Model of flow transportation of bulk cargo by vertical screw conveyors

Abstract

The article considers the model of transporting bulk cargo by flow by vertical high-speed screw conveyors. The peculiarities of mutual movement of cohesive and fine cargoes, in particular, in the conditions of their layer-by-layer movement, are revealed. To analyze the stress-strain state of bulk cargo in the conditions of screw conveying, a special helical coordinate system was used, which made it possible to significantly simplify the solution of the problem. The dependences for describing the shape of the helical surface that restricts the flow of cargo under the condition of incomplete filling of the working space, the volume of the elementary sector of the flow and its center of gravity are derived. The use of the model of layer-by-layer material motion is substantiated, and the distribution of linear and angular velocities of particles in the flow and, accordingly, centrifugal forces is determined. It is shown that for vertical high-speed conveyors, the motion of the flow as a whole and its individual particles retains the laws of helical transporting, which makes it possible to use the model of a material particle with the given parameters to calculate the design and operating modes of the conveyor.