SU1077658A1 - Screen sieve - Google Patents

Abstract

1. SITTING GROUND, including a frame, elastic bands with periodic protrusions fixed in the longitudinal supports, installed across the movement of the rattling material, which is distinguished by the fact that. By increasing the efficiency of the screening process by ensuring uniform self-cleaning of the sieve, the elastic tapes are installed with varying degrees of tension, and the degree of tension of the tapes decreases in the direction of material unloading. 2. A screen according to claim 1, characterized in that the distance between the longitudinal supports on the loading side is less than on the discharge side. 3. Sieve on PP. 1 and 2, characterized in that the frame is made in the form of a trapezoid, the smaller base of which faces in the direction of discharge. (L 4. The sieve according to claims 1 and 2, characterized in that the longitudinal supports are made in a stepped form. J O) SL oo

Description

The invention relates to a technique for the separation of bulk materials, in particular to screening surfaces of vibrating screens, and can be used in the mining, metallurgical and other industrial areas. A sieve is known that contains rubber grates in the form of elastic flax installed in the grooves of parallel supporting rails and fixed at the ends with pieces of tape or cord for self-sealing 1. The disadvantage of this sieve is the low efficiency of the curing process. The closest to the invention of the technical essence and the achieved effect is a screen sieve, including a frame, fixed in long supports elastic belts with periodic protrusions installed across the movement of the screened material 2. The disadvantage of this screen is the low efficiency of the screening process for the impossibility of ensuring uniform self-cleaning of the sieve. The aim of the invention is to improve the efficiency of the screening process by ensuring uniform self-cleaning of the sieve. This goal is achieved by the fact that in the screen of the screen, including the frame attached to the longitudinal supports are elastic bands with periodic protrusions installed across the movement of the screened material, ale. The ribbons are installed with different degrees of tension, and the tension of the belts decreases in the sides of the material unloading. In addition, the distance between the longitudinal supports on the loading side is less than on the discharge side. The frame is made in the form of a trapezoid with a smaller base facing the discharge side. In this case, the longitudinal support is made of stepped forks. FIG. 1 shows a screen sieve, longitudinal section; in fig. 2 the same, top view; in fig. 3 - ribbon waveform; in fig. 4 and 5 screen sieve, top view, option; in fig. 6 - sieve cross section on the discharge side; in fig. 7 - the same from the download side. The screen of sieve contains elastic tapes 1 with periodic protrusions 2, fixed in supports 3 of frame 4 v by preliminary tension C, 50-100 N. Frame 4 is rigidly connected to transverse beams 5 of the box b. Box b with VibratorOm 7 is mounted on springs 8. Frame 4 is made in. as a trapezoid, the sides of which are formed by supports 3. The larger base of the trapezium is located at the loading end of the 9 sieve, and the smaller one at the discharge end of the 10 sieve. At the same time, the distance between the supports 3 of each row of elastic tapes 1 decreases from the value ./, at the place of unloading of material 11 (height / i-, layer of material) to f-2, at the place of loading (height А-х. Layer of material ). Elastic tapes 1 with an initial length of 1e between fasteners (not shown) when mounting the sieve are stretched and secured in supports 3 with pre-tension pAf n / a where 4 (11) 1- preliminary tape elongation, (tension g) , m; F is the cross-sectional area of the ribbon. - normal dynamic modulus of rubber, k) - distance between supports in cross section with coordinate X from loading point. During the operation of the screen box 6 and the frame 4 rigidly fixed on it with the supports 3 under the influence of the disturbing force of the vibrator 7, they are forced to oscillate according to the harmonic law asinurt, where a is the amplitude; CG is the vibration frequency of the vibrator; t - time As a result, forced oscillations of the supports 3 oscillate elastic band 1 with an amplitude (deflection) a (y, t). The shape of the elastic band (deviation from the equilibrium position) has the form of a sinusoid. Due to the resonant vibrations of the elastic tapes 1 with an amplitude of a + a.f, the material segregates on the sieve, the screening efficiency is improved. The height of the bed material material decreases along the length of the screen from the loading place to the place of unloading, as part of the material is sifted along the way. At varying degrees of tension of the tapes, the natural frequency of the oscillation of the tapes decreases as the material rumbles. This design of the screen provides a constant reduction in the distance between the supports, and hence a decrease in the tension of the belts, from the loading to the discharge end of the sieve. This provides a near-resonant adjustment, and therefore a large amplitude of elastic bands of vibrations over the entire surface of the sieve.

The change in the distance between the supports 3 provides ubiquitous resonance of elastic bands, a high level of self-cleaning over the entire length of the screening surface and, consequently, a high screening efficiency.

Another embodiment of the proposed sieve is to provide longitudinal supports 3 of variable width increasing from the loading end of the 9 sieve to the unloading 10 (Fig. 4). If, in the first version of the sieve (Fig. 2), the distance between the supports 3 varies due to the shape the support and its correct installation during installation, the change in the distance between the supports 3 in the second (Fig. 4) is achieved by changing their width.

For ease of manufacture and installation, the width of the supports 3 does not change continuously, but in steps. In this case, the distance between the supports 3 (and hence the tension of the belts) varies in the course of the movement of the material discretely.

The sieve assembled from elastic bands can also have the same width along the entire length of the screen, while the distance between the supports 3 varies from the value of t-at the loading point to the value of tj. in the place of unloading (Fig. 5),

These structural designs of the sieve increase the efficiency of the screening process.

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Claims (4)

1. Sieve screen, including a frame, elastic tapes fixed in longitudinal supports with periodic protrusions, mounted across the movement of the screened material, characterized in that, with. In order to increase the efficiency of the screening process by ensuring uniform self-cleaning of the sieves, the elastic belts are installed with a different degree of tension, and the degree of tension of the belts decreases in the direction of unloading of the material. 2. Sieve pop. 1, characterized in that the distance between the longitudinal supports on the load side is less than on the discharge side. 3. Sieve according to paragraphs. 1 and 2, characterized in that the frame is made in the form of a trapezoid, the smaller base of which is facing the unloading side. 4. Sieve popp. 1 and 2, characterized in that the longitudinal supports are stepped. FIG. 1