SU899155A1 - Method of screening on elastic band-string-type sieves - Google Patents

Description

one

The invention relates to mining machinery, and in particular to methods for separating bulk materials on vibrating screens equipped with elastic string tapes.

Methods are known for separating bulk materials on string-type screens, the elements of the screening surfaces of which can make relative movements and oscillate with accelerations exceeding the accelerations of the screen box 1.

However, these methods do not provide a sufficiently high and regular level of relative displacements of adjacent strings in the vertical plane, which does not allow intensive self-cleaning of such screening surfaces.

There is a method of screening on a string-string sieve, in which the tapes attached to the sides of the frame across the screen in the process

the material moving along them, the floor, oscillatory motion in the plane perpendicular to their longitudinal axis, and on the lower frame parallel to the screen axis are cleaners, made in the form of rails with grooves and protrusions 2.

The disadvantage of this method is that it does not allow to sufficiently effectively intensify the process of self-cleaning of the sieve in combination with an increase in the productivity and efficiency of screening. Particularly difficult to implement this cleaning method

IS for sieves used in fine and fine screening, since it is necessary with high accuracy to ensure the interaction of closely spaced strings with protrusions and

10 grooves of cleaners, which in practice is very difficult. In addition, when vibrating such screening surfaces interaction

tape strings with cleaners significantly changes the parameters of their vibrations, namely, it reduces the level of accelerations transmitted to particles of the material being moved, which reduces the performance of the screening process.

The purpose of the invention is to intensify the process of self-cleaning of the sieve due to the forced acceleration of moving particles of a hard class down between the belts.

The goal is achieved by the fact that when screening bulk material on ribbon-string screens by vibrating them, the installation of adjacent string tapes: ia sieve is displaced relative to each other in a vertical plane by an amount not exceeding half the height of the tapes in their cross section, at the same time, oscillations with an amplitude exceeding the amplitude of those set above by the value of their cross section report to the lower strings.

Such an installation of adjacent string strings provides for regular relative displacements of adjacent string tapes in a vertical plane, which contributes to the intensification of the self-cleaning process of the sieve, and consequently, its performance.

FIG. t shows a portion of a ribbon-elastic strainer operating according to the inventive method in FIG. 2 - installation diagram and movement of string tapes at their vibration excitation in section A-A and the scheme of impact on particles of a difficult material: I - for particles with sizes close to, but smaller or equal to cell sizes, II for particles with sizes close but exceeding cell sizes

The method consists in the fact that in the process of oscillations the adjacent ribbons of the string are moved so that in the extreme upper position their upper edges are at the same level, and in the extreme lower position the upper edges of the lower strings are at a level close to the lower edges of the above ribbons strings. With such relative displacements, adjacent string tapes in one oscillation period have at regular intervals

time different level of acceleration

O.J. This leads to.

l and

that particles of a hard material with dimensions close to, but 5 equal or smaller in size

The cells receive additional accelerations 01 oljT Lz from the side of the below-installed strings, which contributes to the accelerated movement of such

in the particles down into the pods.

In addition, in the extreme lower bends, in each oscillation period, adjacent string tapes are freed from interactions with each other.

S another through the rattling material, which also contributes to the process of intensifying the cleaning of cells from difficult particles. Wedged particles with sizes close

0 but in the process of oscillations of adjacent strings, the large cell sizes are turned over and fall onto the below-installed strings, with which they are subsequently pushed into the tombstone

 product.

The sieve for carrying out the proposed method consists of elastic tapes 1, which are provided with trapezoidal projections 2. The tapes are fixed with the help of resistant bulges 3 in supports. " The ribbons 1 are installed in the supports C with a gap and displaced relative to each other by an amount equal to -J-. In addition, the tension forces Rc and PH of the adjacent ribbons 1 are selected so that, when vibrated, the difference in amplitudes of their oscillations in section maximum deflection is

IL

and and max hwoc

2

The proposed method allows to increase the efficiency of screening, to improve the quality of enrichment of materials due to the elimination of entrenchment of the undersize product, as well as to reduce operating costs.

Claims (2)

Invention Formula The method of screening on elastic band strings by vibrating them, characterized in that, in order to intensify the process of self-cleaning of the sieve due to the forced accelerated movement of particles between the tapes. ribbon-strings are installed through one with an offset in the vertical plane by an amount not exceeding half the height of the ribbons in their cross section, and vibrations with different amplitudes are reported, while the lower-set strings are vibrated with amplitudes exceeding 899,155 I 4 their cross sections. Sources of information taken into account in the examination 1. USSR certificate of authorship If 435862, cl. B 07 B 1/12, 1972. 2. USSR author's certificate M- 466917, cl. B O B 1 / 00,1973. Lh FS / e. / U1-L