Pressure in my plated column?

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Moonlighter
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Pressure in my plated column?

Post by Moonlighter »

OK so I assembled my plated column. Fired it up and started the cleaning run. About 3 hrs of adj heat and water flow from the 3 valves and the controller... with a few leaks in the middle. the still is running. I adjusted power so it stacked plates correctly. However, like several others, the downcomer is below the sight glass. So when its running right you cannot see much. Its not splashing everywhere in the column, but it is bubbling. I think I should see quite a bit more reflux than what I see. HOWEVER, this is a cleaning run and I know water is different than booze when it comes to running these. Out of curiosity, I kicked the boiler (26 gallon milk can). Normally this boiler sings when bumped. This time, not a peep! I killed the controller (which isnt making much sense anyway, seeing how its running on high @ max amperage = 5500w at 244v= 22A) I dont think my controller should apply 5500w to 26 gallons of mash without flooding the column. And I would definitely think that it should give much more bubbles at 100% (5500w) for 26 gallons. As soon as the heat is killed the boiler sings again when tapped. The plates are as follows: 4" Perforated plates, 1.4mm holes on 5mm grid, with 8 plates in 4' of column. Seems in my book, to work out to 8% or so surface area. Thought I read that is what we needed? The plates are designed to hold 3/4" of liquid on each plate. I could see that being a few lbs of pressure, but enough that my boiler is rock solid? It makes me nervous. Does this sound right? I will take it apart tomorrow and make sure nothing is clogged but I did have some vapor/condensation for a while coming form the product condenser. TIA
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frunobulax
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Re: Pressure in my plated column?

Post by frunobulax »

The boiler should never build pressure.
Did you shut the deflag off and see if the product condenser was working? was anything dripping out past your deflag?
You used ALOT of heat to load the plates with water. When it's running a wash, it's alcohol bubbling on the plates while the water passes back down to the boiler.
Once it's set up and running a wash, It will take very little heat to keep the plates loaded.
If you there is a possibility of a blockage, take it apart and check, but it sounds like you were just running it too hard with water.
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Yummyrum
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Re: Pressure in my plated column?

Post by Yummyrum »

Like you said , it will run completely different with alcohol in it .

Just do it :D
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Bushman
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Re: Pressure in my plated column?

Post by Bushman »

OK, I will ask the questions. You mention 3 valves, one to the dephlagmater, one to the product condenser, where is the third valve and what is it's function if not a drain valve? You also mention a few leaks, make sure you take care of those before adding alcohol.
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T-Pee
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Re: Pressure in my plated column?

Post by T-Pee »

The sight glass on my CM is just below the downcomer. That way I can run it so that when distillate is bubbling halfway in the sight glass, I know I'm running the still at optimum without spilling over into the lyne arm.

You should NEVER have pressure anywhere in the boiler system, btw.

tp
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shadylane
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Re: Pressure in my plated column?

Post by shadylane »

Moonlighter wrote: The plates are designed to hold 3/4" of liquid on each plate. I could see that being a few lbs of pressure, but enough that my boiler is rock solid? It makes me nervous. Does this sound right?
8 plates with 3/4" of liquid on each plate = 6 inches of water pressure
That's only a fraction of 1 psi
You can build a cheap and simple manometer if you want more info
Edited
6" wp is 0.2168 psi
Moonlighter
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Re: Pressure in my plated column?

Post by Moonlighter »

I will unassemble it and check. Hate to do so as this was the easiest way to check for leaks before alcohol gets in there. PTFE gaskets are tough to seal. Yes it would run a small stream out the product condenser if I allowed it to. And I agree it was running that controller well above its designed function. But yes even with only 6" of water in the plates it was popping the 1.5" cap off when I removed the clamp. Instantly when the heat is removed the pressure subsides. Just wanted to double check and see if anyone else had noticed this. Wish I had a 5 psi pop off valve that was safe in an ethanol path. If its this hard to stack plates with water, then how are you guys doing water/vinegar cleaning runs?

BTW someone questioned the valves. Yes one at deflag, one at product condenser, one at the spigot ;)
rad14701
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Re: Pressure in my plated column?

Post by rad14701 »

Moonlighter wrote:Wish I had a 5 psi pop off valve that was safe in an ethanol path.
Not the right tool for the job... Shadylane gave you great advice by suggesting a manometer... A 5 PSI pop-off valve is too high of a pressure... We've had these discussions many times... You'd be amazed by how long it takes to bleed down 5 PSI through a small or even moderate sized orifice...
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Re: Pressure in my plated column?

Post by bentstick »

Post and link Deleted for reason of unsafe and not acceptable!
Last edited by bentstick on Fri Dec 23, 2016 9:14 pm, edited 2 times in total.
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rad14701
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Re: Pressure in my plated column?

Post by rad14701 »

But that exact unit isn't recommended as it has a nylon poppet valve rather than stainless steel... Not to mention that it couldn't reduce the pressure fast enough due to restricted size... 54 cfm is not much when it comes to an over-pressure active boiler...
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Re: Pressure in my plated column?

Post by jedneck »

Moonlighter wrote:
BTW someone questioned the valves. Yes one at deflag, one at product condenser, one at the spigot ;)
Right there in bold. Tickin bomb
welcome aboard some of us are ornery old coots but if you do a lot of
reading and don't ask stupid questions you'll be alright most are
big help
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Moonlighter
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Re: Pressure in my plated column?

Post by Moonlighter »

I know enough that this isnt a "ticking bomb". Not sure what my spigot has to do with that. And obviously that pop wont work being brass and nylon. Really dont need the pop valve but safety would be good. Everything is pressure tested to 100 psi so 5 psi doesnt worry me. Would if it was gas. and I have means to vent straight off the pop valve. If it needs to be made I can make it. Guess a 1/2 gallon of water stacked up creates some type of pressure. The still is clean and clear. If someone does have a link to something that would work like the manometer, by all means please post it. Better safe than sorry. I will see if I can find it here in the search. thanks for the help. Merry Christmas!
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jedneck
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Re: Pressure in my plated column?

Post by jedneck »

sorry moonlighter. i was thinkinoutput spout. not water spigot.
welcome aboard some of us are ornery old coots but if you do a lot of
reading and don't ask stupid questions you'll be alright most are
big help
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Re: Pressure in my plated column?

Post by googe »

do some trouble shooting mate, plate area seems ok, tick. power seems ok, tick. bath depth seems ok, tick. what design is your rc?, can your design restrict flow?. 8 plates needs some power, a water run is very different to a alc run, VERY DIFFERENT. you have a output through pc, tick.
Here's to alcohol, the cause of, and solution to, all life's problems.
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bentstick
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Re: Pressure in my plated column?

Post by bentstick »

Nail on the head googe :thumbup: and ya fellas are right The pop offs are junk and un provin,the link is takin off and ya wont need to worry,was only helping I dont have enough experince for that! :yawn:
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shadylane
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Re: Pressure in my plated column?

Post by shadylane »

A manometer is useful to measure boiler pressure
It can also protect a boiler from over pressure and vacuum
This example will blow the water out and vent the boiler around 1/2 psi
Attachments
manometer.jpg
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