Experimental investigations on freeze-drying of particulate matter by using neutron imaging

Abstract

This study shows that changing solid content and particle size leads to different inner and outer porosities and thus, leads to different drying properties. These relationships were investigated with neutron imaging by using maltodextrin as the model substance. The experimental results are assessed based on analyses made with GeoDict (Math2Market). It is shown that particle beds with larger particles (x = 3550 µm) have generally better mass transfer conditions, which are additionally positively affected by lower solid concentrations (c = 0.05 w/w). In contrast heat transfer is generally enhanced in the case of fine particles (x = 70 µm) but impairs with increasing porosity.