With the continuous development of the industry, the requirements for the drying of raw materials are also improved. Most of the atmospheric drying equipments that are closed and close to the closed type are designed as vacuum dryers because vacuum dryers have low drying temperature and high drying rate. A series of advantages such as energy saving, equipment sealing and pollution prevention.
At present, vacuum dryers have been widely used in various industries. After drying the equipment, it can not only eliminate the surface hardening phenomenon which is easy to occur under normal pressure and drying conditions, but also achieve the purpose of sterilization. Mainly because the pressure difference between the inside and the surface of the vacuum drying material is large, under the pressure gradient, the moisture quickly moves to the surface without surface hardening.
Moreover, the vacuum dryer uses vacuum gas, and most of the bacteria in the air can be pumped away with the air, and some of the remaining bacteria will also die or lack vitality due to lack of oxygen, so after drying by the vacuum dryer The sterilization effect is also obvious.
Secondly, the dehumidifying and drying system of the vacuum dryer can achieve low-temperature drying. Since the temperature and pressure of the water are proportional to the vaporization process, low-temperature drying can be achieved at low pressure, and the drying and recovery solvents for foods and agricultural by-products and organic solvent-containing materials are very favorable.
In addition, the vacuum dryer is easier to diversify the product than other drying equipment. Taking food drying as an example, the product can be foamed by controlling the degree of vacuum, thereby producing foods such as embrittlement and instant dissolution, thereby realizing diversification of the enterprise. development Goals.
In addition, vacuum drying has a low drying temperature, relatively low oxygen in the drying chamber, avoids a series of advantages such as fat oxidation and pigment browning, so it is suitable for drying of heat sensitive food materials; plus its cost and drying The cost is relatively low, so it has become an indispensable important production equipment for the plastic food industry.