Behaviour of a conical spouted‐bed dryer for animal blood

A 60° conical bed of inert particles spouted with hot air has been used as a medium for drying animal blood into a powder with little thermal degradation. The spouting and drying performances of the dryer were investigated. A feature of considerable practical significance is the existence of an initial regime of incomplete spouting in which the solids in the annulus are partly held stagnant by friction, causing a reduced pressure drop. A model of the drying process was developed to predict the variations in maximum throughput and product properties with changes in operating conditions. Good agreement between predictions and experimental results was found.