GPM of Chilled Water for Dephlamator and Product Condenser

Hi guys,

Quick question:

I have a 100 gallon vodka still with 2 dephlemators and 1 product condenser.

During GNS runs, how many GPM should each dephlamator and condenser receive?

I am looking at an open loop chiller with 5 GPM output and was curious if this is a good choice.

Thank you.


  • Flow rate is irrelevant - how many tons/btu is the chiller?

  • I am looking at this guy North Slope Chillers NSC1000-110/1 Freeze 1-Ton Industrial Chiller, 12,000 BTU's/hr,

  • I run the range of 0.5(or less) to 5gpm through everything from 2" PC, 4" x1m PC to 8"x1.2m PC, and 4" RC and 8" RC.

    without some other method of cooling, such as water-air HX, or running the chiller overnight on a large reservoir, you will only be able to condense and cool 7.5L/hour of distillate with 12,000btu.. (this is with NO reflux cooling)

    7.5L/hour = .125L/min = 0.113229125Kg/min
    Vapor to liquid: flowrate x evaporation enthalpy       183.4085367  kJ/min
    Liquid cooling:  flowrate x heat_capacity*(Tout - Tin)  27.57566258 kJ/min
    Total energy needed: 210.9841993 kJ/min 11998.46617 BTU/hr

    Also, if you have water coming in at 20c, and going out at 60c, you will be flowing 1.260660846 l/min

  • edited August 2019

    Ok, so without the ability to have a roof based chiller closed loop chiller. What do you recommend (if you dont mind helping me) with this type of setup.

  • edited August 2019

    We run roughly 5 ton and a 600 gallon tank on the 265g still.

    We need to pre-cool the tank to 55f to make it through a full run with reflux and tails collection - about 6 hours.

    It takes the balance of the evening/morning to return the tank back to 55f for the next run.

    Running 2x a day would require supplemental cooling using city water - we basically dump the tank return once the tank is coming close to maximum temp, while re-filling using water.

    We don't run glycol for this reason. We like the flexibility. We'd probably need closer to 10 ton or 1200 gallons to be able to do back to back. Probably that, and to run glycol to push the starting temperature down into the 40s.

    I wish we had 460v service, I'd have big ass roof mount chillers.

    The cheap approach is use city water for cooling, and find a way to reuse the hot water. The colder your water is, the more economical this is.

  • I use a couple 200k btu HX's, that most people use like a modine heater, they are 24x24 and I mount them outside with a mini-split bracket...

    in the winter, if you heat, filling a tote and letting it cool overnight is free heat...

    various threads to read:

    For the RC, you can limit flow by automating, and the small 12x12 unit might be big enough, but I say go for the big 24x24 unit to match the PC:

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