The evaporation rate of a rotary evaporator is greater than that of static distillation apparatus. Moreover, the evaporation rate increases with higher rotation speed. This is, among other factors, due to the greater surface area inside the evaporating flask at one given time. Especially significant is the dissipation at lower rotation speeds. For instance an increase in speed above 200 rpm has a relatively low influence on the evaporation output. A rotation speed above 300 rpm can result in mechanical problems, vibrations and spillage from the heating bath. Thus, considering the advantages and disadvantages of different rotation speeds, the optimum rotation speed is around 250 to 280 rpm.
Achieve higher distillation efficiency when using a rotary evaporator – Impact of rotation speed