CN115889195A - Multi-particle-size grading device with middle coupling rotating cage and grading method thereof - Google Patents

Abstract

The invention discloses a multi-particle size grading device with a middle coupling rotating cage and a grading method thereof, wherein the multi-particle size grading device comprises a pre-separation device positioned in a lower pre-separation area, a middle coupling rotating cage positioned in a middle coupling area and a fine grading device positioned in an upper fine separation area, which are sequentially connected to form a structure which is communicated from bottom to top; the pre-separation device is used for scattering the blocky materials and separating coarse particles for the first time; the middle coupling rotating cage is used for rectifying an airflow field and a material flow field introduced by the pre-separation device, realizing secondary separation to generate coarse powder, and guiding out the coarse powder generated by the fine classification device and the coarse powder generated by self classification; the fine grading device is used for fine sorting for three times to generate fine powder and medium coarse powder. The invention integrates the pre-separation area and the fine separation area through the coupling area, effectively controls the airflow and the material flow, realizes the multi-particle size classification of coarse particles, coarse powder, medium coarse powder and fine powder, and has low resistance and high precision.

Description

Multi-particle-size grading device with middle coupling rotating cage and grading method thereof

Technical Field

The invention relates to the technical field of mineral processing, in particular to a multi-particle-size grading device with a middle coupling rotating cage and a grading method thereof.

Background

In the mineral crushing and grading process, because the particle size of the material generated by various crushing, coarse grinding and fine grinding devices is different from the particle size suitable for grinding, the material needs to be sorted by using a grading device, so that the suitable particle size meeting the requirements of corresponding industrial finished products and grinding devices is very important.

At present, both a rough separation device realized by a V-shaped classifier, a fine separation device realized by a dynamic vortex classifier and a combined classifier with a cyclone dust collector operate independently, and the requirement of multi-particle-level separation cannot be met.

In addition, after the existing multi-rotating-cage classifier is analyzed and tested, the fact that no matter a single rotating cage, a double rotating cage, a three rotating cage and the like are arranged inside the dynamic vortex classifier, obvious defects of non-uniformity, material back-mixing and the like exist in flow field control and material flow control, an effective coupling operation mechanism cannot be formed, fine particles are mixed in the sorted coarse particles, the coarse particles are mixed in the fine particles, and the high-precision multi-particle-grade sorting requirement cannot be met.

Therefore, there is a need to design and develop a multi-particle size classification apparatus to solve the above-mentioned problems that the multi-particle size classification cannot be completed or the multi-particle size classification cannot be completed with high precision.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a multi-particle size grading device with a middle coupling rotating cage and a grading method thereof, which can realize low-resistance, high-efficiency and multi-particle size high-precision sorting operation.

The invention is realized in this way, a multi-particle size grading device with a middle coupling rotating cage, which comprises a pre-separation device positioned in a lower pre-separation area, a middle coupling rotating cage positioned in a middle coupling area and a fine grading device positioned in an upper fine separation area, wherein the pre-separation device, the middle coupling rotating cage and the fine grading device are sequentially connected to form a structure which is communicated from bottom to top;

the pre-separation device is used for scattering the blocky materials and separating coarse particles for the first time; the middle coupling rotating cage is used for rectifying an airflow field and a material flow field introduced by the pre-separation device, realizing secondary separation to generate coarse powder, and conducting drainage and leading out equipment on the coarse powder generated by the fine classification device and the coarse powder generated by self classification; the fine grading device is used for fine sorting for three times to generate fine powder and medium coarse powder;

the middle coupling rotating cage comprises a middle cage, a first shaft system, a first transmission device, a diversion cone, a half volute, a middle coarse powder return pipe and a coarse powder drainage pipe, wherein a hollow cone is arranged in the middle cage, the first shaft system is connected with the middle cage through the hollow cone, the first transmission device is connected with the first shaft system, the diversion cone is matched with the outer edge of the bottom end of the middle cage and is coaxially positioned below the middle cage, and the outer edge of the top end of the middle cage is matched with a fine classifier shell of a fine classification device; the upper end of the hollow cone is matched with a medium coarse powder discharge cone hopper of the fine grading device, the lower end of the hollow cone is matched with the spreader cone, and the medium coarse powder discharge cone hopper, the hollow cone and the spreader cone form a through channel, so that medium coarse powder separated by the fine grading device is guided into the spreader cone; a middle coarse powder return pipe is arranged at the lower part of the spreader cone; the semi-volute is uniformly distributed on the outer side of the middle cage in the circumferential direction, an annular air flow channel is formed between the semi-volute and the middle cage, an air inlet of the semi-volute is connected with an air outlet of the pre-separation device, a coarse powder drainage tube is arranged at the tail end of each semi-volute and is located in a low air speed area of the annular air flow channel, a coarse powder drainage plate matched with the coarse powder drainage tube is arranged at the position, close to the rear of each coarse powder drainage tube, and is installed on the inner wall of the semi-volute, and a certain gap is formed between the coarse powder drainage plate and the outer edge of the middle cage.

Preferably, each coarse powder flow guide plate is provided with a flow guide plate adjusting valve for rotatably adjusting the rotation angle of the coarse powder flow guide plate.

Preferably, the middle-placed cage comprises an upper ring plate, a lower ring plate, a middle partition plate and secondary grading blades, wherein the upper ring plate is positioned at the upper part of the middle-placed cage, the middle partition plate is positioned at the middle part of the middle-placed cage, the lower ring plate is positioned at the lower part of the middle-placed cage, the upper ring plate, the lower ring plate and the middle partition plate are concentric and are connected through a support steel pipe to form a cage frame, and the secondary grading blades are uniformly distributed around the periphery of the middle-placed cage along the axis of the middle-placed cage and are fixed on the cage frame;

the upper portion of the hollow cone is connected with the upper ring plate and the middle partition plate through upper and lower layers of driving steel pipes which are distributed in a staggered mode, the bottom of the hollow cone is directly connected with the lower ring plate, and the hollow cone is connected with the first shaft system through driving round steel.

Preferably, an air outlet seal is arranged on the periphery of the outer edge of the top end of the upper ring plate, a middle coarse powder lower seal is arranged on the periphery of the outer edge of the bottom end of the lower ring plate, and a middle coarse powder upper seal is arranged on the periphery of the outer edge of the upper end of the hollow cone.

Preferably, the first transmission device is positioned below or above the first shaft system.

Preferably, the mid-cage is a hollow inverted truncated cone-shaped cage or a hollow cylindrical cage, and the spreader cone is an inverted cone-shaped cavity.

Preferably, the first shaft system comprises 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 sequentially connected into a coaxial whole through mating flanges; the lower solid shaft section is supported by a lower bearing assembly, the lower bearing assembly is positioned in an inverted lower bearing seat, and the inverted lower bearing seat is connected with a lower bearing seat supporting beam; the middle hollow shaft section consists of a circular steel pipe and a radial plate which is uniformly distributed around the circular steel pipe in the circumferential direction, drive round steel is distributed on the radial plate in a staggered manner, and the drive round steel is connected with the hollow cone; the upper end of the upper solid shaft section is supported by an upper bearing assembly, the upper bearing assembly is positioned in an upper bearing seat, and the upper bearing seat is connected with an upper bearing seat supporting cross beam.

Preferably, the pre-separation device is a static classifier, the static classifier comprises a feed inlet, a coarse particle outlet, a static classifier air inlet, a static classifier air outlet, a scattering plate, a classifying plate, a multi-flow control air pipe and a static classifier shell, the feed inlet is positioned at the top of the static classifier shell, the coarse particle outlet is positioned at the bottom of the static classifier shell, the static classifier air inlet and the static classifier air outlet are respectively positioned at two sides of the scattering plate and the classifying plate, the scattering plate and the classifying plate are positioned between the feed inlet and the coarse particle outlet in the static classifier shell, a scattering channel is correspondingly formed between the scattering plate and the classifying plate, the scattering plate is positioned at the side of the static classifier air inlet and is positioned under the feed inlet, the classifying plate is positioned at the side of the static classifier air outlet and corresponds to the scattering plate, the scattering plate and the classifying plate are respectively in a stepped structure overlapped at a certain interval, and the scattering plate and the classifying plate form a V-shaped structure and are integrally inclined towards the side of the air inlet of the static classifier.

Further preferably, an air inlet regulating valve is arranged on the air inlet of the static classifier; the middle lower part of the air inlet of the static classifier is provided with a plurality of multi-flow control air pipes, and each multi-flow control air pipe is provided with an air control pipe adjusting valve.

Further preferably, the static classifier is in a symmetrical arrangement of a "W" shape, or in a tangential arrangement of a "W" shape, or in a single "V" shape, or in a multiple "V" shape.

Preferably, fine classification device includes that transmission is two, shafting two, quiet blade, cylindricality cage, fine classifier casing and well middlings discharge the awl fill, transmission is two continuous with shafting two, shafting two links to each other with the cylindricality cage, quiet blade and cylindricality cage all are located fine classifier casing middle section inside, quiet blade and cylindricality cage are with high and concentric the distribution of encircleing the cylindricality cage, fine classifier casing top is equipped with the fine powder export, well middlings discharge the bottom of awl fill top and quiet blade and link to each other.

A grading method of a multi-particle size grading device with a middle coupling rotating cage is characterized in that ground materials are fed into a pre-separation device, the materials are sorted through a sorting airflow, sorted coarse particles are discharged from the bottom of the pre-separation device, and powdery materials are brought into an upper coupling area to complete pre-separation;

the dust-containing airflow entering the coupling area directly reaches the splitter cone, the splitter cone guides the dust-containing airflow, then the dust-containing airflow enters an annular area formed by the middle-mounted cage and the half-volute from an air inlet of the half-volute, meanwhile, a driving shaft system I of the driving device drives the middle-mounted cage to rotate, so that annular forced vortex airflow is formed in the area, secondary sorting of materials is completed, the sorted coarse powder is discharged from a coarse powder drainage tube under the guiding action of a coarse powder drainage plate, and the dust-containing airflow passing through the middle-mounted cage rotates upwards to enter a fine separation area;

the dusty airflow upwards flows in the fine separation area, is separated by the fine classification device, the separated medium coarse powder falls into the medium coarse powder discharge cone hopper, then falls into the hollow cone of the medium cage through the medium coarse powder discharge cone hopper, then is guided into the shunt cone and is guided out through the medium coarse powder return pipe, and the fine powder passes through the cylindrical cage and is collected as an industrial finished product.

The invention has the advantages and positive effects that:

1. according to the invention, the middle coupling rotating cage is arranged, the pre-separation device is effectively coupled, and the dust-containing air flow passing through the pre-separation device can be rectified into an annular forced eddy current field around the middle coupling rotating cage without a transition air pipe, so that the bias current phenomenon is avoided; meanwhile, a uniformly distributed stable flow field is provided for the fine grading device, the content of coarse powder brought into the fine grading device is reduced, the height of the fine grading device is reduced, the resistance is reduced, the grading precision is improved, and the efficiency is improved; the integration of the pre-separation area and the fine separation area through the coupling area enables the air flow and the material flow to be effectively controlled, the multi-particle size classification of coarse particles, coarse powder, medium coarse powder and fine powder is realized, the resistance is low, and the precision is high.

2. The middle coupling rotating cage adopts a hollow design, and is connected with a middle coarse powder discharging conical hopper of a fine grading device through an internal hollow conical body, so that middle coarse powder is led out; meanwhile, coarse powder drainage is realized through a coarse powder drainage tube, and influence on classification caused by coarse powder back mixing is avoided.

3. The middle coupling rotating cage can realize the secondary classification of materials, and meanwhile, a transmission device with variable frequency speed regulation can generate coarse powder with a specific particle size required by grinding equipment.

4. The pre-separation device adopts a symmetrical air inlet mode and a multi-flow control air pipe, and regulating valves are respectively arranged on the air inlet of the static classifier and each multi-flow control air pipe, so that the pre-separation airflow field is uniformly distributed up and down, left and right, and stable separation conditions are provided for pre-separation.

5. The invention effectively improves the sorting precision through three-stage sorting of the pre-separation device, the middle coupling rotating cage and the fine grading device.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a sectional view of a multi-particle size classification apparatus according to an embodiment of the present invention, along with a flow diagram of gas and material;

FIG. 2 is a schematic view of the internal structure of a multi-particle size classifying apparatus according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a centrally-mounted coupling cage according to an embodiment of the present invention;

FIG. 4 is a schematic view of an arrangement structure of a half volute and a coarse powder draft tube according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a preseparation device according to an embodiment of the present invention;

FIG. 6 is a schematic view of an arrangement of an air inlet of a static classifier according to an embodiment of the present invention;

fig. 7 is a schematic view of another arrangement of air inlets of a static classifier according to an embodiment of the present invention.

Wherein: 1. a fine separation zone; 2. a coupling region; 3. a pre-separation zone; 4. a second transmission device; 5. a second shaft system; 6. a cylindrical cage; 7. a stationary blade; 8. a fine classifier housing; 9. a first shaft system; 10. arranging a cage in the middle; 11. a spreader cone; 12. a first transmission device; 13. a medium coarse powder return pipe; 14. a feed inlet; 15. an air outlet of the static classifier; 16. grading plates; 17. a breaking plate; 18. an air inlet of the static classifier; 19. a multi-flow control air duct; 20. a coarse particle outlet; 21. an upper bearing seat; 22. the upper bearing seat supports the beam; 23. an upper solid shaft section; 24. an upper companion flange; 25. the air outlet is sealed; 26. an upper ring plate; 27. secondary grading of the blades; 28. a middle partition plate; 29. driving the steel pipe; 30. a lower ring plate; 31. sealing the middle coarse powder; 32. the lower bearing seat supports the cross beam; 33. a hollow shaft section in the middle; 34. a web; 35. sealing the medium coarse powder; 36. supporting the steel pipe; 37. a hollow cone; 38. driving the round steel; 39. a lower companion flange; 40. a dust cover; 41. a lower solid shaft section; 42. reversely placing the lower bearing seat; 43. an air inlet of the half volute; 44. a half volute; 45. a coarse powder drainage tube; 46. a coarse powder drainage plate; 47. a drainage plate regulating valve; 48. an air inlet adjusting valve; 49. a wind control pipe regulating valve; 50. and (4) an integral support.

The open arrows are gas flows, the solid arrows are material flows, and the arrows filled with particles are dust-laden gas flows.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but 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, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Examples

The multi-particle size grading device is divided into a pre-separation area 3 mainly comprising a static grader, a coupling area 2 mainly comprising a middle coupling rotating cage (a part circled by a chain line in the figure) and a fine separation area 1 mainly comprising a fine grading device according to functions; the coupling zone 2 is simultaneously used as a secondary separation zone, and connects the pre-separation zone 3 with the fine separation zone 1 to form a form of communicating from bottom to top. Through the control of air flow and material flow of the three zones, high-precision classification of coarse particles, coarse powder, medium coarse powder and fine powder is realized.

The multi-particle size grading device with the middle coupling rotating cage provided by the invention is explained in detail as follows:

referring to fig. 1 to 5, the multi-particle size classifying device with a middle coupling rotating cage according to the embodiment of the present invention includes a pre-separating device located in a lower pre-separating region 3, a middle coupling rotating cage located in a middle coupling region 2, and a fine classifying device located in an upper fine separating region 1, wherein the pre-separating device, the middle coupling rotating cage, and the fine classifying device are sequentially connected to form a bottom-up through structure.

The pre-separation device is positioned at the bottom and used for scattering the blocky materials and separating coarse particles for the first time; the middle coupling rotating cage is connected with the pre-separation device and the fine classification device and used for rectifying an airflow field and a material flow field introduced by the pre-separation device, so that the airflow field is more uniform and is beneficial to subsequent fine classification, meanwhile, the middle coupling rotating cage can realize secondary separation to generate coarse powder, and drainage and guide equipment are carried out on the middle coarse powder generated by the fine classification device and the coarse powder generated by self classification to avoid back mixing to influence the separation efficiency; the fine classification device is positioned at the top and is used for three times of fine separation to generate fine powder (industrial finished products) and medium coarse powder.

The pre-separation device is a static classifier, the static classifier comprises a feed inlet 14, a coarse particle outlet 20, a static classifier air inlet 18, a static classifier air outlet 15, a scattering plate 17, a classifying plate 16, a multi-flow control air pipe 19 and a static classifier shell, the feed inlet 14 is positioned at the top of the static classifier shell, the coarse particle outlet 20 is positioned at the bottom of the static classifier shell, the static classifier air inlet 18 and the static classifier air outlet 15 are respectively positioned at two sides of the scattering plate 17 and the classifying plate 16, the scattering plate 17 and the classifying plate 16 are positioned between the feed inlet 14 and the coarse particle outlet 20 in the static classifier shell, a scattering passage is correspondingly formed between the scattering plate 17 and the classifying plate 16, the scattering plate 17 is positioned at the side of the static classifier air inlet 18 and under the feed inlet 14, the classifying plate 16 is positioned at the side of the static classifier air outlet 15 and corresponds to the scattering plate 17, the scattering plate 17 and the classifying plate 16 are respectively in a stepped structure overlapped at a certain interval, and the scattering plate 17 and the classifying plate 16 form a V-shaped structure and are integrally inclined towards the side of the static classifier 18.

A plurality of multi-flow control air pipes 19 are arranged at the middle lower part of the air inlet 18 of the static classifier, and the number of the multi-flow control air pipes 19 is set according to the specification size of the device, so that the uniformity of air flow entering is improved; an air inlet adjusting valve 48 is arranged on the air inlet 18 of the static classifier, an air control pipe adjusting valve 49 is arranged on each multi-flow control air pipe 19, and the uniformity of the sorted air flow is realized through the adjustment of the air control pipe adjusting valve 49.

The static classifier is symmetrically arranged in a W shape, or tangentially arranged in a W shape, or arranged in a single V shape, or arranged in multiple V shapes. In this embodiment, the flat multi-flow air control W-type static classifier includes a static classifier air inlet 18, a static classifier air outlet 15, a feed inlet 14, a coarse particle outlet 20, a scattering plate 17, a classifying plate 16, and a multi-flow control air pipe 19, which are symmetrically distributed.

The air inlet form of the static classifier can adopt tangential inlet, or direct insertion inlet, or other insertion forms. Fig. 6 shows an arrangement of the static classifier intake vent 18, in which the center lines of the static classifier intake vent 18 are parallel, and the distance between the center lines is D, and the size of the distance D determines the intake form of the airflow in the left and right portions. Fig. 7 shows another arrangement of the air inlet 18 of the static classifier, D is 0, and the two center lines are completely coincident, i.e. the left and right air flows enter completely vertically.

The middle coupling rotating cage comprises a middle cage 10, a first shafting 9, a first transmission device 12, a diversion cone 11, a semi-volute 44, a middle coarse powder return pipe 13 and a coarse powder drainage pipe 45, wherein a hollow cone 37 is arranged inside the middle cage 10, the first shafting 9 is connected with the middle cage 10 through the hollow cone 37, the first transmission device 12 is connected with the first shafting 9, and the first transmission device 12 drives the first shafting 9 to drive the middle cage 10 to rotate. The diverging cone 11 is matched with the outer edge of the bottom end of the middle-placed cage 10 and is coaxially positioned below the middle-placed cage 10, and the outer edge of the top end of the middle-placed cage 10 is matched with the fine classifier shell 8 of the fine classification device. The upper end of the hollow cone 37 is matched with a medium coarse powder discharging cone hopper of the fine grading device, the lower end of the hollow cone 37 is matched with the spreader cone 11, and the medium coarse powder discharging cone hopper, the hollow cone 37 and the spreader cone 11 form a through channel, so that medium coarse powder separated by the fine grading device is guided into the spreader cone 11; and a medium coarse powder return pipe 13 is arranged at the lower part of the splitter cone 11, so that medium coarse powder is guided out.

The outer side of the middle-placed cage 10 is uniformly and circumferentially distributed around the half volute 44, an annular air flow channel is formed between the half volute 44 and the middle-placed cage 10, an air inlet 43 of the half volute is connected with an air outlet of the pre-separation device, a coarse powder drainage tube 45 is arranged at the tail end of each half volute 44, the coarse powder drainage tube 45 is located in a low air speed area of the annular air flow channel, a coarse powder drainage plate 46 matched with the coarse powder drainage tube 45 is arranged in the position, close to the rear of each coarse powder drainage tube 45, the coarse powder drainage plate 46 is installed on the inner wall of the half volute 44, a certain gap exists between the coarse powder drainage plate 46 and the outer edge of the middle-placed cage 10, coarse powder drainage is achieved through the arrangement of the coarse powder drainage plate 46, and material flow back mixing is avoided.

Each coarse powder drainage plate 46 is provided with a drainage plate adjusting valve 47, and the drainage plate adjusting valves 47 are used for rotationally adjusting the rotation angle of the coarse powder drainage plate 46 to change the gap between the coarse powder drainage plate and the middle cage 10, so that the coarse powder drainage quantity can be adjusted.

The mid-set cage 10 comprises an upper ring plate 26, a lower ring plate 30, a middle partition plate 28 and secondary grading blades 27, wherein the upper ring plate 26 is positioned at the upper part of the mid-set cage 10, the middle partition plate 28 is positioned at the middle part of the mid-set cage 10, the lower ring plate 30 is positioned at the lower part of the mid-set cage 10, the upper ring plate 26, the lower ring plate 30 and the middle partition plate 28 are concentric and are connected through a support steel pipe 36 to form a cage frame, and the secondary grading blades 27 are uniformly distributed around the periphery of the mid-set cage 10 along the axis of the mid-set cage 10 and are fixed on the cage frame; the upper part of the hollow cone 37 is respectively connected with the upper ring plate 26 and the middle partition plate 28 through upper and lower layers of driving steel pipes 29 which are distributed in a staggered mode, the bottom of the hollow cone 37 is directly connected with the lower ring plate 30, and the hollow cone 37 is connected with the first shafting 9 through driving round steel 38.

An air outlet seal 25 is arranged on the periphery of the top end of the upper ring plate 26, and the air outlet seal 25 prevents coarse powder from directly passing through the middle cage 10; the middle coarse powder lower seal 31 is arranged on the outer periphery of the bottom end of the lower annular plate 30, the middle coarse powder upper seal 35 is arranged on the outer periphery of the upper end of the hollow cone 37, and the middle coarse powder lower seal 31 and the middle coarse powder upper seal 35 are combined to prevent the sorted middle coarse powder from being back-mixed again and entering the sorting area.

The first transmission device 12 is located below or above the first shafting 9, the first transmission device 12 can adopt a downward transmission mode or an upward transmission mode, the downward transmission mode is adopted in the embodiment, and the first transmission device 12 is arranged in the splitter cone 11. The first transmission device 12 can be driven by a belt pulley, a speed reducer, a variable frequency motor, a permanent magnet motor and the like in a matching way.

The mid-positioned cage 10 is a hollow inverted circular truncated cone-shaped cage, and can also be designed into a hollow cylindrical cage according to the gas flow direction; the splitter cone 11 is an inverted cone-shaped cavity and is used for guiding dust-containing airflow from the pre-separation device and isolating dust at the position of the lower transmission device 12, and the cone angle of the splitter cone 11 depends on the speed and the direction of the material lifting airflow. The mid-span cage 10 of this embodiment is a hollow inverted truncated cone such that the diverter cone 11 forms an inverted cone with the mid-span cage 10.

The first shafting 9 comprises a lower solid shaft section 41, a middle hollow shaft section 33 and an upper solid shaft section 23, wherein the lower solid shaft section 41, the middle hollow shaft section 33 and the upper solid shaft section 23 are sequentially connected through mating flanges to form a coaxial whole. Specifically, the lower solid shaft section 41 and the middle hollow shaft section 33 are connected through a lower mating flange 39, and the middle hollow shaft section 33 and the upper solid shaft section 23 are connected through an upper mating flange 24; the lower solid shaft section 41 is supported by a lower bearing assembly, the lower bearing assembly is positioned in an inverted lower bearing seat 42, the inverted lower bearing seat 42 is connected with a lower bearing seat supporting cross beam 32, the inverted lower bearing seat 42 transmits stress to an equipment foundation through the lower bearing seat supporting cross beam 32, and a dust cover 40 is arranged on the lower solid shaft section 41; the middle hollow shaft section 33 is composed of a circular steel pipe and web plates 34 which are uniformly distributed around the circular steel pipe in the circumferential direction, the web plates 34 play roles of reinforcing ribs and connecting bridges, drive round steel 38 are distributed on the web plates 34 in a staggered mode, the drive round steel 38 is connected with the hollow cone 37, the drive round steel 38 is divided into an upper layer and a lower layer, the middle hollow shaft section 33 and the hollow cone 37 are connected into a whole, and then the whole middle coupling rotating cage is connected into an axial concentric body; the upper end of the upper solid shaft section 23 is supported by an upper bearing assembly, the upper bearing assembly is positioned in the upper bearing seat 21, the upper solid shaft section 23 is aligned by the aligning of the upper bearing assembly, the upper bearing seat 21 is connected with an upper bearing seat supporting cross beam 22, the upper bearing seat 21 is supported and fixed by the upper bearing seat supporting cross beam 22, and the centrifugal force borne by rotation is transmitted to the integral support.

The fine grading device is a planar vortex fine grader and comprises a second transmission device 4, a second shaft system 5, a static blade 7, a cylindrical cage 6, a fine grader shell 8 and a medium coarse powder discharge cone hopper, wherein the second transmission device 4 is connected with the second shaft system 5, the second shaft system 5 is connected with the cylindrical cage 6, the second transmission device 4 drives the second shaft system 5 to drive the cylindrical cage 6 to rotate, the second transmission device 4 adopts overhead transmission, the upper end of the second shaft system 5 is connected with the second transmission device 4, and the lower part of the second shaft system 5 is connected with the cylindrical cage 6 through a flange; the second shafting 5 is composed of a solid shaft and a shaft sleeve, and a bearing assembly is arranged in the shaft sleeve to support the solid shaft. The static blades 7 and the cylindrical cage 6 are both positioned in the middle section of the fine classifier shell 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 are uniformly distributed on the concentric periphery of the cylindrical cage 6, and the diameter of the cylindrical cage 6 is slightly smaller and is arranged in the static blades 7; the top of the fine classifier shell 8 is provided with a fine powder outlet, a second shaft system 5 is supported on a platform on the fine classifier shell 8 at the fine powder outlet, a medium and coarse powder discharging conical hopper is arranged below the stationary blades 7, and the top end of the medium and coarse powder discharging conical hopper is connected with the bottom end of the stationary blades 7.

The bottom of the fine classifier is provided with an integral support 50 for supporting the fine classifier, and the integral support 50 also bears the centrifugal force of the mid-cages 10 transmitted by the upper bearing support beam 22 of the shafting one 9.

The grading method of the multi-particle-size grading device with the middle coupling rotating cage specifically comprises the following steps:

when the device works, the ground materials are fed into the pre-separation device through the feed inlet 14, fall onto the first-layer scattering plate 17 due to the action of gravity, and then rebound from the scattering plate 17 onto the first-layer grading plate 16, so that the materials are loosened by downward reciprocating impact layer by layer; the sorting airflow enters from an air inlet 18 of the static classifier, passes through the scattering plate 17 and then enters the classifying plate 16 to complete the classification of the loose materials, and coarse particles cannot be taken away by the sorting airflow due to the gravity and the inertia effect and fall to a coarse particle outlet 20 to be discharged; in the falling process, sorting airflow is introduced from the multi-flow control air pipe 19 to clean powdery materials adhered to coarse particles, and the airflow field is ensured to be uniform up and down by adjusting the air inlet adjusting valve 48 and the air control pipe adjusting valve 49; and symmetrical air inlet is adopted, so that the left and right uniformity of the airflow field is ensured, and the powdery material is efficiently brought into the upper coupling area 2 from the air outlet 15 of the static classifier to complete pre-separation.

The dusty airflow entering the coupling area 2 directly reaches the shunting cone 11 without an excessive air pipe, the path is short, the resistance is low, the shunting cone 11 guides the dusty airflow, then the dusty airflow enters an annular area formed by the middle-placed cage 10 and the half-volute 44 from an air inlet 43 of the half-volute, and the transmission device I12 drives the shafting I9 to drive the middle-placed cage 10 to rotate, so that annular forced vortex airflow is formed in the area, and the bias flow phenomenon of a free flow field is effectively eliminated. Meanwhile, the first transmission device 12 is driven by a variable frequency motor, so that the rotation speed of the middle cage 10 can be adjusted, secondary classification of materials is completed, coarse powder with a specific particle size required by grinding equipment is generated, the coarse powder is discharged from the coarse powder drainage tube 45 under the guiding action of the coarse powder drainage plate 46, the corner of the coarse powder drainage plate 46 is adjusted by the drainage plate adjusting valve 47, and the influence of coarse powder back mixing on classification is avoided. The dusty gas stream passing through the centrally disposed cage 10 is rotated upwardly into the fine separation zone 1.

The dusty airflow flows upwards in the fine separation area 1 and enters the static blades 7 to complete the guiding, and the guiding angle of the static blades 7 is adjustable; the guided dusty airflow enters an annular separation area formed by the static blades 7 and the cylindrical cage 6, the second transmission device 4 drives the second shafting 5 to drive the cylindrical cage 6 to rotate, so that separation airflow is formed in the annular separation area, medium coarse powder loses kinetic energy after colliding with the static blades 7 under the centrifugal action, falls into a medium coarse powder discharge cone bucket, falls into a hollow cone 37 of the coupling area 2 through the medium coarse powder discharge cone bucket, is guided into the shunting cone 11, and is guided out through a medium coarse powder return pipe 13; the fines pass through the cylindrical cage 6 due to the air drag force being greater than the centrifugal force and are collected as a finished product.

The high-precision sorting principle of the invention is as follows: with the conventional parameters unchanged, the sorting efficiency is inversely proportional to the cyclic load, and can be expressed as: e = f/(1+C) a; wherein E is the sorting efficiency, f is the throughput of fine powder with a specific particle size, a is the throughput of feeding materials with the specific particle size, and C is the cyclic load; the larger the circulation load is, the higher the concentration is, the circulation load and the concentration of single separation are reduced through multi-stage classification, the requirement of multi-particle size classification is met, and the total separation efficiency is correspondingly improved.

Taking the sorting PO42.5 cement as an example, if the fine powder 45 μm passes through f =94%, the feed material 45 μm passes through a =60%, and the circulation load C =100%, then the sorting efficiency E =78.3%, and a portion of the coarse powder is pre-sorted by secondary classification with a centrally coupled rotating cage to reduce the concentration of the subsequent sorting, assuming that the circulation load is reduced to C =80% at this time, and the total sorting efficiency is improved to E =87%. However, in the closed circuit grinding system, due to the limitation of grinding capacity and separation principle, the circulating load C can not be infinitely reduced, and the throughput a of feeding materials can be changed along with the reduction of the circulating load C, so that the middle coupling rotating cage is set to be variable frequency speed regulation to meet the grading requirements of different particle sizes and effectively improve the total separation efficiency.

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

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (12)

1. A multi-particle size classification apparatus having a centrally coupled rotating cage, comprising: the device comprises a pre-separation device positioned in a lower pre-separation area, a middle coupling rotating cage positioned in a middle coupling area, and a fine classification device positioned in an upper fine separation area, wherein the pre-separation device, the middle coupling rotating cage and the fine classification device are sequentially connected to form a structure which is communicated from bottom to top;

the pre-separation device is used for scattering the blocky materials and separating coarse particles for the first time; the middle coupling rotating cage is used for rectifying an airflow field and a material flow field introduced by the pre-separation device, realizing secondary separation to generate coarse powder, and conducting drainage and leading out equipment on the coarse powder generated by the fine classification device and the coarse powder generated by self classification; the fine grading device is used for fine sorting for three times to generate fine powder and medium coarse powder;

the middle coupling rotating cage comprises a middle cage, a first shaft system, a first transmission device, a diversion cone, a half volute, a middle coarse powder return pipe and a coarse powder drainage pipe, wherein a hollow cone is arranged in the middle cage, the first shaft system is connected with the middle cage through the hollow cone, the first transmission device is connected with the first shaft system, the diversion cone is matched with the outer edge of the bottom end of the middle cage and is coaxially positioned below the middle cage, and the outer edge of the top end of the middle cage is matched with a fine classifier shell of a fine classification device; the upper end of the hollow cone is matched with a medium coarse powder discharging cone hopper of the fine grading device, the lower end of the hollow cone is matched with a shunting cone, and the medium coarse powder discharging cone hopper, the hollow cone and the shunting cone form a through channel so that medium coarse powder sorted by the fine grading device is guided into the shunting cone; a middle coarse powder return pipe is arranged at the lower part of the spreader cone; the semi-volute is uniformly distributed on the outer side of the middle cage in the circumferential direction, an annular air flow channel is formed between the semi-volute and the middle cage, an air inlet of the semi-volute is connected with an air outlet of the pre-separation device, a coarse powder drainage tube is arranged at the tail end of each semi-volute and is located in a low air speed area of the annular air flow channel, a coarse powder drainage plate matched with the coarse powder drainage tube is arranged at the position, close to the rear of each coarse powder drainage tube, and is installed on the inner wall of the semi-volute, and a certain gap is formed between the coarse powder drainage plate and the outer edge of the middle cage.

2. The multi-particle size classification device with a centrally coupled basket according to claim 1, wherein each coarse powder flow guide plate is provided with a flow guide plate adjusting valve for rotationally adjusting the corners of the coarse powder flow guide plate.

3. The multi-particle size grading device with the middle coupling rotating cage according to claim 1, wherein the middle cage comprises 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 middle cage, the middle partition plate is located at the middle part of the middle cage, the lower ring plate is located at the lower part of the middle cage, the upper ring plate, the lower ring plate and the middle partition plate are concentric and connected through supporting steel pipes to form a cage frame, and the secondary grading blades are uniformly distributed around the periphery of the middle cage along the axis of the middle cage and fixed on the cage frame;

the upper portion of the hollow cone is connected with the upper ring plate and the middle partition plate through upper and lower layers of driving steel pipes which are distributed in a staggered mode, the bottom of the hollow cone is directly connected with the lower ring plate, and the hollow cone is connected with the first shaft system through driving round steel.

4. The multi-particle size classification device with a middle coupling rotating cage according to claim 3, characterized in that the top end of the upper ring plate is provided with an air outlet seal along one circle, the bottom end of the lower ring plate is provided with a middle coarse powder lower seal along one circle, and the upper end of the hollow cone is provided with a middle coarse powder upper seal along one circle.

5. The multi-particle size classification device with centrally coupled cages as claimed in claim 1, wherein the first transmission device is located below or above the first shafting.

6. The multi-particle size classification device with center-coupled cages according to claim 1, wherein the center-coupled cage is a hollow inverted truncated cone-shaped cage or a hollow cylindrical cage, and the diverging cone is an inverted conical cavity.

7. The multi-particle size classification device with a centrally-mounted coupling rotating cage according to claim 1, wherein the shaft system one comprises 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 sequentially connected into a coaxial whole through mating flanges; the lower solid shaft section is supported by a lower bearing assembly, the lower bearing assembly is positioned in an inverted lower bearing seat, and the inverted lower bearing seat is connected with a lower bearing seat supporting beam; the middle hollow shaft section consists of a round steel pipe and a radial plate which is uniformly distributed around the round steel pipe in the circumferential direction, and driving round steel is distributed on the radial plate in an staggered manner and connected with the hollow cone; the upper end of the upper solid shaft section is supported by an upper bearing assembly, the upper bearing assembly is positioned in an upper bearing seat, and the upper bearing seat is connected with an upper bearing seat supporting cross beam.

8. The multi-particle size classifying device with a centrally coupled rotating cage according to claim 1, wherein the pre-separating device is a static classifier comprising a feed inlet, a coarse particle outlet, a static classifier air inlet, a static classifier air outlet, a dispersing plate, a classifying plate, a multi-flow control air pipe and a static classifier shell, the feed inlet is positioned at the top of the static classifier shell, the coarse particle outlet is positioned at the bottom of the static classifier shell, the static classifier air inlet and the static classifier air outlet are respectively positioned at both sides of the dispersing plate and the classifying plate, the dispersing plate and the classifying plate are positioned in the static classifier shell between the feed inlet and the coarse particle outlet, a dispersing classifying channel is correspondingly formed between the dispersing plate and the classifying plate, the dispersing plate is positioned at the side of the static classifier air inlet and right below the feed inlet, the classifying plate is positioned at the side of the static classifier air outlet and corresponds to the dispersing plate, the dispersing plate and the classifying plate are respectively in a stepped structure stacked at a certain interval, and the dispersing plate and the classifying plate both form a V-shaped structure and are integrally inclined to the side of the static classifier air inlet.

9. The multi-particle size classification device with a centrally coupled rotor cage according to claim 8, wherein an air inlet regulating valve is disposed on the air inlet of the static classifier; the middle lower part of the air inlet of the static classifier is provided with a plurality of multi-flow control air pipes, and each multi-flow control air pipe is provided with an air control pipe adjusting valve.

10. The multi-particle size classification device with centrally coupled cages as claimed in claim 8, wherein said static classifiers are in a "W" type symmetrical arrangement, or a "W" type tangential arrangement, or a single "V" type arrangement, or a multiple "V" type arrangement.

11. The multi-particle size classifying device with the center coupled rotating cage according to claim 1, wherein the fine classifying device comprises a second driving device, a second shaft system, stationary blades, a cylindrical cage, a fine classifier shell and a medium coarse powder discharging cone, the second driving device is connected with the second shaft system, the second shaft system is connected with the cylindrical cage, the stationary blades and the cylindrical cage are both positioned in the middle section of the fine classifier shell, the stationary blades are at the same height as the cylindrical cage and are concentrically distributed around the cylindrical cage, the fine classifier shell is provided with fine powder outlets at the top, and the medium coarse powder discharging cone is connected with the bottom ends of the stationary blades at the top.

12. The method for classifying a multi-particle size classifying device with a centrally-mounted coupling rotating cage according to any one of claims 1 to 11, wherein the classifying method comprises the steps of feeding the ground material into a pre-separating device, classifying the material by a classifying airflow, discharging the classified coarse particles from the bottom of the pre-separating device, and bringing the powdery material into an upper coupling area to complete the pre-separation;

the dust-containing airflow entering the coupling area directly reaches the splitter cone, the splitter cone guides the dust-containing airflow, then the dust-containing airflow enters an annular area formed by the middle-mounted cage and the half-volute from an air inlet of the half-volute, meanwhile, a driving shaft system I of the driving device drives the middle-mounted cage to rotate, so that annular forced vortex airflow is formed in the area, secondary sorting of materials is completed, the sorted coarse powder is discharged from a coarse powder drainage tube under the guiding action of a coarse powder drainage plate, and the dust-containing airflow passing through the middle-mounted cage rotates upwards to enter a fine separation area;

the dusty airflow upwards flows in the fine separation area, is separated by the fine classification device, the separated medium coarse powder falls into the medium coarse powder discharge cone hopper, then falls into the hollow cone of the medium cage through the medium coarse powder discharge cone hopper, then is guided into the shunt cone and is guided out through the medium coarse powder return pipe, and the fine powder passes through the cylindrical cage and is collected as an industrial finished product.

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