CN111715418B

CN111715418B - Composite grading equipment

Info

Publication number: CN111715418B
Application number: CN202010701312.0A
Authority: CN
Inventors: 郑艳; 闵凡飞; 方菲; 陈军; 刘春福; 吕凯; 任豹; 王传真
Original assignee: Anhui University of Science and Technology
Current assignee: Anhui University of Science and Technology
Priority date: 2020-07-20
Filing date: 2020-07-20
Publication date: 2024-06-18
Anticipated expiration: 2040-07-20
Also published as: CN111715418A

Abstract

The invention discloses composite classification equipment which comprises an inner classification device, a stirring device, a rotary driving device and an outer classification device. The inner grading device is used for realizing preliminary grading sedimentation of mineral particles, and the stirring device is positioned above the outer part of the inner grading sedimentation device; the upper part of the rotary driving device is positioned above the outer part of the inner grading device, and the lower part of the rotary driving device is positioned below the outer part of the inner grading device and is used for providing driving force for the rotary motion of the equipment; the outer classifying device is used for realizing rapid aggregation, classification and sedimentation of fine mineral particles, and is positioned outside the rotary driving device, and the top of the rotary driving device is positioned above the top of the outer classifying device. According to the invention, the gravity and the centrifugal force cooperate to realize the first grading sedimentation and then agglomeration sedimentation of mineral particles in the same device, so that the use efficiency of the medicament is effectively improved, the grading efficiency and the grading precision of the mineral particles are improved, and the device has the advantages of small occupied area, small energy consumption, easiness in operation, low cost and the like.

Description

Composite grading equipment

Technical Field

The invention belongs to the technical field of grading equipment, and particularly relates to composite grading equipment.

Background

The classification equipment is widely applied to separation of ore materials, coal and other granular or powdery materials, and the classification precision is inaccurate and the classification efficiency is low in the classification process, so that fine particles in the underflow are increased. The key of classification is to improve the classification accuracy and efficiency of the operation.

Common screen classification is precisely classified according to granularity, but the screen is easy to block holes and is severely worn; the hydraulic classification is performed according to the settlement speed in a fuzzy classification mode, the equipment structure is simple, the operation cost is low, the occupied area is large, and the classification precision and the classification efficiency are low; the centrifugal classification is fuzzy classification according to radial speed difference, the occupied area of equipment is small, the treatment capacity is large, the classification efficiency is high, but the classification precision is low, and the energy consumption is high; the equipment combining screening and hydraulic classification combines particle size classification and sedimentation (centrifugation) speed differential classification, so that classification precision and classification efficiency can be effectively improved, but the treatment capacity is low, the energy consumption is high, the use condition is strict, and the like.

In order to effectively solve the problems of classification efficiency and classification precision of classification equipment, some solutions are also proposed in the prior patent literature. The chinese patent with the application number 201810131344.4 discloses a cyclone classification column and use it to classify pulp coarse and fine particles, and the device is classified through the screen cloth, can realize the cyclone classification of coarse particle and fine particle two products, can improve classification accuracy and classification efficiency to a certain extent, but adopts the tubular screen cloth, can't avoid the stifled hole problem of screen cloth, and coarse particle is directly discharged after once classifying simultaneously, can't be mingled with fine particle in the coarse particle. The patent with publication No. CN268493Y discloses a hydrocyclone with a filter screen, wherein a filter screen is arranged between a feed pipe and an overflow pipe, the diameter and the shape of the filter screen are consistent with those of an axial zero-speed envelope surface of the hydrocyclone, the lower part of the filter screen is open, and the upper part of the filter screen is connected with the top of a feed cavity, so that the overflow coarse problem can be solved to a certain extent, and the problem of thin underflow clamping is not solved yet; the invention patent of publication No. CN101844115A discloses a three-product cyclone classifying screen, the device is characterized in that a cylindrical screen is connected to the lower port of a cylindrical guide cylinder of a cyclone, the cylindrical screen is sleeved in the cylindrical of the cyclone, the cylindrical screen is sleeved in the conical cylinder, water supplementing is arranged on the conical cylinder, a guide disc is arranged between a central tube and the conical screen, fine particles are screened by the screen through utilizing the pressure difference of the outer cyclone of the lower side wall of a strong centrifugal force field, the circulating current coarse run near the side wall and a top cover of the cyclone is eliminated, the limited upper rate in overflow and the limited lower rate in underflow are effectively controlled, the classifying efficiency and the treating capacity of the cyclone are improved, but the scheme cannot avoid screen blocking, and the problems of 'backflow' phenomenon of the screen at the lower part of the column section and poor classifying effect of the conical section exist. The existing classifying equipment can improve classifying efficiency and classifying precision to a certain extent, but if rapid classifying sedimentation and agglomeration of minerals are to be realized, the rapid classifying sedimentation and agglomeration of minerals are required to be realized on different equipment, the required equipment is more, the occupied area of the equipment is large, the energy consumption is large, the cost is high, the medicament use efficiency is low, and the medicament waste is serious.

Disclosure of Invention

The invention aims to provide composite classification equipment, which has the advantages that the gravity and the centrifugal force are synergistic, the first classification sedimentation and then agglomeration sedimentation of mineral particles are realized in the same device, the use efficiency of a medicament is effectively improved, the classification efficiency and the classification precision of the mineral particles are improved, the occupied area is reduced, and the energy consumption and the cost are reduced.

The technical problems to be solved by the invention are realized by adopting the following technical scheme.

A composite classification device comprises an inner classification device, a stirring device, a rotary driving device and an outer classification device. Wherein the internal classification device is a preliminary classification sedimentation device of the invention, and the stirring device is positioned above the outside of the internal classification device; the upper part of the rotary driving device is positioned above the outer part of the inner grading device, and the lower part of the rotary driving device is positioned below the outer part of the inner grading device and is used for providing driving force for the rotary motion of the equipment; the outer grading device is a conglomeration grading sedimentation device, is positioned outside the rotary driving device, and the top of the rotary driving device is positioned above the top of the outer grading device.

The internal division device comprises an internal column casing, a feeding guide casing, an internal cone casing and an overflow pipe. The feeding guide cylinder is fixed above the top of the inner column casing, tangential feeding ports are symmetrically formed in two sides of the feeding guide cylinder, and the outermost inlet of each tangential feeding port is positioned on the outer side of the upper part of the outer grading device; the inner cone is positioned below the bottom of the inner column casing, the top of the inner cone and the bottom of the inner column casing are arranged in a first annular groove at the bottom of the inner side of the rotary cylinder, and the bottom of the inner cone is a coarse particle discharge hole; the overflow pipe is a large-diameter cylinder pipeline, the bottom of the overflow pipe is located above the inner part of the inner cylinder, the top of the overflow pipe is fixed above the top of the feeding guide cylinder, the surface, connected with the top of the feeding guide cylinder, of the upper part of the overflow pipe is an arc-shaped surface, overflow particles are prevented from gathering at the top of the feeding guide cylinder, and the top of the overflow pipe is an overflow particle discharge port.

The stirring device comprises an upper ear seat, a telescopic rod, a lower ear seat and a stirring body. The upper ear seat is fixedly arranged on the feeding guide cylinder, the top of the telescopic rod is fixedly connected with the upper ear seat through a pin, the bottom of the telescopic rod is fixedly connected with the lower ear seat through a pin, the lower ear seat is fixedly arranged on the stirring body, the stirring body is an arc-shaped block which is more than or equal to 100 degrees and less than 120 degrees, the upper ear seat, the telescopic rod, the lower ear seat and the stirring body are all three, the telescopic rod, the lower ear seat and the stirring body are arranged in a hollow groove of the rotary cylinder, the bottom of the stirring body is positioned above the bottom of the hollow groove, and the height of the stirring body can be adjusted according to requirements.

The rotary driving device comprises a rotary drum, a rotary shaft, a bearing body, a supporting lug seat, a mounting seat, a driving motor and a cylindrical screen. The rotary drum is arranged outside the inner column casing and coaxial with the inner column casing, the inner top of the rotary drum is arranged below the bottom of the feeding guide drum, the inner side of the rotary drum is arranged between the stirring device and the inner column casing and abuts against the outer side of the inner column casing, a rotating shaft is fixed at the top of the outer side of the rotary drum, a hollow groove is formed by the outer convex of the inner bottom of the inner side of the rotary drum and the inner convex of the outer side of the rotary drum, the bottom of the hollow groove is a agglomerated particle discharge hole, the inner bottom of the inner side of the rotary drum and the inner bottom of the outer side of the rotary drum are connected through four arc-shaped reinforcing ribs, the outer top of the rotary drum is slightly lower than the inner top of the rotary drum, the inner diameter of the stirring body is slightly larger than the outer convex diameter of the inner bottom of the rotary drum, and the outer diameter of the stirring body is slightly smaller than the inner convex diameter of the outer inner bottom of the rotary drum; the rotary shaft is connected with the driving motor through a supporting lug seat fixed in the top of the outer grading device, a through hole in the top of the outer grading device and a mounting seat above the top of the outer grading device, a bearing body is mounted above the supporting lug seat, the bearing body comprises a bearing and a bearing seat, the bearing is used for supporting and fixing the rotary shaft, the bearing seat is used for fixing and mounting the bearing, and a circular stop block is mounted on the rotary shaft above the bearing body and used for fixing the bearing body; the cylindrical screen is arranged below the bottom of the rotary cylinder, the top of the cylindrical screen and the bottom of the rotary cylinder are arranged in a second annular groove at the bottom of the outer cylinder, the screen bars of the cylindrical screen are longitudinally arranged, the screen bar spacing of the cylindrical screen can be adjusted in the sliding grooves at the top and the bottom of the cylindrical screen as required, the outer side of the cylindrical screen is provided with an arc-shaped baffle with adjustable height, and the bottom of the cylindrical screen is provided with an undersize particle discharge hole; the rotary shaft have three, evenly arrange in the top of rotary drum, the support ear seat have three, evenly arrange in the top of outer column casing, the mount pad has three, evenly arrange in the top of outer column casing for fixed driving motor, driving motor have three, evenly arrange on the mount pad, the bearing body have three, evenly arrange in support ear seat top.

The outer grading device comprises an outer column casing, an outer cone casing and a dosing tube. Wherein the outer column cylinder is arranged outside the rotary cylinder, and the top of the outer column cylinder is positioned above the top of the overflow pipe; the outer cone is positioned below the outer column casing, the bottom of the outer cone is fixedly connected with the top of the outer column casing through bolts, and the bottom of the outer cone is a sieve particle discharge hole; the three dosing pipes are uniformly arranged below the top of the outer column casing, the specifications of the three dosing ports are completely the same, the multi-point dosing is convenient to realize, and the sedimentation speed of mineral fine particles is improved.

When the slurry to be separated enters the feeding guide cylinder from the tangential feeding port at a certain speed under a certain pressure through the pump, then enters the inner cylinder, the slurry is subjected to spiral downward centrifugal motion under the action of initial acting force, the coarse particles are subjected to larger gravity and move downward in the inner cylinder under the action of gravity, enter the inner cone 1, then are discharged through the coarse particles discharging port at the bottom of the inner cone, the finer particles are subjected to smaller gravity, move upward in the inner cylinder, then overflow from the overflow port at the top of the overflow pipe, and enter the rotary cylinder; the driving motor drives the rotating cylinder to rotate by driving the rotating shaft to rotate through rotating the driving motor frequency converter button, so that the cylindrical screen is driven to rotate; simultaneously, the medicament enters the rotary drum from the medicament adding pipe at a certain speed under a certain pressure, the medicament and overflow particles are accelerated to be mixed and agglomerated under the action of the stirring body, the mixed and agglomerated particles move downwards along the inner wall of the rotary drum under the action of gravity, part of fine particles enter the outer cone through the strip-shaped screen of the cylindrical screen to become sieve-penetrating particles, and the sieve-penetrating particles are discharged through a sieve-penetrating particle discharge hole at the bottom of the outer cone; the larger particles continue to move downwards under the action of gravity and are discharged from an undersize particle discharge hole at the bottom of the cylindrical screen. After the agglomeration, classification and sedimentation are completed, the motor frequency converter button is driven to rotate, the rotating speed is adjusted to 0, and the power switch is turned off.

Compared with the prior art, the invention has the beneficial effects that the gravity and the centrifugal force cooperate to realize rapid grading sedimentation and agglomeration sedimentation in the same equipment, effectively improve the use efficiency of the medicament, save the use amount of the medicament, have the advantages of small occupied area, small energy consumption, high grading efficiency and the like, and overcome the defects of the prior art.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

fig. 2 is a schematic view of the internal classification device and stirring device structure of the present invention.

Detailed Description

The invention is further described below with reference to specific embodiments and illustrations in order to make the technical means, the creation features, the achievement of the purpose and the effect achieved by the invention easy to understand.

As shown in fig. 1, a composite classification apparatus includes an inner classification device 1, a stirring device 2, a rotation driving device 3, and an outer classification device 4. Wherein the internal grading device 1 is a preliminary grading sedimentation device of the invention, and the stirring device 2 is positioned above the outside of the internal grading device 1; the upper part of the rotary driving device 3 is positioned above the outer part of the inner grading device 1, and the lower part of the rotary driving device is positioned below the outer part of the inner grading device 1 and is used for providing driving force for the rotary motion of equipment; the outer classifying device 4 is a agglomerate classifying sedimentation device of the present invention, and is located outside the rotary driving device 3, and the top of the rotary driving device 3 is located above the top of the outer classifying device 4.

As shown in fig. 1 and 2, the internal classification device 1 comprises an internal column 11, a feed guide 12, an internal cone 13 and an overflow pipe 14. Wherein, the feeding guide cylinder 12 is fixed above the top of the inner column cylinder 11, tangential feed inlets 121 are symmetrically arranged at two sides of the feeding guide cylinder 12, and the outermost inlet of the tangential feed inlets 121 is positioned at the outer side of the upper part of the outer grading device 4; the inner cone 13 is positioned below the bottom of the inner column 11, the top of the inner cone and the bottom of the inner column 11 are arranged in a first annular groove 311 at the bottom of the inner side of the rotary drum 31, and the bottom of the inner cone 13 is provided with a coarse particle discharge hole 131; the overflow pipe 14 is a large-diameter cylindrical pipeline, the bottom of the overflow pipe is located above the inner part of the inner cylindrical shell 11, the top of the overflow pipe 14 is fixed above the top of the feeding guide shell 12, the surface, connected with the top of the feeding guide shell 12, of the upper part of the overflow pipe 14 is an arc surface, overflow particles are prevented from being gathered at the top of the feeding guide shell 12, and the top of the overflow pipe 14 is provided with an overflow particle discharge port 141.

As shown in fig. 1 and 2, the stirring device 2 includes an upper ear seat 21, a telescopic rod 22, a lower ear seat 23 and a stirring body 24. The upper ear seat 21 is fixedly installed on the feeding guide cylinder 12, the top of the telescopic rod 22 is fixedly connected with the upper ear seat 21 through a pin, the bottom of the telescopic rod 22 is fixedly connected with the lower ear seat 23 through a pin, the lower ear seat 23 is fixedly installed on the stirring body 24, the stirring body 24 is an arc-shaped block which is more than or equal to 100 degrees and less than 120 degrees, three upper ear seats 21, the telescopic rod 22, the lower ear seat 23 and the stirring body 24 are arranged in a hollow groove 313 of the rotary cylinder 31, the bottom of the stirring body 24 is positioned above the bottom of the hollow groove 313, and the height of the stirring body 24 can be adjusted according to requirements.

As shown in fig. 1, the rotary driving device 3 includes a rotary drum 31, a rotary shaft 32, a bearing body 33, a support lug 34, a mounting seat 35, a driving motor 36, and a cylindrical screen 37. The rotary drum 31 is arranged outside the inner column drum 11 and is coaxial with the inner column drum 11, the inner top of the rotary drum 31 is arranged below the bottom of the feeding guide drum 12, the inner side of the rotary drum 31 is arranged between the stirring device 2 and the inner column drum 11 and is abutted to the outside of the inner column drum 11, a rotary shaft 32 is fixed at the outer top of the rotary drum 31, a hollow groove 313 is formed by the outer convex of the inner bottom of the inner side and the inner convex of the outer side of the rotary drum 31, the bottom of the hollow groove is a agglomerated particle discharge hole 312, the inner bottom of the inner side and the inner bottom of the rotary drum 31 are connected through four arc-shaped reinforcing ribs, the outer top of the rotary drum 31 is slightly lower than the inner top, the inner diameter of the stirring body 24 is slightly larger than the outer convex diameter of the inner bottom of the rotary drum 31, and the outer diameter of the stirring body 24 is slightly smaller than the inner convex diameter of the inner bottom of the outer side of the rotary drum 31; the rotary shaft 32 is connected with the driving motor 36 through a supporting lug seat 34 fixed in the top of the outer grading device 4, a through hole in the top of the outer grading device 4 and a mounting seat 35 above the top of the outer grading device 4, a bearing body 33 is arranged above the supporting lug seat 34, the bearing body 33 comprises a bearing and a bearing seat, the bearing is used for supporting and fixing the rotary shaft 32, the bearing seat is used for fixing and mounting the bearing, and a circular stop block 321 is arranged on the rotary shaft 32 above the bearing body 33 and used for fixing the bearing body 33; the cylindrical screen 37 is arranged below the bottom of the rotary drum 31, the top of the cylindrical screen 37 and the bottom of the rotary drum 31 are arranged in a second annular groove 412 at the bottom of the outer cylindrical drum 41, the screen bars of the cylindrical screen 37 are longitudinally arranged, the screen bar spacing of the cylindrical screen 37 can be adjusted in a sliding groove 372 at the top and the bottom of the cylindrical screen 37 according to the requirement, a height-adjustable arc-shaped baffle 371 is arranged outside the cylindrical screen 37, and the bottom of the cylindrical screen 37 is an undersize particle discharge port 373; the three rotary shafts 32 are uniformly arranged at the top of the rotary drum 31, the three supporting lugs 34 are uniformly arranged in the top of the outer column casing 41, the three mounting seats 35 are uniformly arranged above the top of the outer column casing 41 and used for fixing the driving motors 36, the three driving motors 36 are uniformly arranged on the mounting seats 35, and the three bearing bodies 33 are uniformly arranged above the supporting lugs 34.

As shown in fig. 1, the outer classifying device 4 includes an outer cylinder 41, an outer cone 42, and a dosing tube 43. Wherein the outer cylinder 41 is arranged outside the rotary cylinder 31 with its top above the top of the overflow pipe 14; the outer cone 42 is positioned below the outer column 41, the bottom of the outer cone is fixedly connected with the top of the outer column 41 through bolts, and the bottom of the outer cone 42 is provided with a sieve particle discharge hole 421; the three dosing pipes 43 are uniformly arranged below the top of the outer column casing 41, and the three dosing ports 43 are identical in specification, so that the multi-point dosing is conveniently realized, and the sedimentation speed of mineral fine particles is improved.

When in use, slurry to be separated enters the feeding guide cylinder 12 from the tangential feed inlet 121 at a certain speed and then enters the inner cylinder 11 through the pump, the slurry is subjected to spiral downward centrifugal motion under the action of initial acting force, the coarse particles are subjected to larger gravity and move downward in the inner cylinder 11 under the action of gravity and enter the inner cone 13, then the coarse particles are discharged through the coarse particle discharge hole 131 at the bottom of the inner cone 13, the finer particles are subjected to smaller gravity and move upward in the inner cylinder 11, and then overflow from the overflow hole 141 at the top of the overflow pipe 14 and enter the rotary cylinder 31; the driving motor 36 is rotated to drive the frequency converter button, and the driving motor 36 drives the rotary drum 31 to rotate by driving the rotary shaft 32, so that the cylindrical screen 37 is driven to rotate; simultaneously, the medicament enters the rotary drum 31 from the medicament adding pipe 43 at a certain speed under a certain pressure, the medicament and overflow particles are accelerated to be mixed and agglomerated under the action of the stirring body 24, the mixed and agglomerated particles move downwards along the inner wall of the rotary drum 31 under the action of gravity, part of fine particles enter the outer cone 42 through the strip-shaped screen of the cylindrical screen 37 to become sieve-penetrating particles, and are discharged through a sieve-penetrating particle discharge hole 421 at the bottom of the outer cone 42; the larger particles will continue to move downwardly under the force of gravity and drain from undersize particle outlet 373 at the bottom of cylindrical screen 37. After the agglomeration, classification and sedimentation are completed, the frequency converter button of the driving motor 36 is rotated to adjust the rotation speed to 0, and the power switch is turned off.

In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a compound classification equipment, includes interior grading plant, agitating unit, rotary drive device and outer grading plant, its characterized in that: the stirring device is positioned above the outside of the internal dividing device; the upper part of the rotary driving device is positioned outside the stirring device, and the lower part of the rotary driving device is positioned below the outer part of the inner grading device; the outer grading device is positioned outside the rotary driving device, and the top of the rotary driving device is positioned above the top of the outer grading device;

The inner grading device consists of an inner column casing, a feeding guide cylinder, an inner cone casing and an overflow pipe, wherein the feeding guide cylinder is fixed above the top of the inner column casing, tangential feeding ports are symmetrically arranged on two sides of the feeding guide cylinder, and the outermost inlet of the tangential feeding ports is positioned on the outer side of the upper part of the outer grading device; the inner cone is positioned below the bottom of the inner column casing, the top of the inner cone and the bottom of the inner column casing are arranged in a first annular groove at the bottom of the inner side of the rotary cylinder, and the bottom of the inner cone is a coarse particle discharge hole; the overflow pipe is a large-diameter cylinder pipeline, the bottom of the overflow pipe is positioned above the inner part of the inner cylinder, the top of the overflow pipe is fixed above the top of the feeding guide cylinder, the surface, connected with the top of the feeding guide cylinder, of the upper part of the overflow pipe is an arc-shaped surface, and the top of the overflow pipe is an overflow particle discharge port;

The stirring device consists of an upper ear seat, a telescopic rod, a lower ear seat and a stirring body, wherein the upper ear seat is fixedly arranged on a feeding guide cylinder, the top of the telescopic rod is fixedly connected with the upper ear seat through a pin, the bottom of the telescopic rod is fixedly connected with the lower ear seat through a pin, the lower ear seat is fixedly arranged on the stirring body, the stirring body is an arc-shaped block with the angle of more than or equal to 100 degrees and less than 120 degrees, three upper ear seats, three telescopic rods, three lower ear seats and three stirring bodies are arranged in a hollow groove of the rotary cylinder, the bottom of the stirring body is positioned above the bottom of the hollow groove, and the height of the stirring body can be adjusted according to requirements;

The rotary driving device consists of a rotary drum, a rotary shaft, a bearing body, a supporting lug seat, a mounting seat, a driving motor and a cylindrical screen, wherein the rotary drum is arranged outside the inner cylindrical drum and is coaxial with the inner cylindrical drum, the inner top of the rotary drum is arranged below the bottom of the feeding guide drum, the inner side of the rotary drum is arranged between the stirring device and the inner cylindrical drum and abuts against the outer part of the inner cylindrical drum, the outer top of the rotary drum is slightly lower than the inner top, the inner diameter of the stirring body is slightly larger than the outer convex diameter of the inner bottom of the rotary drum, the outer diameter of the stirring body is slightly smaller than the inner convex diameter of the outer inner bottom of the rotary drum, the outer top of the rotary drum is fixedly provided with the rotary shaft, the outer bottoms of the rotary drum are outwards convex and inwards convex to form a hollow groove, the bottoms of the hollow groove are provided with a agglomerated particle discharge hole, and the inner outer bottom of the rotary drum and the outer bottom of the rotary drum are connected by four arc-shaped reinforcing ribs; the rotary shaft is connected with the driving motor through a supporting lug seat fixed in the top of the outer grading device, a through hole in the top of the outer grading device and a mounting seat above the top of the outer grading device, a bearing body is arranged above the supporting lug seat, the bearing body comprises a bearing and a bearing seat, and a circular stop block is arranged on the rotary shaft above the bearing body; the cylindrical screen is arranged below the bottom of the rotary cylinder, the top of the cylindrical screen and the bottom of the rotary cylinder are arranged in a second annular groove at the bottom of the outer cylinder, and the bottom of the cylindrical screen is an undersize particle discharge hole;

The outer grading device consists of an outer column casing, an outer cone casing and a dosing pipe, wherein the outer column casing is arranged outside the rotary casing, and the top of the outer column casing is positioned above the top of the overflow pipe; the outer cone is positioned below the outer column casing, the bottom of the outer cone is fixedly connected with the top of the outer column casing through bolts, the bottom of the outer cone is provided with a through sieve particle discharge hole, and three dosing pipes are uniformly arranged below the top of the outer column casing.

2. A composite classification apparatus as claimed in claim 1, wherein: the screen bars of the cylindrical screen are longitudinally arranged, the screen bar intervals of the cylindrical screen can be adjusted in the sliding grooves at the top and the bottom of the cylindrical screen as required, and the outer side of the cylindrical screen is provided with an arc-shaped baffle with adjustable height; the rotary shaft have three, evenly arrange in the top of rotary drum, the support ear seat have three, evenly arrange in the top of outer column casing, the mount pad have three, evenly arrange in the top of outer column casing, driving motor have three, evenly arrange on the mount pad, the bearing body have three, evenly arrange in support ear seat top.