Considering the space occupied by the gap between the round bottles, the actual occupied area is larger than the above calculated area, which can be roughly divided by the previous coefficient of 0.9. That is: 0.38 ÷ 0.9 = 0.42 m2。 The freeze-drying machine with 0.42 ~ 0.5 square meters of plate area can be selected. Then calculate the water content. In addition, what the user needs to freeze dry is a vial of penicillin, which needs the function of tamping.

According to these information, the model can be selected. The freeze-drying area of this model is 0.5 square meters, the freezing capacity is 10kg, and it has the function of hydraulic pressure plug, which fully meets the needs of users. The selection of refrigerants is prohibited or restricted because some Freon refrigerants can destroy the ozone layer. At present, most brands have used refrigerants that do not contain fluorine and do not destroy ozone to produce freeze-drying machines. The key manufacturing process and parts of freeze-drying machine the design and manufacturing process of freeze-drying machine and the selection of parts are directly related to the quality, reliability and service life of freeze-drying machine.

In order to make the cooling and heating temperature of the plate layer uniform, most of the freeze-drying machine manufacturers use hollow sandwich plate layer with internal spacer, which is circulated in the plate layer by the intermediate fluid of temperature transfer. The old or backward manufacturing method is to make holes on the upper and lower plates or one of the plates, weld the metal plate and the spacer by plug welding, and then machine them. Due to the special working conditions of low temperature, vacuum, even high temperature and pressure of freeze-drying process, this kind of welding method may leak temperature transfer fluid at the plug weld after a certain period of service. In the vacuum state, the temperature transfer fluid atomizes instantaneously, causing the freeze-dried products to be polluted and scrapped. The new or advanced manufacturing method is that the upper and lower metal plates are not perforated, and are made by using special internal welding equipment, which fundamentally eliminates the occurrence of leakage.