Patent ID: 6546646
Filing Date: 2003-04-15
Classification: F26B

Abstract:
A process for removing moisture from a material without substantially spoiling the material, said process comprising:(a) subjecting the material to a controlled humidity environment, said environment being at a temperature and partial vapour pressure of water which do not spoil the material, and, in which the partial vapour pressure of water of said environment is substantially below saturation; (b) selectively and differentially irradiating at least one selected area of the material, the at least one selected area being less than the entire area of the material, without substantially irradiating a non-selected portion of the material, the selective and differential irradiation being in the environment with an amount of microwave irradiation effective to increase the moisture at the surface of the material whereby the partial vapour pressure of water at the surface of the material is greater than the partial vapour pressure of water of the environment whereby moisture is transferred from the surface to the environment, wherein the amount of said microwave irradiation and the selected area which is irradiated do not spoil the material; and (c) maintaining (i) the temperature of the environment, and, (ii) the partial vapour pressure of water of said environment substantially below saturation, whereby the material is not spoiled during step (b); said amount of microwave irradiation being sufficient to substantially maintain said vapour pressure at the surface of the material, until a required amount of moisture has been removed from said material, without substantially reducing the surface temperature of the material and being sufficient to maintain the surface temperature of the material at substantially the same temperature as the dry bulb temperature of the environment.