Evaporators refer to the equipment used for evaporation, which have a great variety of types. It’s well-known that rotary evaporators are one of the commmon and essential evaporators, widely used for the evaporation, concentration, crystallization, drying, separation, and solvent recovery in many fields, and mainly used for continuous distillation of large amounts of volatile solvents under reduced pressure. In the following, the accessories of the rotary evaporators will be fully discussed.
Rotary Evaporator Accessories
There are really a great number of rotary evaporator accessories suppoeting its normal operation, specifically as follows:
- Condenser: a device used to condense gaseous solvents matching with the chiller.
- Motor: a device powered by electricity used to supply motive power for the whole rotary evaporator equipment.
- Evaporation flask: a device used to contain sample and keep rotating to facilitate evaporation by enlarging evaporation area. It can be also called the rotating flask.
- Thermostatic water or oil bath: a device used to heat the evaporation flask.
- Thermostat control: a device used to control the temperature of thermostatic water or oil bath.
- Receiving flask: a device used to collect solvents.
- Vacuum pump: a device that removes gas from sealed equipment to leave behind a partial vacuum.
- Chiller: a device used to cool equipment .
Rotary Evaporators’ Operation
The working process of rotary evaporator is a consecutive process under a reduced environment. There are several steps for the operation:
a. Under reduced pressure, the evaporation flask was continuously rotated while the solvent was being distilled. The evaporation flask is a pear-shaped or round-bottomed flask with a standard ground mouth connection. It is connected with the pressure reduction pump through a serpentine condenser.
b. After substances get evaporated by heating, the gas-phase substances will go into condensing part to get condensed. In this step, gas substances are transferred through the glass tubes.
c. After gas-phase substances got condensed into liquid-phase, the liquid-phase substances will be transferred into receiving flask, which is the final destination of extracted substances. And then users will take the receiving flask out of rotary evaporator equipment.
During the whole working process, there is always a vacuum pump providing a vacuum environment for the rotary evaporator, which guarantees the whole system work in a reduced environment and the automatic feeding system formed by the pressure difference between atmosphere pressure and vacuum pressure.
Types of Evaporators
Evaporators are the equipment used for evaporation, which is used in the process of turning a liquid into a gas or vapor. Evaporators mainly consist of a heating chamber and a evaporation chamber. The former makes the liquid boil and vaporize by providing the heat required for evaporation. The latter separates the liquid and the gas completely. There are several main types of evaporators, which are falling film evaporators, nucleate boiling evaporators, flash evaporators and direct contact evaporators. Among them, nucleate boiling evaporators can continue to be classified into six types, such as climbing film evaporators, short-tube vertical evaporators, long-tube vertical evaporators, etc. Though possessing similarities, they differ from each other in some aspects as well and are applicable for different types of evaporation.