Valve & Pressure

[knightt]

After reading most of this website, perhaps with the exception of the flavoring section, I still am unsure about why there is a valve on most of the stills after the condenser.

I have a couple of questions.

1. Why would you want a valve here?
2. If you turned it off, would pressure not build up inside?
3. Does the entire still need to be "leak free"?
4. How much pressure Do I need to manufacture this thing too? Right now I am thinking of the thermometer and how i am going to insert into the copper. Unfortunately I don't see any brass or copper sticker nodes, so a good soldering job is out of the question.
5. I don't see the pressure talked about much on the site, if there will be pressure, would a PSI gauge be useful?

Thanks

Brendan

[tracker0945]

Some of these things take a bit to get your mind around but it will all become clear as you read and study more.
But to answer your questions,
1 the valve is to control liquid flow rate
2 not unless you have sealed the top of the column (which is a no no)
3 yes
4 very little
5 not required

Cheers and happy reading

[Hawke]

I haven't seen any designs with a valve after the condencer. There is a valved reflux design, has two valves. One controls the amount of reflux, the other controls take-off. But those valves are under the condenser. Which is open topped.
Next is the Vapor management, has a gate valve to control take-off rate. (Again, under the reflux condenser and before the product condenser.) Top of column is open or has a vent hole.

Most thermometer mounting is done with a short piece of 1/4" copper tubing with a cork or wood grommet. Just drill a hole that the 1/4" copper will fit into and solder it in.

If you want a thermo on a potstill, just use a T fitting at the top of your riser and find a cork of the correct size. Potstill doesn't need a thermo as it will do what it wants anyway.

[snuffy]

After reading most of this website, perhaps with the exception of the flavoring section, I still am unsure about why there is a valve on most of the stills after the condenser.

I have a couple of questions.

...
2. If you turned it off, would pressure not build up inside?
...
4. How much pressure Do I need to manufacture this thing too? Right now I am thinking of the thermometer and how i am going to insert into the copper. Unfortunately I don't see any brass or copper sticker nodes, so a good soldering job is out of the question.
5. I don't see the pressure talked about much on the site, if there will be pressure, would a PSI gauge be useful?

Thanks

Brendan

The stills are open to atmosphere. In a pot still, through the condenser. In a column still, at the reflux condenser. So the pressure is very small. The backpressure is about the same as you'd get from an open length of 1/2" or 3/4" pipe. It's measurable, but it's not very much. You're blowing much more pressure when you blow up a balloon. Think of it as blowing just hard enough to make bubbles through a straw in a tall glass.

If you are thinking of putting a pressure gauge on the boiler, it will have to be the lowest pressure range you can find. In the US, the units would be column inches of water and the range would be less than 5" (much less than 1 psi). The lowest range mechanical gauges are 10 column inches and they cost $40US-$120US. Many of the digital gauges are not rated to the temperatures found in stills.

A U-tube or slant-tube manometer using mineral oil would probably do the trick, especially if it was arranged so the oil was as hot as the vapor. I'll have more data on pressures in about a month, as I'm planning some tests. If pressure is a useful thing to measure, I'll be prototyping some DIY gauges.

I think pressure data may turn out to be useful. The reason nobody has been putting gauges on is the pressure is so low and the gauges are expensive.

[pHneutral]

I haven't seen any designs with a valve after the condencer.

The PDA-1 has the valve after the condenser.

So essentially you drive it by equalizing it first with no flow, waiting a bit, and then cracking it open a tiny bit at a time. As the run progresses, and the temperature rises, you'll need to occasionally adjust it a SMALL amount to get the drip rate you want. If you adjust it too severely in the open direction, the column might flush, and you have to equalize it all over again.

If its equalized before you open it up for use, only the first mls are from the initial unequalized vapor, then the pure foreshots come over since they are sitting there, right at the top of the column, waiting to be brought over. And then the rest.

[knightt]

The stills are open to atmosphere. In a pot still, through the condenser. In a column still, at the reflux condenser. So the pressure is very small. The backpressure is about the same as you'd get from an open length of 1/2" or 3/4" pipe. It's measurable, but it's not very much. You're blowing much more pressure when you blow up a balloon. Think of it as blowing just hard enough to make bubbles through a straw in a tall glass.
expensive.

I still don't get it. It his to be "leak free, but it also has to be open to the atmosphere? If the vapor was going into the atmosphere, I would call that a leak.

If you put a hole on the top of a reflux column (with a condenser at the top) would the vapors not just float out the top?

How are the cooling coils open to the atmosphere in a pot still? is the alcohol not moving through a tube surrounded in water? if it was open somehow (perhaps by a perforated pipe) would the water not fill the pipe?

Why is not perforating the top of a still pot a good idea?

There is something here I am not getting. Thanks for bearing with me. I think I am starting to understand the importance of valves though. It might be one of those things I will have to do to really understand. I got really excited about distilling when I heard of a friend visiting a bootlegger. There was many promises to introduce me and teach me how to do it, but they fell through and I am left to figure it out on my own and rely on your expertise here. I do really appreciate your help.

[brewmaker1]

The idea of a reflux still is as the vapors rise, something (packing, condenser) cools it back to liquid state and it drops. As the liquid is dropping it is cleaning the vapor that is rising, which in turn cools and drops (reflux). The condenser on top is the big cooler. Vapor won't get past the condenser unless it's too hot or not enough cold water is running through the condenser. The same thing happens when the vapor goes through the liebig or worm, only reversed. The water in on the outside and the vapor is on the inside.

[rad14701]

Welcome to the forums, knightt... Sounds like a little more research into the theory behind the different type of stills, as well as distillation theory in general, is in order... We try not to say read, read, read, to new members if at all possible... However, we can't answer the same basic questions for every new member simply because they haven't done adequate research...

The answers to your questions are here in the forums and on the parent site... Finding the answers to your current questions will also answer several questions that haven't come up yet as well... You owe it to yourself, as well as the membership, to give the parent site at least one complete read through, more like three, before asking questions here in the forums... The more times you visit the parent site, the more sense the whole process will make because you will start to assimilate what may otherwise seem like disparate bits of information...

Good luck, and good reading...

[Ugly]

However, we can't answer the same basic questions for every new member simply because they haven't done adequate research...
Good luck, and good reading...

I agree to an extent but the forum is here for questions. Ask away someone will answer in a fashion that makes sense. Proper learning requires that the same information be presented to the human brain in three different fashions before that data can be cross referenced intelligently in most humans. I thought your questions were reasonable and it's sometimes hard to glean what's going on with the process because of new (to the beginner) terminology etc. This is the Novice distillers section, the section I assume is designed to let people ask questions that might prevent misunderstandings or potential fatalities or that weren't clear from a simple round of RTFM (read the F* manual). It takes just as much time to berate a new distiller as it does to point them in the right direction. If I wasn't interested in supplying the data I'd pass by the thread.

My humble opinion is that you will learn more by actually building a simple still and running it than by reading re reading and planning all day. It will force you back to reference information that suddenly makes sense in your circumstance. Simply follow the cheapest most basic design plans to the letter and learn to run it. Run it a dozen times with a cheap wash and then start making hooch you want to drink.

You'll be back building your dream still before you know it.

[trthskr4]

What type of still do you want to build, pot or reflux? If you want whiskey, rum, brandy and other flavored drinks you want a potstill. If you want vodka, a reflux.

Both stills are always open to atmosphere somewhere or it'll explode on the heat up. Reflux rigs need to be equalized and you don't want any product running out during equilibrium or it'll never equalize, it'll just keep pumping out lower than expected abv. so it has to have the output shut off. So there is a hole above the reflux condenser which opens it to atmosphere but the condenser doesn't let any vapor past it, it condenses it back to liquid and it falls back toward the boiler. A pot still is open to atmosphere through the condenser (worm or liebeg) all the time.

[tracker0945]

By NO LEAKS, we mean in all of the joints of the boiler, column, condenser etc. must be leak proof for safety reasons.
The still itself must not be sealed off from the atmosphere though.



Cheers.

[snuffy]

Open to the atmosphere means any vapor has to pass through a condenser and turn to liquid before it exits the still. So the only stuff coming out is liquid. Vapor leaks are bad because alcohol vapor is dangerously flammable and can be explosive. and wasteful, too.

[knightt]

What type of still do you want to build, pot or reflux? If you want whiskey, rum, brandy and other flavored drinks you want a potstill. If you want vodka, a reflux.

Both stills are always open to atmosphere somewhere or it'll explode on the heat up. Reflux rigs need to be equalized and you don't want any product running out during equilibrium or it'll never equalize, it'll just keep pumping out lower than expected abv. so it has to have the output shut off. So there is a hole above the reflux condenser which opens it to atmosphere but the condenser doesn't let any vapor past it, it condenses it back to liquid and it falls back toward the boiler. A pot still is open to atmosphere through the condenser (worm or liebeg) all the time.

Thanks very much. Because of your posts I was able to hone in what I didn't understand. I did several hours of reading and many more of just thinking about it.

I think I have enough of the idea to start with a pot still and then when I want vodka, move to a reflux.

I had already replied here, but it looks as though my message didn't make it to the forum.

You have all been an enormous help. I will post pics and stats of my still as soon as I get it assembled and try a few practice runs.

I also think I will do a leak test by covering the outside joins with soap, and boil water while plugging the whole thing up. If I get bubbles before the cork pops out, we have leaks. If not, we are good to go. I do copper plumbing though, so I somehow doubt if there will be any leaks.

Pics to come!

[trthskr4]

No don't cork it We're talking less than 1 psi under normal conditions while running, you'll be able to see or smell a leak cause it'll bubble or steam on a normal run of water.

You can always do 3 slow distillations on a vodka wash through a pot still. That"s what Wineo's plain ol sugar wash was made for. But you'll still want another still if you enjoy this hobby.

[snuffy]

if you test it with plain water and the place you're using is cool, you'll see steam at the leaks. It's a good idea to do the first test with water because it will get rid of some of the flux residue and other dirt from the assembly process.

Alcohol vapor is invisible, so you won't see the leaks unless they also blow enough liquid to bubble.

[junkyard dawg]

Alcohol vapor is invisible,

huh?

its visible, if there is enough of it...

once you see it you will know why its called spirits tho...

[punkin]

if you test it with plain water and the place you're using is cool, you'll see steam at the leaks. It's a good idea to do the first test with water because it will get rid of some of the flux residue and other dirt from the assembly process.

Alcohol vapor is invisible, so you won't see the leaks unless they also blow enough liquid to bubble.

Jd's got ya Snuff, turn off your reflux condensor during a run if you don't believe him

[snuffy]

I stand corrected, but I'd rather find leaks with water given the choice. The vapor is much easier to see and far less flammable.

I had trouble with some small leaks in my thumper fitting that I couldn't see. I thought I sometimes smelled something when I got my nose close to the area, but I had a hell of a time finding it. It finally showed up by bubbling. Then it drove me nuts, because I could never get them to solder up until I put huge globs on to cover the whole damn area. I hate trying to resolder joints. (8=X

I've seen it when there was a lot coming through (like not having the cooling water on) What's that coming out the condenser?!?!! I didn't consider that a leak, more like a #@##$%! disaster about to happen.

[punkin]

I've seen it when there was a lot coming through (like not having the cooling water on) What's that coming out the condenser?!?!! I didn't consider that a leak, more like a #@##$%! disaster about to happen.

Yes, walked out to the shed one morning to see an airlock in the condensor line and vapour pouring out with highproof distillate condensing and dripping off the roof above the column

Lucky i was cooking with electrickery at the time.

[HookLine]

Yes, walked out to the shed one morning to see an airlock in the condensor line and vapour pouring out with highproof distillate condensing and dripping off the roof above the column

Lucky i was cooking with electrickery at the time.

Glad you're still with us.

Hooray for the modern magic of electrickery.