(611d) Measurement of Flowrate of Particulate Solids

Accurate and reliable measurements of flow rate, in a real time framework, are often useful and sometimes critical to the control of processes involving particulate materials. In this presentation we first consider gravity driven bulk solids flows and review the development of the slot flow meter, SFM, a device analogous to the notch weir, with particular reference to potential applications in the wheat industry and its use in controlling screening circuits in mineral beach sand processing. We then outline the operating principles of a variant of the SFM, in which the process solids are fluidized, potentially attractive for high temperature use.

Dilute particulate flow systems, as encountered in spray drying fines return lines for example, can also benefit from reliable real time flow measurement. Though there is apparently no established and accepted measurement technology for dilute particulate flows in transport lines we have demonstrated that they can be reliably and accurately monitored and measured using an acoustic technology based on time of flight measurements and attenuation of the interrogating sound wave. We also comment on some success in the use of acoustic interrogation in monitoring dense phase pneumatically conveyed solids flows.