How to define a hot air circulation oven in drying technology

In the production and life of human beings, it is often the case that a certain object needs to be removed from moisture. Such objects may be solid or liquid or gaseous. In most cases, the moisture content of an object is moisture, and sometimes it is other components such as inorganic acids, organic solvents, and the like. This process of removing moisture from an object is referred to as "dewetting." We divide the method of dehumidification into several categories according to the working principle, and drying is one of them.

In general, the process of dehumidifying by physical methods using a thermophysical hot air circulating oven is referred to as "drying." The utility model is characterized in that the phase change process such as volatilization, condensation and sublimation of the moisture in the material is separated from the object by heating, cooling, decompression or other energy transfer to achieve the purpose of dehumidification. Dehumidification methods that do not have this feature are generally not included in the scope of drying technology.

Some dehumidification means, such as liquids are heated and concentrated, although they are also characterized by thermophysical dehumidification, it is customary not to think that enrichment is a drying technique. With the development of the times, people have gradually incorporated some new dehumidification technologies that are not thermophysical methods into the field of drying technology, such as molecular sieves and supercritical fluid extraction. Therefore, the definition and scope of drying technology is a customary concept that is constantly expanding.

The drying equipment commonly used in the production of traditional industrial hot air circulating ovens mainly includes: box drying, tunnel drying, simple drying, drum drying, belt drying, tray drying, paddle drying, fluidized bed drying, and spraying. Bed drying, spray drying, air drying, vacuum freeze drying, solar drying, microwave and high frequency drying, infrared heat radiation drying, etc., and hot air circulation oven drying method. In addition, in various industries, such as grains, fruits and vegetables, wood, tea, dairy, Chinese herbal medicines and other industries, there are also proprietary drying technologies and equipment suitable for their own characteristics. These traditional drying technologies have a long history, mature and reliable, and have been widely used all over the world.

In recent years, a number of new drying technologies have emerged internationally. Representative examples include: pulse combustion drying, collision flow drying, impact through drying, sonic field drying, supercritical fluid drying, superheated steam drying, contact adsorption drying, and the like. These new technologies have some breakthroughs in mechanism compared to traditional drying technologies, but they still need to be improved in industrial applications. At present, these new drying technologies in China are still in the stage of preliminary research.