AN EXPERIMENTAL STUDY OF PARTICLE FLOW VELOCITIES IN SOLID-LIQUID FOOD MIXTURES

The design of equipment to sterilise solid-liquid food mixtures continuously requires that the flow properties of such mixtures be understood. Little information is available on food flows, which can consist of high solids fractions of particles of a range of densities in non-Newtonian and viscous liquids. A metal detection system which can log two types of particle in the same experiment has been constructed and used in a loop flow rig to study flows of single particles and carrot-water mixtures. Results can be correlated using the particle Froude number; some preliminary analysis is presented to suggest that data can be correlated against 1/Fr_p. The effect of solids fraction on particle flow velocity has been investigated; greatest variations in the particle velocity appear for stratified flows for solids fractions between 10-20%.