Suspended solids distribution in agitated, baffled vessels containing three concentric cooling coils

New experimental data are presented on the axial and radial distribution of solid particles suspended in a baffled, agitated liquid for the common - b ut previously uninvestigated - geometry of multiple concentric cooling coil s around the impeller. Particle distribution trends are identified in relat ion to impeller speed, liquid height, and number of radial flow impellers o n a single shaft. Interpretation of the results is in terms of material bal ances and also by a new application of an approach taken from the field of air pollution control. The latter estimates the surplus fraction of suspend ed solids that remain confined within the innermost coil because of its imp ediment to solids transport in the radial direction. Fair agreement is obta ined between these retained solids estimates from material balance and from coil impediment considerations. (C) 1999 Elsevier Science Ltd. All rights reserved.