Chemical Engineering - Process Equipment and Plant Design

In common bubble cap distillation column design practice, riser area is approximately equal to (where, A_a = Annular passage area, and S_a = Slot area)

Heat transfer co-efficient, h_G(K_cal/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 h_G = 0.0176G^0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to

In the agitators, the power required will be changed with the increase of diameter of agitator (D) as

Apex angle of conical heads used in the bottom heads of chemical process equipments is usually

Pressure drop due to pipe fittings can be estimated by the equation,
, where, L_e = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and D = diameter of the fitting. The value of (dimensionless) for 45° elbow and 180° close return bends would be respectively around