Particle fraction and velocity measurement in gas-powder streams by capacitance transducers

A simple, economical and accurate technique, based on the different dielectric constants of solids and gases, has been developed to determine instantaneous, in-situ void fractions and particle velocities in gas-powder streams. Two different electrode configurations were investigated for sensitivity and flow-regime dependency. Stationary, as well as high speed cinematographic, calibrations were performed. The technique is suitable for process control.