A new criterion to estimate the capacity of steeply inclined settlers of arbitrary cross-sectional shape

Abstract

Steeply inclined settler technology has been long used to separate liquid and solid phases in dilute streams in various industries. In the present paper, a new model to account for the capacity of this kind of settler, in the particular case of those consisting of a set of inclined conduits, is proposed. The model combines a mass balance similar to that leading to the Ponder, Nakamura and Kuroda theory of inclined settlers and a particle trajectory approach to derive a simple relation between settling element length, particle settling-mean flow velocity ratio and geometric characteristics. Two new dimensionless parameters are derived to account for shape effects in the mass balance and when comparing settler capacity at equal conduit cross sectional area. Good agreement with previous experimental results and less conservative results than previous models have been found.