CS240876B1 - Multi-plate vibrating screen for very fine sorting of granular materials - Google Patents

Abstract

The multi-surface vibrating screen consists of a set of sieve surfaces placed one above the other, which are flexibly attached at their free ends from the input side by tensioners and mounted on the transverse and longitudinal guide supports of the housing, solving the problem of clogging of the sieve surfaces when sorting ore and non-ore raw materials and building materials with a separation size below 1 mm. Above the output side of the sieve surfaces (8a, 8b, 8c, 8d, 8e) a pair of contact vibrators (9) is attached to the housing as a source of linear vibrations*, for example at a frequency of frequency of 5θ Hz and on a transverse sliding bridge (10), above a horizontal plane passing through the center of gravity of the same sorter, on the one hand an additional vibrator (12) as a series of circular oscillations with a lower frequency than the pair of vibrators (9), for example ?5 Hz and on the other hand an identical additional vibrator (15) connected to a timer. In this case, the input parts of at least two upper screen surfaces (8a, 8b) up to their first transverse supports (5a, 5b) are elastically held only by tensioners (7).

Description

BACKGROUND OF THE INVENTION The present invention relates to a multi-area vibratory screen for very fine screening of granular materials, which is intended to ensure that the critical screen area according to which the screening mesh size is maintained is kept to a minimum with a mesh blockage. marginal grain

It is known that with a small screening size, especially in wet screening methods, the clogging of the vibrating screens is a major obstacle to successful screening and can be difficult to screen with a screening size below 2 mm without any cleaning measures. For separating sizes below 1 mm in wet sorting processes, the efficiency of smaller amounts of water is also reduced by the formation of bales which, after leaving a part of the water, begin to collapse at the top of the sieve, roll along its entire length and fall into the overspill. shares. In order to reduce the possibility of formation of bales even where, for technological reasons, it is not possible to use larger amounts of shower water and at the same time to increase the sorting performance, so-called so-called " sorting in thin layer · The used sorter therefore has a larger number of sorting areas, even if the actual sorting according to the desired dividing size only takes place on the bottom surface.

However, it is also possible to separate the individual grain sizes separately. By pre-sorting, the decisive sieve area with the smallest mesh is significantly relieved and the grain spectrum of the material entering it is narrowed. As a source of uniform elliptical oscillations by the composition of movements of a circular source of oscillations with motion from a source of rectilinear oscillations, for example, three non-weighted vibratory drives are used, which work in autosynchronization®

The above-mentioned disadvantages are eliminated by a multi-area vibrating screen for very fine sorting of granular materials, consisting of a set of superimposed screen surfaces which are elastically attached

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- 2 at their free ends from the inlet side by tensioners and mounted on transverse and longitudinal guide supports of the cabinet. Its essence lies in the fact that above the outlet side of the screen surfaces a pair of contact vibrators is mounted on the cabinet. 50 Ha and on a transverse sliding bridge, above a horizontal plane passing through the center of gravity of the same separator, on the one hand a vibrator as a source of circular oscillations with a lower frequency than the two above mentioned vibrators, eg 25 Hz; the inlet portions of the at least two upper sieving surfaces are flexibly held only by the tensioners up to their first transverse supports., The multi-surface vibrating screen according to the invention allows sorting of even very fine grains without clogging of the sieving surfaces, by switching the auxiliary vibrator additionally ·

An exemplary embodiment of a multi-area vibrating screen according to the invention with five screening surfaces _m i is schematically shown in the attached drawing in a vertical longitudinal axial section.

The multi-surface vibratory sorter according to the invention consists of an inclined sorter housing 1, which can be suspended or supported on springs (not shown).

Individual sets of peripheral longitudinal guide supports 3 and 3b are obliquely fastened to the longitudinal walls of the sorter housing 1 according to the number of screen areas in several rows. 3c. 3d. 3e, mostly three-piece, only the upper two sets 3a, 3b are two-piece · Longitudinal edge guide supports 3a. 3b. 3c. 3d. 3e, the angles 4a are reinforced at their lower ends. 4b, 4c. 4d, 4e, mounted perpendicularly to the longitudinal walls of the sorter housing 1. Between the individual parts of the longitudinal guide supports 3a. 3b. 3c, 3d, 3e transverse supports 5a are arranged in rows one above the other. 5b. 5c, 5d ' 5e, fastened by their ends in the longitudinal walls of the sorter housing 1. The inflow surface 6 is reinforced by a retaining wall 6 which simultaneously holds the tensioners whose resilient mounting allows resonance oscillations. 3b, 3c «3d, Je, and transverse supports

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3 »3 **

5 ', 5b, 5c, 5d, 5e are loosely positioned mesh surfaces 8a, 8b, 8c,

8d, 8Co At their upper ends, the screen surfaces 8a, 8b, 8c,

8d. 8c are fastened by elastic tensioners 2 and are attached to the angles 4a at their lower ends. 4b, 4c, 4d, 4e® As is apparent from FIG. 4 and already mentioned above, at the inlet side of the two upper sieve surfaces 8a, 8b are in front of the first transverse supports 5a. 5b omitted the respective parts of the longitudinal guide supports 3a, 3b. At the sloping top wall at the outlet side 1b of the sorter housing 1 is attached at least one pair of contact vibrators, designated as a source of linear oscillations at 2920 rpm (about 50 Hz); On a transverse bridge 10, longitudinally displaceable peripheral guiding angles 11, fixed to the longitudinal walls of the sorter housing 1, is mounted a vibrator 12 as a source of circular oscillations at a frequency of 1460 rpm (about 25 Hz). A further vibrator 13 with the same direction and number of vibrations as the vibrator 12 is similarly slidably mounted on the lid of the housing 1 on the bridge 14. The inclined bottom 1c of the separator housing 1 has an outlet 15 at its lowest end and separately The multi-surface vibrating sorter according to the invention operates at the same time: the separated material is fed to the sorter by the inlet sheet 2, the final pre-screen with water leaves through the outlet 15 and the oversized product is discharged through the outlet trough 16 sorting® The two vibrators 2 keep the mesh of the fine screening surfaces in resonance, limiting the possibility of settling the boundary grains in their meshes. By placing the vibrator 12 as a source of circular oscillations above the horizontal plane passing through the center of gravity of the sorter,sheet 8a. 8b. 8c, 8d, 8 An elliptical and adjustable within certain limits® Vibrator 12 serves to accelerate material feed at the inlet sides of the screen surfaces 8a. 8b, 8c. 8d, 8e «, especially the upper ones with larger meshes and a slowing of the feed at the outlet of the sieve sheets®. 3 b, so that they oscillate with a greater oscillation than the sorter housing 1 itself. The vibrator 13 connection is controlled by a timing unit (not shown) outside the sorter ® vibrator.

240 876-4 is switched on only at certain changeable intervals and for a variable short time, whereby the autosynchronization temporarily changes the elliptical oscillations of the sorter to a rectilinear and greater amplitude, preferably perpendicular to the screen plates 3a, 3b, 3c, 3d. 3e to loosen their meshes clogged with marginal grain © Only short-term engagement is usually sufficient to clean clogged mesh meshes ©

In pilot tests with barite screening for flotation fineness, with bottom sieve and 0.355 mm mesh, the vibrator 13 was switched at 4 minute intervals for 4 seconds. The tests were carried out without screen cleaning βα, βι., Ββ, βίί, ββ. throughout the tests, t _o j © © 60 hours, with interruptions necessary for the conduct of tests and evaluation of results

The invention can be used, for example, for wet screening for the treatment of ores, non-metallic raw materials and building materials, preferably for screening with a separation size below 1 mm.

Claims (2)

SUBJECT OF THE INVENTION 240 876 1 «Multi-area vibrating screen for very fine grading of granular materials, consisting of a set of superimposed sieve surfaces which are resiliently attached to the free ends from the inlet side of the tensioner and supported on transverse and longitudinal guide supports of the housing; Aside from the screen surfaces (8a, 8b, 8c, 8d, 8e), a pair of contact vibrators (9) is mounted on the housing as a source of linear vibrations * iap? _e with a frequency of 50 Hz and on a transverse sliding bridge (10), above a horizontal plane passing through the center of gravity of the same sorter, a single vibrator (12) as a source of circular vibrations of less than a pair of vibrators (9), e.g. identical vibrator (13) connected to the timer » Multi-area vibrating screen according to claim 1, characterized in that the inlet portions of the at least two upper sieve surfaces (8a, 8b) are only held flexibly up to their first transverse supports (5 "5b") by the tensioners (7) o.