Tech Lic . Me 64, Acta Polytechnica Scandinavica. Stockholm 1970

Abstract:

The behaviour of non-cohesive bulk materials is studied in order to find a pressure distribution that can be used for calculation of vertical screw conveyors.

A new calculation methods for vertical screw conveyors is presented. Regard is paid to the larger fillings that can be obtained in modern conveyors furnished with a special feeding apparatus.

Diagram containing non-dimensional parameters for calculating efficiency, transport capacity, and axial force on screw are given. The diagrams make it possible to design conveyors with maximum efficiency.

Experiments show good agreement between theory and tests.

Experiments with rotating screw and counter-rotating transport tube show that centrifugal forces are not necessary in order to obtain transport in the well-filled conveyor. However, calculation diagrams are not given for this case. It is shown in this paper that there is no advantage in rotating the tube, as transport capacity is only moderately raised and furthermore rotating tubes are very inconvenient in practice.

The importance of the feeding apparatus should be pointed out. When the feeding apparatus is removed and the conveyor operates as a conventional conveyor, the capacities are only about 20% of the capacities received, when the feeding apparatus is operating.

Finally a calculation methods is outlined for transporting materials, supposed to have high internal friction.