Experimental Study of Dehydration of Solid Domestic Wastes with Screw Press

Abstract

The experimental study of the dehydration of solid domestic wastes by screw press is an actual scientific and technical task as one of the components for solving the problem of creating scientific and technical bases for the design of highly efficient working bodies of machines for the collection and primary processing of solid domestic wastes. The dehydration research of solid domestic wastes with screw press was conducted with the help of planning of the second order experiment. The regressive dependences of such indicators of the dehydration process as the final relative humidity and the density of solid domestic wastes, the maximum power of the drive motor and the energy intensity of dehydration from the main parameters of influence were obtained: initial relative humidity and density of solid domestic wastes, angular speed of screw, radial clearance between the screw and housing, the core diameter of the screw is on the last turn. The surfaces of responses to the target function are constructed — the energy intensity of dehydration of solid domestic wastes and their two-dimensional cross sections in the planes of optimization parameters. Parametric optimization of the dehydration process of solid domestic wastes by the criterion of its minimum energy intensity is carried out. It is determined that the minimum energy intensity of dehydration of mixed solid domestic wastes is 172,3...306,3 kWh/t for the optimal values of the parameters of the technological process of dehydration: angular speed of screw 51,84...54,73 rpm; the ratio of the radial clearance between the screw and the body to the outer diameter of the screw on the last turn (7,10...8,71)·10^–3; the ratio of the core diameter of the screw to its outer diameter at the last turn of 0,710...0,765, and for the wet fraction of solid domestic wastes, the minimum energy intensity of dehydration is 30,7...158,5 kWh/t for optimal values: angular speed of screw 36,91...47,20 rpm; the ratio of the radial clearance between the screw and the body to the outer diameter of the screw on the last turn (5,45...10,45)·10^–3; the ratio of the core diameter of the screw to its outer diameter at the last turn of 0,740...0,757.