Experimental and Numerical Investigation of the Characteristics of Spray-Freeze Drying for Various Parameters: Effects of Product Height, Heating Plate Temperature, and Wall Temperature

Abstract

A spray freeze dryer was developed by combining a spraying system and a freeze-drying system. Experiments for three cases with different product heights were conducted. The experimental data are compared with a numerical simulation based on the spray-freeze drying model by Liapis and Bruttini^{[ 1 ]} and the finite volume method in a fixed grid system. The physical characteristics of the spray-freeze-dried particles are investigated using scanning electron microscopy and a particle size analyzer. The temperature profiles of the product for the three experimental cases are measured experimentally and computed numerically, and the effects on the drying time of various parameters, including the product height, the heating plate temperature, and the chamber wall temperature, are analyzed.

Keywords:

• Finite volume method
• Packed particles
• Porous media
• Spray-freeze drying
• Sublimation