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burk

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  1. Also pay attention to BOD and COD requirements for your waste. Using published values (we're not in production) we were going to use a significant proportion of my towns capacity for BOD if we put our stillage down the drain. They made it clear that we would not get approval if that were the case. We have to divert most of our stillage waste into other disposal paths. (In our case livestock feed). Other distillers in Vermont are direct spraying stillage onto fields.
  2. Max, Thanks. I was hoping that someone who knew better would speak up. Real world trumps back of the envelope yet again. I worked in a field where 4 exhanges would be low. I also assumed even mixing, and I should have known better. I also didn't realize that ethanol vapor sinks. So the sensible solution like you suggest is ethanol vapor monitoring sensors. I'm going to edit my response to suit.
  3. They were rather excellent and eye opening seminars. My plans were changed (we'll be now arranging for a boiler cutoff on cooling water failure, among other things. Luckily, we were already designing with safety in mind.) We're planning on the boiler being firewalled, but that firewall will be near barrel storage so let's do these calcs for my sense of well being. On the barrels, if we take 2% per year as a notional number for evaporation, and assume it to be purely EtOH (it won't be). We can calculate Barrel Vapor per hour per Barrel 53 Gal * 0.02 = 1.06 Gal / Year 1.06 Gal / 8760 H/ hear = .000121 Gal/hour now, I trained as a chemist, so I prefer metric, so 0.00021 * 3.785 = 0.000458L or 0.458 mL per Bbl per Hour. I'm making an assumption about %by volume, which how LEL are shown. (chemists can mean all sorts of things by %, and I was an analytical protein chemist, so this is out of my expertise). I'll assume volume of pure gas at stp / volume of space. So let's get the volume of the Ethanol. First we need the mass of EtOH: 0.458 mL * 0.789 g/mL = .361 g EtOH Next we need moles of EtOH 0.361g / 46.07 g/mol = .00784 mol EtOH One mole of an ideal gas at STP occupies 22.4L (just a fact) 0.00784 mol * 22.4L / mol = 0.176 L So that's volume EtOH per Bbl per Hour. Now the LEL for EtOH is 3.3%. Can we take from that how much space the room would need to have to be under LEL? I think we can. 0.176L / 0.033 = 5.33 L. That's the space at which the amount of EtOH coming off a single barrel in one hour would be restricted to to be at LEL for Ethanol. Awfully small space. Awfully small amount of ethanol. Your room will have many liters. (A cubic meter is 1000L). Assuming some air exchange and reasonable breathing space, I don't think you can get to LEL from just angel's share. I'd worry much more about vapor from dilution if you dilute in that space. In normal circumstances you probably won't get to LEL, but as Max pointed out, abnormal circumstances happen. Mitigate that risk. Treat the space as having potential vapor hazard, with alarms and proper explosion proof equipment. NB: I'm not a safety expert, I'm just explaining the math. PLEASE, SOMEONE CORRECT ME IF I'M WRONG. [EDIT: AND THEY DID CORRECT ME. See Max's response, and if the angel's share is highter then you'd expect that will increase the amount as well.] To finish the calculations, you will need: 1. The volume of the barrel storage (not counting the barrel volume, which will not be negligible). 2. Air exchange. (if 4 exchanges per hour, divide by 4) 3. Number of Barrels stored (multiply by number of barrels) Of course, as an analytical chemist, I would, if I needed this number accurately, measure it. (I don't know what the test method is). This is just a back of the envelope calculation which gives you the order of magnitude for just the angel's share. I assumed EtOH to be ideal (it probably isn't), STP ( we usually don't keep rooms at 25C any more), %EtOH of Angel's share to be 100, Angel's share to be 2%/year, and evaporation rate to be constant (it won't be). So it's just an estimate. Chuck Burkins
  4. burk

    Hoga stills

    Thanks Bob and Curtis. We're thinking about stills right now, and I'm gathering info. -burk
  5. burk

    Hoga stills

    Hi Curtis, I've seen you recommend NeverStandStill more than once on this forum. What's your experience with their stills? -burk [in the planning stages of setting up our distillery, so this isn't a rhetorical question!]
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