Drying kinetics of paddy drying with graphene far-infrared drying equipment at different IR temperatures, radiations-distances, grain-flow, and dehumidifying-velocities

Abstract

Graphene has a high electric heating conversion rate and can be used as a new heat source for far-infrared drying equipment to improve drying efficiency and reduce energy consumption. This study aims to investigate the drying kinetics of graphene far-infrared paddy drying equipment The infrared (IR) temperatures of 35, 40, 45, 50, 55, and 60 °C; distances between radiations of 25, 30, 35, and 40 mm; grain flow of 5.0, 6.0, 7.0, 8.0, and 9.0 kg/min; and dehumidifying air velocities of 4, 5.5, 7, and 8.5 m/s were studied for appropriate drying time and optimal paddy quality. Simultaneously, the drying kinetics, moisture diffusion coefficient, and activation energy were observed. Experimental results show that the coupling degree of Midilli was superior, specifically, the Deff of paddy was 4.83–16.371 × 10−9m2/s, an activation energy of 47.44 kJ mol−1 and a heat efficiency of 71.11% were achieved at a drying temperature of 60 °C. The far infrared drying of graphene has high moisture diffusion coefficient and thermal efficiency. By analyzing the kinetics and energy of drying process, a basis for formulating drying strategies could be provided to realize the research and development of new drying machinery.