But many people are not very clear about the specific use of vacuum freeze-drying machine, the matters needing attention for vacuum freeze-drying machine is not very understanding, let's go to a more comprehensive understanding of vacuum freeze-drying machine. Shou first let's look at the use method of vacuum freeze dryer:
1. Open the general power switch on the left side of the case of vacuum freeze dryer, and the air pressure digital display is atmospheric pressure 110pk;
2. Press and hold the total opening key on the control panel of the vacuum freeze dryer for more than three seconds, and the temperature number shows the actual temperature of the cold trap;
3. Start the qianou vacuum freeze-dryer refrigerator and pre-cool it for more than 30 minutes;
4. Put the sample into the sample rack, cover it with plexiglass, and start the vacuum pump;
After the pressure display of the vacuum freeze dryer is stabilized, record the temperature and pressure values.
6. Record the temperature and air pressure before shutdown;
7. Press the air charging valve on the control panel of the vacuum freeze dryer, and immediately shut down the vacuum pump;
8. When atmospheric pressure is displayed digitally, open the plexiglass cover and take out the sample;
9. Turn off the refrigerator of the vacuum freeze-dryer, press the master switch for more than three seconds, and turn off the master power switch after zui;
10. After the ice in the cold trap completely turns into water, open the outlet valve on the left side of the case to drain 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.
After learning how to use a vacuum freeze dryer, let's get together in hangzhou to see what we need to pay attention to in our daily life.
1. The sample shall be prepared by vacuum freeze drying mechanism with the maximum surface area, which shall not contain acid-base substances or volatile organic solvents;
2, the product must be completely frozen into ice, if there is residual liquid will cause gasification jet;
3. Note that the cold trap of vacuum freeze dryer is about -65 ℃, which can be used as a low-temperature refrigerator. However, it must be operated with heat preservation gloves to prevent frostbite.
4. Before starting the vacuum pump, check whether the water outlet valve is tightened, whether the air charging valve is closed, whether the contact surface between the plexiglass cover and the rubber ring is clean and free of dirt and is well sealed;
5. In general, the vacuum freeze dryer shall not be used continuously for more than 48 hours;
6. During the freezing process, the temperature of the sample will gradually decrease. The sample can be taken out and warmed for a period of time before continuing to dry, so as to shorten the drying time.