According to the heating method, the dryer is divided into convection, conduction, radiation, dielectric and other types.

Answer:

The electromagnetic field of the wet material is selectively absorbed and converted into heat for drying. The dielectric dryer is used to dry the inside of the wet material by the action of the high frequency electric field.

This type of dryer does not use dry media, high thermal efficiency, the product is not contaminated, but the drying capacity by the metal wall heat transfer area constraints, the structure is more complex, often under vacuum operation; radiation dryer is the use of a variety of radiation

The heat is transferred from the heat source through the metal wall to the wet material, and the resulting wet steam can be removed by means of reduced pressure suction, passing a small amount of purge gas or condensing it on a separately provided low temperature condenser surface.

Convection dryer, also known as direct dryer, is the use of hot dry media and wet material in direct contact with convection way to transfer heat, and the generated steam away; Conductive dryer, also known as indirect dryer, which uses conduction