Vacuum freeze dryers are very common in daily life, but many people are not very clear about how to use vacuum freeze dryers, and do not know the precautions of vacuum freeze dryers. Let’s go to a more comprehensive understanding of vacuum. Freeze dryer. First of all, let's take a look at the use of the vacuum freeze dryer:
1. Turn on the main power switch on the left side of the vacuum freeze dryer chassis, and the air pressure digitally displays the atmospheric pressure 110pk;
2. Press and hold the total switch key on the control panel of the vacuum freeze dryer for more than three seconds, the temperature will be displayed as the actual temperature of the cold trap;
3. Start the refrigerator of Xianou vacuum freeze dryer, pre-cooling for more than 30 minutes;
4. Put the sample into the sample rack, cover the plexiglass cover, and start the vacuum pump;
5 After the air pressure of the vacuum freeze dryer is stable, record the temperature and air pressure.
6. Record the temperature and air pressure values before shutdown;
7. Press and hold the inflation valve on the control panel of the vacuum freeze dryer, and immediately turn off the vacuum pump;
8. When the air pressure is displayed as atmospheric pressure, open the plexiglass cover and take out the sample;
9. Turn off the refrigerator of the vacuum freeze dryer, press and hold the main switch for more than three seconds, and finally turn off the main power switch;
10. After the ice in the cold trap is completely melted into water, open the water outlet valve on the left side of the case to drain the water, and clean the inner wall of the cold trap with a dry cloth, and cover with a large piece of filter paper to prevent dust.
After understanding how the vacuum freeze dryer is used, we will follow the project of Xinshengde Import and Export Co., Ltd. to see what needs to be paid attention to in daily life.
1. The surface area of samples should be expanded as much as possible to prepare samples with a vacuum freeze dryer, which must not contain acid-base substances and volatile organic solvents;
2. The product must be completely frozen into ice, if there is residual liquid, it will cause vaporization and ejection;
3. Note that the cold trap of the vacuum freeze dryer is about minus 65 degrees, which can be used as a low-temperature refrigerator, but it must be operated with insulation gloves to prevent frostbite;
4. Before starting the vacuum pump, check whether the water outlet valve is tightened, whether the inflation valve is closed, and whether the contact surface between the plexiglass cover and the rubber ring is clean and free of dirt and well sealed;
5. Under normal circumstances, the vacuum freeze dryer shall not be used continuously for more than 48 hours;
6. During the freezing process of the sample, the temperature gradually decreases. You can take the sample out to warm up for a period of time and continue to dry to shorten the drying time.