Effect of moisture and temperature on thermal conductivity of pigeon pea seeds

Abstract

The thermal conductivity of agricultural seeds has been used as engineering parameter in the design of process and machines for drying, storing, aeration and refrigeration. The thermal conductivity of white and red pigeon pea seeds with changes in moisture content and temperature was investigated using the transient heat transfer method. The thermal conductivity of white and red pigeon pea seeds increased from 0.2387 to 0.3497 Wm^-1k^-1 , and 0.2375 to 0.3425 Wm^-1k^-1 respectively, as the moisture content increased from 5 to 35% w.b. Thermal conductivity of white and red pigeon pea seeds increased significantly (p<0.05) from 0.2643 to 0.3543 Wm^-1k^-1 , and from 0.2711 to 0.3311 Wm^-1k^-1 respectively, as temperature increased from 10 to 70 ℃. The Arrhenius type equation was used to study the temperature dependence with an activation energy of 3.93 and 2.68 KJ/mol for white and red pigeon pea seeds respectively. The relationship between the thermal conductivity and temperature was analyzed.