experimenting using a rotary evaporator

Undoubtedly, the applications of industrial mini volume rotary evaporators range from medical, industrial, and basic science. However, choosing the right instrument among a plethora of manufacturers as well as models is not a walk in the park.

First, as it is with most laboratory equipment, the choice has to be based on application, which is easier after having a look at specific separation, cleaning as well as concentration needs. However, to make your selection process a breeze, here are some of the things that you need to consider;

Rotation Speed Range (RPM)

Rotating the evaporation flask or mixing mechanically (by stirring) results in forced convection of the liquid layers. That way, a uniform temperature is maintained evenly. However, the speed of rotation has to maximize the turbulence inside the flask.

scientist using a rotary evaporator

With a higher rotation rate, the rate of distillation also rises to a point whereby the fluid is pressed against the walls of the flask by centrifugal force hence decreasing the turbulence inside.

Vacuum (MM HG)

With higher ambient pressure, the temperature of ebullition as well gets higher. Alternatively, the reverse is true, and hence by creating a vacuum, those substances with a higher boiling at lower temperatures can be distilled. Therefore, it will be significant if you need to prevent damage to temperature-sensitive substances.

Flow Rate (PSI)

Several multiport evaporators will allow single gas port adjustments, which is necessary can be shut completely. Therefore, ensure that the flow rate is tuneable, should be similar across all the ports, and to be better, be from start to the end, to mean no nitrogen outbursts.

Sample Size

Distilling several samples at the same time in the laboratory can immensely affect workflow as well as increasing uniformity within the multiple sample evaporations.

Bumping

Without the air bubbles as nucleation, or when the liquid is not moved in any way, evaporation will not take place and hence will overheat. Therefore, the convection current won’t distribute input heat faster enough, meaning evaporation starts when the liquid gets to the surface (bumping).

Bumping can result in large part of the liquid being taken down and hence significant losses. To avoid bumping, shaking, or stirring, the liquid can be done or by merely using boiling stones.

Moreover, when looking to purchase a rotary evaporator, you can consider some other things, such as the reputation of the manufacturer, condenser, pressure, and temperature. Also, you need to evaluate some production issues in general, such as industry knowledge as well as the experience depth of the company.

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