What preparations should be made for the freeze dryer before operation

* when using the freeze dryer for several times, all parts of the instrument must be thoroughly cleaned, stainless steel parts shall be cleaned with ethanol, and plexiglass shall be cleaned with normal saline The ampoules were cleaned by ultrasonic cleaning machine
Before freeze-drying, pre freezing must be carried out If you want to move, you need to prepare a low-temperature refrigerator, a low-temperature refrigerator at minus 40 degrees Celsius, or a low-temperature refrigerator at minus 80 degrees Celsius It usually takes about four hours to place the items to be dried in a low-temperature refrigerator or liquid nitrogen It can be observed directly from the outside After the items are completely frozen and firm, you can carry out freeze-drying experiments and put the items Quickly move into the freeze dryer tray to ensure the freeze-drying effect The main engine and the vacuum pump are connected by a green vacuum pipe, and the international standard clamp is used for the connection In order to effectively prevent air leakage, a rubber sealing ring is designed in the clamp In the method of preventing air leakage, apply a proper amount of vacuum grease on the rubber ring, and then clamp it with a clamp, so that the joint can be more closely fitted together If the clamp is not tightened, it will cause air leakage, which will cause the digital display value of the instrument panel to be greater than 20Pa when vacuuming At this time, the air tightness of the vacuum pump and the glass cover of the freeze dryer should be checked There are two power sockets on the right side of the main unit of the freeze dryer One is to connect the power line of the vacuum pump to the main unit, and then plug the main power supply on the second freeze dryer into the power supply Check whether the vacuum pump oil is added before the operation of the vacuum pump, otherwise it cannot operate normally The oil level shall not be lower than the center line of the oil mirror When the vacuum pump is used at the beginning, it will shake strongly and become stable slowly If the air tightness is not good, some vacuum grease should be applied to the sealing rubber ring above the cold trap, and the plexiglass cover should be lightly screwed on the rubber ring, and the air tightness should be tested when the vacuum pump is opened To ensure the integrity of the gas seal.