SIMULTANEOUS MOISTURE AND HEAT TRANSFER IN POROUS SYSTEMS WITH PARTICULAR REFERENCE TO DRYING

Based on an examination of the liquid-vapor equilibria and of the mass and energy transfer processes in porous systems, a theory has been developed for simultaneous mass and heat transfer during the pendular state of such systems. A set of differential equations is presented which, when solved with the appropriate initial and boundary conditions, yields the complete moisture content, temperature, and pressure history of the system. By theoretically simulating various drying processes it is shown that during the falling rate period the evaporation-condensation mechanism is the governing mechanism of drying. The application of the theory to transient heat conduction in the presence of moisture and to transient vapor transfer through porous media is also illustrated. © 1969, American Chemical Society. All rights reserved.