Analysis of RF Heating Uniformity with Cylindrical Electrode Plates and Adding Polypropylene

The Radio frequency (RF) heating is a treatment for agricultural products instead of chemical methods of disinfection, resulting damage life health and environment. RF heating was used and developed for a long time. The main problems that are non-uniform heat distribution. It is problem that cause cold spot and hot spot contribute to the viability of insects and loss quality of product, respectively. In this study, to improve uniformity heat distribution of rice samples with cylindrical electrode plates and adding polypropylene (PP) in cavity as a new strategy. An applicator simulation models were evaluated temperature distribution uniformity with electric field intensity and power loss density were occurred. An applicator structure consisted of high 50 mm, inner diameter is 40 mm and outer diameter is 160 mm with copper thickness is 0.5 mm. Polypropylene was placed in different positions with cylindrical shape, thickness is 10 mm. A 50 W, 27.12 MHz RF system was used to generate electric field in experiment. The results showed that using cylindrical electrode plates was not occur hot spot but has over heat surround inner conductor. That can be reduce and improved the temperature distribution uniformity with adding PP material.