Key operating points of medicinal small freeze-drying machine:

1、 Preparation before use

-Equipment inspection:Check if there are any signs of damage or deformation on the main unit, drying chamber, drying rack, and other components of the freeze-drying machine. Check the oil level and quality of the vacuum pump. If the oil level is insufficient or the oil quality is turbid, it is necessary to add or replace the special oil in a timely manner.

-Cleaning equipment:Use a neutral cleaner to wipe the interior, shelves, condenser tubes, and other parts of the freeze-drying machine to remove impurities and pollutants left over from the last use.

-Material preparation:Evenly distribute the materials to be freeze-dried into shallow petri dishes or specialized freeze-drying bottles, with a liquid level thickness not exceeding 1.5cm, to ensure uniform heat transfer. For high sugar and high protein materials, protective agents (such as seaweed sugar) should be added to prevent collapse during the freeze-drying process.

2、 Operation process

-Pre freezing operation:Turn on the refrigeration machine and wait for the temperature of the cold trap to drop below -40 ℃. Place the packaged materials into the cold trap for pre freezing until they are completely solidified, avoiding direct placement in the freeze dryer that may cause excessive ice crystals and damage to the cell structure. The pre freezing time is generally 2-4 hours, depending on the characteristics of the material.

-Vacuum drying:Quickly transfer the pre frozen material to the drying rack and cover it with a transparent freeze-drying cover to ensure sealing. Turn on the vacuum pump and observe if the vacuum level can reach below 50Pa. Maintain a cold trap temperature of -50 ℃ and a vacuum degree of 10-30Pa for 12-24 hours (adjusted according to material thickness), during which more than 90% of the upstream free water is removed.

-Analyze drying:Gradually increase the shelf temperature to 25-30 ℃, maintain a vacuum degree of 5-10Pa, and continue for 4-8 hours. Monitor the surface temperature of materials through infrared thermometers to avoid overheating and deactivation of active ingredients.

-Dry termination judgment:Observe that there is no new frost formation in the cold trap, the material temperature is approaching the shelf temperature, and the vacuum degree is stable without fluctuations.

3、 Maintenance and upkeep

-Daily maintenance:After each use, promptly clean the residual materials and condensed water in the drying chamber to keep the interior of the drying chamber clean. Regularly check the oil level and quality of the vacuum pump oil. When the oil level is below the minimum mark or the oil quality becomes dirty or emulsified, the vacuum pump oil should be replaced in a timely manner.

-Regular maintenance:Every 500-1000 hours of operation, conduct a comprehensive inspection of the refrigeration system to check if the refrigerant pressure is normal and if there are any leaks. Test the sealing performance of the vacuum system and replace worn seals. Check whether the connections of various components in the electrical control system are loose, calibrate temperature, vacuum and other sensors to ensure the accuracy of equipment operating parameters.