Dachang vacuum drying equipment is to be placed in a closed drying drying chamber, vacuum system vacuum and the dry material is continuously heated, so that the material inside the water by a pressure difference or differential concentration diffusion to the surface, the water molecules in the surface of the material to obtain sufficient kinetic energy, in overcoming the intermolecular attraction, escape into the vacuum chamber to the low pressure space, thereby pumped out by the vacuum pump process. Vacuum drying can easily recover useful and harmful substance, and can achieve good sealing performance. From environmental protection sense, have person for " green dry vacuum drying ".

In a vacuum, material moisture, lower boiling point of vaporization process is accelerated, so it is especially suitable for temperature sensitive and easily decomposable material. Vacuum drying mainly in low vacuum region. The moisture content of grain in the vaporization process, its boiling temperature and the ambient pressure is proportional to, the high moisture grain is placed in a closed in the drying cylinder, so that the drying cylinder to form and maintain certain vacuum degree, while the drying cylinder food is continuously heated, so that the grain interior through the water pressure difference diffusion to the surface, after vaporization pumped out by the vacuum pump, vacuum low temperature continuous high moisture grain drying. Vacuum drying moisture evaporation temperature decreased from 100 ℃to 40℃, the evaporation temperature is lower than the starch gelatinization temperature, not on food grain damage. Avoid food grain expansion and cracking, can guarantee the grain after drying the product quality. Ensure the material after drying the original color, flavor and taste, nutrition, quality basically unchanged, is the true sense of the low temperature drying, hot air drying under low temperature and a completely different. Especially for auto parts and pieces of metal processing after cleaning, use ( Dachang vacuum drying, dehumidifying machine ), can quickly dry parts surface and internal screw hole ( oil ) and difficult to remove moisture place, use the effect of good

Dachang vacuum freeze drying (vacuumfreezedrying ) technology is that the material is first frozen, then under vacuum conditions temperature, to reach the final purpose of ice sublimation drying. The heating infrared heating, microwave heating, the heat is fast making ice sublimation, also can make product surface damage. Vacuum freeze drying technology can keep the product the original color, flavor and taste, shape and nutrients, especially on the thermosensitive material drying, green food production is a promising method for drying.