There are four parts in the whole rotary evaporator equipment – condensing part、evaporation part、vacuum pump、receiving part. Each of them is in charge of different work. Following are the parts of rotary evaporator and their functions :
1. In the evaporation part, evaporation flask rotates in a constant speed to facilitate evaporation by enlarging evaporation area.
2. Vacuum pump removes gas from the sealed equipment to leave behind a partial vacuum, in order to create a continuous feed system and keep the purity of extracted solvents.
3. Condensing part cools the equipment and turns extracted solvents from gas into liquid.
4. Then the solvents liquid goes into receiving flask for users to get.
How does a rotary evaporator work?
In the diagram above, you can see some of the components that make up your typical rotary evaporator. While the specific layout and functionality may change from product to product, the general concept does not.
- A water bath (or other liquid) is heated.
- A rotary flask (containing both solvent and sample combined) is lowered into the bath and partially submerged. (Note: We recommend borosilicate glass for its ability to withstand both extreme temperatures and solvents)
- Pressure is reduced in the air-tight system via a vacuum. This also prevents volatile vapors from escaping into the air and creating a potentially hazardous situation.
- A motor rotates the flask at a set speed, while precisely regulating the temperature of the bath.
- The temperature of the bath is set just high enough to evaporate the solvent while leaving behind the sample. (Note: The water bath prevents the sample from burning/combusting during this process!)
- The heated solvent vaporizes and travels upwards through the glass and into the condenser.
- The condenser has a self-contained, chilled fluid running through it in a spiral pattern, maximizing surface area. The cooling occurs via a connected chiller.
- When the heated solvent vapors come into contact with the cooled glass of the condenser, they condense, returning to liquid form.
- Gravity once again takes hold of the pure, condensed solvent, dripping it into the collecting flask (or receiving flask).
- The sample is left behind in the rotary flask, and the pure solvent has now been separated into the receiving flask. In most cases, the solvent is so pure that it can be re-used several times!