The principle and function of dryer
Issuing time:2017-11-10 13:37
Drying machine is a kind of mechanical equipment to reduce the moisture of materials by using heat energy. It is used for drying the objects. Drying machine through heating to make the wet content of the material (generally refers to water or other volatile liquid components) vaporized to escape, in order to obtain a specified wet content of solid materials. The purpose of drying is for material use or further processing needs. For example, the drying of wood before making wood mold and woodware can prevent deformation of products, and the drying of ceramic billet before calcination can prevent cracking of finished products. In addition, the dried material is also easy to transport and storage, such as drying the harvested grain to a certain wet content below, to prevent mildew. Because natural drying is far from meeting the needs of production development, various mechanized dryers are more and more widely used.
The drying process needs to consume a lot of heat energy, in order to save energy, some materials with high moisture content, suspension or solution containing solid matter are generally dehydrated or evaporated by mechanical heating, and then dried in the dryer to get dry solid.
In the drying process, heat and mass (wet fraction) should be transferred at the same time to ensure that the moisture vapor partial pressure (concentration) on the surface of the material is higher than the moisture vapor partial pressure (concentration) in the external space, and ensure that the heat source temperature is higher than the material temperature.
Heat from the high temperature heat source in a variety of ways to the wet material, so that the surface of the material wet vaporization and escape to the external space, so that there is a difference in the surface and interior of the material wet content. The internal moisture diffuses to the surface and vaporizes to reduce the moisture content of the material and gradually complete the drying of the whole material.