Closed System of Layer Dryer Development Using High Voltage Electric Field Technique

Abstract

Industrial energy intensive processes are being forced to explore alternative ways to reduce their energy consumption. In food industry, the hot air drying (HAD) is an energy intensive process. In order to reduce the energy consumed during its operation, therefore, the alternative processes had been investigated. One promising alternative is the electrohydrodynamic (EHD) to enhance the heat mass transfer. Thus, this research aims to design and construct the hybrid EHD/HAD dryer for dehumidification of food materials and agricultural products. The EHD system consists of an AC power supply, a structure of multiple electrode pins, and an aluminum plate functioned as electrical discharge unit. The syatem can be applied with high voltage electricity in the range of 0-22 kV. Results showed that, the influence of corona wind flowing above tested samples increases the drying rate considerably. In addition, the hybrid system of combined EHD/HAD unit with a conventional hot air drying system as the back-end process, can dramatically reduces the moisture content in tested samples. Moreover, the kinetics of the hybrid EHD/HAD drying technique can enhance faster drying rate over the hot air drying technique alone. Furthermore, the Page’s mathematical simulation simulation model is suitable for describing the drying kinetic behaviors of these tested samples. In conclusion, this designed and constructed dryer is applicable for drying of food and agricultural products.