"vairox" wrote in message
oups.com...
lots of replies! I'm trying to distill alcohol without an open
flame,
ethanol boils off at 78.4C (174F) and I don't want a source that is
going to constantly turn on and off because it will lower the temp
and
then have to get back to where it was and cycle again and again... I
was hoping there was some sort of heating device that you just turn
to
whatever temp you want and it stays there... maybe one of those $800
lab hot plates I don't know.

it doesn't seem like it would be all that hard to have an electric
hot
plate that stayed at a certain temp, but then again I'm no
electrician.


Well when I was doing that some 30 years ago (me being a process
control engineer at the time, and my flatmate an industrial chemist) I
designed and built a pulse width modulated driver for a normal kettle
element which was part of a control loop based on a type 'k'
thermocouple located at the bend point of our still. Worked
splendidly - the heater element maintaining a steady state of light
boiling. Discard the first few drops distilled - they contain the
ketones that give you a hangover !!!!

AWEM