Double boiler "style" build question...

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Guerilla Distillah
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Double boiler "style" build question...

Post by Guerilla Distillah »

OK, let me start by saying I am not a physics teacher or professor anywhere, nor am I any kind of engineer. Just a logical, rational guy who likes to build shit. A buddy of mine and I have been contemplating a Bain Marie style boiler setup. Unfortunately, a lot of the fab work is proving to be probably prohibitive with the equipment we have access to. That said, I wanted to know if anyone could point out any obvious downsides or dangers I am missing to the idea of setting up a pot slightly larger than my current boiler, and simply submersing my boiler two thirds of the way up on stilts inside the larger pot with heater elements on the bottom for raising and controlling the boiling of the water below? Obviously, you have to deal with the constant evaporation of near boiling water, but beyond that I don't see anything but the inconvenience factor. Any thoughts here? Happy to answer questions if I haven't covered everything. Again, please be nice or constructive, I'm just looking to avoid disaster and disappointment.

GD
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cuginosgrizzo
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Re: Double boiler "style" build question...

Post by cuginosgrizzo »

Hi GD.

It just wouldn't work. You need to have a sufficiently high temperature difference between your heating medium (the boiling water) and the wash in the boiler in order to be able to transfer enough heat to the wash. Water at ambient pressure boils at 100C (at sea level), and it will never be any hotter than that. So with an open external boiler you just won't be able to heat efficiently the wash to the required temperature. In order to raise the boiling temperature either you use a different medium (glycol, oil) with a higher evaporation temperature, or you raise the pressure by enclosing said medium. Raising the pressure has all the obvious security issues you well know.
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shadylane
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Re: Double boiler "style" build question...

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Guerilla Distillah
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Re: Double boiler "style" build question...

Post by Guerilla Distillah »

cuginosgrizzo wrote:Hi GD.

It just wouldn't work. You need to have a sufficiently high temperature difference between your heating medium (the boiling water) and the wash in the boiler in order to be able to transfer enough heat to the wash. Water at ambient pressure boils at 100C (at sea level), and it will never be any hotter than that. So with an open external boiler you just won't be able to heat efficiently the wash to the required temperature. In order to raise the boiling temperature either you use a different medium (glycol, oil) with a higher evaporation temperature, or you raise the pressure by enclosing said medium. Raising the pressure has all the obvious security issues you well know.

So if I simply use the correct gallonage of say...peanut oil(the highest flashpoint of the average grocery store available oils) it would work? simply welding "feet" to my 1/2 barrel keg to raise it above the HWH element? How large a gap between vessels? \

Thanks
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