Rotary evaporators, also known as “rotovaps,” are devices that are used to remove solvents from a solution via the process of evaporation. This leaves behind desired precipitates (extracts) that can be collected and further refined if necessary.
Rotary evaporation is widely used in solvent extraction and is one of the most popular solvent evaporation methods due to its optimal extraction and performance.
But how does it work?
How Does a Rotary Evaporator Work?
To understand how a rotary evaporator works we must first offer a few words on solvent extraction, which is also known as liquid-liquid extraction.
Liquid-liquid extraction is a method used to separate materials, taking advantage of relative solubility by using two different solvents – typically water and another nonpolar organic compound.
The desired compound flows from one solvent to the other due to differences in chemical potential, but once the extract is concentrated in the solute, that solvent must then be removed to recover the pure extract.
This is the point at which evaporation recovery methods are used – such as rotary evaporation.
Rotary evaporation takes advantage of the fact that different liquid solvents have different boiling points, which diminish under decreased pressure.
The evaporator itself consists of several highly specialized parts; including two flasks, a receiving (collecting) flask as well as a “rotary evaporation” flask, a drive motor, a heating water bath, a vacuum pump inlet, and a condenser.
The rotovap contains a vacuum pump that lowers the pressure within the system while the rotary flask spins over or in the heating bath, increasing the surface area of the solvent inside of the flask and speeding up its evaporation. As the rotary evaporation flask rotates, it is heated evenly by the heating bath which rapidly boils away the solvent.
This leaves the extract behind in the rotary flask, and as the solvent boils away, it rises into the condenser, on the sides of which it cools. As the solvent cools on the sides of the condensers it drips down into the receiving flask, which collects it so it can be recovered for further liquid extraction.
The extract and solvent can both be recovered from the two flasks. Rotary evaporation is fast and efficient and offers significant benefits over other extraction and solvent recovery methods.
Are There Benefits to Rotary Evaporation?
Rotary evaporation is used for extract and solvent recovery for numerous reasons, such as the fact that the process requires relatively low energy consumption, is fast and efficient, and has a large production capacity.
Rotary evaporation removes solvents much more quickly than can be accomplished under atmospheric pressure, and equally important is the fact that rotovaps are generally easy to use.
They are also less likely to cause thermal decomposition of the extract than other types of evaporators since they use lower temperatures, thanks to the fact that they contain a vacuum system that lowers the boiling point of the solution in the flask.
Rotary evaporation systems are also beneficial because the process can be largely automated and involves less manual involvement on behalf of the attendant technician.
All in all, this makes rotary evaporation highly efficient and cost-effective while yielding high-quality results and effective solvent recovery.
Where Can You Get Rotary Evaporators and Parts?
Using high-quality rotary evaporators and parts and maintaining your facility’s systems is tantamount to recovering high-quality extracts. For those looking for high-quality rotary evaporators and parts, HiTechTrader (HiTechTrader.com) has it all.
They carry a wide range of rotovaps from Buchi as well as rototherms and a wide range of evaporator parts including but not limited to glassware, centrifuges, pumps, vacuums, and vapor ducts.
Visit their website via the link above or contact them directly at Sales@HiTechTrader.com or at 609-518-9100.
