Solar Drying

Abstract

Introduction The heat from the sun coupled with the wind has been used to dry food crops for preservation for several thousand years. Other crops such as timber need to be dried before they can be used effectively, in building for instance. This sun-drying has often developed into solar-drying, where the drying area is in an enclosed ventilated area – often with polythene, acrylic or glass covering as a more efficient harnessing of the elements of the drying operation. There are innumerable designs in use and each has its advantages and disadvantages. However, there are three basic designs upon which others are based: solar cabinet dryer, tent-dryer, and solar tunnel dryer. These are discussed below after a brief description of the principles of drying.