Whether the drying process of the drying equipment belongs to the physical process

There are three main ways to remove moisture from a material: filtration, evaporation, and drying. Filtration is an effective method for separating solid particles contained in a suspension. Evaporation usually refers to the process in which a solution or a substance contains water which is vaporized and separated by heat. If the result of evaporation is only a change in the concentration of the substance, it is called concentration when it remains in a liquid state. If the purpose of evaporation is to remove moisture from the solid material, it is called drying. If the moisture is sublimed and removed in the solid state, it is called sublimation drying. The drying process of the drying equipment has no chemical changes and belongs to the physical process.
 

Drying is both the oldest unit operation and one of the most modern applications. At present, people's understanding of drying technology is still superficial. In many respects, there is still a situation of “knowing it but not knowing why”, especially the structure, properties and composition of the materials to be dried are different, it is difficult to find a scientific unity. Regularity also requires the constant efforts of science and technology workers to mature them in order to better serve humanity.
 

The purpose of drying is to reduce the quality of materials to facilitate transportation; reduce the moisture content of materials to facilitate long-term storage and storage; in some places, drying is a process requirement. For example, the drying of coal is a requirement for combustion, and the drying of minerals is a necessity for smelting. In human life, there is a large amount of heat energy, which is consumed in various drying processes. According to the statistics of industrialized countries, the energy consumption of the drying process accounts for about 15% of the total energy consumption of the national economy .
 

The use of drying technology is quite extensive. Drying technology is applied in many areas of the national economy. The main substances to be dried are: food, grain, fruits and vegetables, tea, Chinese medicine tablets and proprietary Chinese medicines, western medicine preparations, dairy products, biological materials, dyes, chemical fibers, Paper and pulp, wood and wood products, various polymers, coal, mines, etc. Due to the wide application of drying technology, people who study drying technology and equipment.