SU956054A1 - Method of dry separation of solid materials - Google Patents

Description

 The invention relates to the field of dry gravitational separation of solid materials, such as coal and rock, and can be used in coal, mining, metallurgical, chemical and other industries. The known method of dry separation of materials involves fluidization of finely dispersed bulk materials under the action of an upward air flow followed by particle separation C. The disadvantage of this method is the low separation efficiency of the source material, moreover, the separation requires constant regeneration, which complicates technological scheme. There is a method of dry separation of materials, including the separation of the source material according to density in an air stream directed perpendicularly to the free falling material 2. The disadvantage of this method is the high cost of carrying out, since the implementation of the method requires a preliminary clear classification of the source material into narrow size classes. The closest to the invention to the technical essence and the achieved result is the method of dry separation of solid materials, including the supply of the source material to the separation zone, pneumatic separation of the source material with separation By size and pneumatic separation of each size class 3. The disadvantage of this method is the low quality of the separation. The purpose of the invention is to improve the quality of separation. The goal is achieved by the fact that before feeding the source material into the separation zone, it is accelerated, pneumatic separation of the source material is carried out with air flow directed along the horizontal component of the velocity of the previously overclocked starting material, and pneumatic separation of each size class is achieved. the horizontal component of the velocity. the pre-dispersed starting material / and the air flow rate for pneumatic separation to zhdogo class is determined from the ratio of -, where y Te § - free fall acceleration of - particle size; y is the density of the material; jg is the air density. The method is carried out as follows. The source material, before being fed into the separation zone, is dispersed then separated by air flow directed along the horizontal component of the velocity of the pre-dispersed starting material, the material is divided into coarseness, then each Kjriacc coarseness is separated by air flow directed oppositely to the horizontal velocity component previously the accelerated starting material, wherein the air flow rate for pneumatic separation of each class is determined from the ratio given above. Figure 1 shows the device, a general view; figure 2 - section aa in figure 1; figure 3 - section bb in fig. 1. The device in which the method is carried out consists of a conveyor 1 with which the source material, for example coal, is fed to the classifier 2. Classifier 2 contains a bowed upper shaft 3, in which the material is accelerated to a given speed and fed the direction of the air flow generated by the fan 4. The box of the classifier 2 in the lower part is provided with cells 5 for outputting material of a corresponding size. Each cell 5, in its turn, is an accelerating shaft in which the material is accelerated and fed counter to the air flow created by the fans 6. In the air flow the material is divided into coal and rock and flows respectively through the heat to the conveyors 7 and 8. Similarly executed cells of all classes. The only difference is that for each material size the air flow rate is determined, which is determined from the ratio i -a-ir. where (is the acceleration of free fall; O is the particle size; Ut is the material density; 7Gw is the air density. Exhaust air enters channel 9, from which it is sucked by the fan 10, and the capacity of the suction fan exceeds the total performance of all classifier fans by 5- 10%, which ensures the discharge in all channels and chambers of classifiers and eliminates the release of dust into the environment. A cyclone separator 11 is installed at the suction channel of the fan 10. Purified air from the entry cyclone t through channel 12 to the classifier fans. Excessive (5-10%) purified air is emitted into the atmosphere through a window. The separation process by size is carried out as follows. The initial product, after entering the accelerating shaft 3, receives an initial velocity in the direction of the air the flow created by the fan 4. In this case, the stored kinetic energy of particles of angle and rock of equal size will be unequal due to the difference in their densities. The particles of the rock, which have more energy, will tend to fly more horizontally in free fall. In the field of action of the air flow generated by the fan 4, the forces of dynamic pressure, proportional to the equivalent area of the particle and the square of the speed of the air flow, begin to act on the particles. In this case, particles in the process of falling begin to be classified according to size; the larger ones will pass horizontally from the entry point into the stream a smaller distance, and the smaller ones will go a longer way. If the particles had not previously been stored in kinetic energy, then the particles of coal, having a lower density, would have flown more horizontally than the clocks of the rock of the same size. Taking into account the action of three factors: the weight of a particle, stored kinetic energies and dynamic head of the flow, particles of coal and rocks of the same size in the free fall in the air flow will pass horizontally the same distance, i.e. material will be sorted by size, and any classification scale by appropriate installation of cells 5. The cells.5 of the classifier n, p density also represent the accelerating shaft, hitting into which the material of all classes is accelerated to a given speed and you ode shaft is provided opposite the air flow supplied by the fan used in the cell kazkdogo class. particles srgl and rocks of the same

size, has a different density, under the action of the 4x pressure head of the air pstok in the free ps1Division will move along different trajectories. Lighter particles will fly along the horizontal distance and into the chutes of the conveyor 8, above which are similar class chutes. The rock particles, as more heavy, will fall into the chute of the conveyor 7. The kinetic energy of the particles stored in the booster shaft (cells) will contribute to a clearer separation of material by density 5. The rock particles, which have a large mass and kinetic energy, will pass through the opposite airflow horizontal distance. That is, the enrichment process is carried out with the free fall of particles under the influence of two factors: the dynamic pressure of the air flow and the kinetic energy of the particles moving counter to the horizontal flow of compressed air. At the same time, the air flow rate is set accordingly for each size class of the material on the basis of setting the same direction of the resultant forces from the dynamic head of the flow and the weight of the particle in all classes.

We set the direction of the resultant, for example, 45 to the horizontal plane. In this case, the following relationship must be maintained, i.e. the equality of the dynamic head forces and the weight of the material

u-f From here air speed

H

iqj- -Tm

at.

where 5 is the dynamic resistance coefficient (form factor); P - particle size; WY air density; f is the density of the material (rock). The application of the method of dry separation of solid materials will allow

improve the quality of separation, reduce the risk of environmental pollution, simplify the technological scheme and reduce capital and operating costs.

Claims (3)

1. Dry separation method solid materials, including the supply of source material to the separation zone, pneumatic separation of the source material with particle size separation and pneumatic separation of each size class, which, in order to improve the quality of separation, before the source material is supplied to the separation zone, it is accelerated, pneumatic the source material is separated by an air stream directed along the horizontal component of the velocity of the previously overclocked outcome. material, and the pneumatic separation of each size class is carried out by an air stream directed oppositely to the horizontal component of the velocity of the pre-dispersed starting material. 2, the method according to claim 1, wherein the air flow rate for the pneumatic separation of each class is determined from the ratio -I H - T, m one 6 where is the acceleration of free fall; 40-a - particle size; the density of the material; jg is the air density. Sources of information taken into account during the examination 45 1. Bedran N.G. Coal fortification. M., Nedra, 1978, p. 84-8. 2. Taggart A.F. (Handbook of mineral processing. TZ, M., Metallurgizdat, 1952, p. 40150 402. 3. Kovalenko V.I. The enrichment of non-metallic minerals. M., Nedra, 1967, p. 216 (prototype).