Wear reducing of ventilation mill suction plates based on the multidisciplinary research

Abstract

The aim of this paper is to present the investigations of the possibilities of increasing the wear resistance of the ventilation mill parts for coal grinding in power plants, by application of optimum hard coating technologies. High velocity of sand particles in the ventilation mill causes strong wear of the suction plates. The input data for plate modification are based on 3D numerical simulation of multiphase flow in grinding mill. The mixture model of the Euler-Euler approach is used. The results obtained in the numerical simulation serve for the selection of optimum redesign of the suction plates. To improve surface properties, the hard, wear-resistant coatings were created by hardfacing, technologies by manual metal arc and self-protecting flux core electrodes. Before applying hardfaced suction plates in the exploitation conditions, it is necessary to study model hardfaced samples. The experimental tests of redesigned suction plates during the real exploitation conditions show that the proposed technology of hardfacing gives good results. The relative weight loss of the suction plates after 1440 h period of exploitation in real conditions is very small 1-3%. The application of proposed technology can reduce the number of possible repairs and extends the period between them, resulting in significant economic effects.