1988 Volume 50 Issue 2 Pages 47-54
To calculate drying stresses in a brown rice kernel by applying the numerical method proposed in the previous papers, the time required for drying and the dimensionless radial coordinate of the kernel have to be divided into a number of increments, Δt and ΔR, respectively. In the present paper, the calculations of drying stresses in a brown rice kernel were carried out using various increments, Δt and ΔR, at a given drying condition to estimate an error in calculation. As a result, it could be found that the fitting values of Δt and ΔR were 0.04 hours and 0.05, respectively, to perform the stress calculation in a rice kernel without noticeable error.
More calculations were carried out using the above values of Δt and ΔR under other drying conditions. Based on the calculated results, changes of cracked rice percentage with drying conditions were discussed by considering that the crack generation in a brown rice kernel depended primarily on the drying drying stresses. It was pointed out that the changes of the cracked rice percentage were highly dependent on the equilibrium moisture content which related with temperature and humidity of the drying air.
