Rotary evaporators are primarily used to continuously distill large amounts of volatile solvents under reduced pressure. In particular, the concentration of the extract and the distillation of the receiving liquid in the chromatographic separation can separate and purify the reaction product. The basic principle of a rotary evaporator is vacuum distillation, that is, under reduced pressure, the distillation flask is continuously rotated as the solvent is distilled. Structure: The distillation flask is a pear or round bottom flask with a standard ground port, connected to a pressure reducing pump via a highly refluxing serpentine condenser, and the other opening of the reflux condenser is connected to a receiving flask with a grinding port. It is used to receive the evaporated organic solvent. There is a three-way piston between the condensing tube and the decompression pump. When the system is connected to the atmosphere, the distillation flask and the liquid-receiving flask can be removed and the solvent is transferred. When the system is connected with the decompression pump, the system should be reduced. Pressure state. When using, depressurize first, then start the motor to rotate the distillation flask. At the end, stop the machine and then pass the atmosphere to prevent the distillation flask from falling off during rotation. As a heat source for distillation, it is often equipped with a corresponding constant temperature water tank.
(1) Rotary evaporator use method:
1. Height adjustment: manually lift and turn the hand wheel above the machine column, and turn it to rise and reverse to decrease. Electric lift, the hand touches the rise button and the main unit rises, and the hand touches the down button to lower the main unit.
2. There are two external joints on the condenser for connecting the cooling water. One end is connected to the water and the other end is connected to the water. Generally, the tap water is connected. The lower the condensed water temperature, the better the effect. The upper port is equipped with a vacuum connector and the vacuum pump is connected. The tube is used for vacuuming.
3. Turn the speed control knob to the minimum before starting the machine, press the power switch indicator light, then slowly turn to the right to the required speed. Generally, the large evaporation bottle uses medium, low speed, high viscosity solution with lower speed. The flask is a standard interface No. 24, and is supplied with two flasks of 500 ml and 1000 ml, and the amount of the solution is generally not more than 50%.
(B) Rotary evaporator notes:
1. The glass parts should be handled gently and gently, and should be washed, dried or dried before installation.
2, each grinding mouth, sealing surface sealing ring and joints need to be coated with a layer of vacuum grease before installation.
3. The heating tank must be filled with water before it is energized. It is not allowed to dry without water.
4. RE-52B must be screwed into the fuse hole (19) to avoid damage to the flask.
5, if the vacuum can not be pumped up to check.
(1) Whether the joints are sealed or not.
(2) Sealing ring, whether the sealing surface is effective.
(3) Whether the vacuum grease between the main shaft and the seal ring is coated.
(4) Whether the vacuum pump and its hose are leaking.
(5) Whether the glass piece has cracks, chipping or damage