Energy saving in spray drying process

Abstract

Spray drying is the key process in the manufacturing of detergent powder. This process needs a large amount of heat for water evaporation. Saving heat while maintaining product quality is an important factor for the successful functioning of the process. The objective of this study is to minimize energy consumption and to maximize production yield while maintaining product quality. We are interested in bulk density and energy consumption in the production of detergent powder which use Sodium Tri Poly Phosphate (STPP) and Zeolite as component materials. Design of Experiment (DOE) is used in this work in order to optimize the influencing parameters. Experiments are performed with the hot air flow rate varied from 65,000.00 to 72,000.00 kg/hr, slurry feed rate ranged from 25.50 to 31.00 ton/hr and atomized pressure ranged from 50.00 to 55.00 bars. The results of both components show that the bulk density increases with a corresponding decrease in slurry feed rate and an increase in atomized pressure. An increase in hot air flow rate also increases bulk density of Zeolite based detergent powder. The ratio between energy consumption and powder output indicates energy saving. Both STPP based and Zeolite based detergent powder have similar trends. Energy consumption to powder output ratio decreases with an increasing of the slurry feed rate, hot air flow rate and atomized pressure. The optimal condition obtained is applied and can reduce cost 2 million baht a year.