As the price of fossil fuels escalates, engineers and operators are being asked to mitigate operating costs by recycling process streams, thereby minimizing their utility consumption per unit production. Thermal drying of super absorbent polymer (SAP) is a prime application where reusing exhaust air and condensate streams benefit the energy footprint of the conveyor dryer. SAP drying yields effluent streams with sufficient internal energy to financially justify modifying the configuration of the dryer for heat recovery.
Buhler Aeroglide in Cary, N.C., conducted a study using a numerical approach to identify and quantify potential energy savings through mass and energy balances. Opportunities for heat recovery include cascading airflow, air-to-air heat recovery and condensate flashing.