Airless drying : its invention, method and applications : Techno-economic analysis

The first airless drying patnet application number GB 8726456 was filed on 12.11.87 under the title Method and apparatus for energy efficient drying. The aim of the invention is, by replacing drying achieved partly or wholly by the passage of heated air through a dryer with drying achieved by recirculation within the dryer of superheated atmospheric pressure steam generated from the moisture in the material being dried, to enable the thermal energy used for drying to be recovered at a useful temperature, i.e. at >100 o C, by condensing the steam vented from the dryer and at the same time to recover that steam as distilled water, while compressing the vented steam prior to condensation can enable its latent energy to be recovered at <100 o C