Rotary evaporator application areas: used to separate a large number of components with high volatility; used to remove residues or decolorization; suitable for products with high viscosity and easy to freeze; used for heat-sensitive materials. The open and direct construction of rotary evaporators also makes them very easy to maintain and repair. In addition, these evaporators are designed with various safety features (dry heat shutdown, over temperature protection, soft start spin, over current protection).
 
This time, the editor will take you to learn about Rotary Evaporator Problems and solutions to Rotary Evaporator Problems, including problems such as Rotary Evaporator Solvent Temperature being too high.
 

1. The method of preventing solvent spraying during rotary evaporation

a. The temperature should not be too high, and the temperature of the water bath should not exceed 30 degrees Celsius, so that the Rotary Evaporator Solvent Temperature will not be too high.
b. Don't pack too much. If it is a low boiling point solvent, you can consider not heating it and adjust the vacuum degree slowly.
c. Replace the recycling bottle with a larger capacity. Generally speaking, the smaller the volume of the recycled bottle, the easier it is to bump.
d. The vacuum pressure should not be too high, no one should leave during the steaming process, always pay attention, and open the vacuum valve as soon as there are signs of ejection.
e. For the solvent with low boiling point and easily turbulent spray, operate the rotating steam exhaust port with your fingers to properly exhaust and pressurize.
f. First spin externally in the water bath until water mist appears outside the flask, and then gradually reduce the volume of the water bath contact until it is stable and not turbulent.
g. Use anti-shock and anti-boiling balls, which can be poured back after spraying. This requires ensuring that the explosion-proof ball is clean, so it must be cleaned before each use.  

2. How to choose the right temperature of the rotary evaporator

The best way to use a rotary evaporator is known as the golden "Δ20°C rule". In order to fully condense the steam, the temperature of the cooling circulator should be set about 20°C below the steam temperature. For example, at a bath temperature of 50°C, a solvent vapor temperature of 30°C is produced, followed by condensation at 10°C.
 

3. How to choose the pressure of the rotary evaporator

The pressure and temperature of rotary evaporation are very important. In general, there is a linear relationship between the temperature of the water bath and the evaporation rate. The more energy you use in the evaporation process and the more energy is removed from the condensing part, the more efficient the distillation will be. The premise is that you also need to take care that the condenser has sufficient cooling capacity and is stable under pressure.  

4. Air leakage detection of rotary evaporator

Rotary Evaporator Problems How to detect the leak of rotary evaporator?
Rotary evaporator is a conventional equipment and instrument in the laboratory. It is a common phenomenon that air leakage occurs during use. Air leakage brings you a lot of troubles during the test process, which slows down the normal vacuum distillation speed and reduces the efficiency. If there is a large air leak, the location of the air leak can be quickly found and resolved quickly. However, under normal circumstances, many air leaks cannot be found. Here is a simple and small method:
 
Connect the rotary evaporation instrument and the vacuum pump, connect the rotary bottle and the collection bottle, then close all the valves, open the vacuum pump and let the rotary evaporator work. When it cannot be pumped to more than 0.09, it means that there is a slight leakage in the whole system. At this time, please connect the pipeline to the air release valve and connect the water source. And open the valve, use negative pressure to suck water into the rotary evaporator, so that each glass space in the rotary evaporator is filled with water. (When the water fills the condenser and the collecting bottle, the rotating bottle and the dynamic sealing system of the rotating shaft, the water will generate a certain weight. At this time, in order to avoid damage to the instrument, the personnel must cooperate with the hands to hold each part firmly.) At this time, you can Observing the bubbles in the entire vacuum system, it means that there is a problem of poor sealing in this place, and then you can find the problem and do further plugging treatment.
 
ZZKD is an enterprise integrating production and trade, providing experimental and production equipment, located in Henan Province, China. Only provides customers with cost-effective and personalized customized equipment. ZZKD's main products include a series of equipment for evaporation and extraction, including rotary evaporators (RE-5002 rotary evaporator, R-1005 rotary evaporator, D-R-1050 rotary evaporator, etc.), glass reactors, vacuum pumps, etc. So far, we have gained rich experience and ISO9001, CE and other related certifications in this field. If you need, please contact us in time~