1. Maintenance of vacuum freeze dryer in use:
The surface area of the sample shall be expanded as much as possible, and it shall not contain acid-base substances and volatile organic solvents. The sample must be completely frozen into ice. If there is residual liquid, it will cause gasification jet. Note that the cold trap is about minus 65 degrees, which can be used as a low-temperature refrigerator, but you must wear insulating 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 well sealed. Generally, the machine shall not be used continuously for more than 48 hours.
During the freezing process, the temperature of the sample gradually decreases. The sample can be taken out and warmed up for a period of time (still in the frozen state) and continue to dry to shorten the drying time. Liquid crystal display, Chinese interface, with sample drying curve. After the imported compressor is additionally provided with a heat exchanger, the refrigerating capacity is increased and the water catching capacity is improved.
Large cold trap opening, no inner coil, with sample pre freezing function. The precooling frame can be used as a guide barrel to speed up the drying speed. The cold trap and operating 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, ordinary sample tray with adjustable spacing. Novel design, small volume, convenient operation, reducing the occupation of laboratory table. Optional nitrogen charging valve.
2. Maintenance of vacuum freeze-drying machine when it is switched on and off:
Turn on the main power switch on the left side of the vacuum freeze-drying machine cabinet, and the air pressure digital display is atmospheric pressure 110pk. Press and hold the general switch key on the control panel for more than three seconds, and the temperature digital display is the actual temperature of the cold well. 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 air pressure values.
Record the temperature and air pressure before the shutdown of vacuum freeze-drying machine. 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 water outlet valve on the left side of the chassis to drain water, clean the inner wall of the cold trap with a dry cloth, and cover a large piece of filter paper to prevent dust.
