How can Sihuan freeze-drying pharmaceutical freeze-drying machine prevent the vacuum pressure from falling during use

Sihuan freeze-drying pharmaceutical freeze dryer is a freeze-drying device that freezes water-containing substances into a solid state, and then sublimates the water in it from a solid state to a gaseous state to remove water and preserve the substance
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Today we are going to talk about freeze drying technology
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Freeze-drying is a drying technology using the principle of sublimation.
It can quickly freeze the dried material at low temperature, and then in a suitable vacuum environment, the frozen water molecules are directly sublimated into a process of escaping water vapor
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The product usually obtained by freeze-drying is called lyophilisate, and this process is also called freeze-drying
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In the freeze-drying process, because the material is at a low temperature before drying, and the ice crystals are evenly distributed in the material, the condensation phenomenon will not occur due to dehydration during the sublimation process, and the foaming and oxidation of water vapor are avoided
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What is the reason why the vacuum pressure of the Sihuan freeze-drying pharmaceutical freeze-drying machine cannot be lowered during use? 1.
The pump temperature is too high
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It is likely that the pump casing or inner wall of the four-ring freeze-drying pharmaceutical freeze-drying machine pump is worn, and the motor rotor is pivoted, causing damage to both sides
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2.
What is wrong with the freeze-dried oil valve (1) The oil quantity is too small and the sealing is not strict
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(2) The oil is yellow-brown due to environmental pollution
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(3) The oil quantity is normal, the oil pipe is blocked, and there is no proper residual oil in the pump cavity
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3.
The air inlet filter of the freeze dryer is blocked
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The surface area of ​​samples in Sihuan freeze-drying pharmaceutical freeze dryer should be as large as possible, and should not contain acid-base substances and volatile organic solvents, and the samples must be completely frozen
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If there is residual liquid, it will cause a vaporizing jet
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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
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Before starting the vacuum pump, check whether the water outlet valve is tightened, 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
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Generally, the continuous use of the machine does not exceed 48 hours
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During the freezing process, the temperature of the sample is gradually reduced, the sample can be taken out and preheated for a period of time (still in the frozen state) and continue to dry to shorten the drying time
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