Analysis of energy consumption for microwave hopper dryer on a pilot scale

Abstract

Abstract In this study, a pilot scale microwave hopper dryer was fabricated and used for drying the plastic pellets. The electromagnetic field analysis was conducted according to the positions of the waveguide and reflector for the highest dissipated energy was determined. The experimental setup was prepared by placing the waveguide in the middle of the cylindrical cavity and the cone for scattered reflection at the position facing the waveguide by the electromagnetic field analysis results. The experiments were carried out at two microwave powers (1 and 2 kW), 5 pulsed microwave (off–on time ratio—0.2, 0.4, 0.6, 0.8, 1.0). As a result of the experiment, it was confirmed that 2 kW of power is required to dry 25 kg of plastic pellets, and the pulsed microwave off–on time ratio is less than 0.4, the pellets are damaged. Therefore as a final concluding result, to prevent breakage plastic pellets, microwave power of 2 kW and 0.6 microwave off–on time ratio was selected as the most appropriate combination for drying plastic pellets using the microwave hopper dryer. Assessment of the specific energy requirement in microwave power and off–on time ratio showed that the value with 278.36 MJ/kg.