Process intensification in spray dryers by turbulence enhancement

Zbicinski et al.(1) reported that increasing the inlet turbulence levels in a small tunnel dryer with the aim of process intensification resulted in a n increase in drying performance using sprays consisting entirely of water. A pair of experiments for each set of conditions was produced by varying t he inlet turbulence intensity in the second experiment while holding other conditions constant. The results of three such pairs of experiments have be en studied using the computational fluid dynamics code, CFX4. The effects o f varying several model parameters and conditions were considered in order to investigate the sensitivity of the model for this problem. Although the simulations consistently predicted levels of cumulative evaporation substan tially below the measured values, increased cumulative evaporation was alwa ys predicted when inlet turbulence was enhanced. The simulations predicted improvements of between 5 and 11%, which are significantly less than the me asured maximum improvement of 16.6% for these cases.