What does it sound like? (Vapor escapes/huffing)

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gurkan
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What does it sound like? (Vapor escapes/huffing)

Post by gurkan »

Hello everyone, it is my first post other than the instruction, and as a true rookie it has to be a post that I ask for help with something :)

For the last two weekends, I'm trying to make my first still work without any malfunctions and safety issues so I really took my time with tests and improvements. The pot still, which is a 17lt pressure cooker and a flake stand with worm appears to be free of leaks and works like a charm according to my test runs with water first and a vinegar second. Except, it makes a sound that I find it close to what previously mentioned in other threads as "huffing", but also I've read in other threads that it may also be vapor escaping situation.

While building my still, out of being a novice I've accidently bent horribly a part of 3/8 copper pipe and made it totally useless so my pipeline became shorter than I expected. The worm is less than 1 meter and it barely makes 2-3 swirls until it reaches to bottom and goes out from the flake stand through the hole to drop the product. So, I ordered extra few meters of pipe because I thought that if it's huffing, then maybe making the worm longer will decrease the speed of vapor and will prevent the huffing. But, if it's something different, or maybe something dangerous, I'd like to know before I start to boil the flammable real deal in the house I sleep.

So, if anyone can identify the sound by just hearing it, I uploaded the sound I hear down below. Hopefully someone can tell me what's going on.
https://vocaroo.com/12nqQ4cirwHJ

Thanks in advance.
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EricTheRed
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Re: What does it sound like? (Vapor escapes/huffing)

Post by EricTheRed »

Piccies?
My fekking eyes are bleeding! Installed BS Filters - better! :D
Life has gotten interesting!
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gurkan
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Re: What does it sound like? (Vapor escapes/huffing)

Post by gurkan »

EricTheRed wrote: Mon Jan 17, 2022 7:13 amPiccies?
I'm really embarrassed of the setup by its amateur craftsmanship especially after seeing some of the setups I've seen in this forum but, here...
IMG_20220117_183103~2.jpg
IMG_20220117_183355.jpg
IMG_20220117_183412~2.jpg
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still_stirrin
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Re: What does it sound like? (Vapor escapes/huffing)

Post by still_stirrin »

When you run the boiler (with an alcohol wash, not water), stick your finger briefly at the spout (discharge end of the worm). Does it “suck” your finger, or is it “puffing” on your finger? If you feel it suck (huffing), it is because the vapor is rapidly collapsing/condensing in the tubing. If you feel it blowing out (puffing), then you have incomplete condensing in your (short) worm.

But here’s the dilemma: a 3/8” soft copper tube is marginally too small for the vapor production rate in your boiler. That will push the vapors through too fast and the vapor won’t have enough time to “lose it’s heat” in the condenser and it will puff out. Adding more length to the worm will provide more surface area to which the vapor can transfer it’s heat.

But, the frictional flow loss in the longer pipe will cause the vapor to accelerate as the vapor density decreases due to the pressure loss. This causes the pressure in the boiler to increase (in order to keep pushing the vapor into and through the worm), and as a result the boiling point of the wash will increase (ideal gas law). That (increased boil temperature and pressure) will change the constituents and their ratio in the produced vapor.

So, you don’t want either huffing, or puffing to occur in the worm. A better solution would be to increase the ID of the tubing you use in the worm. Increasing from 3/8” tubing to 1/2” tubing will slow the vapor flow, reducing frictional loss (pressure drop) and avoid pressurizing your boiler. And it will increase the conducting surface area in the flake stand that the vapor will condense on minimizing the puffing of vapor out of the spout.

Finally, to eliminate the rapid collapse of vapors within the worm, you need a gradual cooling, or temperature gradient in the flake. You need the top of the water to be warm, possible even hot while the bottom (where the outlet spout of the worm is) to be cool, but not cold. Ideally, the water would be near the temperature you want the condensate to exit, neither warm nor cold. That will help reduce huffing and hopefully avoid puffing.
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still_stirrin
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Re: What does it sound like? (Vapor escapes/huffing)

Post by still_stirrin »

Looking at your added photos, I suspect that the vapor is puffing out of the spout. The length of copper you have is long when compared to the tubing ID. That will result in vapor acceleration and pressurization of the boiler as I described previously. It will make your setup dangerous.

Get larger diameter tubing.

Also, there is no advantage to raise the tubing so high above the flake, as it comes off of the boiler. That “riser” simply isn’t needed and you could use some of that length in your worm. But again, I advise against using the 3/8” copper tubing because of flow restrictions.
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Re: What does it sound like? (Vapor escapes/huffing)

Post by Rrmuf »

Search on Huffing..... Here is one (of a few) thread it ill yield.

viewtopic.php?f=63&t=13272

In my case, some time ago it ended up being related to a mistake in hooking up the cooling water connections backwards (i.e. cold input connected to the hot end of my PC etc. ... quickly fixed but I understand there can be other causes. I don't know where to start in your case. Good luck :-)
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Re: What does it sound like? (Vapor escapes/huffing)

Post by Rrmuf »

Quick question on your setup: Is your hot plate cycling on/off? I don't know if that can be an issue.
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still_stirrin
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Re: What does it sound like? (Vapor escapes/huffing)

Post by still_stirrin »

Long small ID tube test: Get a drinking straw and a clothes pin. Put the clothes pin on your nose so you can’t breath through your nose. Then, take the drinking straw and place it between your lips and breath through it. Time how long you can breath like this before passing out.

Even with as much pressure you can exert on the straw, you won’t move enough air to sustain. This is what’s happening in your 3/8” soft copper tubing. It’s “choking” just like you did when trying to breathe through the straw.

Get a larger diameter tubing.
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gurkan
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Re: What does it sound like? (Vapor escapes/huffing)

Post by gurkan »

Thank you everyone for taking the time and answering.

still_stirrin, during my next run I will try to hold my finger method and see if it's sucking or pushing the air/vapor, I didn't know that trick, thank you.
still_stirrin wrote: Mon Jan 17, 2022 7:49 am Also, there is no advantage to raise the tubing so high above the flake, as it comes off of the boiler. That “riser” simply isn’t needed and you could use some of that length in your worm
The riser is that high only because I somehow believed that higher the pipe goes above the boiler, more quality product I will get from the still. Now I trust what you said and realized I might be wrong. I will lower the pipe down and add it to the length of the worm.
still_stirrin wrote: Mon Jan 17, 2022 8:34 am Long small ID tube test: Get a drinking straw and a clothes pin. Put the clothes pin on your nose so you can’t breath through your nose. Then, take the drinking straw and place it between your lips and breath through it. Time how long you can breath like this before passing out.

Even with as much pressure you can exert on the straw, you won’t move enough air to sustain. This is what’s happening in your 3/8” soft copper tubing. It’s “choking” just like you did when trying to breathe through the straw.

Get a larger diameter tubing.
ss
And now reading your last post, it seems like the safest approach in my situation to make the initial voyage of vapor shorter if I can't increase the diameter (for now). But I will definitely make it bigger once I'm confident of what I'm doing.
Last edited by gurkan on Mon Jan 17, 2022 9:31 am, edited 1 time in total.
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Re: What does it sound like? (Vapor escapes/huffing)

Post by gurkan »

Rrmuf wrote: Mon Jan 17, 2022 7:59 am Search on Huffing..... Here is one (of a few) thread it ill yield.

viewtopic.php?f=63&t=13272

In my case, some time ago it ended up being related to a mistake in hooking up the cooling water connections backwards (i.e. cold input connected to the hot end of my PC etc. ... quickly fixed but I understand there can be other causes. I don't know where to start in your case. Good luck :-)
Does the recording in the link sounds similar to you? If so maybe it's simply because I cool it wrong (using a bottle(500ml) of ice until it melts and let it float on the surface) and maybe I ordered a new set of copper pipes for nothing :)
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Re: What does it sound like? (Vapor escapes/huffing)

Post by gurkan »

Rrmuf wrote: Mon Jan 17, 2022 8:01 am Quick question on your setup: Is your hot plate cycling on/off? I don't know if that can be an issue.
Actually yes, but I don't know if it's related to the case either. Because even if it's cycling, I've never experience a temperature drop and changed my mind on removing the thermostat from hotplate after seeing that hotplate efficiently does its job.
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Re: What does it sound like? (Vapor escapes/huffing)

Post by still_stirrin »

gurkan wrote: Mon Jan 17, 2022 9:28 am
Rrmuf wrote: Mon Jan 17, 2022 8:01 am Quick question on your setup: Is your hot plate cycling on/off? I don't know if that can be an issue.
Actually yes, but I don't know if it's related to the case either. Because even if it's cycling, I've never experience a temperature drop and changed my mind on removing the thermostat from hotplate after seeing that hotplate efficiently does its job.
When the thermostat turns the heat on and off, it does the same thing with vapor production. This is the greatest misunderstanding new hobbiests have: that the temperature of the boil will control the quality of the product. But that’s wrong.

The heat input (kW) determines the rate of boil. The heat input is the energy that is needed to excite the liquid molecules to change phase to a vapor. More heat —> more vapor production. Yet the temperature of the boil is determined by the mixture at any given point because of the composition of the mixture, which changes continuously throughout the boil.

So, the thermostat control will start and stop vapor production as the hotplate cycles on and off. That certainly could account for a “pulsing” of vapor at the spout. Eliminate the thermostatic control and your vapor production will smooth too.

But, this doesn’t undo any of my discussions previously about the length or diameter of the vapor tube. Those physics still are relavant.

Here’s a suggestion: replace the 3/8” riser section of your potstill with a short piece of 1” ID rigid pipe, a 90* elbow, and another short piece of 1” ID rigid pipe. Then reduce to 1/2” ID soft copper tubing for the worm (again, I suggest replacing the 3/8” copper as soon as possible). The riser does not need to be tall (6” to 10” is plenty). And the lyne arm (the short horizontal piece from the 90* elbow) can be 3” to 6”.

The 1” ID pipe will allow the vapor produced in the boiler to exit with a slow velocity and minimal flow friction/pressure drop. Then, the larger diameter worm will likewise give a good flow area while providing adequate surface area for the vapor to condense upon in the flake stand.

Be safe —> do it right. It may mean a little more expense right now, but the performance will improve dramatically.
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Re: What does it sound like? (Vapor escapes/huffing)

Post by Rrmuf »

+1 on the safety concern: such a small orifice right at the boiler.
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Re: What does it sound like? (Vapor escapes/huffing)

Post by gurkan »

Little update, I've eliminated thermostatic control in hotplate to see if the vapor will be smoothed but now the hotplate releases smokes above and below and stinks like melted pvc and metal, and in darkness I can literally see the redness on the hotplate. So I chickened out and tomorrow I'll bring it to an electrician to check, before I actually destroy the house :)
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Re: What does it sound like? (Vapor escapes/huffing)

Post by NZChris »

It wasn't a thermostat, it was a simmerstat.

A thermostat controls temperature.

A simmerstat controls power by turning the power on and off for a percentage of time, which is great for cooking your dinner, but a nuisance for a distiller. When you bypass or remove the simmerstat, you have to use another method to control the power to the plate or you get into trouble very quickly.

BTW, pressure cookers are a dangerous option for building a still because they can hold a LOT of pressure, enough to destroy your house if something goes badly wrong.
They usually have some type of rubber seal that will break down and contaminate your product.

I wouldn't be surprised if this thread ended up in the What Not To Use area of the forum.
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Re: What does it sound like? (Vapor escapes/huffing)

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gurkan wrote: Mon Jan 17, 2022 12:30 pm Little update, I've eliminated thermostatic control in hotplate to see if the vapor will be smoothed but now the hotplate releases smokes above and below and stinks like melted pvc and metal, and in darkness I can literally see the redness on the hotplate. So I chickened out and tomorrow I'll bring it to an electrician to check, before I actually destroy the house :)
... Good call :shock: You might be better off getting an older style hotplate that is controlled with a truly variable voltage dial. I know the induction hot plates I find here are NOT that. Also for safety's sake if nothing else, you might look to get a proper larger diameter riser. I know you are trying to manage cost, but the potential for it to get clogged by puking or ANYTHING and pressure invisibly rising in the boiler is very dangerous!
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