Flow rate measurements in a draft tube baffle crystallizer using a radioactive flow follower technique

Flow rates produced by two different propellers (designated PR-L and PR-R), designed and manufactured by two different companies and used in a draft tube crystallizer, have been measured by means of a neutrally buoyant radioactive flow follower technique. Comparison of the results indicates that the flow rates produced by the propeller PR-L were higher than the propeller PR-R. From the measured flow rates, the characteristic flow numbers of the propellers were calculated and used to predict the behaviour of the propeller for varying operating conditions. The flow numbers ranged from 0.3 to 0.5 and 0.4 to 1.3 for PR-R and PR-L respectively.