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Questions about Boiler Sizing

OK, so with money burning a hole in my pocket from selling the house and moving into the wife's condo, I am switching from the 380L electric that was about to ship to me from @Smaug to a 1000L steam with agitator. A local brewer just got a 20HP boiler (~700k BTU) for about $9k, so going steam is cheaper than I thought..

Is this the right size? A 12HP would probably run the still, as vendome says 500kbtu for 250g still, 750k if mash cooker ran at the same time...

Also, these questions are probably for the big boys like @RedDoorDistillery can answer best... this 1000L-SA will be the main still or stripping still..

  • Should I get a 380 steam for a spirit still, or just use a 380 electric?
  • Will gin or whiskey really benefit from steam other than being able to put higher proof into still?


  • I could not answer the Steam and size of boiler as I only use Electric immersion. For Vodka or Gin being able to start a Spirits run higher than 40% would be very nice. The benefit to Whiskey would be the ability to ferment on the grain and distill on the grain.

  • yeah, I figured maybe you looked at steam at some point... with the 1000L being steam with agitator, we can distill on the grain for the stripping run... just deciding if the spirit still should be steam... 40% limit is there, but not sure if it is enough...

  • Nothing stopping you from using the same still. To speed things up, if you had a large enough condenser you could just swap in a pot head to strip, and column for the spirit.

    You should be able to fill it plenty with 3-4 strip runs, depending on how deep you go.

    20hp is plenty big, I've got some other specs in front of me that have about 275-300lbs hr for startup and 100lbs/hr during the run for a 1000l setup. That's less than 10hp I think.

  • Oh, forgot to mention, trying to stay F1 occupancy and not go H3, so collecting strip runs might put me over the MAQ, but if create a separate 1hr room to store them in....... 10HP is 345lbs/hr... hmmm.. maybe I don't need 20Hp... waiting for boiler guy to call back..

  • For a 250gal still either a 10 or 15 HP could work. Possibly even a 5HP if your willing to wait for long heat up times. Definitely don't want to go 20 HP unless you get modulating burners. A standard on/off boiler will short cycle if over sized.

  • Thanks!... his had 2 gas valves feeding different areas...... I wonder if it could go half speed I can't wait to for the boiler guy to call, I am going to pester the crap out of him... the brewer said they told him 1HP per bbll (30gallon bbl) and 3 for his Hot Liquor tank, he had a 15 barrel system, so 20HP makes sense, I would only be boiling 8 bbl max...

  • Go bigger if it's feasible. Time is money on heat up, also you can have a hot loop installed for endless hot water out of the same boiler.

  • OK, the boiler guy called, he has done both boilers at cigar city brewing, green bench, pair-o-dice that i mentioned, and my friend Jay at Barleymow just ordered his.. He normally does hospitals and such, we are like pet projects for his company... the one for Pair-o-Dice he said is 2 stage, and he can tune the gas pressure on the first stage down to what I need... we will go somewhere between 10 and 20hp based on his decisions... now to decide inside or outside, he said ajax has a new one built for outdoor, and that is what one brewery is doing...

  • Sounds safer

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • Nice. Keep the details coming. I would also opt for outside.

  • edited February 2014

    Are you talking about a 15psi boiler - or a high pressure boiler. I don't think locating a low pressure steam boiler outside is any safer - and you have the additional cost of the enclosure to deal with. Suspect if someone put a low pressure boiler outside - it was due to space or layout issues, and not safety. High pressure? Another story - but what then - you blow up the guys standing around outside? :)

    But - going with a high pressure boiler will likely subject you to additional regulatory/safety restrictions, check with plumbing and fire for more details. You mentioned you wanted to minimize your exposure to more stringent safety requirements, so I thought I'd throw this out.

  • Steam generator

    StillDragon North America - Your StillDragon® Distributor for North America

  • I was talking about the burner involved in it being in the building that the distilling is happening in. I was thinking that if there is no ignition source (as in a direct fired steam generating boiler) in your distilling area it would be safer.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • @grim - low pressure... >15psi, probably 7-10psi @punkin has it nailed, ignition source away from still makes fire marshal happy, but then again, there are several legal, recently opened, open flame alembic distilleries making excellent product and not blowing up... the outside boiler is built for outside by the manufacturer, installed by a boiler expert, and in a county/city that likes to over-regulate, so I am sure regulatory/safety are taken into consideration..

  • Nuts, I clearly jinxed myself - just got back from meeting with Building, Fire, and Zoning - They say H-3, no questions unless I want to bring an attorney to the board of adjustment. This makes town number 3 who've said no-way to F-1. Next step is to see if the landlord can pull some strings. Cotherman - let me know how you make out.

  • tell them to look in the NFPA 13:

    NFPA 13 Section 5.3 is clearly titled "Classification of Occupancies and Commodities" so it does, in fact deal directly with occupancies. Furthermore, the document uses the word 'occupancy' in reference to the exact same hazard levels as the LSC, (General, Low, Ordinary, and High).

    NFPA 13 defines Ordinary Hazard(group 2) as "where the quantity and combustibility of contents are moderate to high" - this describes the product we are dealing with.

    NFPA 13 Annex A is 'Explanatory material", which means that it is uses to explain things, and one would think that this is when a discrepancy or question arises, such as we have here, one would go to here to clear it up.. In the beginning of the annex, it states that this explanatory material in not actually part of the code, but is there to help explain.

    NFPA 13 A.5.3.2 specifically calls a distillery an OH-2 occupancy.

  • the other thing you can do is hire Steve Dalbey with Distillery Code Consulting..

  • that being said, with a space of occupancy H3, you can store an unlimited amount of any proof you want...

  • I saw a Dirty Jobs episode about a rum distillery.
    The steam generator was set at 1 bar output and the pressure to the still boiler was set at 0.5 bar. Is this typical?
    I remember in the video they stated the boiler charge was 105 gallons or so.

    Just to avoid confusion, I call a boiler the thing under a still head and call a steam generator the thing that can power the boiler with live steam. (Both are boilers, yes, but for our clear understanding we ought to call that "contained nuclear reactor" a steam generator.

    All you guys are on the right track because I cannot supply steam generators from China, I have tried. They must be tested and certified by licensed professionals in the country that they are installed and that is beyond our scope. Good on you guys to share here and help a brother out by finding a way to save two thirds the costs.

  • @Lloyd - I will say steam boiler or steam generator do differentiate from here on out..

    yes, 7-10psi, or ~.5-.7 bar is typical low pressure steam for distilling and brewing....

  • At this point I have to ask a question about cost effectiveness...

    Assuming that I cant get natural gas, and propane is usually more expensive than electric, is using a steam generator more cost effective than direct electric heat? For me it'd have to be an electric powered steam generator most likely... or a very efficient propane one. (i think electric is about 80-90% the cost of a similar propane heater)

  • Using steam comes at a price - the steam generator, piping, valves, gauges, etc. But also has advantages like very rapid heat up times and never being able to scorch the mash like direct fire or elements can. The safety issue of having live steam and the dangers of that are offset by not having a need for high electric power or an open flame close to the still.
    Your choice of fuel is usually going to be made based on your location. In southern United States natural gas is much cheaper than propane but are about the same price for me in Yangzhou. The cheapest for me by far would be coal but that's too inconvenient to use.

  • I think if I were on an island like fiji, I would be looking at solar... pump a light oil or even glycol through a glazed heat exchanger... you can get 180 degrees F out of a standard residential solar panel... panel, possibly a mirror, and I think you could get heating potential for nearly free...

  • edited February 2014

    What about waste oil burners? free/cheap fuel used a lot by guys doing foundry type work

    Homemade oil/waste oil burners - Harnessing the power of hot grease

    There are commercial makers of these burners too e.g.

    Clean Burn - The Best Solution For Waste Oil

  • Had one of these fellas at my old work. Heated a bloody great big workshop with roller doors open during the winter.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • No one has mentioned yet (unless I missed it) that putting in a steam boiler ONLY to heat a still is just not cost efficient.

    Most distilleries using steam are using the steam for everything. In the brewing process, distilling, and anything else they can think of.

    If you are only running the still with it, a better option is a steam jacketed boiler with an immersion heater in the jacket.

  • I can get really cheap wood to fire a boiler but it would mean i needed constant cuttng and feeding and a whole operation just to run the boiler.

    at some point a steam boiler may be in order but for now i'll have to stick with electric.

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