METHOD OF CONTINUOUS SUBLIMATION DRYING OF THERMOLABILE MATERIALS Russian patent published in 2002 - IPC

FIELD: drying technique; sublimation drying of thermolabile materials, for example drugs, medical preparations and food-stuff. SUBSTANCE: method of continuous sublimation drying consists in forming granules and freezing granules of capillary porous material in vacuum, additional drying of material in field of infra-red radiation; granules with partially dried outer surfaces form layer of granules moving downwards which are subjected to continuous radiation in upper portion of layer by microwave field; layer of material being dried is blown by inert gas flow, for example, argon; residual pressure above upper surface of layer is maintained according to saturation temperature of sublimable vapors equal to minimum freezing temperature; in layer of one third of height from upper surface does not exceed cryoscopic temperature of product; temperature on lower surface of layer of material being dried is set in flow of inert gas not above temperature reducing its biological activity by performance at residual pressure of water vapor corresponding to cryostatic temperature of material freezing; when granules are moving inlayer, difference in change of pressure of water vapor between upper and lower surfaces of layer is maintained constant in the course of continuous drying of material. EFFECT: intensification of continuous sublimation drying process in vacuum at retained high quality of final product. 2 dwg