Process Equipment and Plant Design
Heat transfer co-efficient, hG(Kcal/hr.m² .°C) and mass velocity of air, G (kg/hr.m² ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as hG = 0.0176G0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to
Plate tower is preferred over packed tower, if the operation involves liquids containing dispersed solids
In operations involving large temperature changes. (e.g. distillation), plate towers are preferred over packed towers as the packing may be crushed due to large temperature changes
Plate tower is perferred, if interstage cooling is required to remove heats of reaction or solution
The total weight of a dry plate tower is usually much more than that of a dry packed tower designed for the same duty