SU1696005A1 - Method of separation of loose materials and device for its realization - Google Patents

Abstract

The invention relates to the mining industry, in particular to air methods of mineral processing, and m. used in the chemical industry, in the production of building materials and other branches of the national economy. The purpose of the invention is to increase the separation efficiency. The source material is fed to the separation zone, is exposed to a heated air stream (HP), divided into large and small fractions. The fines fraction is withdrawn, and the coarse fraction is fed to the screening in an oscillatory mode. In this case, EPs, which act on the source material, are subjected to pulsations with a frequency equal to the natural frequency of screening oscillations. VP pulsations are carried out in a channel by smooth narrowing of its cross section. The distance between sections is determined from the ratio I v / v, where is the distance between the closest narrowing of the channel cross section, m; A is the wavelength of acoustic oscillations of EP at a selected frequency, m; v is the velocity of the airspace, m / s; v- extracted from the spectrum of the frequency of the ripple VP, 1 / s. A device for implementing the method contains a separation chamber (RK) 1 with a grid 2, estrus 3 and 4 for separated fractions with a rotary E

Description

The invention relates to the mining industry, in particular, to the air methods of mineral processing, and can be used in the chemical industry, in the production of building materials and other sectors of the national economy.

The purpose of the invention is to increase the separation efficiency.

The method for separating loose materials is carried out as follows.

The source material is fed to the separation zone, is exposed to it with heated air flow, and is divided into coarse and fine fractions. The fines fraction is withdrawn, and the coarse fraction is fed to the plant in an oscillatory mode. The air flow, which affects the source material, is subjected to pulsations with a frequency equal to the natural frequency of screening. The pulsations of the air flow are made in the channel by planar constrictions of its cross section, and the distance between the legs is determined from the ratio

I 1 v

I -A-,

where I is the distance between the nearest narrowing of the cross section of the channel m;

I - dpina wave acoustic oscillations of the air flow at a selected frequency, m;

v — air flow velocity, m / s;

v - frequency of air flow pulses isolated from the spectrum, 1 / s.

The drawing shows a device for implementing the proposed method for separating bulk materials.

The device includes a separating chamber 1 with a grating 2, an estrus 3 and 4 for separated fractions with a rotary gate 5 between them, mounted in the bottom

parts of the separation chamber 1, the supply device 6, consisting of the feeder 7 and the discharge drum 8 and located above the divided gel chamber 1, the air inlet device 9 made of the fan 10, the discharge pipe 11 and the air heater 12, and the cyclone 13 located in opposite side walls of the chamber 1, and the vibrating screen 14, connected with chutes 3 and 4. The inner surface of the discharge of the discharge pipe 11 in longitudinal section is made in the form of a sinusoid. The air supply device 9 is configured to control the speed of the air flow in the nozzle 11. At the screen 14, a displacement sensor 15 is installed to regulate the speed of the air flow in the nozzle 11. The sensor 15 is connected

with fan 10. Screen 14c, with screens 16 and 17, rests on elastic elements (springs) 18 of an elastic suspension. Cyclone 13 is connected by an inlet pipe 19 with a chamber 1 and an outlet pipe 20 with an air duct

21 and with an air passage device. Lattice 2 is made of segments of the core chain.

The device works as follows.

The feeding device 6 feeds the raw material into the chamber 1, the flow of the raw material is divided by the grid 2 into separate vertical layers between which narrow gaps are formed. AT

These slots are guided from the device 9 by a stream of compressed air, heated by the heater 12, through the pipe 11. In this case, the air is separated from the raw material with simultaneous drying. During the separation process, the dust particles are separated by an air stream and partially carried away to the nozzle 19 and the cyclone 13, where they are heated and dried. Small

the fractions are deposited in chamber 1 at gate 5 and enter the chute 4 and then on sieve 17 of screen 14. From the cyclone 13 through the automatic shutter, the dried pulverized particles are periodically dumped into the bunker of the finished product. This also includes the fine fraction, having separated from the large fraction in the process of screening with screens 1 b and 17 screen 14.

The oversize product of the screen 14 is fed for further processing into a hammer mill. After passing through the grating 2, the material falls under the periodic impact of a pulsating air jet, which is formed in the pipe 11 with regular periodic smooth constrictions of the flow area. At high velocities of the air flow, turbulence occurs in it, which is characterized with the frequency spectrum of acoustic oscillations. As a result, the energy of the flow is distributed across the spectrum of vibrations, turbulent friction inside the flow and friction of air particles against the walls of the nozzle 11 increases, the energy dissipative losses increase, and the resistance of movement increases. The sinusoidal longitudinal direction of the internal walls of the nozzle 11 makes it possible to arrange the oscillations of air particles in one of the selected frequencies, to suppress the turbulent spectrum of associated frequencies, i.e. All the energy of the spectrum is combined, concentrating the frequency of the air flow in one working frequency. The operating frequency is the frequency of oscillation of the air flow, equal to the natural frequency of oscillation of the screen. The pipe 11 performs the function of a resonator that converts a continuous air stream into a pulsating one. Pipe 11 generates air flow oscillations, which, interacting with a continuous flow of bulk material, converts it into a continuous flow with discrete features, i.e. the material is fed to the screen 14 by separate portions, and the frequency of supplying the portions to the screen 14 and the forced frequency of oscillation of the screen 14 of its drive are consistent with the natural frequency of the spring-loaded part of the product, i.e. a resonance phenomenon is used. This makes it possible to reduce dissipative (hysteresis) friction energy losses in the structural material of elastic elements 18, which, in turn, increases their service life. The setting of the frequency of the pulsations to the resonance with the natural frequency of oscillation of the screen 14 is carried out automatically by the signal of the sensor 15 according to the maximum amplitude

oscillations of the screen 14. The regulation of the 45 th pulsations of the air flow is carried out by changing the speed of the air flow in the pipe 11.

50

Claims (5)

1. The method of separation of bulk materials, including the supply of source material in the separation zone, the impact on the material heated air flow, separating the material into large and small fractions, outputting the small fraction, supplying the large fraction to screening in an oscillatory mode, characterized in that, in order to increase separation efficiency, the air flow is subjected to pulsations with a frequency equal to the natural frequency of screening oscillations. 2. A method according to claim 1, characterized in that the pulsations of the air flow are made in the channel by periodic smooth narrowing of its cross section, and the distance between the sections is determined from the ratio where I is the distance between the nearest narrowing of the channel cross section, m: D, - the length of the wave of acoustic oscillations of the air flow at the selected frequency, m, v — air flow velocity, m / s;  - frequency extracted from spectrum air ripple not eye, 1 / s. 3. A device for separating bulk materials, inserting a separation chamber with a grating, chutes for separated fractions with a rotary gate between them, installed in the lower part of the separation chamber, feeding a device located above the separation chamber, an air supply device made of a fan, a discharge pipe and a heater, and a cyclone located in opposite side walls of the separation chamber, and a vibrating screen connected with chutes for separated fractions, characterized by that, in order to increase the separation efficiency, the inner surface of the walls of the injection pipe in the longitudinal section is made in the form of a sinusoid. 4. The device according to claim 3, characterized in that the air supply device is adapted to adjust the speed of the air flow in the discharge pipe. 5. The device according to p. 3 and 4, distinguish) nc-air flow in the injection pipe with the fact that it is equipped with a mounted tower, while the displacement sensor is connected sensor on a vibrating screen, a pe-fan with a fan, displacement to control the speed