Studies on the Spray Freeze Drying of Milk Powders

A spray freeze drying plant for the drying process of thermal sensitive materials was developed. An experimental research was performed with milk powders as raw materials. The result shows that the feed fluid could be quickly frozen under -40~30℃,and the plant could reduce drying time from previous 48 (in a vacuum freeze-drying condition ) to 10h. Finally,a measure and an analysis was made of the powder shape of the dried products.