Shear device for measurement of wall friction in designing granular moving bed filters

A new measuring method and device for measurements of flow properties of filter granules and pellets of larger particle sizes, particularly for wall friction measurements, is proposed. A bidirectional stress gage is employed in the new shear device. The shear ring is 200 mm in internal diameter. The shear path of the specimen of particulate solids is long enough to measure wall friction coefficients of large granules and rocks considered as moving bed filter media. Several tests with different granular materials and using different shear rings have been performed.