My condenser is acting strange

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theBEARD
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My condenser is acting strange

Post by theBEARD »

Hello brothers distillers. Can someone tell me why my liebig condenser is puffing like train while is producing moonshine?
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RC Al
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Re: My condenser is acting strange

Post by RC Al »

Because you need to change the water flow rate down with a valve, the condenser should be hot to roughly halfway along the length, otherwise turn the power down

Do a search on Huffing
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still_stirrin
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Re: My condenser is acting strange

Post by still_stirrin »

It’s either “huffing” or “puffing”.

Huffing is due to vapor collapse in the stillhead, sometimes called “ shock cooling”. It’s caused by the coolant flowing too fast or the water is too cold and the vapors collapse/condense abruptly, sucking air back into the condenser. You want the temperature gradient in the condenser to be gradual, not abrupt.

Puffing is when you’re “over running” the condenser, pushing uncondensed product vapors out the spout. Back off the heat input to reduce the vapor production. Another trick is to put some very lightly packed copper scrubby in the condenser outlet to increase the surface the vapor contacts to improve heat transfer. What’s happening is the vapors are moving too fast to give up enough heat to the vapor tube to fully condense all the vapors.

Sometimes you can have both huffing and puffing. But you should be able to feel it at the spout. Either way, you need to make adjustments to your operations.
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Rrmuf
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Re: My condenser is acting strange

Post by Rrmuf »

This is a new one: I haven't any evidence of huffing at all but I never had my shotgun condenser hot halfway up. I always just made sure my water flow was adequate to keep the whole thing cool to touch (the water outflow might get luke warm after a good length of garden hose but no more).

What I am inferring here is that I should turn the water flow in my condensor down a bit and the condenser should be a bit warmer? But, to repeat, I *never* had any huffing. How else might I detect that the supposed water overflow is a problem or inefficiency?
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still_stirrin
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Re: My condenser is acting strange

Post by still_stirrin »

Rrmuf,

Shotguns are a little different. The multiple vapor tubes provide more vapor conducting surface area in contact with the water jacket making them much more efficient. As a result, they are shorter so the gradient will be shorter too. If your shotgun has baffles in the shell (the water jacket), then you may be able to feel a slight gradient along the length. If not, you may not feel it unless you slow the water flow rate more.

Of note, the tube bank (multiple vapor tubes) give the vapor multiple paths to flow which keeps vapor velocity in check while the vapor tube walls provide a large surface area to conduct heat through.
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Rrmuf
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Re: My condenser is acting strange

Post by Rrmuf »

still_stirrin wrote: Fri Dec 04, 2020 4:54 am Rrmuf,

Shotguns are a little different. The multiple vapor tubes provide more vapor conducting surface area in contact with the water jacket making them much more efficient. As a result, they are shorter so the gradient will be shorter too. If your shotgun has baffles in the shell (the water jacket), then you may be able to feel a slight gradient along the length. If not, you may not feel it unless you slow the water flow rate more.

Of note, the tube bank (multiple vapor tubes) give the vapor multiple paths to flow which keeps vapor velocity in check while the vapor tube walls provide a large surface area to conduct heat through.
ss
Aha. OK. Good to know. So if I read you correctly, unless I experience some kind of huffing, I really shouldn't worry about it
Thanks for the clarification.
-- Rrmuf
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Yummyrum
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Re: My condenser is acting strange

Post by Yummyrum »

This
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Dancing4dan
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Re: My condenser is acting strange

Post by Dancing4dan »

Thank you Yummyrum and Still_stirrin for some great info. Love that video. There is more great information in the video than just the subject at hand.
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subbrew
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Re: My condenser is acting strange

Post by subbrew »

Don't want to high-jack the thread but I am having a similar situation. I have a small (14 inch) SS condenser, with about an 8 gal boiler, old two milk pale style. If the boiler is only about half full, the condenser will huff and it acts like it is getting an oscillation going. The huff slowly builds until puff, I can hear the boiler erupting and it sends a blast of steam out the condenser. Then it will start all over. I am wondering if the huffing is causing a pressure pulse and it increases until the low pressure side of the pulse causes a flash of boiling? That flash causes the puff.

Anyhow, thanks to this and other threads I will try throttling the cooling water as I have always figured my condenser was so small I had better give it all I can and thus have kept the outlet water cold.
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subbrew
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Re: My condenser is acting strange

Post by subbrew »

Wanted to follow up on the last post. I had thought one possibility was pressure fluctuations. The first couple of times it happened it was very windy and the big pole shed I am in flexes with wind gusts cause pressure changes. But it was doing it last night when it was totally calm. Also I was not getting any huffing I could hear. It would just be dripping along and all of a sudden it would blast out steam. Not even a regular pattern to it, like every five minute or something. Sometimes it would 7 or 8 minutes between blasts and sometime only one. I am using a hot plate for heat and I could get it to blast less when I turned the power down on the hot plate. Just strange why it will have an eruption, boiling event like that. The previous night I ran it over 6 hrs with the same set up and it did fine. I shut down for the night. Started up where I left off and it blasted the entire time until I was into tails and decided that was far enough. I tied lowering power, increasing power, lowering condenser flow, and increasing condenser flow and nothing stopped it. Anyone have any thoughts?
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Yummyrum
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Re: My condenser is acting strange

Post by Yummyrum »

You’re using a Hot plate . I think that might be the problem .
They cycle the element on and off . When the element is on , there will be more heat applied to the boiler and extra vapour produced . Then it cycles off and the production from the boiler will slow down .

You will be fighting a loosing battle if you are adjusting coolant flow for a temp gradient in the liebig .

You should be using a power controller . This smoothly regulates the power to the element rather than cycling it on/off to keep an average power
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Re: My condenser is acting strange

Post by The Baker »

Yummyrum wrote: Wed Apr 21, 2021 7:36 pm You’re using a Hot plate . I think that might be the problem .
They cycle the element on and off . When the element is on , there will be more heat applied to the boiler and extra vapour produced . Then it cycles off and the production from the boiler will slow down .

You will be fighting a loosing battle if you are adjusting coolant flow for a temp gradient in the liebig .

You should be using a power controller . This smoothly regulates the power to the element rather than cycling it on/off to keep an average power
If you use the same hotplate you will have to remove or bypass the simmerstat first.

Geoff
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