in a counter-flow of the gas or vapour

Full Title

Drying solid materials or objects by processes involving the application of heat (in specific machines or apparatus F26B9/00 - F26B19/00) > by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air > the materials or objects to be dried being moved by gravity > in a counter-flow of the gas or vapour