Bain-Marie Still Controls?

I am meeting with a local controls company tomorrow to talk about controls for my 500L bain-marie 3-phase agitator setup (I am planning on running a 8" CD column). My question is what are essential controls to have and what are "wish list" controls? I have watched the video on SWEDES Controls to get some ideas but wanted to ask the community! Thanks in advance.


  • edited February 2015

    Here would be my need/want list:


    Phase-angle/SSR control on all elements

    Temperature controlled dephlegmator (PID w/ proportional control) - assume recirc cooling

    Temperature controlled product condenser (PID w/ proportional control) - assume recirc cooling

    Vapor Temp above dephleg.

    All Class A RTD's.


    (maybe?) Ramp/Soak controller with PWM on all elements (always wondered if this was a better way to run a bain marie as you could directly control speed of HTF heat up). You would need to sink a probe into the jacket for this. This would not work with water, you'd need to use oil.

    Boiler liquid temperature (to monitor heatup)

    Distillate temperature (for alarm/auto-shut down)

    Boiler Vapor Temperature (would be interesting to monitor, not at all necessary)

  • Assuming you are using glycol you should monitor the bath temperature. Absolutely agree with ramped warm up or you will burn your thermal transfer fluid.

    You need a maximum temperature control on the bath as the thermal transfer fluid always has a problem with degrading with excessive temperature, no matter which fluid you use.

    Boiler vapour temperature to use to shut down boiler power on strip runs. You can extract the last part of the available alcohol with the thermal energy stored in your glycol. It depends on your boiler insulation and bath volume.

    Temperature control of the bath. This is your control on the amount of energy going into the wash. If you wish you can optimise the thermal gradient during the run to compensate for the changes in boiler temperature during the run.

  • Thanks for the input!

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