Experimental study of microchannel heat exchanger for desublimation in freeze drying process

Abstract

This research proposal aims to apply the knowledge of compact heat exchanger of the Heat Transfer Group from the Department of Mechanical Engineering, of the EESC-USP, in condensers of industrial freeze dryers. Freeze-drying is a high energy demanding process which is used for drying food or pharmaceuticals ingredients. This implies in high operational costs for the food and pharmaceutical industries. The high energy costs are mainly due to the vacuum and cooling systems, which remain in operation throughout the process cycle. Most of researches about freeze-drying are related to the determination of optimized protocols of drying time duration, temperature and pressure for a determined product. Another feature which has been studied is the heat and mass transfer model for a specific product, mostly in the pharmaceutical industry. In this proposal, the study is directed on a component of a freeze-dryer. We seek to study and evaluate experimentally a compact heat exchanger, consisting of microchannels, which minimizes the energy demand to frost growth on the freeze-dryer condenser. The vapor desublimation that occurs in a freeze-dryer condenser is required for the pressure remains low and the drying rate keeps at the highest level possible. It is expected, at the end of this work, a better comprehension of the desublimation process occurring over the surface of compact heat exchangers.