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Rotary evaporators are vital instruments found in most research and chemical laboratories. They are used in applications that require efficient solvent removal and distillation.

Rotary evaporators are based on the principle that solvents have a wide range of boiling points that decrease as pressure is reduced and that materials with lower boiling points evaporate more rapidly which is a critical aspect in its different applications.

Due to the distillation efficiency, rotary evaporators are preferred over standard distillation systems for the majority of Evolve clients.

What is rotary evaporation?

A rotary evaporator is a device used in chemical labs that efficiently removes solvents from samples by an evaporation process. These devices consist of the following parts:

  • Condensate tube: The condensate tube consists of a double serpentine condenser that uses acetone and dry ice to condense the sample.
  • Evaporation flask: The flask evaporates the sample by rotating at a constant speed and temperature.
  • Receiving flask: The receiving flask recycles the condensed sample.
  • Evaporation tube: The evaporation tube is a rotating support shaft for the sample and the sample is cycled through the vacuum system in the evaporation tube.
  • Rotary motor: The rotation of the motor is the force that rotates the evaporation bottle with the sample.
  • Vacuum system: The vacuum system lowers the pressure of the rotary evaporator system.
  • Bath kettle: The bath kettle heats the sample with oil or water.


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How are solvents evaporated in a rotary evaporator?

Rotary evaporators perform a very distinct and efficient process. The sample is placed in a round bottomed flask. The flask is then placed in the heated water bath and rotated. The pressure is reduced with a vacuum pump. The solvent is drawn away from the sample, which forms as a thin film on the inner surface of the flask, while the compound remains. The solvent is cooled in the glass condenser which is collected in the collection bottle.

What is the purpose of the rotary evaporator?

Rotary evaporators serve many purposes depending on the industry. In general, by using an evaporation and condensation process, these devices remove volatile solvents from a liquid mixture.

These evaporation devices are used for the distillation of volatile solvents, solvent recovery, separation, drying, crystallization, and concentration and are used in the fields of biotechnology, chemical, and pharmaceutical industries.

Rotary evaporators are most commonly used to extract cbd from marijuana, to extract water from juice, to extract chemical substances in chemical and biochemical labs, and in molecular cooking for the preparation of extracts and distillates.

What is the major advantage of using a rotary evaporator?

The major advantage of using a rotary evaporator is higher evaporation efficiency and better accuracy. It uses a vacuum system that is used to remove the solvent which lowers the boiling point. This eliminates the need for high-temperature distillation.

Immersed in a heated water bath, the rotating evaporating flask increases the surface area of the material which speeds up the distillation process. Forced convection keeps the mixture evenly heated and mixed which promotes even, stable evaporation.

Since solvent removal is efficient and fast, this saves time and increases productivity in the lab.

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