huffing and pulsing

[Dan P.]

I have a worm, about 19' of 1". It has started huffing and pulsing like a mad thing, it also makes quite a lot of clanging and gurgling sounds, and I cannot work out why. It huffs a good deal, but it pulses A LOT, and very crazily.
Some factors;

There are no leaks I have been able to find.
It is not dead level, but it is not crazily wonky either. It is a pretty nice worm, professionally made.
It does not huff or pulse when a thumper is between it and the boiler.
It does not huff or pulse during the early heads/foreshots.
It does not huff or pulse after the alcohol is almost all gone (below 10%abv output).
It started huffing and pulsing when I changed the boiler from 60ish litres to 30 litres.

Is it possible that my condenser is oversized? The clanging suggests vapour collapse that is making it huff and pulse.. could be related to size...maybe?

Any thoughts appreciated.

[planethax]

I thought that meant you had a low spot and the vapour was condensing and pooling?

[Tokoroa_Shiner]

What kind of boiler do you have and what is your heat source?

[Dan P.]

Boiler is a copper pot, heat is propane.
The thing that makes it wierd is that it is not consistent. If it were just a low spot, all things being equal it would pool consistently. But in actuality it pulses almost not at all below around 10%abv. It's very odd.

[Odin]

My old potstill had a Liebig and that Liebig puffed when I threw too much power at the rig. In a strip run. Especially when alcohol was almost depleated and cooling water (recirculing) became warmer ...

Not sure if this info helps though.

Odin.

[googe]

I would guess the Thumper is a more stable vapor dispenser, more alc less water, more power means more turbulence of substances. does it do it if you run it really slow?. I'd say you would get more noise froma larger diameter pipe than a smaller, like a megaphone. The clunking could just be falling distillate in the boiler being emphasized by the worm.
What wash?, how fast are you running it?.

[goose eye]

How many coils you got in it.
Worm got to be level or it gonna lope.
How fast you chargeing it with the doublein keg
in line.
How hot your water in your cooling barrel

So I'm tole

[Dan P.]

I don't generally use a thumper, I just noticed that the huffing and pulsing is much less when one is used.
The barrel is a hogshead or something of similar size, so the water never gets hot more than about a third of the way down.
I think it may have to do with the size and the power usage, as googe suggests.
It's not really a problem, it's just annoying, and it didn't use to do it, the only thing having changed is the size.

[Edwin Croissant]

The common denominator I see that is different is the volume above the boiler. It is a long shot but it might be resonance between the worm and the volume above the boiler. Maybe a scrubby (make sure you do not block the worm for obvious reasons) at the beginning of the worm will isolate the two from each other.

Just my 2 cents,

Edwin

[Prairiepiss]

How fast are you running the still?

[Dan P.]

How fast are you running the still?

Fast or slow, it's the same.

[Dan P.]

The common denominator I see that is different is the volume above the boiler. It is a long shot but it might be resonance between the worm and the volume above the boiler. Maybe a scrubby (make sure you do not block the worm for obvious reasons) at the beginning of the worm will isolate the two from each other.

Just my 2 cents,

Edwin

Edwin, I "intuit" that you may have a solution or at least the beginning of a solution here.
My boiler has a big-ass cap to it.
I feel that the vapour collapsing in the condenser must suck vapour from the cap, making a mild vacuum, and re-equalization from the atmosphere, causing the back and forth huffing and pulsing.
Now I think of it, when the boiler was bigger, I also used to have about a meter of 1" between the lyne arm and the condenser. The vapour would have been cooler on reaching the condenser, and the condensation less sudden, and what sudden pressure changes there were from collapsing vapour would have been spread out over the greater distance.
I am running some spirit tomorrow; I will try a little packing. If that doesn't work, I'll re-instate the longer connection.

[Dan P.]

Well, I put some ss scrubbers in the lyne arm, without much effect, so I stuffed about a quarter of a scrubbie up the "out spout", and both huffing and loping was stopped completely.
I'm convinced it's something going on with the size and/or diameter of the worm vs. boiler., and the effect of vapour collapse etc., rather than the usual problems of wonky worm and/or leaks.

[rad14701]

It almost sounds like the size of the worm is causing shock cooling with the smaller boiler... Does it still huff when you do a really fast strip...??? How about adding some scrubber up at the top end of the worm so any cool air has to hit that before shock cooling the vapor in the boiler... Might work better than at the output end...

[Dan P.]

It almost sounds like the size of the worm is causing shock cooling with the smaller boiler... Does it still huff when you do a really fast strip...??? How about adding some scrubber up at the top end of the worm so any cool air has to hit that before shock cooling the vapor in the boiler... Might work better than at the output end...

I think you are right on with the shock cooling, but scrubbers at the money end solve the problem just fine. Or maybe scrubbers in the lyne and at the money end both are what's working. I think blocking off the atmospheric influx (money end) is probably what's doing most good.