A HETEROGENEOUS FLOW MODEL FOR THE EFFECT OF SLIP AND FLOW VELOCITIESON FOOD STERILIZER DESIGN

Designing plant to sterilise two-phase food mixtures in flow is compli cated by velocity gradients in the liquid and slip velocities between solid and liquid. The model of Mankad et al. (1995 Chem. Engng Sci. 50 , 1323-1336) for the effect of particle-liquid slip on a homogeneous f ood flow has been extended to the case of heterogeneous flows. It has been used to model a stratified flow through a combination of a heatin g and holding tube over a range of process conditions: flows where vel ocity differences are minimised appear best in terms of minimal proces s time. More data on the behaviour of real flows are needed. (C) 1997 Elsevier Science Ltd.