Evaluating performances of a small-scale 50 Ω radio frequency heating system designed for home applications

Abstract

Industrial-scale radio frequency (RF) heating systems have been extensively used in processing agricultural products and foods. However, small-scale RF heating systems for household applications are yet to be realized. The purpose of this study was to develop small-scale 50 Ω RF heating systems and evaluate its heating performances with cooked rice (moisture content (MC) of 62.5 ± 0.5% wet basis (w.b.)). Two RF systems (13.56 and 27.12 MHz) were developed, and the heating rate, heating uniformity, and energy efficiency of cooked rice samples were compared between the developed RF units and a 2450 MHz microwave (MW) oven under static conditions. Results showed that the RF heating systems had smaller temperature differences and better heating uniformity than the MW oven under similar overall heating rate and the same input power (700 W) levels. The 13.56 MHz RF system performed better than the 27.12 MHz one. These findings may provide some clear performance indicators and guidelines for domestic application of small-scale 50 Ω RF heating systems.