Vacuum drying process and arrangement

摘要

In drying process, the material to be dried is heated in a chamber (1) and subjected to a vacuum generated by a pump (5). The whole of the vapour removed from the material during the drying process is drawn out of the drying chamber without contact with another medium (1) by the vacuum pump (5), compressed by the pump, and returned for use as a medium to heat the raw material.Also claimed are a drying arrangement having a pressure-tight heated drying chamber connected to the inlet side of a vacuum pump, and the use of a screw-type vacuum pump to generate a vacuum in a drying chamber, to compress the vapour from the dryer, and to feed the compressed vapour back to the drying chamber as a medium to heat the raw material.