Rotary Evaporators’ Troubleshooting and Solutions



Rotary evaporator
Rotary Evaporator

Rotary Evaporators’ Troubleshooting and Solutions

A rotary evaporator is an indispensable equipment for the processes of evaporation, concentration, crystallization, drying, separation, and solvent recovery in many fields, and it is mainly used for continuous distillation of large amounts of volatile solvents under reduced pressure. It’s necessary to learn something about the troubleshooting and solutions of rotary evaporators, which will be discussed in the following.

  1. The power indicator light doesn’t work when turn on the power switch.

There are three possible reasons. Firstly, the power cord isn’t connected or is connected incorrectly. Secondly, the power switch fails. Last but not least, the circuit board fails. If it’s the first reason, the solution to this trouble is that the power supply should be turned on correctly. If it’s the second or third reason, stop using it immediately and contact the manufacturer immediately.

2. The power indicator light works but the rotary evaporator doesn’t rotate.

There are three possible reasons as well. The bearing may russt, or there is a malfunction of the motor or the circuit board. Once it happens, stop using immediately and contact the manufacturer.

3. There is an abnormal sound in using.

The possible reasons can be concluded as follows. The internal gear may wear, or the driving section lacks of oil, or the motor fails, or the sealing ring wears. If it’s one of the first three reasons, stop using immediately and contact the manufacturer. If it’s the last reason, just replace the sealing ring.

4. There is an abnormal lifting.

There are two reasons for the trouble. One is the failure of the circuit board or the motor, and the other is that the bearing for lifting may rust or wear.

How does a rotary evaporator remove solvent?

A rotary evaporator is mainly used to continuously distill a large amount of volatile solvents under reduced pressure, such as extraction by distillate and a receiving liquid for chromatographic separation.The basic principle of a rotary evaporator is to evaporate sample materials with evaporation flask’s continuous rotation. The process can be descriped as follows:

  1. Turn on the chiller. Press the power button and the cooling button to lower the desired temperature and then cycle.
  2. Turn on the pump to circulate water.
  3. Install the distillation flask and secure it with a clamp. Turn on the vacuum pump and start rotating after a certain vacuum is gained.
  4. Adjust the height and rotation speed of the distillation flask and set the appropriate water bath temperature.
  5. Stop the rotation after steaming, then pass the atmosphere, stop the pump, and finally remove the distillation flask.
  6. Stop the chiller as well as the water bath, turn off the water circulating pump, pour out the solvent in the receiving flask, wash the buffer ball, and remove the flask.

How does a rotary evaporator work?

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.

Can a rotary evaporator remove water?

The answer is “YES”. The rotary evaporator is widely used in removing water from materials, which is to concentrate substances. Removing water by a rotary evaporator is commonly used in the kitchen, such as the concentration of fruit juice, which is to remove water from fruit juice. Besides, there are other examples of removing water from substances.

Related Articles:

How to Use a Rotary Evaporator?

What are Applications of a Rotary Evaporator?

What are Advantages of a Rotary Evaporator?

Related Products:


50L-100L Rotary Evaporator

50L Dual Condenser Rotary Evaporators


50L-100L Rotary Evaporator

R-1050A 50L Vacuum Rotary Evaporator


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