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Topic: Rotary Evaporator Question  (Read 2531 times)

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Offline Eshai

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Rotary Evaporator Question
« on: January 30, 2014, 02:49:42 PM »
I have had the following problem when distilling ethanol from spirits, and was curious if anyone else had experienced something like this wen using a rotary evaporator.

During use, the distillate would readily condense in the neck of the apparatus (the narrow part which extends through the motor and into the condenser coil) and drop back into the boiling flask.

My oil bath was well above the boiling point of ethanol (over a period of roughly two hours, I ended up stabilizing the temperature at about 90 degrees C). It held this constant temperature for roughly two more hours, and still no distillate managed to "make it up" the neck and into the condenser.

Would anyone kindly be able to give me some insight into what my potential problem may be?

Thanks in advance.

Offline Dan

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Re: Rotary Evaporator Question
« Reply #1 on: January 30, 2014, 04:45:32 PM »
The vapour tube will not get hot enough to distill ethanol at atmospheric pressure, you will need to apply a vacuum for the evaporator to work.

What you have at them moment is essentially an air reflux condenser.
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Offline Eshai

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Re: Rotary Evaporator Question
« Reply #2 on: January 31, 2014, 07:39:00 AM »
Dan, thank you very much for your reply.

/bows

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