EHD-Enhanced Drying With Auxiliary Heating From Below

Abstract

The present study investigates the possible drying enhancement provided by auxiliary heating to the sample in addition to the application of electric field. The electric field is produced by charging a needle electrode with direct current at a sufficiently high voltage. The auxiliary heating is provided through a thermofoil heater attached to the bottom plate of the sample container. The samples used are 3 mm and 6 mm glass beads saturated with water. Both positive and negative corona discharges have been employed. Two sets of experiments have been conducted, with and without cross-flow, at 1 kV increment from the corona threshold voltage until the occurrence of sparkover. For each case, a companion experiment was carried out simultaneously under the same ambient conditions but without the application of electric field or auxiliary heating. The result of which is used as a basis in the evaluation of drying enhancement using electric field (with or without cross-flow). The drying enhancement is evaluated as a function of the governing electric field parameters. In addition, the performance of EHD drying is compared with the conventional drying techniques.