Measurement of particle velocity distribution in a vertical channel

Experimental measurements of particle velocity as a function of radial position using a novel arrangement of non-intrusive optical probes are described for an upward co-current gas—solids flow in a cylindrical vertical channel. Optical beams were used to measure particle velocities along the chord lines employing a cross-correlation technique to calculate the mean particle velocity along the chord. The application of the technique is illustrated for gas—solid mixtures for different sizes of monodisperse particle sizes (100–1 500 μm) and volume fractions (0.002–0.02). This method provides an alternative to conventional laser Doppler anemometry (LDA) instrumentation for measurement in dilute gas/solid mixtures and, unlike LDA, enables the velocity field within the entire cross-section to be measured simultaneously.