RADIO FREQUENCY DRYING OF CERAMICS AND FIBREGLASS

Radio frequency (RF) heating and drying has been used by the ceramics and fibreglass industries for many years. Products such as filters and cellular structures, catalytic converter substrates, ceramic fibre mat and insulation, and fibreglass strands and rovings can all be dried using RF energy. Conventional drying of such products presents many challenges to manufacturers, notably long drying times and high labour and energy costs. RF energy heats the entire volume of the product uniformly, greatly improving both the drying time and quality, while RF ovens allow products to be moved on a continuous conveyor system. In addition, RF energy only heats the water in the product, so there is little wasted heat used to heat the oven structure. The principle of RF drying is explained and the potential technologies and challenges are addressed.