IMPROVEMENT OF VIBRATING FEEDERS-SCREENS FOR MINING AND METALLURGICAL INDUSTRY

Abstract

The main scientific and practical results of the improvement of  vibrating feeders-screens for mining and metallurgical industry are  presented on the basis of dynamic calculation of the vibrating feederscreen with two differently directed self-balancing vibrators. Methods  of theoretical generalizations are described using mathematical statistics, physical and mathematical modeling, computation and feasibility studies, laboratory and full-scale experimental studies, industrial  tests in the conditions of operating enterprises using standard and new  methods. Mathematical modeling and calculation of the parameters of  a vibrating feeder of the PVG type are proposed. It is recommended  when choosing dynamic parameters of the feeder, to use the vibration  transmission coefficient, which is taken within the limits (1.5  –  3.5)g,   and in heavy loading modes, is up to 5g. It is shown that during preparation of breeze coke in the crushing body, from 10 to 50  % of fine  material is received from its bunker with a particle size of 0  –  3  mm,  which is additionally re-milled, reducing the quality of coke. A vibrating feeder-screen with a spatial oscillation of the working element will  increase the efficiency of screening of the material by 15  –  20  % and  will improve the self-cleaning of the screen. The driving forces of the  exciters are directed at different angles of 15 and 45° to the screening surfaceand are attached from each other at a distance equal to half  width of the box, i.e. 600  mm. It is established that in the resonance  mode at a constant amplitude with increasing frequency the coefficient  of the vibro-displacement regime increases according to a quadratic  dependence, at a working frequency of 100 rad/s it also increases from  the loading edge of the feeder to the unloading and from one side to  another, the value of which varies within 2.62  –  2.84.