Original title: Precautions for use and maintenance of rotary evaporator Rotary evaporator is a kind of evaporation instrument widely used in laboratory. It is suitable for reflux operation, rapid evaporation of a large amount of solvents, concentration of trace components and reaction processes requiring stirring. The rotary evaporator system can be sealed and decompressed to 400 to 600 mm Hg; the solvent in the distillation flask is heated by a heating bath, and the heating temperature can be close to the boiling point of the solvent; at the same time, the rotary evaporator system can rotate at a speed of 50 to 160 revolutions per minute, so that the solvent forms a film and the evaporation area is increased. In addition, under the action of the high-efficiency cooler, the hot steam can be quickly liquefied and the evaporation rate can be accelerated. Usage of rotary evaporator: 1. Turn on the low temperature coolant circulation pump 。 Note that press the power button and then press the cooling button to start the cycle after the temperature is reduced to the required temperature. 2. Turn on the water pump to circulate water 。 3. Mount the distillation flask and secure with a clip 。 Turn on the vacuum pump and start to rotate when there is a certain vacuum. 4. Adjust the height of distillation flask , spin speed, and set that appropriate bath temperature. 5. Stop rotating after steaming ? Open the atmosphere again, then stop the water pump, and finally remove the distillation flask. 6 Stop the low-temperature cooling liquid circulating pump, stop the water bath for heating, turn off the circulating water of the water pump, pour out the solvent in the receiving bottle, and clean the buffer ball and the receiving bottle. Precautions for use of rotary evaporator: 1. When in use, a small vacuum should be pumped first. (About 0.03 MPa), and then start the rotation to prevent the distillation flask from falling off; when stopping, rotary vacuum evaporator ,thin film distillation, stop the rotation first, hold the distillation flask by hand, open the atmosphere, and stop the vacuum pump when the vacuum degree drops to about 0.04 MPa to prevent the distillation flask from falling off and sucking back. 2. Each interface ? Sealing surface, sealing ring and joint shall be coated with a layer of vacuum grease before installation. 3. Water must be added before the heating tank is powered on. ? Dry firing without water is not allowed. 4. If the vacuum degree is too low, pay attention to check the joints. Air tightness of vacuum tube and glass bottle. 5. During rotary evaporation of air-sensitive substances Connect a nitrogen balloon to the exhaust port, introduce a burst of nitrogen to discharge the air in the rotary evaporator, and then connect the sample bottle for rotary evaporation. After steaming, release nitrogen to boost the pressure, then turn off the pump, and then take down the sample bottle and seal it. 6. If the sample is very viscous ? Slow down the rotation speed and rotate slowly by hand to form a new liquid level to facilitate the evaporation of solvent. Maintenance method of rotary evaporator: 1. Carefully check the instrument before use to see whether the glass bottle is damaged and whether the interfaces are matched. Handle with care. 2. Wipe each interface with a soft cloth (napkin can be used instead), and then apply a little vacuum grease. Vacuum grease must be covered after use to prevent dust and sand from entering. 3. Each interface shall not be tightened too tightly, and shall be loosened and loosened regularly, so as to avoid seizure of the connector caused by long-term locking. 4. Turn on the power switch first, and then let the machine run from slow to fast. When the machine is stopped, the machine should be in a stop state, and then turn off the switch. 5. The Teflon switches at all places shall not be tightened with excessive force, which is easy to damage the glass. 6. After each use, all kinds of oil stains, stains and solvent residues left on the surface of the machine must be wiped with a soft cloth to keep them clean. 7. Loosen each PTFE switch after shutdown. The PTFE piston will be deformed if it is still in the working state for a long time. 8. Regularly clean the seal ring. The method is: take down the seal ring, check whether there is dirt on the shaft,wiped film evaporator, wipe it with a soft cloth, then apply a little vacuum grease, and reinstall it to keep the shaft and seal ring smooth. 9. The electrical part shall be free of water and moisture. Huagao Instrument returns to Sohu to see more Responsible Editor:. toptiontech.com