New type of microwave vacuum low temperature drying has been successfully applied to the drying of Chinese herbal pieces

Microwave drying technology is a drying method widely used in recent years. Its drying range covers almost all aspects of the national economy, such as wood, food, tea making, Chinese medicine, chemical industry, etc. today, Xiaobian will focus on the application of microwave vacuum low-temperature drying in Chinese medicine drinks.

Traditional Chinese medicine slices have strict requirements for drying. Too high a temperature will destroy the nutritional and pharmacological components in the medicinal materials. Generally, they will be dried in the sun or at low temperature. However, the traditional drying method can only be used for enterprises with relatively small output. The traditional drying process is not only slow and uneven, but also a little careless in the drying process will lead to pollution of traditional Chinese medicine. If these medicinal materials are not tested, they will flow into the market, It will have a great impact on the health of consumers.

Microwave vacuum low-temperature drying equipment is a new type of microwave energy application equipment that combines microwave energy technology and vacuum technology. It combines a series of advantages of microwave and vacuum drying, overcomes the shortcomings of conventional vacuum drying such as long cycle and low efficiency. In the drying process of general materials, it has the advantages of high drying output, good quality and low processing cost. Microwave vacuum low-temperature drying equipment is a technology integrating electronics, vacuum, mechanics As a high-tech product integrated with many disciplines such as thermodynamics and program control, it is a new technology and process developed on the basis of in-depth research on physical changes of substances, internal and external heat and mass exchange and moisture transfer process under vacuum conditions during drying. Microwave vacuum drying equipment is composed of microwave generator, vacuum drying chamber, material rotating disk, vacuum system and electronic control system.

In industrial production, many articles can not be dried under high temperature conditions, such as some drugs, chemicals, nutritional foods, and high-grade Chinese herbal medicines such as ginseng and velvet antler. In order to ensure product quality, the drying treatment must be carried out under the condition of less than 100 ℃ or room temperature. It is well known that the pressure decreases and the boiling point of water decreases. For example, under an atmospheric pressure (101.3 kPa), the boiling point of water is 100 ℃, The boiling point of water is 40 ℃ at 0.073 atmospheric pressure (7.37 kPa). Under the vacuum condition, heating the object can make the water inside the object evaporate without temperature rise. Since it is difficult to conduct air convection heat transfer under vacuum conditions, only relying on heat conduction to provide heat energy to materials. The conventional vacuum drying method has slow heat conduction speed and low efficiency, and it is difficult to control the temperature, and the heated materials will also produce internal and external temperature differences. Microwave heating is a kind of radiation heating, in which the microwave directly interacts with the object, so that its inside and outside are heated at the same time. It does not need to transfer heat through convection or conduction, so it has fast heating speed, high drying efficiency and high drying quality.

Lantai microwave has summarized a set of processes suitable for drying various pieces of herbal medicine after experimental drying. When the pieces of herbal medicine are dried by microwave vacuum low-temperature drying equipment, the microwave medicinal material dryer retains the effective pharmaceutical ingredients in Chinese medicinal materials to the maximum extent. Microwave can also kill various molds and insect eggs in the medicinal materials, and prevent mildew and insect borers during storage. All this is because: microwave heating is to make the object itself become a heater, which is called the overall heating method. It does not need the process of heat conduction, so it can achieve uniform heating in a short time. This feature can make the materials with poor heat conductivity heated and dried in a short time, improve the energy utilization rate, and make the size of the heating furnace smaller than that of the conventional heating furnace. At the same time, when the material is under the action of microwave electromagnetic field, the overall temperature of the material rises. At this time, due to the evaporation of water on the surface of the material, the surface temperature decreases; Thus creating a temperature gradient with high inside and low outside, and the direction of this gradient is exactly the same as the direction of water evaporation. Therefore, the efficiency is high and the effect is good!

Shanghai Lantai microwave equipment manufacturing Co., Ltd