A parallel-beam radiometric instrumentation system for the mass flow measurement of pneumatically conveyed solids

This paper describes the design and experimental evaluation of a radiometric instrumentation system that has recently been developed for the measurement of volumetric concentration, velocity and mass flow rate of pneumatically conveyed solids. The system employs 'micro' beam collimation of gamma radiation to generate multiple, parallel interrogation beams of small cross-sectional area. This configuration is shown to almost eliminate the geometrical errors associated with more conventional divergent-beam interrogation. Experimental results obtained off-line using idealized flow models, and also on-line using a pneumatic conveyor, demonstrate the performance of the system and highlight where further development is needed.