Energy Consumption of a Pilot-Scale Spray Dryer

Abstract

Factors affecting the energy consumption of a pilot-scale spray dryer have been studied. The feedstock employed was instant coffee solution (50–150 gl−1). Its feed rate ranged from 0.83 to 1.9 mls−1 and the inlet air temperature from 473–533 K. The specific energy consumption E s (3,000–5,500 kJkg−1) decreased with increasing feed rate and temperature difference across the dryer and increased with solids concentration. Values of E s obtained were consistent with Baker and McKenzie's[ 10 Baker , C.G.J. ; McKenzie , K.A. Energy consumption of industrial spray dryers . Drying Technology 2005 , 23 ( 1–2 ), 365 – 386 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar] ] adiabatic dryer model. The thermal loss factor η decreased with increasing evaporation rate. Attempts to correlate product moisture content with the operating variables met with limited success.