Operational characterization of a spray dryer for drying water, caustic soda and sodium chloride solutions

The spray drying of distilled water, 50 % w/w NaOH, 10 % w/w NaOH, and 25 % w/w NaCl solution was investigated. Operating conditions, dryer design and inherent properties of the liquids affected performance operational trends and degrees of dryness. The various phenomena observed indicated the difficulty in predicting the performance or suitability of any dryer for the purpose of drying a liquid without an investigative task. The maximum values of exit mass flow rate of dried liquid, dryer temperature, heat transfer coefficient, specific energy supplied and moisture content removed were 0.015 kgs-1 for 25 % w/w NaCl solution, 402.6 K, 4.85 Wm-2K-1, 1, 941, 937.04 Jkg-1 and 0.217 for distilled water respectively. The exit mass flow rates increases with specific energy supplied for all the liquids, except for 50 % w/w NaOH solution which decreases with specific energy supplied. The possibility of exploring, competing or improving quantitatively and qualitatively on the conventional mode of drying some of these liquids industrially seems promising, with the aim of overcoming their inherent and present challenges.