is 10 to 80°. There are through holes in the middle of the first layer of spreading plates to the second to last layer of spreading plates, and the lowest layer of spreading plates is a blind plate. The diameter of the center through hole of the first layer of spreading plates is (0.1 to 0.9) times the diameter of the coarse powder outlet at the bottom of the inner cone 14, and the diameter of the center through hole of the second layer of spreading plates to the second to last layer of spreading plates is (0.1 to 0.9) times the diameter of the center through hole of the upper layer of spreading plates adjacent to them. Figure 6a, taking three layers as an example, it includes connecting rib plate 26, spreading plate I 27, spreading plate II 28, and spreading plate III 29. Spreading plate I 27 is connected to the coarse powder outlet at the bottom of the inner cone 14 through the connecting rib plate 26, spreading plate II 28 is connected to spreading plate I 27 through the connecting rib plate 26, and spreading plate III 29 is connected to spreading plate II 28 through the connecting rib plate 26. The coarse powder entrained with the unselected fine powder falls on the spreading plate I 27 from the bottom of the inner cone 14, part of it is scattered from the edge of the spreading plate I 27, and part of it falls from the middle hole to the spreading plate II 28; then part of it is scattered from the edge of the spreading plate II 28, and part of it falls from the middle hole to the spreading plate III 29; and then all of it is scattered from the edge of the spreading plate III 29. The stacked static spreading plate structure prolongs the material residence time and increases the spreading range, which is conducive to the separation of fine powder from coarse powder. A wear-resistant layer is welded on the inner side of the connecting rib plate 26 to prevent wear and falling off under the scouring of materials. The angle α formed by the outer edge of the spreading plate I27 and the center line of the coarse powder outlet at the bottom of the inner cone 14 is 10-80°, the angle β formed by the outer edge of the spreading plate II28 and the center line of the bottom of the spreading plate I27 is 10-80°, and the angle γ formed by the outer edge of the spreading plate III29 and the center line of the bottom of the spreading plate II28 is 10-80°; the diameter A of the central through hole of the spreading plate I27 and the diameter C of the coarse powder outlet at the bottom of the inner cone 14 are proportional: A=(0.1-0.9)C, the diameter B of the central through hole of the spreading plate II28 and the diameter A of the central through hole of the spreading plate I27 are proportional: B=(0.1-0.9)A, and the lowest spreading plate III29 is a blind plate.

[0060] Preferably, the fluidized bed is evenly distributed with a plurality of horizontal holes, V-shaped holes or nozzles. All three methods can further sort the materials.

[0061] See also Figure 7a , are horizontal holes, the fluidized bed inclination angle ε is relatively gentle, ranging from 8° to 40°, and the fluidized bed 19 adopts horizontal openings to reduce the blockage of the holes by granular materials. The hole width G and the hole spacing B are alternately and evenly distributed, and G / B=0.2~5.

[0062] See also Figure 7b , is a V-shaped hole. The fluidized bed 19 adopts a V-shaped hole. The lower edge of the hole is horizontal, and the upper edge forms an angle ζ with the horizontal, which is 5° to 20°. The V-shaped hole can further reduce the blockage of the hole by granular materials, and the particles entering the hole are also easier to escape.

[0063] See also Figure 7c , is a nozzle type, the fluidized bed 19 adopts a nozzle 30, the nozzle 30 is a circular steel plate welded on the top of the circular ring segment, and 2 to 20 air holes are evenly opened along the circumference in the middle of the circular ring segment. To prevent the air holes from being blocked, the hole forms an angle θ with the axial direction of the circular ring segment, which is 20° to 90°.

[0064] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents, and 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 dual-fan combined dynamic powder classifier, characterized in that: The invention comprises a combined powder selecting machine, a cyclone and two fans, wherein the combined powder selecting machine comprises a feed port, a dynamic spreading plate, a rotating cage assembly, a driving device, a flow guiding device, an inner cone, a static spreading plate, a fluidized bed and an outer shell; the feed port and the dynamic spreading plate are located above the rotating cage assembly or below the inner cone, the dynamic spreading plate is located below the feed port, the rotating cage assembly is connected to the driving device, the flow guiding device is distributed along the circumference of the rotating cage assembly, the inner cone is connected to the flow guiding device and is located below the flow guiding device, the static spreading plate is connected to the bottom of the inner cone and the static spreading plate is connected to the bottom of the inner cone. The fluidized bed is located below the static spreading plate; a coarse powder outlet is arranged at the bottom of the outer shell, two air inlets are arranged at the lower sides, and a fine powder outlet is arranged at the upper side; the coarse powder outlet is located below the fluidized bed, cyclones are symmetrically arranged on both sides of the combined powder classifier, and two fans are located on both sides of the combined powder classifier according to the direction of the air inlet, the fine powder outlet is connected to the corresponding cyclone feed inlet, the cyclone outlets on both sides are connected to the air inlet of the corresponding side fan through the air duct, and the air outlets of the two fans are connected to the air inlet of the corresponding side outer shell through the circulating air duct; The static spreading plate is stacked, and each layer of the stacked static spreading plate is provided with a connecting rib plate and a spreading plate. The first layer of the spreading plate is connected to the bottom of the inner cone through the connecting rib plate, and each layer of the spreading plates is connected by the connecting rib plate. The angle α formed by the outer edge of the first layer of the spreading plate and the center line of the coarse powder outlet at the bottom of the inner cone is 10-80°, and the angle formed by the outer edge of the second layer of the spreading plate to the lowest layer of the spreading plate and the center line of the bottom of the upper layer of the spreading plate adjacent to it is 10-80°. Through holes are provided in the middle of the first layer of the spreading plate to the second to last layer of the spreading plate, and the lowest layer of the spreading plate is a blind plate. The diameter of the central through hole of the first layer of the spreading plate is 0.1-0.9 times the diameter of the coarse powder outlet at the bottom of the inner cone, and the diameter of the central through hole of the second layer of the spreading plate to the second to last layer of the spreading plate is 0.1-0.9 times the diameter of the central through hole of the upper layer of the spreading plate adjacent to it; A plurality of horizontal holes, V-shaped holes or nozzles are evenly distributed on the fluidized bed.

2. The dual-fan combined dynamic powder concentrator according to claim 1, characterized in that: When the feed port and the dynamic material spreading plate are located above the rotating cage assembly, the dynamic material spreading plate is installed on the outer edge of the upper plane of the rotating cage assembly, and the surface of the outer shell body located directly above the dynamic material spreading plate is provided with multiple feed ports evenly arranged along the circumference, and a buffer plate is provided at the upper part between the outer side surface of the rotating cage assembly and the inner side surface of the guide device, and the buffer plate is installed on the outer shell body.

3. The dual-fan combined dynamic powder concentrator according to claim 1, characterized in that: When the feed port and the dynamic material spreading plate are located below the inner cone, the dynamic material spreading plate is located at the lower part of the inner cone. At this time, the dynamic material spreading plate is controlled by a separate frequency conversion drive, and the feed port extends from the outer shell to the top of the dynamic material spreading plate.

4. The dual-fan combined dynamic powder concentrator according to claim 1, characterized in that: The two air inlets are volute-type air inlets, and the air inlets form a rotating volute along the outer shell. There is an eccentric distance E between the center of the volute and the center of the outer shell, E=0.1~0.8R, and R is the radius of the outer shell.

5. The dual-fan combined dynamic powder concentrator according to claim 1, characterized in that: The two air inlets are tangential air inlets, and the air inlets enter tangentially along the outer edge of the housing.

6. The dual-fan combined dynamic powder concentrator according to claim 1, characterized in that: The two air inlets are direct-entry air inlets, and the center lines of the air inlets coincide with the center line of the outer shell.

7. A process system using the dual-fan combined dynamic powder concentrator according to any one of claims 1 to 6, characterized in that: It includes grinding equipment, dust collector I, conveying equipment, dual-fan combined dynamic powder classifier, dust collector II and venting fan, the air outlet of the grinding equipment is connected with the dust collector I, the material outlet of the grinding equipment is connected with the material inlet of the conveying equipment, the material outlet of the conveying equipment is connected with the material inlet of the combined powder classifier, the coarse powder outlet of the combined powder classifier is connected with the material inlet of the grinding equipment, the air outlets of the two fans are also connected with the air inlet of the dust collector II; the air outlet of the dust collector II is connected with the air inlet of the venting fan.

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