Directed loading of the high-speed screw conveyor from the bunker

Abstract

The results of the investigations of high-speed conveyor loading with bulk cargo are given. It is established that directional compressed flow produces dynamic pressure resisting the centrifugal motion of the load during its rotation and ensures the efficient filling of the screw conveyor operating space. Parameters of the guiding platform which application provides the feed velocity flow corresponding to the axial velocity of cargo transportation by the screw conveyor at the assigned coefficient of its filling is substantiated.Statement of the problem. The stability of transport-technological systems for bulk materials transportation is determined by the reliability and stability of the bunkers operation [1, 2]. This applies especially screw conveyors (SC), where their fill factor and, relatively, effectiveness are generated in the loading area and depend on both loading hole parameters and operating modes of the SC [3,4]. For high-speed SC, at their bunker loading, achievement of the fill factor rational values and ensuring the calculated effectiveness is complicated by the effect of centrifugal forces occurring during the rotation of the screw operating element. It is possible to reduce the centrifugal forces influence and increase the screw conveyor fill factor by generating directional flow, which vertical velocity component resists the centrifugal forces occurring during the screw conveyor rotation and the axial component corresponds to the speed of the bulk transportation by screw conveyor. Therefore, the investigation of the processes of high-speed conveyor directional loading resulting in SC effective loading is important.Analysis of the available investigation results. To provide the given coefficient of high-speed SC filling the forced loading systems, particularly, feeders of various types are used [1,4]. However, their application significantly increases the cost of bulk transportation and can be suggested for vertical screw conveyors loading. For horizontal screw conveyors loading it is efficient to use gravity loading systems where the bulk after exiting from the bunker acquires certain kinematic energy [3,4,5, 7]. At the direct bulk drop, the increase of particles velocity height wise the flow causes its dilution preventing the effective high-speed SC loading [5, 6, 7, 8].The objective of the paper is to provide bunker loading of high-speed SCs by generating directional compressed flow of the bulk cargo with high kinetic energy of the flow in order to resist the centrifugal forces from the SC rotating operating element complicating their filling with bulk cargo.Statement of the problem. Such compression can be reached by application of inclined guiding platforms installed in the flow path [9]. Moreover, the use of guiding platforms makes it possible to coordinate the horizontal component of the SC filling velocity with the axial speed of cargo transportation.Let us consider the bulk cargo outflow from the bunker with the implementation of compressed directional flow, Fig. 1. We choose coordinate s...

Design development and study of an elastic sectional screw operating tool

“…Operating conditions, which affect the performance of screw conveyors by using a discrete element method (DEM) to simulate single-flight screw conveyors with periodic boundary conditions, are considered in [18][19][20]. In the works of [21][22][23] mathematical models of the process of feeding bulk materials into bunkers of screw conveyors are proposed, and operating modes of inclined screw conveyors are considered, allowing to develop their new designs with a justification of rational parameters. The analysis of known works shows that a considerable reduction in the damage caused to agriculturallyproduced materials can be achieved by employing elastic surfaces, which are attached to the screw blade.…”