Measurement of flow properties of bulk solids

Abstract

To design reliable devices for the handling of bulk solids, knowledge of the flow properties of these bulk solids is essential. For the measurement of flow properties, numerous types of shear testers are available. This paper reviews developments in the design of new shear testers. Some new results of the experimental work carried out with shear testers are presented. After a short description of the measured flow properties of bulk solids and the basic principles of shear testers, the design and/or results of some devices (Jenike shear tester, unconfined yield strength test, triaxial tester, True Biaxial Shear Tester, ring shear tester, wall friction tester) are presented. The developments and investigations reported were made with two considerations in mind. On the one hand, knowledge of the behaviour of bulk solids should be enlarged. For this goal, very specialised shear testers, e.g. the True Biaxial Shear Tester or the triaxial tester, are required. On the other hand, simpler testers have been developed to permit straightforward measurement of the flow properties used for practical applications, e.g. silo design. In addition, it is shown that the results obtained with a shear test are dependent on the kind of shear tester and the shear procedure.