Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering Transport Technology
P.A.F. Witvliet Lange bandtransporteurs voor bulkmaterialen.
Literature survey, Report 94.3.TT.4341, Transport Engineering and Logistics.
The belt conveyor is a frequently used, reliable continuous transportation system. Since the first design in 1795 the simple basic principle of the belt conveyor has always remained the same: an endless belt revolving over one or more drive pulleys and a return pulley.
Until the late seventies the belt conveyor was mainly used for in-plant transport of bulk materials. Trucks or trains were used for the long-distance haulage of bulk materials. This situation changed during the oil crisis in the seventies. Fuel became very expensive and other, more energy-efficient ways of transport had to be found. The belt conveyor is such an energy-efficient transporting method.
The most frequently used type is the troughed belt conveyor with steelcord belt. The material is carried on a rubber belt, troughed by idlers. A single layer of parallel steel cables, completely imbedded in rubber, functions as the longitudinal tension element. Another type of conveyor is the 'cable-belt'-conveyor. Here the belt acts as a supported beam, troughing naturally under the material load. The belt is supported on steel cables located in grooves formed on the underside of the belt. These cables take all the longitudinal stresses.
Because of the possible high belt-stresses the drive engineering of long-distance belt conveyors requires special attention, in particular the drive
arrangements for starting and stopping the belt. During starting and stopping rapid changes in belt velocity have to be avoided, to prevent the development of large dynamic stresses.
Current research activities focus on the analysis of the dynamic behaviour and reducing the energy-consumption of the belt conveyor. Vertical and horizontal curves are another subject of research. The behaviour of the belt in curves should be critically analysed to ensure problemfree functioning of the belt conveyor.
Due to better understanding of the behaviour of the belt and the drive characteristics, low factors of safety and lighter constructions have become possible. These developments make the belt conveyor even more economically attractive.
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