Steam Build Feedback Request

Steam powered cooking and distillation devices.

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GrdnVrtyDstllr
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Joined: Thu Oct 08, 2020 11:43 pm

Steam Build Feedback Request

Post by GrdnVrtyDstllr »

Hi Everyone,

I've been distilling for a 10 months on a 20litre NZ-made pot still and have had a lot of success. I've been fermenting on-grain, and pressing using a mop-press, and would like to have the option to strip bourbon wash on-grain using steam. I came by a great 100l vessel that happened to have a lot of 1" and 4" ferrules, and before I assemble everything, I hope I could get some feedback on the attached image.
Steam-Still-1small.jpg
Build plan:
2 10AMP elements going into the keg (RCD @ wall using the stove outlet).
Steam goes from (A) into (B) (2"), which reduces to 1" at (C), and through the Steam Wand (D).
I've left a 2" port for a Manometer/Pressure Relief Valve directly above (C).
4" diameter riser to a stupidly large shotgun condenser I inherited.
I'll make copper washers wrapped in PTFE tape in lieu of silicone (a strategy suggested by corene1 *I think*)

Questions:
1. Safety - Anything glaring I'm missing in terms of safety?
2. I've read about steam hammering on this forum, and am wondering if this is something I should try to engineer for? I was considering some sort of poppet valve that would be like a spring-loaded vacuum relief valve at the "manometer arrow" in the image, but have also read that introducing oxygen into the boiler is also possibly dangerous.
3. Are there any other pictures that would allow for better feedback?
4. Is there enough copper contact? Any suggestions for how you would add more if it's not enough? I have a lot of junk copper lying around.

Thank you everyone for your advice.

GVD
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shadylane
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Re: Steam Build Feedback Request

Post by shadylane »

Looks like a good setup.
I don't see any safety issues.
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Dancing4dan
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Re: Steam Build Feedback Request

Post by Dancing4dan »

I like steam for stripping runs and use it almost exclusively.

Steam has some serious safety considerations that are exponentially higher than other distilling methods. Over pressure and under pressure can both be catastrophic. Any failure involves scalding liquid and likely to spill ethanol adding to any fire that may occur! :shock:

I make the following suggestions based upon my LIMITED experience. :D

A manometer can help prevent a under pressure/vacuum based failure that can occur when a steam rig is shut off and allowed to cool creating a huge vacuum as well as act as a pressure relief point. Cooling steam can collapse both boiler and pot as well as the intersecting lines. A manometer that is open to atmosphere is a MUST.

Consider switching your steam column, arm and leg to the same size of tubing. Change your steam outlet perforated copper to a SS mesh tube used for draining wart from a mash instead of the perforated copper. Your steam leg output holes need to manage all of the steam your boiler can produce. Don’t think yours will do that.

Your steam column reduces in size between steam column and your steam leg. This will cause increasing steam velocity and pressure. Steam is then restricted further by the steam outlet holes at the bottom of your steam leg. Your steam leg and outlet will act as a restriction and you will have pressure build up. You should be able to go full boil and not have relief valve/ manometer blow off. I use 3/4 copper from boiler to steam leg outlet.

Corn has higher viscosity and will cause greater back pressure than just a water charge in the pot. Corn can cook on your outlet as well causing problems. Corn is a bitch.

I use a manometer AND a separate pressure relief similar in concept to a old pressure cooker relief valve. This gives two places for steam to blow off. The manometer gives a visual of steam pressure and a second place for steam relief if there is a pressure spike. The manometer will blow all of it water out followed by steam in an over pressure. It will suck in the water and then suck air on an under pressure.

My set up is built so there is some distance between my boiler, electric controller and the pot. Done with the intent of putting distance between the operator and steam if there is a blow off. Pressure relief valve is on the boiler column. Manometer is on the pot. Controller is away from everything by itself and has a kill switch. I ran repeated test boils with water to ensure everything worked as intended. Anything that can go wrong eventually will! Plan on failures.

Pressure relief needs to come on gently in the event of a over pressure. Spring loaded valves don’t allow for slow in my experience.

It can take a while to heat the still pot with steam. I use additional propane heat to the still pot while stirring to help bring the pot up to temperature. The preheat of the still pot decreases “steam hammering” to nil.

Others have more experience and expertise and will chime in.

Be safe! Steam is a huge step up in risk potential.
"What harms us is to persist in self deceit and ignorance"
Marcus Aurelius
I’m not an alcoholic! I’m a drunk. Alcoholics go to meetings!
fzbwfk9r
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Location: Smack Dab in the Middle of God's country. Saskatchewan!

Re: Steam Build Feedback Request

Post by fzbwfk9r »

D4D has some good info there

I have a couple Q's. should the holes on the steam wand be better served on the bottom VS the top of the wand?

in addition to a manometer, would a cup/ball bearing work well for a secondary pressure relief? ( or if you have ability to create, an old tech pop valve )
Say, 3/4" pipe with a 1-1/2 => 3/4 reducer on it, with the 3/4 worked through so a 1.4375" stainless ball bearing sits on the 3/4. lap in a good seal on that pipe. the 1.5 cup would hold the ball if the pressure started to escape (1-1/8" ball on a 1/2" pipe?)

When building the mano, I think it would work well to make it tall enough that the liquid stays in the unit, but the gas can get by the lower "U" and bubble up through. just like an "S" bubbler air lock. That way, you wouldn't risk blowing liquid all over, and you wouldn't pull any back into the boiler on vacuum.
If you want to limit your unit to under 1.1PSI, use 30 inches of water in the mano.
Say 72" down to the U then 62" up with a 90* elbow to an exhaust port vented safely. fill it so there's 30" on either side of the U.
At 1.1psi, the pressure would push all the liquid to the outlet side and as soon as the U is out of water, gas passes safely to the outlet side and the 60" of water sits there allowing the gas bubbles to move out to the exhaust port.
And if there is a catastrophic pressure spike, the liquid can simply vent out the exhaust also. As a backup, the ball bearing would allow another vent.
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