INDUSTRIAL APPLICATION OF ELECTRICAL TOMOGRAPHY TO CONVEYING PROCESSES

This paper discusses the recent experimental application of a dynamic imaging technique, capacitance tomography, to the dilute-phase pneumat ic conveying of two granular products. Images acquired after a bend, l ocated downstream of an upward vertical leg, have proved useful in ide ntifying the point at which the flow becomes homogenized once again. G enerally such methods can only be used if the fluid is electrically no n-conducting or of very low conductivity. However, through careful cal ibration it is demonstated that measurements can be made for the limit ing case of silca solids in distilled water. Analogous measurements of solids content of aqueous slurries, but with higher conductivity elec trolytes. can be performed using resistance tomography. The results pr esented here indicate that quantitative measurements can be made which suggests that both capacitance and resistance tomography should have a number of technical applications, in particular, for design of pneum atic and hydraulic conveyors.