A rotary evaporator is a laboratory device used for the gentle removal of solvents from samples by evaporation under reduced pressure. This process is especially useful for separating volatile substances from non-volatile compounds, concentrating solutions or solvent recovery.
How Does It Work?
The rotary evaporator works on three main principles:
- Reduction of pressure (via a vacuum) which lowers the solvent's boiling point.
- Rotation of the flask increases the liquid’s surface area, improving the rate of evaporation.
- Heating gently provides the energy needed for phase transition without degrading sensitive compounds.
The solvent evaporates from the sample, rises into the condenser and then cools and collects in the receiving flask.
Components of a complete rotary evaporator system.
Rotary Evaporator & Glassware
Being BB-RE2A Automatic Lift 2L Rotary Evaporator
The main rotary evaporator unit consists of the following components:
- Evaporation flask: This flask contains the sample and is partially immersed in a heated water or oil bath.
- Motorised unit: Rotates the flask to increase surface area, for a faster evaporation rate.
- Heated bath: Maintains a constant temperature to gently warm the sample and is normally stainless steel coated for corrosion resistance.
- Collection flask: Collects the condensed solvent.
- Condenser: Cooled by either water from a tap or a recirculating chiller, the purpose of this part is to condenses the solvent vapour into the collection flask.
Vacuum Pump
Vacuubrand PC 3001 VARIO select vacuum pump
The vacuum pump reduces the boiling point of the solvent, allowing evaporation at lower temperatures. Chemistry diaphragm pumps are generally used in rotary evaporators as they are highly solvent resistant. The Vacuubrand PC 3001 & PC 3004 VARIO select vacuum pumps are an excellent choice, the VARIO technology automatically regulates the vacuum by adjusting the speed of the pump to optimise the process time (saving energy consumption and increases service life). The automatic evaporation mode on the controller detects the boiling point and adjusts the vacuum accordingly.
Chiller
Huber Minichiller 280 OLÉ
The condenser part on the rotary evaporator requires cooling in order to condense the evaporated solvent vapour. Typically, this is done by using circulated tap water or a recirculatory chiller. Using a chiller is beneficial as they save you water, are more cost effective long term and easy to use. The Huber Minichiller range are suitable option and they use natural refrigerant gases, helping labs become more sustainable.
How can Be Scientific help you?
Be Scientific offer a range of different capacity rotary evaporators manufactured by Being Scientific to suit users applications. From our 2L & 5L benchtop models with a choice of manual or automatic lift mechanism to the larger scale units starting from 10L up to 50L capacity. We also offer accompanying vacuum pumps and chillers to offer a complete solution.
Explore our range of rotary evaporators on our website or get in touch with one of our equipment experts to discuss your application requirements. (https://www.bescientific.co.uk/products/rotary-evaporators.html)