Течение маслосодержащего материала в канале шнека маслопресса

Abstract

The paper presents an analysis of the basic operational concepts for the screw channel of the oil press. The channel is chosen by the authors as the object of research. The subject of the study is the the flow velocities distribution for the oil-containing material in the channel of the local auger of the second section of the oil press and the influence of the channel parameters on the performance of the press. The mathematical modeling of the flow of oil-containing material in the channel of the oil press screw is used as a research method. Of the proposed simplifying assumptions for the flow in the auger channel, three assumptions are considered and further developed. The cross section of the channel is assumed to be rectangular. The developed hydrodynamic model, in contrast to previously published works, takes into account the presence of a gap δ between the edge of the screw spiral and the inner surface of the pressing cage, as well as the non-uniformity of the movement velocity for points on the screw. A fundamentally new point in the formulation of the problem is that the velocity is not assumed to be constant on the side walls of the channel. The coordinate dependence of the velocity vz on the rectangular boundaries of the screw is presented. The flow of viscoplastic material is obtained in the form of four components, which are determined by the pressure gradient, the flow of material along the axis of the screw channel, the movement of the side walls of the channel and the viscoplastic material through the gap between the screw spiral and the pressing cage. Simple analytical expressions containing only simple elementary functions are derived for the flow velocity of a viscoplastic material. The found solutions of hydrodynamics use the Newtonian model of fluid flow but can be easily generalized to non-Newtonian Bingham viscoplastic rheology. The results demonstrated can be employed to optimize the parameters of the oil press augers, increase its productivity and oil yield.