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Condenser BTUs
Posted: Sun May 24, 2015 5:52 pm
by SurlyTaco
Hey, so my dad and I are working on our first still. I live closer to town, so I picked up the raw gear, and him, being a) old and b) a power engineer for ever, he's rather good with pipe, so he'll show me a thing or two about assembly. I was talking to him about the condenser, and how the rig will be open to the atmosphere so no pressure can build up. We're planning on building a valved reflux still. I know it's not the finest setup for whiskey or rum, but I like how we can also ramp it up for neutral spirits, fuel, and in a pinch we could just distill water--we're both on wells.
Dad asked about the condenser coil specifically, and the water flowing through it. We're going to use well water, either at his place or mine, which is damn cold, like 2-3C so we'll have a wicked delta-T. So, the point of the condenser is to knock down all the ethanol and flammable vapours, right? We're curious how many BTUs that will take. Is it possible to over-cool the vapour coming off? I think the answer is no, but over cooling can be an issue in some circumstances.
Oh, also we've ordered a 50 quart SS pot to boil the mash in. We're planning on using propane rather than an immersion element, but is there any reason we couldn't build a stand out of angle iron and use a wood fire under the still? The heat is less controllable, yeah but .. the mash'll only boil so fast.
Re: Condenser BTUs
Posted: Sun May 24, 2015 6:24 pm
by Bigbob
Hi SurlyTaco, yes it is possiable to over cool your condenser, it's called 'shock cooling'. Not good. Also it's possiable to use a wood fire to heat your mash, but it's very uneven in heat, and not able to get the consistent heat you need. You really need to read crankys post in novices where this is all discussed. Slow down and do it right.
Re: Condenser BTUs
Posted: Sun May 24, 2015 6:59 pm
by SurlyTaco
The spoon feeding sticky? I'm not sure I remember a bit about shock cooling. I'll go check it out again ...
Re: Condenser BTUs
Posted: Sun May 24, 2015 7:22 pm
by ranger_ric
A couple of notes:
1. I think it would be very possible to do stripping runs using wood on a pot still.... I am not familiar with a valved reflux still so I would have to defer..
2. On the cooling water.... I came to a startling discovery on my last run... I converted over to using the water in my pool to my liebig... I was able to set the valve and I did not have to touch it again. The problem or worry that I see from "shock cooling" / vapor collapse is that it makes my pot shake and the lid on my pot violently rise up and down as the vapor crashes in the liebig. The only thing I can see bad happening from that is that it might degrade the seal on your lid and cause a leak of the vapors from the pot.... that would be ugly especially over any kind of fire... Nice discussion point to bring up
Re: Condenser BTUs
Posted: Mon May 25, 2015 5:55 am
by Hound Dog
Yes it's possible to overcool the condensate over your packing in a reflux still. The cold condensate will tend to build up on top of the packing rather than go down into it for further distillation.
You say "the mash will only boil so fast". Well the rate of boil is what you need to be able to control. If you build something to control ducted heat from your wood fire it is feasable. If you plan on throwing burning logs under a boiler like you see on TV, you better be quite experienced with your reflux setup. An even and steady temperature is best.
If you are really wanting to distill water you need to make one out of all stainless. Copper will make your water taste like an old penny in your mouth.
There's a bit more to this than fitting pipe to make something worth drinking. Give her hell though.

Re: Condenser BTUs
Posted: Mon May 25, 2015 12:55 pm
by SurlyTaco
Hound Dog wrote:If you plan on throwing burning logs under a boiler like you see on TV, you better be quite experienced with your reflux setup. An even and steady temperature is best ... Give her hell though.

Heh, even though I have a tv it hasn't really been on in a few years so I
can't get my bad habits from those guys. I'll make my own bad habits!
So, time to read up on coils, methinks. I don't expect I'll ever build a fire under my still. I was mostly just curious.
Re: Condenser BTUs
Posted: Mon May 25, 2015 4:26 pm
by Hound Dog
Re: Condenser BTUs
Posted: Mon May 25, 2015 8:31 pm
by SurlyTaco
Thanks! I think we'll have the basic fitting down but it's good to know we can cool vapour too much. It sounds like the minimum level to knock down a water run is abouuuut right to start with on a stripping run.