Adsorption Characteristics of Thin Silica-Gel Layer and Simulation in the Fixed Layer

Abstract

The purpose of this paper is to design dehumidifier for drying at ordinary temperatures.
The adsorption characteristics of thin silica-gel layer were measured and analyzed as follows:
(1) The adsorption process of silica-gel was in the first falling rate period. (2) The relation between equilibrium moisture content and the relative humidity was expressed well by the formula of Chen-Clayton obtained by the method of least squares. (3) The latent heat of vaporization of water in silica-gel was calculated precisely from the Clausius-Clapeyron's equation. (4) The relation between the equilibrium moisture content and the absolute humidity in the same temperatures could be adequately approximated by linear formula.
From the results of above (1) to (4), unsteady state equations for heat and mass transfer in silica-gel particles and air were formulated. Using these equations the simulation of temperature and humidity of air through the fixed thick layer, and moisture adsorption and temperature in silica-gel particles, for the adsorption process was performed. The feasibility of the silica-gel dehumidifier for cereal grain dryer at ordinary temperatures was confirmed by the simulation.