CN1042320A - Super particle classification method of vacuum-centrifugal type and device - Google Patents

Abstract

A kind of vacuum-centrifugal type ultrafine dust stage division and device, different and allow the space of material stream passed each other by making a series of vacuums, and be aided with an additional centrifugal force field in each space, make the different particulate of particle diameter correspondingly be in the different air-flow fields, the device of realization the inventive method is made up of multi-stage vacuum-centrifugal classification chamber, its classification point can reach 1 μ or below 1 μ, to the particulate of particle diameter below 40 μ can with the time tell some levels, classification point is adjustable continuously.Accuracy height of the present invention, applicability is strong, can extensive use in laboratory and industrial production.

Description

Super particle classification method of vacuum-centrifugal type and device

The present invention relates to a kind of method and apparatus that is used for the classification and the separation of ultrafine dust, belong to the technical field of powder technology.

At present, for the classification and the separation of particulate material, generally be processes such as employing airflow centrifugal power screening, such as, common wind rice machine is exactly application of weight is carried out sorting with solid material in air-flow a method in the rural area, but these methods all are unsuitable for the classification and the separation of ultrafine dust.The French Patent (FRP) (FR2587-094) that announce November nineteen eighty-three has disclosed a kind of suspension gravity filter that has vacuum extractor; it is caught suspension and can collect the suspension of sedimentation under the state of vacuumizing by two dividing plates that have grid and micropore that are across in the air-flow; but its measure that vacuumizes just is used for collecting the suspended particulates separated by dividing plate (from air-flow) or to have caught, rather than really as the separating particles or the means of particulate being carried out classification.

For fear of above-mentioned weak point of the prior art, so that accurately carry out the classification and the separation of ultrafine dust material, the present invention proposes the device that a kind of method that adopts vacuum deposition and centrifugal action to combine is carried out ultrafine dust classification and the method for separating and realized this method.

Realize that method of the present invention is: different and allow the space of material stream passed each other by making a series of vacuums, and be aided with an additional centrifugal force field in each space, make the different particulate of particle diameter correspondingly be in different air-flow fields, thereby realize the super-fine classified of material and separation.Use this method that ultrafine dust is carried out classification and separation, its classification point can reach lu or below the lu, and can according to different the requirement particulate be told some grades simultaneously by particle diameter to the particulate of particle diameter below 40U, and classification point is adjustable continuously.This method both can be used for laboratory small lot material sorting, also can be used for industrial production.

The basic principle that realizes the inventive method is: under the absolute vacuum condition, the particle of any particle diameter all has the identical rate of settling, and under other condition, the particulate that particle diameter is different, because the surface area difference will have the different rates of settling, the macroparticle sedimentation is very fast.If system is under a certain vacuum, the air motion direction of carrying particulate secretly vertically upward, air velocity is V, the speed with respect to air-flow of particulate sedimentation is U, then the relative settlement speed particle that satisfies U-V=0 will be suspended from midair in theory.If satisfying the diameter of the particulate of following formula is De, then the particle of D＞De is sedimentation, and the particle of D＜De will rise with air-flow.By the different space of a plurality of vacuum is set, the utilization said method separates repeatedly, can reach the order ground that makes ultrafine dust classification and separation.

Accompanying drawing one is a kind of realization device of the present invention.(1) is the street cleaner among the figure, and (2) are the vacuum degree control valve, and (3) are material outlet, (4) be street cleaner's drive motors, (5) are loam cake, and (6) are housing, (7) be material inlet, (8) are fuse, and (9) are dust collecting brush, (10) be the mouth valve of bleeding, (11) are dust arrester, and (12) are thrust bearing, (13) be axle, (14) are revolving valve, and (15) are the auxiliary air inlet, (16) be vacuum meter, (17) are Ω _Outward, (18) are the door district, (19) are Ω _In

Describe the present invention in detail below in conjunction with embodiment.

The device of realizing the inventive method is shown in accompanying drawing one, and it is made up of multi-stage vacuum-centrifugal classification chamber (only having drawn two among the figure).It is basic identical that each grading room all has two vacuums, but the different space Ω of the air-flow rate of climb _Outward, Ω _InAnd space, door district, wherein Ω _OutwardThe space be ring-type, Ω _InBe column, Ω _OutwardOverlapping Ω _In, corresponding speed is respectively V _OutwardAnd V _In, at Ω _OutwardWith Ω _InBetween have one fan-shaped, can be by " the door district " of motor driven rotary, this district's air-flow rate of climb is Ve, the rotating speed in this district makes that just in time limit relative settlement speed is that the particulate of Ue=Ve is at the uniform velocity garden Zhou Yundong in this district.Therefore, under the limit that nothing is scratched, satisfy the particulate of this condition just and will on " door " district track, do the stable state of motion for a long time.And the particulate of particle diameter D＞Ve will be brought into Ω by air-flow _In, and owing to the effect that is subjected to ascending air V＞Ve enters back one-level separated space; The particulate of D＞De will be thrown to Ω under centrifugal action _Outward, and in the air-flow of V＜Ve, obtain bigger absolute settlement speed U-V _Outward, and fall in the dust collecting container of separated space bottom.In the one-level separated space of back, vacuum is higher, and particulate resulting " buoyancy " and viscous force are littler, and its critical particle diameter De will move to reducing direction.If the longest particle diameter of the time of staying in previous stage and the one-level space, back correspondingly is made as De1 and De2, because after previous stage is handled, the particulate of all De＞De1 is all own in theory separates from air-flow, has only the particulate of D＜De1 to enter the back level.Similar with prime, the back level can be come out the separation of particles of all D＞De2 again.So in back one-level (in fact arbitrary level all similarly), will receive the particulate of particle diameter between De2-De1, thereby reach the order ground of classification and separation.If regulate the relative vacuum degree difference of each grading room, particle diameter and the distribution that just can regulate gained products at different levels.

In order to make grading room remain the airflow field of even rising, have auxiliary air inlet (15) in the side that drives fuse rotating shaft (13) by motor, auxiliary air imports the Ω of fuse through the endoporus of the axle of hollow _In(19) space.Locate the vacuum that the vacuum degree control valve (2) of pipeline throat is controlled each grading room with being arranged at grading room outlet (3).The internal diameter of inter-stage connecting pipe is much smaller than the grading room internal diameter, and to guarantee particulate material high-speed motion in connecting pipe, free settling not has bigger initial velocity to enter the circular motion track after entering grading room simultaneously.Motor (4) drives street cleaner (1) work to remove connecting pipe contingent clogging after long-term work.Dust arrester revolving valve (14) is communicated with the grading room bottom when work with dust arrester (11), particulate is clamp-oned under the help of dust collecting brush (9) in the dust arrester (11), when dust arrester fills with, close revolving valve, utilization is bled or the mode of taking dust arrester is taken out material, after utilizing the mouth (10) of bleeding to make empty dust arrester reach the vacuum consistent again, can open revolving valve again and continue the material of filling from the grading room bottom with grading room.

When using the present embodiment device, material to be fractionated transports down at air-flow and tangentially enters the grading room that the cross section is a garden shape via material inlet (7).After material enters grading room, at Ω _Outward(11) space rotation, the bigger material of particle diameter will be deposited to the grading room bottom under the gravity effect simultaneously, and will be driven in the dust arrester by dust collecting brush (9).Dust arrester revolving valve (14) is opened when dust arrester filling material, and dust arrester cuts out after filling material, to guarantee the stable gas pressure of grading room.Taking off dust arrester when revolving valve cuts out pours out material wherein, and empty dust arrester loaded onto, will vacuumize in the dust arrester with the mouth valve (10) of bleeding, treat that its vacuum equates with grading room or slightly high at 5% o'clock, can open revolving valve again, be communicated with grading room to the passage between the dust arrester.After the less particulate of particle diameter entered grading room, the door district (18) that will cross fuse (8) under the air-flow effect entered in (19), and and then (entered Ω through auxiliary air inlet (15) at auxiliary air _In(19)) effect arrives subordinate down and does further sorting.Thrust bearing (12) drives fuse (8) rotation to form the centrifugal force field in door district through axle (11) transmission, and loam cake (5) plays the effect that keeps the fuse axis of rotation simultaneously.Spiral helicine street cleaner (1) is under motor (4) drives, and slowly rotation is to get rid of possible material deposition.Vacuum difference between at different levels is regulated by vacuum degree control valve (2), and is shown by vacuum meter (16).

Accuracy height of the present invention, applicability is strong, can be used widely in laboratory and industrial production.

Claims (3)

1, a kind of method that makes ultrafine dust classification and separation that vacuumizes, it is characterized in that by making a series of vacuums different and allow the space of material stream passed each other, and be aided with an additional centrifugal force field in each space, make the different particulate of particle diameter correspondingly be in the different air-flow fields.

2, a kind of device of realizing claim 1 is characterized in that it is made up of multi-stage vacuum-centrifugal classification chamber, and each grading room has Ω _In, door district and Ω _OutwardThree spaces are by vacuum degree control valve control vacuum.

3, a kind of device as claimed in claim 2 is characterized in that each grading room has first and second air intake; The bottom of grading room is equipped with one by the fuse driving dust collecting brush that rotating shaft drove; Fuse inside is the garden column space.