Clogging Model for Coarse and Fine Filtering Cloths of Filtering Cylindrical Elements, Preventing Sedimentation of Mechanical Impurities in Their Gap

Abstract

In this paper we propose a method for preventing sedimentation of solid particles in the lower part of the gap between filtering cylindrical elements of coarse and fine purification by increasing the size of the meshes and total thickness of the first downstream gas flow layers of the fine filtering element in excess of the maximum diameter of solid particles. Experimental corroboration for the proposed method showed absence of solid particles’ sedimentation in the lower part of the gap between filtering cylindrical elements of coarse and fine purification and clogging of their meshes. As a result of the experiments, we found that the maximum sedimentation of mechanical impurities inside the first screens of the fine filtering cloth is achieved when their meshes’ size and screens’ thickness are, respectively, equal to three and two and a half maximum diameters of a solid particle. We developed a mathematical model that describes the clogging dynamics of filtering elements, where pressure losses in the first section with constant mesh sizes of all screens and in the second section with a sequential decrease in mesh sizes have different clogging rates and therefore are calculated separately from each other. The clogging process at each section of the multilayer filter cloth is represented as a successive decrease in the effective screening area of the screen meshes. The mathematical model makes it possible to prevent the sedimentation of mechanical impurities in the gap between gas filter elements of coarse and fine purification and allows to analytically determine the clogging degree at any time of operation, depending on the pressure losses’ values.