Pressure

[tolona]

Can anyone tell me how much pressure (psi) is developed in a still at say 180-200 degreesF? Has anyone messured this. I know this would slightly depend on what's down the line in terms of length, thumpers, cooler coils etc. I read one time that an old-time RR steam engine developed at a head of steam about 5 to 8 psi; I would have thought more. But then I thought, in a steam engine you are going to have to add water to the boiler every once in a while, but you don't want to let off the pressure to do this. How was this done? >>>>>> The injector pump, which was powered of course by the engine. Now the guy who invented this pump was a flippin genius. It made RR possible. I think this may have relevance to the distilling art......................sm

[Ayay]

Stills contain a combustible mix. The pressure is atmospheric + or - a bees' dick. If you are measuring a bees' dick then there is something to consider. Steam boilers using only water under pressure are a completely different kettle of fish!

[olddog]

There's no presure in an open vessel, presure will only occur when the outlet is closed. Just like there is no pressure in a saucepan with boiling water, but if you seal it up Kaboom!!!!

[rad14701]

tolona, please do more reading before someone gets hurt... Think about it... You're talking about pressurizing explosive vapor... The parent site can help you with the fundamentals...

[grunger]

my still creates just under 1/100th of a bees dick of pressure.

btw currently potstill, +-80" worm in 60 gallon rain bucket. .

[Hack]

The ideal still will build as little pressure as possible to get the job done.

My original setup had 3/8" copper line coming off a stainless mixing bowl cap that was held on with a bungie cord. I also run a thumper which creates some back pressure. If I ran the heat too high it would develop enough pressure to start leaking past the flour dough seal. When I upgraded to a 2" column and a tapered lyne arm to a 3/8" condenser this stopped happening and increased my collection rate. When I increased the size of the condenser to 5/8" copper tubing, I greatly increased the collection rate.

So the moral of the story is a larger column and tapered lyne reduces pressure and increases collection rate and so does increasing the diameter of your condenser, or the most restrictive point in your rig. Pressure at a certain temp isn't a constant thing it varies according to how restrictive your vapor path is.

[rad14701]

Any small amount of pressure that might build in a still would be measurable in inches of mercury, not in pounds per square inch (US measurements)... The amount of potential pressure should be that small...

[tolona]

Hell Rad, if we took our momma"s advice we wouldn't be doin' this in the first place... Would we? It puts me in mind of the Gerry Spence story which he likes to tell about the country lawyer who was defending an old boy against his dog biting the neighbor. His arguments were, In the first place, His dog was home that day, and in the second place, his dawg don't have no teeth..... And in the third place..... HE don't Even Have a Dawg....................

[rad14701]

Hell Rad, if we took our momma"s advice we wouldn't be doin' this in the first place... Would we? It puts me in mind of the Gerry Spence story which he likes to tell about the country lawyer who was defending an old boy against his dog biting the neighbor. His arguments were, In the first place, His dog was home that day, and in the second place, his dawg don't have no teeth..... And in the third place..... HE don't Even Have a Dawg....................

I fail to see any significance between the advice that members have given and your less than humorous reply... If you aren't going to take this craft/hobby seriously then perhaps you should find an alternate place to reminisce... We have better things to do, like helping people who take safety seriously and actually have a desire to learn...

[tolona]

Rad, find a girl I would recommend your local library or the dollor store....... This will solve all your problems.

[rad14701]

Rad, find a girl I would recommend your local library or the dollor store....... This will solve all your problems.

Must be troll season, folks... Moderators might as well lock or delete this entire topic...

[drmiller100]

Can anyone tell me how much pressure (psi) is developed in a still at say 180-200 degreesF? Has anyone messured this. I know this would slightly depend on what's down the line in terms of length, thumpers, cooler coils etc. I read one time that an old-time RR steam engine developed at a head of steam about 5 to 8 psi; I would have thought more. But then I thought, in a steam engine you are going to have to add water to the boiler every once in a while, but you don't want to let off the pressure to do this. How was this done? >>>>>> The injector pump, which was powered of course by the engine. Now the guy who invented this pump was a flippin genius. It made RR possible. I think this may have relevance to the distilling art......................sm

most stills use well under 1 psi. The VM stills use pressure to control reflux, although it is a very small amount of pressure.

I think it is funny people think the explosive vapors stuff causes the still to blow up if it ever saw pressure.

[Hack]

The VM stills use pressure to control reflux, although it is a very small amount of pressure.

I think it is funny people think the explosive vapors stuff causes the still to blow up if it ever saw pressure.

A properly built VM is open above the reflux coil. It builds no pressure. A VM controls the reflux by varying the take off rate.

I don't see anything funny about people potentially harming themselves in any way. Too much pressure will rupture a still, combine that with potentially explosive vapor, and a heat source that may even be an open flame and the results could be anything but funny.

[blanikdog]

... I think it is funny people think the explosive vapors stuff causes the still to blow up if it ever saw pressure.

What's so funny about it? Could you expand on this? Just curious.

blanik

[drmiller100]

... I think it is funny people think the explosive vapors stuff causes the still to blow up if it ever saw pressure.

What's so funny about it? Could you expand on this? Just curious.

blanik

There is HUGE energy in the steam and compressed steam contained in a still. There are videos out there of hot water heaters shooting up through roofs, destroying homes. Old timer stories of locomotives cooking off. A really bad deal.

I personally have talked to two different people who built a still incorrectly and blew the top off it. For sure a really bad deal.

All that, and add home built electricity, running water, metal tanks, and a HUGE chance to get electrocuted.

I have never heard of a still blowing up because of "explosive vapors." I am assuming "explosive vapors" refers to the vapors actually igniting. This would require a significant leak an ignition source, and an enclosed space.

But hey, I'm really new at this. Is explosive vapors a bigger danger then I'm thinking????

[olddog]

Can't you get it into your head, that unless a vessel is sealed with no output for vapours to escape, its impossible to explode by pressure

[Hack]

Can't you get it into your head, that unless a vessel is sealed with no output for vapours to escape, its impossible to explode by pressure

My original setup only had a 3/8" copper line coming off a stainless mixing bowl cap. The cap was held on by a bungie cord and sealed with flour paste. When I ran my propane burner wide open to heat up, and about the time the heat had crossed the lyne arm and I was waiting for my thumper to heat up, enough pressure would build up to pop the seal loose on the cap. Now If my cap was bolted or solidly clamped down, it would have continued to build pressure without my knowing. Would it have blown up? I don't know, maybe. I think it's possible. This was a vessel that had output for the vapor to escape, but was still capable of building pressure.

If you build pressure faster than the outlet can releive it, somethings going to give.

[Dnderhead]

""Is explosive vapors a bigger danger then I'm thinking""
no! it takes fuel and oxygen ,in the still you have the fuel but no oxygen.(it is purged from still by vapors)
if there was a explosion, more then likely it whould be vapors escaping into a enclosed room. (keep room ventilated/no leaks)
any good designed still can not develop presser, always open to atmosfear, or some "weak link" (like the lid on a pot still)

[Ayay]

Hey drmiller100, the only thing that will persuade me that you are not a troll is for you to post some pictures of your still.

Nah...cancel that, a troll can grab any pic off the web.

[squidd]

... I think it is funny people think the explosive vapors stuff causes the still to blow up if it ever saw pressure.

What's so funny about it? Could you expand on this? Just curious.

blanik

.... There is HUGE energy in the steam and compressed steam contained in a still. ....

Tried to respond DR, but decided to bang my head against a big rock instead.

squidd

[Husker]

People, please stop feeding the troll's!



H.

[grunger]

agreed Husker. Had a bad feeling about this one from the begining.

[blind drunk]

agreed Husker. Had a bad feeling about this one from the begining.

ditto

[tolona]

What? I come on to this board to ask a simple question and I draw fire from the likes of Rad Valentino. I will not be drawn into these petty arguments... I have whiksky to run... Olde Mike Gardner drank a pint of it and went home and stole one of his own plows and hid it in the woods, and didn't know where it was when he was sober, and had to get drunk again to find it..... from Mark Twain "Roughing it"

[Ayay]

Tolona is another troll! You have whiskey to run, can't spare the time etc. Let's see it.

Irrelevant quotes won't do it either.

A simple question you say...how many more do you have up your sleeve? F**k the answers, keep the simple questions comin it the way of the troll.

[myles]

Well on the premise that this was just a misguided question with good intentions - there is loads of info available for budding model steam engineers.

Steam engines NEED to build up pressure in order to work. Stills do NOT. Pressure in steam engines is GOOD. Pressure in a stil means BAD BADA BOOM.

Two different applications of the same basic theory. The only time you want pressure in a still is to lift a few inches of fluid in a thumper and that is much lower than a steam engine pressure. Does that help at all.

[Adverse Effects]

i am going to be a sort of a troll (not really just stating a point that most of you wont know because you have not built / used a Ponu still)

the Ponu still will build up a few PSI but that is because of its design i am in the posses of working out a better way for it to be made to get around this problem

[rad14701]

Adverse Effects, your Ponu still is a very unique exception... Lots of room for tweaking that particular design... I still have the itch to try building one...

[nh_yankee]

In order for an explosion (caused by alcohol vapors igniting) to occur a condition where the vapors are between the lower explosive limit and the upper explosive limit (LEL and UEL), a sufficient amount of Oxygen and a source if ignition must exist in the confined space of a still. It is more likely to have the boiler rupture because of pressure build up (corn stuck in the outlet) and the vapor flash over outside than to have vigorous combustion (eg explosion) in the still as the water vapor and alcohol vapors have driven off any Oxygen. No O2 no combustion.

[eternalfrost]

just curious... whats the advantage of a 'ponu'?

didnt read through the page just looked at the schematic. seems overly complicated to do something that other dead simple designs have been proven to excel at (VM LM or a simple pot)

especially if you are saying it can build up pressure.... bad news