How to maintain vacuum freeze dryer

1. Maintenance of vacuum freeze dryer in use

The surface area of the sample should be expanded as much as possible, and it should not contain acid-base substances and volatile organic solvents. The sample must be vaporized completely, and the sample must be frozen completely. Note that the cold trap is about 65 degrees below zero, which can be used as a low-temperature refrigerator, but you must wear insulation gloves to prevent frostbite. 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, free of dirt and good sealing. In general, the machine should not be used continuously for more than 48 hours. During the freezing process, the temperature of the sample gradually decreases. After the sample is taken out and warmed for a period of time (still in the frozen state), the sample can be dried continuously to shorten the drying time. Liquid crystal display, Chinese interface, with sample drying curve. After the imported compressor is equipped with heat exchanger, the cooling capacity is increased and the water catching capacity is improved. The cold trap has large opening, no inner tube and sample pre freezing function. The precooling frame can be used as a guide barrel to speed up the drying process. The cold trap and operation surface are all stainless steel, corrosion resistant, easy to clean, transparent bell cover. Transparent bell type drying chamber, safe and intuitive. Stainless steel sample rack, common sample disk spacing adjustable. It has the advantages of novel design, small volume, convenient operation and reducing the occupation of laboratory table. Nitrogen charging valve is optional.

2. Maintenance of vacuum freeze drying machine

Turn on the main power switch on the left side of the vacuum freeze-drying machine case, and the air pressure digital display is atmospheric pressure 110pk. Press and hold the total on key on the control panel for more than three seconds, and the temperature number shows the actual temperature of the cold trap. Start the refrigerator and precooling for more than 30 minutes. Put the sample into the sample rack, cover the plexiglass cover, and start the vacuum pump. After the air pressure digital display is stable, record the temperature and pressure values. Record the temperature and air pressure before the vacuum freeze-drying machine stops. Press and hold the charging valve on the control panel and turn off the vacuum pump immediately. When the air pressure digital display is atmospheric pressure, open the plexiglass cover and take out the sample. Turn off the refrigerator, press and hold the main on key for more than three seconds, and finally turn off the main power switch. After the ice in the cold trap is completely turned into water, open the outlet valve on the left side of the cabinet 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.