METHOD AND DEVICE FOR DRYING BULK CAPILLARY-POROUS MATERIALS

摘要

The invention relates to the vacuum drying of bulk materials. The method includes heating a material, loading said material into drying chambers, and carrying out heating and vacuum generation in cycles, i.e. heating the material in a flowing layer using a heat carrier with a temperature of up to 300°C until the material reaches a temperature lower than its decomposition temperature, and generating a vacuum with rapid pulsed vacuum action with an incremental single or repeated reduction in pressure within a range of from 0.1 MPa to 0.0001 MPa, and then maintaining the vacuum until the temperature of the material stabilizes. A device for implementing this method comprises two vacuum chambers with heaters disposed therein, a system for loading and unloading material, and one or several receivers with pumps connected in parallel thereto, said pumps being connected to the inlet of a drying chamber via a system of vacuum pipes. The vacuum drying chambers have a conical form at the base, which is connected to a heat carrier circulation system for heating or cooling material in a flowing layer, and are equipped with heated jackets. The vacuum line and the heat carrier circulation line are provided with heated cyclone filters and heat exchanger-condensers with condensate collectors. The invention makes it possible to reduce drying time and enhance the quality of the dried product.