An experimental study for drying Pisum sativum on an electric dryer and a heat pump dryer

Abstract

A study of drying parameters on the drying process of Pisum Sativum bean was carried out. The effects of drying temperature of moisture air from 40°C to 80°C on the drying time and on the drying kinetics were demonstrated not only on conventional electric dryers but also on heat pump dryers. Besides, checking the steady operation of the heat pump dryer was also considered. The results show that, when temperature rises, the shorter time and the faster removal of moisture content can be obtained for both dryer systems. Drying in an electric heater at 80°C took only 1 hour 45 minutes, but the broken skin of pea seeds happened. The comparison of heat pump dryer and electric dryer was presented with the shorter drying time on heat pump than electric dryer as a result of removing water vapor from moisture air at the evaporator of heat pump, it led to the reduction of specific humidity of air entering the drying chamber. And the last impressive result which can be seen is that the drying rate of a heat pump is higher than an electric dryer at the same drying temperatures beside the energy consumption of electric dryer is 2.76 times as much as that of heat pump dryer.