What is a rotary evaporator?
Published on November 23, 2023
What is a rotary evaporator
Lab device of rotary vacuum evaporator is a popular instrumental tool used for effective evaporation of liquid or its fractions under conditions of reduced pressure. Among the privileges that such possesses, the following can be emphasized:
- Providing uniform heating of the material that is being distilled;
- stimulating the active process of vaporization of liquid substances;
- guaranteed safety when working with flammable, intensely odorous and toxic components;
- adaptable to the gentle treatment of temperature-sensitive and foam-prone materials;
- high productivity and efficiency;
- time optimization of processes;
- cost minimization due to the possibility of solvent regeneration.
The mechanism of operation of the rotary evaporator, based on the use of vacuum distillation, includes the following key components:
- evaporation flask;
- electric motor;
- heating chamber;
- a return cooler with a vacuum relief valve;
- a tank for collecting vaporized materials.
The refrigeration system of the condenser and the vacuum or water pump are connected separately.
The first example of a laboratory rotary evaporator was introduced in the mid-twentieth century by a biochemist from the United States, Lehman Craig. In the beginning, chemists were a little skeptical, for the distillation was successfully carried out on the most basic of equipment. However, the benefits in labor and time savings were soon appreciated by the researchers. The device allowed evaporation to be carried out more efficiently, especially in the case of large volumes of solvents, and it required a minimum of manual work.
The apparatus underwent several modifications, including the introduction of a variety of additional improvements to improve ease of use. As a result, it has become highly sought after, and today it can be found in almost any research laboratory.
Modern versions of the apparatus are often equipped with additional features that help to increase productivity and simplify the workflow. These may include an electronic control unit and a display for precise control of flask rotation and heating.
How Does a Rotary Evaporator Work?
The fundamental principle behind the operation of the rotary evaporator is the use of a physical characteristic of liquids, namely the dependence of the boiling point on the external pressure. This means that by reducing the pressure in the reaction vessel, we can effectively reduce the temperature required to boil the working mixture. For example, normal ethanol at atmospheric pressure starts to boil at +78.4 °C, while at a pressure of 40 mmHg this process starts already at +19 °C.
The evaporation process in a rotary evaporator takes place in a special flask, which is subjected to rotational movement by an electric motor. Under the influence of rotation, the surface of the flask is evenly covered with a layer of liquid, creating a thin film. It is from this film that the vaporization process takes place. Due to the extensive surface area of the film, the rate of vaporization of the liquid is much higher compared to standard distillation devices.
Note that rotary evaporators have quite a few interesting advantages:
- Efficient evaporation.
- Ability to control the parameters.
- Energy savings.
- Increased productivity.
In summary, vacuum rotary evaporators are efficient and convenient devices that allow distillation and concentration of substances at minimum cost and maximum controllability of the process.
What does a rotary evaporator do
Rotary evaporators are in demand in processes such as
- chemical synthesis;
- cold solvent extraction;
- solvent distillation;
- liquid concentration;
- drying of powders;
- purification of substances;
- reaction in the deflegmation zone;
- separation of the mixture into fractions.
This equipment is used in the chemical, cosmetic, perfume, petrochemical and food industries, in pharmaceuticals. This equipment is appreciated for its simple design, multi-functionality, low losses and many other qualities. If you are interested in buying such equipment for the laboratory, explore the offered assortment in the online store chemist.eu