How to operate the freeze dryer

Operation method of freeze dryer 1.
Turn on 2.
Prefreeze - put the sample tray into the prefreeze rack and place it in the cold trap, and the thermometer probe is placed on the upper sample tray and covered with a sealed cover
.
Tap the "Chiller" switch on the screen and prefreeze for 3 hours
.
3.
Replace the drying rack - after the prefreeze is over, take the sample tray out of the cold trap, quickly put it into the drying rack, place the drying rack above the cold trap, cover it with plexiglass cover, and the drying hood is in contact
with the lower end "O" sealing ring.
4.
Drying - check whether the inflation valve is tightened, click the screen "vacuum gauge", such as the vacuum degree is displayed as 110kPa, click "vacuum pump", the vacuum pump starts running, the vacuum degree drops rapidly, to below 20Pa is normal
.
5.
Dryness check - after a dry run for time, check the sample curve and visual sense that the sample has been dried, slowly unscrew the inflation valve, and make the pressure in the freeze dryer rise back to 110kPa
.
Click "Vacuum pump" to turn off the vacuum pump
.
Click "Vacuum gauge" to turn off the vacuum gauge
.
6.
End drying - remove the plexiglass cover and take out the sample tray
from the drying rack.
Click "Refrigerant" to turn off the compressor
.
7.
Finishing - after the moisture in the cold trap melts, it flows out of the inflation valve, pay attention to reception
.
8.
After each use, be sure to record the use time, accumulate 300 hours, and change the oil
.
Precautions for freeze dryer: 1.
Do not frequently power switch during operation, if the refrigerator stops running due to incorrect operation, it cannot be turned on immediately, and it can be reopened after 20 minutes to avoid damage to the
refrigerator.
2.
After each freeze drying, after the ice on the cold trap coil turns into water, clean it with a hand towel and unscrew the "inflation valve" to inflate the cold trap with a hand towel, so as to avoid damaging the vacuum gauge
。 3.
The prepared sample should expand its surface area as much as possible, which should not contain acids and alkalis and volatile organic solvents; 4.
The sample must be frozen into ice, if there is residual liquid, it will cause vaporization spray; 5.
Note that the cold trap is about minus 65 degrees, which can be used as a low-temperature refrigerator, but be sure to wear thermal gloves to avoid frostbite; 6.
Before opening the vacuum pump, check whether the water valve is tightened, whether the inflation valve is closed, whether the contact surface between the plexiglass cover and the rubber ring is clean and dirt-free, and well sealed; 7.
Under normal circumstances, the equipment cannot be used continuously for more than 48 hours; 8.
During the freezing process of the sample, the temperature gradually decreases, and the sample can be taken out and warmed up for a period of time (still in a frozen state), and the air drying continues to shorten the air drying time
.