Development of industrial freezing dryer
Although the production of freeze-dryer in China has a history of more than 20 years, it can not meet the needs of the development of freeze-drying industry in terms of quality and specifications. Some enterprises and institutions have to spend foreign exchange to import freeze-dryer.
Without foreign exchange index units, they have to design and manufacture the freeze-dryer by themselves. The freeze-dryer is a collection of various sciences. It is difficult to manufacture a kind of equipment in our department, which makes these units expensive, long manufacturing cycle and difficult to guarantee quality.
In order to realize the localization of industrial freeze dryer, in 1986, the Technical Development Fund Committee of Mechanical and Electrical Machinery Industry of the Ministry of Machinery and Electricity issued a project for the development of industrial vacuum freeze dryer, which was jointly undertaken by Huazhong University of Technology and Zhejiang Vacuum Equipment Factory. After three years of research and development, it was identified by experts in April 1989. In order to meet the design requirements for the performance indicators of the machine, it has advanced domestic level. First, the technical performance indicators should reach or close to the level of similar products imported from abroad.
The special function of freeze-dryer is to make our self-developed freeze-dryer reach the international level in the 1980s. In the process of development, we absorb the advanced technology at home and abroad. According to the requirements of freeze-drying process, we adopt the following special functions. 1. Shelf spacing can be adjusted arbitrarily to suit users. It is not necessary to drag the shelf components out of the box to realize arbitrary adjustment. The maximum distance is 120m, and the minimum distance can be overlapped.
4. The heat transfer in the drying box with pressure regulating device is closely related to the pressure inside the box. When the vacuum is relatively high, the heat transfer mainly depends on conduction and radiation, and the sublimation surface temperature of the product is low. In order to enhance heat transfer, pressure regulating device can be used to properly increase the pressure inside the box and increase the heat of the product. Accelerate the process of sublimation.
1. Within the range of temperature used by freeze-dryer, the direction of refrigerant in the medium evaporator of freeze-dryer is generally dry evaporator. The evaporation temperature is lower and the refrigerant is R 22. The stratification of oil and R 2 will occur at low temperature . From the point of view of oil return, it should be considered as above. It is advantageous to enter and exit, but considering the liquid separation, area utilization ratio and preventing the liquid