Correct steps for stopping the refrigeration dryer

Freeze dryer is a technical method that freezes water containing items in advance, then sublimates their moisture in a vacuum state to obtain dry items.

Freeze dryer is a technical method that freezes water containing items in advance, then sublimates their moisture in a vacuum state to obtain dry items. Items that have undergone freeze-drying treatment are easy to preserve for a long time, and can be restored to their pre freeze-drying state and maintain their original biochemical characteristics after adding water.
Vacuum freeze-drying technology has extensive applications in fields such as bioengineering, pharmaceutical industry, food industry, materials science, and deep processing of agricultural and sideline products, and its scale and field are still expanding. Therefore, vacuum freeze-drying will undoubtedly become an important application technology in the 21st century.
A freeze dryer is composed of a refrigeration system, a vacuum system, a heating system, and an electrical instrument control system. The main components are drying oven, condenser, refrigeration unit, vacuum pump, heating/cooling device, etc. The refrigeration system is an important component of freeze-drying machines, known as the "heart of freeze-drying machines".
The refrigeration system mainly consists of the following components: compressor, refrigerant, oil separator, water condenser, drying filter, intercooler, sight glass, solenoid valve, hand valve (top cover valve), expansion valve, evaporator (plate type exchanger, rear box condensing coil), vapor liquid separator, return air filter, pressure gauge, pressure control relay, CPCE (energy regulator), safety valve, refrigeration pipeline, etc.
The correct steps for stopping the freeze dryer:
1. Record the temperature and air pressure values before shutdown;
2. Slowly press and hold the inflation valve switch of the freeze-drying machine, wait for the vacuum value to rise to around 100 and start turning off the vacuum pump;
3. When the pressure digital display shows atmospheric pressure, open the organic glass cover and take out the sample;
4. Turn off the refrigerator, press and hold the main power button for more than three seconds, and then turn off the main power switch;
5. After the ice in the cold trap has completely melted into water, open the water outlet valve on the left side of the chassis to drain the water, clean the inner wall of the cold trap with a dry cloth, and cover it with a large piece of filter paper to prevent dust.