ONLINE MEASUREMENT OF MASS-FLOW OF PNEUMATICALLY CONVEYED SOLIDS

CSIRO has developed an ultrasonic attenuation and transit time techniq ue and a microwave transmission technique for on-line determination of the mass flow of pneumatically conveyed solids. In a comparative plan t trial on a single burner line at Bayswater power station. the ultras onic technique determined the coal density and velocity with rms error s of 3.9 and 5.9% relative respectively; the microwave technique succe ssfully determined the coal density with an rms error of 6.2% relative , but was unable to accurately determine solids flow velocity at the l ow coal densities typical of the trial. In a plant trial at a direct s melter, the microwave technique successfully determined the mass Row o f pneumatically conveyed iron ore lines feeding the smelter. with an r ms error of 10.2% relative.