How to Use a Rotary Evaporator?

A rotary evaporator (rotovap or rotavap) refers to a kind of equipment for solvent evaporation under reduced pressure, which is composed of a vacuum system, a heated water or oil bath, a condenser and a motor that rotates the evaporation flask. They cooperate with each other and all play an essential role in the working process of a rotary evaporator. As its name suggests, what special is that the evaporation flask can rotate. It is an essential equipments for the processes of evaporation, concentration, crystallization, drying, separation, and solvent recovery in pharmaceutical, chemical and bio-pharmaceutical fields and other fields.

Using Methods of a Rotary Evaporator

Only when rotary evaporators are used properly can they play greater role and function in many fields. There are some instructions that can be followed in order to use rotary evaporators better and more properly.

Connect the hose to the condenser tap. Connect the vacuum pump with the vacuum rubber hose for vacuuming.
Fill the tank with water (preferably pure water). If you use tap water, leave it for a day or two before using .
The method of adjusting the host Angle: Simply loosen the main unit and the column to connect the screw to the main unit and tilt it between 0 and 45 degrees.
Switch on the condensate water, switch on the power supply, connect the evaporator with the host machine (do not let go), open the vacuum pump to reach a certain vacuum degree before releasing your hand.
Method to adjust the host height: Press down the pressure bar at the bottom of the heating tank, adjust the radian left and right to make the host machine reach the proper position, and then the required height can be reached by leaving the pressure bar.
Turn on the speed switch green light, adjust the speed knob next to the left side, and the evaporation bottle starts to rotate. Turn on the temperature switch green light, adjust the temperature adjustment knob heating tank on the left side to start automatic temperature control heating, and steam into the trial run. The temperature and vacuum can be evaporated to the receiving bottle as soon as the desired range is reached.
Turn off the low temperature coolant circulating pump, turn off the water bath to heat, turn off the pump circulating water, pour out the solvent in the receiving bottle, wash the buffer ball, and receive the bottle. After steaming, stop rotating, then pass the atmosphere, then stop the pump, and finally remove the distillation flask.
After the evaporation is completed, first turn off the speed-regulating switch and the temperature-regulating switch, and press the lower pressure rod to raise the main unit. Then close the vacuum pump and open the vent valve above the condenser to communicate with the atmosphere. Remove the evaporator and the evaporation process is over.

The whole equipment consists of several parts to make the process go smoothly. Extracted solvents will be extracted through evaporation and then be transferred into condenser which connects with chiller in order to cool the equipment down. Gas solvents will be turned into liquid solvents when it goes into the condenser. Then liquid solvents will go into the receiving flask, so that users can get the extracted solvents easily. The whole process is carried out under the condition of vacuum.

Tips on Using a Rotary Evaporator

Keep the whole equipment sealed, so that the vacuum can be maintained. In this way, the continuous feed system can continue during the whole process. What’s more, the vacuum can keep extracted solvents pure. So users need to keep the flask clamp tight to prevent air from coming into the equipment.In addition to mastering the use of rotovap, users should also master the matters needing attention in rotovap:

The most important thing is to handle the glass pieces gently, wash and dry them after use;

Secondly, the heating tank should be filled first and then electrified. Dry burning without water is strictly prohibited. A small amount of vacuum grease should be uniformly applied to the grinding instrument before installation.

To ensure the safety of the precious solution, the simulation test should be done first.

At the end of the work, close the switch and unplug the power plug.