Reducing the likelihood of material hanging when loading a coarse crusher

Abstract

Many years of experience in the operation of coarse cone crushers of the type KKD 1500/180 at a number of enterprises of Metinvest Kryvyi Rih has shown that when mineral raw materials are loaded into the flowing part of the crusher feed path, uneven feeding occurs as a result of large elongated pieces hanging in the intake pit, which leads to significant periods of idle and unproductive operation of crushers, resulting in significant unproductive costs for their elimination. The aim of the work was to conduct laboratory studies related to determining the reduction of the probability of formation of stable forms of material suspension when loading it into a coarse crusher. To achieve this goal, an empirical-analytical research method was used, where the hypothesis was put forward that the probability of the appearance of hang-ups in the crusher feed path can be significantly affected by the configuration of a specially configured deflector grate located in the intake pit of the raw material fed by weight to the crusher entrance. To test this hypothesis, laboratory devices have been developed that can simulate the processes of material suspension in the crusher feed path in two-dimensional and three-dimensional forms. As a result of the laboratory experiments, it was found that the configuration of the deflector grid does affect the probability of hang-ups in the feed path and their probability of hang-ups in the two-dimensional laboratory setup was reduced by 20%, and in the three-dimensional one - by 24.1% compared to the currently existing crusher feed path. The analysis of the results shows that the lowest probability of hang-ups in the three-dimensional laboratory model is provided by a transverse grate in a row with one longitudinal rod. Moreover, the contour formed by the entry points of the transverse rods of the grating into the side wall of the receiving pit should be equidistant to the contour of the rock cushion on the same wall. The distance between the equidistant and the forming curve should be at least two maximum rock block sizes. The use of such a grid can significantly reduce unproductive downtime of the crusher and significantly reduce the material costs involved in the process of crushing mineral raw materials.