May 30

Do Rotary Evaporators Need Chillers?

Chillers and Rotary Evaporators work hand in hand. It is true that a rotary evaporator does not require a chiller, but for temperature accuracy and convenience purposes, a chiller provides an effective and cost-efficient cooling option. Sometimes tap water is used for cooling purposes, but the stability required for sensitive lab samples often makes the use of tap water chilling not viable.

What is a Rotary Evaporator?
A rotary evaporator, according to Wikipedia is “a device used in chemical laboratories for the efficient and gentle removal of solvents from samples by evaporation.” Often referred to as a rotovap, there are typically four major components: heat bath, rotor, condenser and solvent tray.

Why use a Rotary Evaporator?
A rotary evaporator is often utilized because it is the fastest and most efficient method to remove low boiling organic chemicals from a mixture of compounds. The rotovap works by employing three simple methods. The first is to increase the rate of evaporation of the solvent by reducing the pressure to lower the solvent boiling point. The second is to rotate the sample to increase the effective surface and the third to simply heat the solution. A rotovap will be found in most laboratories and research facilities.

What does a Chiller do for a Rotovap?
In the simplest of explanations, Rotovaps require cooling and ideally a recirculating chiller supplies that cooling. A chiller is used to ensure that the rotovap has sufficient cooling at the precise temperature. For the solvent to vaporize properly in the rotary evaporator, cooling must be added because during evaporation, the solvent evaporated is warm. Typically, a chiller will pump cool fluid (typically water or a water/glycol mixture) to the process to remove the heat and the warm fluid returns to the chiller.

Rotary Evaporator Chillers
Chillers for Rotary Evaporators must have a high cooling capacity because of the high temperature of the solvent vapor. It is not uncommon to find a chiller with a higher cooling capacity with a smaller temperature range, which for a rotary evaporator works perfectly. For example, the BV Thermal Systems MC050 chiller with a cooling capacity of 1702 watts @ 20°C and a temperature range of +5° to +30°C is better suited than the BV Thermal Systems low temperature MCLT050 with a cooling capacity of 425 watts @-20°C and a temperature range of -20° to +30°C.

Still need Assistance.
If you need assistance determining the correct size chiller to use with your Rotary Evaporator, the Sales Engineers at BV Thermal Systems are able to answer your questions. Just call 209-522-3701 or send an email to

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