Effective Thermal Conductivity of Wheat Flour

Abstract

The effective thermal conductivity for three kinds of wheat flour (soft, medium, hard) was measured at selected moisture contents, temperatures and bulk densities. The transient heat flow method using twin probe was used for the determination of the effective thermal conductivity. The effects of moisture content, temperature and bulk density on the effective thermal conductivity of wheat flour were investigated. Observed values were compared with the calculated values from the thermal conductivity of air and wheat flour, using the typical several kinds of the heat conduction model. Therefore, the series/parallel model of which the ratio of the parallel gas phase was written as a function of moisture content, temperature and porosity was proposed.