My still has imploded!!!! Digiboil 35L

[AppleWood50]

So a few days ago I was maybe 2 hours into a 25l stripping run when I got a call from my daughter. She had been In a car crash and was on the way to the hospital. Stupidly I forgot to turn the still off and gone straight to the hospital.

When I got to the hospital about 45 mins later I remembered that I left the still on. I thought stupidly, ah it'll be fine. As i run my still outdoors. So I asked my wife just to watch the drain and the condenser outflow going down the drain. I told her, if the water stops flowing shutdown the still immediately.

Stupidly I thought, the only thing that could really go wrong was the condenser water flow pipes could kink. After all, the riser and condenser was 2 inch copper pipe. Even if the still puked, 2 inch copper pipe should be to large to block up.

The wash ran for about 3 hours unattended then my wife shut it off. I got back home and found that my entire boiler had imploded!

The boiler was charged with 25 litres of 14% abv sugar wash, running on 2400w and the collection vessel had filled to about 7 litres of 30% low wines.

So the run had definitely continued and collected maybe 70% of the alcohol from the wash. But the entire boiler has collapsed.

Setup details

20 inch 2 inch copper riser, 22 inch 2 inch shotgun condenser with 4 x 15mm pipes inside. Digiboil 35l boiler. All connected with TCs.

I'm very disappointed as the digiboil was basically brand new and im sure that it can not be repaired. But I'm more curious about what gone wrong here?

Please guys, no bashing on leaving the still semi unattended. I know I fucked up. Please keep in mind though that I did run this outdoors and not inside.

[subbrew]

Had to be a blockage some place in the line which did not allow air to suck back as the still cooled. In the pic I see a hose going down on the left side of the picture. If that is your product line, it should not be in a hose but aside from that, if it is down in the product, as the still cooled it tried to draw product up the hose but just too much head due to the height, developed a vacuum and collapsed the sides.

[still_stirrin]

Dumb assed move AppleWoods.

Hope your daughter is OK.

You got lucky … this time!

What’s that? Is it a plastic hose on your product outlet? Shame on you.

It seems you’re more dangerous than you think.
ss

[Ben]

Get yourself a brass or stainless hammer and pound it back out, gentle blows... if you beat it like it owes you money things will go south, use a chunk of wood to back it up. If the sealing surfaces weren't compromised you should be fine. Your Measurement markers won't be accurate anymore

You need to find and understand the blockage, that's unsafe. A still will do this with a thumper attached but otherwise should not, it should be a zero pressure system.

[TwoSheds]

Even a rubber mallet would probably bang that back out well enough, then fill it with water and look for leaks!

Edit: Small leaks or even cracks may be repairable with silver solder. As others said, don't give up on it, but proceed carefully.

I know folks suspect blockage, but I wonder if this could happen even without a blockage. Still shuts off, vapor output stops, starts to cool and pull cold air in and BAM! cold air coming back in the vapor path cools the vapor even faster, which pulls in more cool air, which cools even faster, and you have a runaway cooling situation making a vacuum faster than your PC can let air in!

Just a theory, and not one I want to test...

[Stonecutter]

I assume you created a vacuum atmospheric pressure/ physics and all that. It’s like trying to dissect what happens when you throw gas on a fire.
I understand you not wanting to catch a thrashing, but the fact of the matter is that this is exactly the kind of stuff that is used to make an argument against the legalization of home distilling. I certainly wouldn’t want to be your neighbor at this point. Very fortunate the only thing damaged was your still.
Here’s a vote for this topic being placed into the “what not to use/do” section.

I hope your daughter is doing ok.

[SmokyMtn]

Maybe give knitting a try. This hobby just isn't for you.

[jonnys_spirit]

Agree that something was blocking the vapor path or perhaps output was submerged in the . I've shut my pot still down after every time I've used it (sounds too obvious?) and never had a boiler implode - 3" riser, 2" shotgun or 1/2" liebig probably run hundreds of times....

Cheers!
-j

[NormandieStill]

I know folks suspect blockage, but I wonder if this could happen even without a blockage. Still shuts off, vapor output stops, starts to cool and pull cold air in and BAM! cold air coming back in the vapor path cools the vapor even faster, which pulls in more cool air, which cools even faster, and you have a runaway cooling situation making a vacuum faster than your PC can let air in!

Just a theory, and not one I want to test...

Nah. Unless the output was so small as to make it near impossible for liquid to leave. A shotgun condenser isn't going to do that.

I think the best explanation is that the tube directing the output into the collection jar ended up below the liquid level forming a vacuum when the still cooled.

[squigglefunk]

digiboil? more like digifoil !

[MiddleOfTheWorld]

perhaps output was submerged

This right here, you have a hose in your output line and if that's dipped under the product, well you just hade a airlock.

Atmosphere sure is heavy handed when you least expected . Remember vacuum cannons can make things go supersonic.

well at least you didn't blow up your house

[Smog]

Being who I am, I would load it with hot water, block the top vapor port and start the boiler to pressurise it back in place.

... or use an air compressor set to max 5 psi

[Kareltje]

Being who I am, I would load it with hot water, block the top vapor port and start the boiler to pressurise it back in place.

... or use an air compressor set to max 5 psi

You got a point.
But I still do not understand what went wrong.

[cob]

All the above admonitions apply. That said were you able to push out the dents by hand?

If not or to refine the appearance cut a piece of 2x4 or 6 to the inside diameter then round

the cut ends some for a compound curve. slide inside and work the dents at the point

furthest from the sharp kinks. sometomes I make one end large for support 2x8-10-12

and the other as small as 2" sure to match the inside curve or you will make dents

from the inside out, and the smoother the buck you make the cleaner the work will be..

Good luck.

edit to address Smog's post. I have used air on corney's and it took upwards of #175 to move

the stainless. It moved, It was loud, And it was in containment, but it didn't split, hydraulic

(water) pressure would be more controllable but you need an airless. and containment.

[Smog]

Clearly, OP have a ball valve on the output of the vapor path because no effing way an airlock caused by a hose standing in liquid would allow the vacuum to build up.

As the vessel cools down, the vacuum would have pulled the spirit back in the vessel.

I call it, OP have a valve somewhere that could also allow the vessel to pressurise and could have killed his wife while he is in the hospital with his daughter.

[shadylane]

@ AppleWood50


Something ain't right.
Do you have any pics of the plumbing on the top of the still and the output end of the silicon hose.
It took a 100% blockage to hold enough vacuum to squish the boiler.
Whatever caused it to suck flat, could have also caused a major life changing catastrophe.

[Dancing4dan]

I suspect the hose was sealed to bottom of the collection vessel to create a seal.

[Stonecutter]

I suspect the hose was sealed to bottom of the collection vessel to create a seal.

+1
Without some info from AppleWood50 we’re all just shooting from the hip here but that sounds like a simple explanation. KISS

[psf]

I suspect the hose was sealed to bottom of the collection vessel to create a seal.

and then it rained.

[HDNB]

i have a CIP on my column. i bumped the valve once when the still was running, releasing a few ounces of cold water, directly into an operating column.
also equipped with a 3psi prv/vacuum release. you should have heard that little fucker scream like a train whistle for about 7-10 seconds (seemed like 2 minutes)

no damage. the amount of water was small. the vent on the prv is also very small. i believe you would need full vacuum to collapse the tank, so the output would have to be fully blocked....you haven't said anything about finding the full blockage yet, so do that before you worry about pounding out a dent. You did ask how it could have happened, i'd say that's the only way that could have happened. be glad it wasn't an explosion.

[elbono]

If that hose is on the output and is fairly soft (at the temp it was at) it will flatten when suction starts, causes more suction, more collapse....

Suction sucks!

I've seen a railcar tanker collapsed by a small suction conveying system blower. It's amazing how much force "vacuum" can exert.

[cob]

[Dancing4dan]

If that hose is on the output and is fairly soft (at the temp it was at) it will flatten when suction starts, causes more suction, more collapse....

Suction sucks!

I've seen a railcar tanker collapsed by a small suction conveying system blower. It's amazing how much force "vacuum" can exert.

Yeah. I think that’s the likely culprit.

[subbrew]

Clearly, OP have a ball valve on the output of the vapor path because no effing way an airlock caused by a hose standing in liquid would allow the vacuum to build up.

Actually it could. He would be drawing a column of water (actually a water/alcohol solution) up the hose. It doesn't take much pressure to cause an implosion like that. If the solution was drawn 30 inches up the tube it would be 2.2 psi on all of the surface. Lot of surface, lot of pressure

[Smog]

Actually it could. He would be drawing a column of water (actually a water/alcohol solution) up the hose. It doesn't take much pressure to cause an implosion like that. If the solution was drawn 30 inches up the tube it would be 2.2 psi on all of the surface. Lot of surface, lot of pressure

A round shaped vessel require quite a bit of sustained vacuum to implode.

Pulling water 30 inches up a tube is something you can do with your mouth and lungs. Can't implode a digiboiler unless the hose was completely collapsed and hard blocked. Having the end of the output hose standing in an open pot of alcohol/water will not allow enough vacuum by itself.

( ever siphoned a gaz tank using a tube ? That vacumm you were holding with your tongue against the end of the tube was the same as 30 inches of water. Can't crush a stainless tank with that)

[shadylane]

I'm thinking 30 inches of water equals 1.08 psi

[acfixer69]

Actually it could. He would be drawing a column of water (actually a water/alcohol solution) up the hose. It doesn't take much pressure to cause an implosion like that. If the solution was drawn 30 inches up the tube it would be 2.2 psi on all of the surface. Lot of surface, lot of pressure

A round shaped vessel require quite a bit of sustained vacuum to implode.

Pulling water 30 inches up a tube is something you can do with your mouth and lungs. Can't implode a digiboiler unless the hose was completely collapsed and hard blocked. Having the end of the output hose standing in an open pot of alcohol/water will not allow enough vacuum by itself.

( ever siphoned a gaz tank using a tube ? That vacumm you were holding with your tongue against the end of the tube was the same as 30 inches of water. Can't crush a stainless tank with that)

Vacuum is much greater the 30 inches of water it can approach 30 inches of Mercury. Plus atmospheric pressure on the surface. Easily implode a thin wall boiler.

[jonnys_spirit]

Actually it could. He would be drawing a column of water (actually a water/alcohol solution) up the hose. It doesn't take much pressure to cause an implosion like that. If the solution was drawn 30 inches up the tube it would be 2.2 psi on all of the surface. Lot of surface, lot of pressure

A round shaped vessel require quite a bit of sustained vacuum to implode.

Pulling water 30 inches up a tube is something you can do with your mouth and lungs. Can't implode a digiboiler unless the hose was completely collapsed and hard blocked. Having the end of the output hose standing in an open pot of alcohol/water will not allow enough vacuum by itself.

( ever siphoned a gaz tank using a tube ? That vacumm you were holding with your tongue against the end of the tube was the same as 30 inches of water. Can't crush a stainless tank with that)

Vacuum is much greater the 30 inches of water it can approach 30 inches of Mercury. Plus atmospheric pressure on the surface. Easily implode a thin wall boiler.

Also consider that vacuum would be in the tube as well as the boiler volume - estimated depleted 1/2 or more after a strip run... 35l Boiler started with 25l charge and more than 7l low wines boiled off...

Sounds plausible if not likely!

Cheers,
j

[HDNB]

i'd buy that for a dollar, hot flexible tube draws distillate back up but collapses closed on itself from the -1.08pressure (thanks for the math shady)

once the hose was sealed on itself, still continued to cool building negative pressure until whoompf.... (that's the technical term)

[Yummyrum]

I suspect a lot of the mystery is under the tape.

Sorry you had a bad day , hope the Daughter didn’t get as crumpled as your still .

Two good lessons learned .Don’t leave the still unattended and another good reason not to use synthetic hose on the output of a still .