EVALUATION OF ENERGY-CONSERVATION POTENTIAL BY EXHAUST AIR RECIRCULATION FOR A COMMERCIAL-TYPE HEATED-AIR BATCH HAY DRYER

Energy conservation in drying and processing operations is essential i n order to improve the reliability of low and moderate temperature ren ewable energy systems, and to reduce operating costs and energy consum ption in systems using high-energy content fossil fuels in farms and p rocessing plants especially in industrialized economies. An experiment al evaluation of energy conservation potential by recirculating exhaus t air in a commercial heated-air batch hay dryer is presented. The des ign of the exhaust recirculation unit is such that only about 30% of t he total exhaust air is recirculated through the heater inlet. Experim ental tests were conducted on the dryer with and without exhaust air r ecirculation. Maximum energy savings of 27% and 17% were achieved with exhaust air recirculation during fall and summer dryer operation, res pectively.