Microwave vacuum drying technology

Vacuum drying, also known as analytical drying, is a drying method in which the material is placed under a negative pressure condition, and the boiling point under a negative pressure state is appropriately heated or the material is solidified and then dried by a melting point by cooling.

The boiling point of the melting point in the material under the negative pressure state decreases with the increase of the vacuum degree. At the same time, the vacuum pump gap is used to reduce the water vapor content, so that the water and other solutions in the material can get enough kinetic energy to leave the surface of the material. Vacuum drying Because the air is isolated under the negative pressure condition, the chemically changed materials which are easily oxidized during the drying process can better maintain the original characteristics, and the material can be better protected by vacuuming after injecting the inert gas. Common vacuum drying equipments include vacuum drying ovens, continuous vacuum drying equipment, and the like.

Characteristics of vacuum drying: The process of vacuum drying oven is to place the dry material in a closed drying chamber, and vacuum the vacuum system to continuously heat the material to be dried, so that the moisture inside the material is poorly diffused to the surface by pressure difference or concentration. The water molecules obtain sufficient kinetic energy on the surface of the material to escape the low pressure space of the vacuum chamber after overcoming the mutual attraction between the molecules, thereby being evacuated by the vacuum pump.

In the vacuum drying process, the pressure in the drying chamber is always lower than the atmospheric pressure, the number of gas molecules is small, the density is low, and the oxygen content is low, so that materials which are easily oxidized and deteriorated, and flammable and explosive dangerous goods can be dried. It can play a certain role in disinfection and sterilization of medicines, foods and biological products, which can reduce the chance of material contamination or inhibit the growth of certain bacteria. Because the temperature of water during vaporization is proportional to the vapor pressure. Therefore, the moisture in the material can be vaporized at a low temperature during vacuum drying, and low-temperature drying can be achieved. This is advantageous for the drying of heat sensitive materials in certain pharmaceuticals, foods and agricultural by-products.