ABSTRACT
One of the major problems with classical vacuum drying is the relatively long retention time required, which sometimes may be as long as 100 h. Since thermal degradation is a time-temperature-related process that doubles for every 10°C increment, a long residence time may result in product deterioration, even at low processing temperatures. The Vacu Jet Drying (VJD) system, designed for continuous processing of liquid materials at relatively high temperatures with a short residence time, appears to be advantageous over the vacuum-tray, vacuum-drum, or freeze-dryers. The system uses indirect heating of the liquid feed, sudden adiabatic expansion, and vacuum drying with mixing in series to evaporate solvents from the liquid feed and get a powdery product.
