Abstract
A porous solid sphere 3.92 cm in diameter was soaked with water and dried in a fluidized bed maintained at a constant temperature between 80°C and 140°C. The pressure increase and the temperature profiles within the solid sphere were continuously measured. The pressure increase ΔP, which has been utterly ignored heretofore, was found to be enormous (30 to 246 mmHg).
The dynamic effective diffusivity and the flow equation interrelating the gradient of concentration and that of the total pressure provided data to predict accurately this pressure increase during the course of drying.
The evaporation temperature Tc was also predictable by solving the flow equations and a simplified equation of heat transfer simultaneously.
