Thermal Properties of Fuzzy and Starch-coated Cottonseeds

Abstract

Bulk thermal properties (heat capacity, thermal conductivity, thermal diffusivity) of fuzzy and starch-coated cottonseeds were determined in the temperature range of 20–50°C as a function of bulk density (256–600 kg/m3) and moisture content (2–50% d.b.). The heat capacity of the cottonseeds remained almost constant with increasing bulk density and it linearly increased with increasing moisture content. It was determined to be between 1·20 and 2·95 kJ/kg K and between 1·31 and 3·16 kJ/kg K for the fuzzy and the starch-coated cottonseeds, respectively. The thermal conductivity linearly increased with increasing density and moisture content. It ranged from 0·0859 to 0·4422 W/m K for the fuzzy cottonseed and from 0·1318 to 0·5219 W/m K for the starch-coated cottonseed. The thermal diffusivity linearly decreased with increasing density and moisture content. It was obtained between 0·48×10−4and 1·51×10−4m2/s for the fuzzy cottonseed and 0·53 ×10−4and 2·17×10−4m2/s for the starch-coated cottonseed. Linear regression models for estimating these thermal properties as functions of the bulk density and the moisture content fitted the experimental data well. The starch coating did not significantly affect the heat capacity of the cottonseed. However, it led the thermal conductivity and the diffusivity to increase.