SU899163A1 - Pneumatic classifier - Google Patents

Description

The invention relates to the pneumatic classification of various rashes of which mineral raw materials and is intended for the separation of materials with a grain size of up to 20 mm into two products by boundary size. (, 1) mm.

The apparatus can be used to enrich and dedust granular materials in the mining, chemical, metallurgical, coal and other areas of the industry.

A pneumatic classifier is known for separating bulk materials in a horizontal air flow, in which a louvered grating is installed to eliminate the difference in height at the beginning of the interaction of a monofraction material with a continuous medium. This classifier is designed to produce three or more classification products at the same time and is used to separate the material along the boundary grain (7.0-0.8) mm 1.

The disadvantage of the device is the low quality of the classification products due to the presence of a separation zone in which collisions of small and large particles are inevitable.

and with chamber walls in the separation zone.

In addition, installing a louvre grating at a certain angle depending on the boundary size of separation can, to some extent, increase the accuracy of particle deposition only of a certain monofraction, which corresponds to this angle.

10 lattice installation. In the actual classification process, at the same time, a large number of particles of other monofractions are involved, for which this certain angle of the grid installation leads to an undesirable (from the point of view of the deposition accuracy) change of particle trajectories and, therefore, clogging of all of the classification products without exception.

It is also known a device that contains an inclined camera, on one side of which a grille is installed with an adjustable gap between the louvers. The material is separated here when the material is poured from one louver to another by winding it with air 2.

The disadvantage of the device is, firstly, the presence of a separation zone,

Claims (3)

30 where chartz collisions between themselves and with the walls of the apparatus are possible, and secondly, the impossibility of homogenizing the air flow throughout the plane of the lattice due to the shape of the louvre that contributes to the formation of vortex zones behind them. A classifier for bulk materials is also known, which includes a chamber, tapering in the course of the material movement, with an inclined grating of a device for loading the raw material and unloading a large product located inside it, and a fine product outlet 13. The disadvantage of the device is the poor quality of separation. The purpose of the invention is to improve the quality of the separation of the material. The goal is achieved by the fact that the length of the narrowing part of the chamber is 0.81, 2 lattice lengths, and the cross-sectional area of the output patrol is one times smaller than the area of the living cross-section of the lattice. The drawing shows the proposed device, the overall appearance. The classifier has a tapering chamber 1, in the upper part of which there is a nozzle 2 for introducing the input material into the chamber. Under the nozzle, obliquely to the horizon (оС 25-30 °), the distributor is located on the grid 3. The top part of the grid is fixed directly to the floor by the nozzle 2, the lower part is connected to the hopper 4 to collect a large product. The loading of the material into the apparatus, as well as the discharge of separation products is carried out through sluice feeders 5, ensuring the sealing of the chamber of the apparatus from the side of loading and unloading of the material. air enters the classifier through the side window 6. The flange 7 of the separation time is connected to the cyclone to catch the fine fractions. Experimental studies show. That the length of the narrowing chamber should be equal to 0.8-1.2 of the length of the lattice L, and the cross-sectional area of the output patrol S ,, 5j is 4-6 times smaller than the area of the living cross-section of the Speui lattice. At values of I 0.81, the separation zone decreases, therefore, both small and large particles, which have not passed the delamination process, are captured by the air flow and carried away into the cyclone, thereby deteriorating the quality of the fine product. With C 1.2 L, there is also a decrease in the efficiency of the process of separating the granular material due to the sedimentation of small particles in a narrowing chamber and sliding them into the bunker of a large product. The reduction in the efficiency of separation is also caused by a violation of the Spew (4-6) 5 "ratio, as with S" olw f "the possibility of capturing large particles with rapidly accelerating air flow increases, while with Snotm t; -5p" w, small particles are deposited in the chamber of the apparatus. Classifier works as follows. When the fan is turned on, a uniform air flow is created in the chamber of the classifier 1 along the grid plane. The source material is fed by the feeder through pipe 2 to the distribution grid 3 of the classifier. The flow of material is penetrated by thin jets of air, and at this time it is stratified by particle size. Fine particles, as lighter ones, are carried into the upper part of the delamination layer and enter the narrowing part of the chamber and, together with the air, are removed from the apparatus into the cyclone. Changing the separation boundary is done by adjusting the air flow. Large particles slide along a grating and are collected in the bunker 4 of a large product, from which they are discharged by means of a blueuz gate 5. The installation operates under discharge, which eliminates dust emission into the environment. The use of a pneumatic classifier will improve the quality of separation and the efficiency of classification into small classes by 15-18%. Pneumatic classifier, which includes a separation chamber, which narrows in the course of the material, with an inclined lattice located inside it, devices for loading the initial material and unloading a large product, and an outlet with a small product, in order to improve the quality of material separation, the length of the narrowing part of the chamber is 0.8-1.2 the length of the lattice, and the section of the outlet section is 4-6 times smaller than the area of the living section of the lattice. Sources of information taken into account in the examination 1. USSR author's certificate in application No. 2652660 / 29-03, cl. In 07 In 4/06, 1979. 2. The UK patent number 1419337, cl. In 2 N, pub. 1975. 3. USSR author's certificate for application number 2796717 / 29-03, cl. B 07 B 4/08, 1979.