SU686781A1 - Bar screen - Google Patents

Description

one

The invention relates to the field of mechanical engineering, primarily mining, and can be widely used in the mining industry in self-propelled crushing and screening units, in stationary transfer stations and in crushing and screening plants.

A grate screen is known, including grates with ridges forming a flat screening screen, forming a material flow, a duct, side boards, screen supports, vibrators, and a grate depreciation system 1.

The disadvantage of this design is the difficulty in removing the sub-strand product from the top of the bed of the screened material.

The decrease in the screening efficiency of the undersize product increases with an increase in the thickness of the material layer at the screen in connection with an increase in the additional resistance of the lower layers to the passage through them of lightning fractions from the overlying material.

This circumstance leads to incomplete extraction of the undersize product (fine fractions) and their clogging of the oversize product, which in some cases is completely unacceptable.

In addition, such screens have a limited capacity determined by the effective conditions of screening out a layer of material in cross section and cannot be used in loading devices of mining machines working together with a downhole excavator where a sharp increase in layer thickness takes place during unloading. Bucket directly onto the grate screen.

The aim of the invention is to increase the screening efficiency of the sublattice product from the upper layers of the screened material.

Claims (2)

This is achieved by the fact that the ridges of the grates in the cross section of the screen are installed along a curvilinear surface with a radius of curvature varying towards the unloading ends of the grates, and the radius of the curvilinear surface varies according to: where RO, RX are the radii of curvature in the initial section and in section at a distance from the initial section; X is the current coordinate; i is the length of the grate; e - the basis of natural logarithms. FIG. 1 shows the grate, a plan view; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. 2; in fig. 4 — node I in FIG. 3. The grate screen consists of a set of grate 1 pivotally mounted on axis 2. The grate is fixed in the working position by springs 3 of the screen damping system installed on the foundation 4. The ends of the axis 2 are mounted in two detachable bearings 5 transmitting loads from the screen through supporting glasses 6 on the foundation 4. In the front part of the screen, a box 7 is installed, forming a flow of rock mass 8 directed to the screen 8. The box rests on the foundation 4 through the supporting rubber pads 9 and the brackets 10. On both sides to robe mounted vibrators 11 to initiate forced oscillations screen providing flow The screening process. In order to exclude lateral blanks of material from the screen, the sides 12 are installed along the extreme grates. The ridges 13 of the grates 1 are installed in such a way that they form a curved surface B in any cross-section of the screen, for example, BB, the radius of curvature of which gradually changes as displacement of the cross section to the free ends of the grate. The difference in the levels of the ridges of 13 neighboring grates (AH) in any section along the length of the screen is always greater than twice the amplitude of the grate oscillations a (see Fig. 4). The device operates as follows. When vibrators 11 are turned on in the box 7 and the grate 1, steady-state oscillations occur. Under the action of oscillations of the hearth, the mass 8 is transported along the box 7 to the grate 1 and is passed through as it moves towards the free ends of the grate. Due to the curvature of the screening surface of the screen in cross section, an additional movement of material from the peripheral part to the axis of the roar occurs (in the direction of arrows G). The material is actively moving, as a result of which the upper layers fall into the zone of direct contact with the grate bars, which ensures a more complete cessation of the undersize product. Thus, the present invention provides an increase in the efficiency of screening of the undersize product and an increase in the accuracy of sieving the rock mass into fractions. At the same time, the roar is able to roar a thicker layer of material, which increases its performance and makes it possible to use the roar when cycling the rock mass from the excavator bucket to it. The performance of the proposed rumble increased by 35-40%, the economic effect per machine is 30,000 rubles. in year. Claim 1. Gang grater, including grates with ridges mounted on the axle, axle supports, vibrators and grate depreciation system, characterized in that, in order to improve the screening of the undersize product from the upper layers of the screened material, the ridges of the grate in the cross section of the screen mounted along a curved surface with a radius of curvature varying in the direction of the discharge ends of the grate. 2. A screen according to claim 1, characterized in that the radius of the curved surface varies according to: RX RO, where RO, RX are, respectively, the radii of curvature in the initial cross section and in the cross section at a distance from the initial cross section; X is the current coordinate; i is the length of the grate; e - the basis of natural logarithms. Sources of information taken into account in the examination 1. Spivakovsky A. F. and others. Vibration conveyors, feeders and auxiliary devices. M., “Mechanical Engineering, 1972, p. 232. VU2.