Herms coil

[Nullnvoid]

So I managed to score this coil that I was hoping to turn into a herms. It's pretty big is my only worry.

Is there such a thing as too big?

Will be getting a custom made pot to suit.

 

[TwoCrows]

Yes , Can be an issue with the friction of liquid and the ability of the pump to push it thru.

5 to 15 mtrs is the norm.

 

[Nullnvoid]

Righteo cool. I'll have to get the tape measure out to see how long it is.

 

[DJ_L3ThAL]

What max size brew are you planning on doing with it mate?

 

[Nullnvoid]

Probably 65-70l?

 

[DJ_L3ThAL]

Might be a bit long then mate, as the response (ramp) rate timing on HERMS systems is a combination of the right length coil in a smallish volume of water so that the element can be sized to be able to quickly raise the temperature and get it ramping.

With a longer coil you have a higher risk of overshooting the desired temperatures because the wort has a longer time it is in the coil and will have more heat transferred into it.

The HERM-IT coil is sized for up to triple batches (I believe) so would be the sort of size you are looking for. Some specs from the website here (some other brewers may be able to chime in with the actual coil length which is what you go by when determining heat exchanger efficiency and doing calcs for heat transfer rates etc):

HERMIT COIL
12mm OD coil
304 Stainless steel.
Approx dimensions:
Dia 95mm
Total length 250mm
Length to top o...
http://onlinebrewingsupplies.com/herm-it-r-coil/hermit-coil

PS. That's a frikken nice score, looks to be at least 4 times longer than a HERM-IT coil going by eye, so would suit either WAY larger batches (ie. case swap collab brews, however getting enough electricity may be a problem), or putting it directly into a HLT where the volume of water is larger. That may work by having smaller changes in temperature of the HLT water temp and getting decent ramp times. You'd need to just trial it unless you want to geek out and go to the thread where Adr0 (from memory) did a whole lot of theoretical calculatrions with Matlab on ramp times, coil lengths and water volumes.

 

[malt junkie]

I think we all know just how far a hermit can be pushed; with a 3600w element and a decent pump 100L mash should be no drama. We've ramped the swap mashes(2hl) with 2400w hermits (slowly oh so slowly). End of the day it always comes down to flow rate vs power, the coil you have there is huge dude and while it is a thing of beauty it will slow flow to almost a trickle.

 

[Mardoo]

I'm not sure too long will be an issue if the volume of water is not too huge. As far as I understand it, the crucial relationship is the ratio of coil length to water volume in the HEX. If the wort spends a long time in the coil, but the water is very close to the wort temperature, overshoot will not be so much of an issue. If the volume of water is not too large, then overshoot becomes less of an issue. Where's Adr_0 when we need him and the model he built?

If it turns out to be too long and you decide it's unworkable, it might work for the collab/swap HEX's I am working on. I could buy it from you in that case. I have one coil courtesy of Martin's generosity, but will need a second for our current setup. However, maybe PM Adr_0 and ask whether he could plug your coil into his model to determine appropriate water volume.

 

[malt junkie]

I'm not sure too long will be an issue if the volume of water is not too huge. As far as I understand it, the crucial relationship is the ratio of coil length to water volume in the HEX. If the wort spends a long time in the coil, but the water is very close to the wort temperature, overshoot will not be so much of an issue. If the volume of water is not too large, then overshoot becomes less of an issue. Where's Adr_0 when we need him and the model he built?

If it turns out to be too long and you decide it's unworkable, it might work for the collab/swap HEX's I am working on. I could buy it from you in that case. I have one coil courtesy of Martin's generosity, but will need a second for our current setup. However, maybe PM Adr_0 and ask whether he could plug your coil into his model to determine appropriate water volume.

Did you need a second keg for the second hex? happy to donate to the cause.

 

[Mardoo]

Also donated by Martin Thanks so much for the one you gave.

 

[Nullnvoid]

Thanks all for your help.

I need to measure it proper, but it's big and heavy so might be too big me. I can get a pot custom made for it to whatever it would need to be so thats not a problem but it might still be overkill for the system I am building. However it was free so I couldn't turn it down

Perhaps I could sell it (either for the collab system or to someone else) and buy a coil more suitable. I'll get in touch with Adr_0 when I have the measurements and see if he can help with water volume.

Mardoo, I think for the collab brew it would have to go into a 50l keg. It wouldn't fit in a 19l.

 

[Mardoo]

A beaut of an immersion chiller in that case!

 

[Nullnvoid]

The more I look and think about it, the more of a beast it seems. Will get a better picture with something for size comparison tonight!

 

[Nullnvoid]

So here is a couple more photos with size comparison. This is a 20litre cube.

If my rough measurements are accurate ish then the outer coil is approximately 13 metres!! So it's probably 23 metres at least all up.

 

[Mardoo]

**** me. Chiller all the way.

 

[Benn]

Impressive coil Nullnvoid

 

[Mardoo]

What's the tube diameter on that? Looks greater than 1/2". BTW, what was that originally taken from?

 

[Nullnvoid]

I'll have to check the diameter of the tube. I thought it was 1/2" but am terrible with sizing.

I have no idea what it was taken from. I meant to ask but forgot. He has had it lying around for a couple years apparently and wasn't sure if he would ever get around to using it.

 

[JB]

Mardoo, I think for the collab brew it would have to go into a 50l keg. It wouldn't fit in a 19l.

Hey Nully I might have something in the shed it might fit into. I'll have a look & measure it up.

 

[technobabble66]

If it matters to determine the length more accurately, could you fill the entire coil with water (make sure there's not air bubbles), then drain and measure the volume/weight of water (or just measure the weight difference in the coil between empty & full).
Then measure the exact internal diameter of the tube.
From there it should be kinda easy to calculate the length of the tube of x diameter to be filled by y volume of water.
But probably doesn't need to be that accurate ..