SS Convoluted Counterflow Wort Chiller?

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LBussy

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Does anyone know of a stainless steel convoluted counterflow wort chiller? Midwest used to have one but all links seem to be broken now.
 
This one is sort of convoluted right?
Not really. They use a wrap outside the inner tube to cause churn in the cooling water. The "convoluted" ones use a spiral-grooved inner tube to churn the wort's flow. Something like this:
1617109296803.png
 
opinion... I think the regular tube construction is superior only in that there are no channels for debris to get stuck, much like the narrow channels and corners in a plate heat exchanger. The rifling adds surface area but the turbulence effect likely adds little benefit as the flow is not laminar to begin with; the constant 360 turning in the regular coil is sufficient to churn the wort as it spins it's way through the tubing. A non-rifled counter-flow with a couple more turns will be equal in surface area as well as efficiency.

I work at a place that used to make copper tube heat exchangers for compressed air and gas, which is a "fluid" like wort. I've studied them for 20 years now. The spiraled heat exchangers were a marketing gimmick in our industry albiet slightly more efficient. Everyone uses plate style now but it is only because they are less expensive (and smaller) than making copper tube. I personally think the SS counter-flow option is the best available for the purpose.
 
Thanks, @Mr. Vern. I was going to reach out to a couple ME's I know but I guess you've saved me the hassle.

I definitely don't want plates. Without starting a religious debate let's say I prefer the SS. I don't suppose you know offhand the factor for thermal conductivity between them? My research tells me it's 296
k
for SS and 401
k
for copper. If that's correct, one would need 35% more surface area in a SS coil to do the same cooling.
 
I agree with the selection of S.S.. You will have a loss of efficiency but I do not have the values handy. My copper tubing handbook is more for pressure & temperature limits. S.S. is stronger so maybe a lower wall thickness can compensate, I plan on researching more and making one soon. I would also make sure to have a spiral wrap to help separate the tubes, make use of as much surface area as possible.

I just figured I would have a slower flow rate to achieve the same Temp. Differential, using 50' of SS -vs- copper
 
Thanks, @Mr. Vern. I was going to reach out to a couple ME's I know but I guess you've saved me the hassle.

I definitely don't want plates. Without starting a religious debate let's say I prefer the SS. I don't suppose you know offhand the factor for thermal conductivity between them? My research tells me it's 296
k
for SS and 401
k
for copper. If that's correct, one would need 35% more surface area in a SS coil to do the same cooling.

The difference is significantly greater than you think. Copper is generally around 400, SS is less than 20 depending on the alloy.

Here is one reference: Heat Exchangers: Copper vs. Stainless Steel - AccuServ Heating and Air Conditioning
 
The difference is significantly greater than you think. Copper is generally around 400, SS is less than 20 depending on the alloy.
Oh crap, you're right. I read my table wrong. Let's make sure I don't do any Apollo missions. That means you'd need 97% more (almost double) in SS.

Just for a real world point of reference this chiller works quite well.
And there's one with twice the surface area. :) I like the TC fittings already on that one - saves me from trying to solder.
 
The difference is significantly greater than you think. Copper is generally around 400, SS is less than 20 depending on the alloy.

Here is one reference: Heat Exchangers: Copper vs. Stainless Steel - AccuServ Heating and Air Conditioning

You are correct in noting the difference in thermal conductivity of the metals. However the thing that truly matters are the film coefficients you can achieve on the hot and cold side. When you go to calculate the overall transfer coefficient in a fluid/fluid exchanger the thermal conductivity of the metal works out to be one of the smaller factors (within the confines of the application discussed here). What velocity you can achieve on the hot and cold side makes a much larger difference.
 
I like that so far we're having a good technical discussion - love it when my Engineering brethren stop by for a beer!

I understand the point about probably not needing a convoluted tube. Makes sense I guess.
 
I have used plate chillers when brewing with friends but stuck with my copper immersion chiller and a pump / bent tube to cause some swirling inside the kettle. I cool nearly completely (5 gallons) in about 10 minutes. Minnesota water helps of course.

I know you are asking about plate chiller specifics and probably have a setup that needs it. If so that's not helpful info. But on the off chance you are doing 5 gallon batches, there are simple options that aren't much longer for cool-down time.
 
I hear ya. I spend more time on brewing-related projects (e.g. my sig) than I do the brewing. I enjoy it though, so I guess that's what counts.
 
I like that so far we're having a good technical discussion - love it when my Engineering brethren stop by for a beer!

I understand the point about probably not needing a convoluted tube. Makes sense I guess.


My unsolicited $0.02. Copper/Stainless do not matter in this use case, the thermal difference is for all real purposes negligible. You should be more concerned about weight if you are moving it, and relative galvanic properties of your exchanger material and end fittings if this thing is sitting full of water for extended periods of time (as in you don't really drain the water side between brew days.). Most importantly price, whichever option gets you the most surface area for the money is the winner if cash is a constraint.

As for the convoluted tube exchanger, there are just too many pockets that are at 90° relative to the flow path and I'd be worried about thorough cleaning. With a plate exchanger I wouldn't sweat it as the face velocity should be more than enough to sweep the material out.
 
Weight, price, and galvanic properties are not a concern for my use case. I mean I'm not made of money but I've wasted more money by trying to save money in this hobby than I care to admit.

Some plate exchangers allow thorough cleaning, some do not. I feel better about "assuming" a cleaner flush got to all of the pipe than I do assuming the same of a plate exchanger. We're bordering on religious preferences here but I am happy to say I've had a counter-flow chiller since 1995 and I've yet to have any issues I can attribute to cleaning or sanitizing the coil.

I understand the comment about the convoluted tube and tangential flow. That does make a lot of sense.
 
Stout also makes an SS with triclamp fittings.. it's what I ended up with after using a smaller kegco SS one for a while. I ultimately went with a plate chiller though because it just took ages... it was nice to not need a hop spider though.

I forget what my temps were, i want to say i had boiling wort going in, 75-80degF ground water and 113degF egress at first. I'd recirculate until I got close to 90 and then switch to ice water and run out at pitching temps. WIth the kegco my egress was closer to 130 at first, and it took 25-50% longer to chill. The flow was faster though, just not enough coils and contact area.

https://conical-fermenter.com/Counterflow-Wort-Chiller.html
https://kegco.com/products/stainless-steel-counterflow-chiller
I'm much happier with my plate chiller, but I get people have a preference. If i had unlimited access to cold water i'd use the CFC still but ground water in Texas is usually 80degF. I reverse flush with cleaner while cleaning my kettles and then forward flush with sani and blow air through to dry. Same procedure for plate chiller as the counter flow ones and no issues keeping any of them clean.
 
I have a convoluted copper CFC. The copper will surely conduct some heat! Be sure you connect it up in such a way as you don't need to be near while it's being used.

I recirculated for 5 minutes, then reached over it to turn a pump on and permanently burned two stripes onto my under arm. Ouch!
 
I use a CFC in order to not recirculate - that's the key advantage, for me anyway. Granted my CFCs have been homemade, but I have never had the exit wort a degree or two away from the cooling water input. I want to say we've been using 25' of 3/8" copper (with a garden hose external.) It works fine, I was wanting to move to SS, however.
 
57 foot of copper cooling surface area. Lost 3 foot in a kink( was supposed to be 60 foot ) so I had to go with a larger diameter circle to keep from kinking. Granted this was built for my 100 gallon kettles but I've been using it for years on my 20 gallon kettles. Built for under $300. Cools like no other. It cools to incoming water temp with a chugger pump running full blast in one pass. If it is in heat of the summer and my incoming water is hotter than I want due to long run in drinking water hose I will throw the herms coil in a bucket of ice water as a second cooling coil. It does take a minute to get all that copper cooled down after running boiled wort through it for the whirlpool and sanitizing stage though. 1/2 inch copper inner pipe. Been contemplating buying 2 of the Stout chillers and doing city water on the first and glycol through the second to achieve maximum cooling in a short amount of time for the 100 gallon kettles instead of this copper chiller. I also have no plans of ever running a plate chiller.
 

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I use a CFC in order to not recirculate - that's the key advantage, for me anyway. Granted my CFCs have been homemade, but I have never had the exit wort a degree or two away from the cooling water input. I want to say we've been using 25' of 3/8" copper (with a garden hose external.) It works fine, I was wanting to move to SS, however.
This is indeed the info I was looking for... I have some 40 or 50 feet of 3/8" copper and intend to make a counter flow chiller (I guess this is the CFC...) using a water hose. May I ask you the batch size that you can knock down with such a 25' length? Would it make sense to solder a copper electric wire spiral wound on the copper pipe in order to slightly increase the contact surface, and above this, to generate some turbulences in the cooling water flow...?
 
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May I ask you the batch size that you can knock down with such a 25' length?
When I had my 25' (AC lines) with a hose just like you mention, it was not a matter of batch size as flow rate. Basically, we ran it in siphon mode and never restricted it in any way. So, it took a 15-gallon batch however long it takes a 15-gallon batch to pass through the tube once. I also used a small section of cross-drilled racking cane at the end of the line to inject some aeration. I say that to provide some context to the flow rate. It was fast enough to suck in some air and do a pretty good job.

Would it make sense to solder a copper electric wire spiral wound on the copper pipe in order to slightly increase the contact surface, and above this, to generate some turbulences in the cooling water flow...?
I don't think there would be a good return on your time investment there. With a 3/8" line at 25' I think there will be a ton of internal turbulence to make sure things cool down. Keep in mind this was back in the 90's before we knew we were doing things all wrong. :) Ignorance is bliss, and it worked without over-thinking it.
 
I don't think there would be a good return on your time investment there. With a 3/8" line at 25' I think there will be a ton of internal turbulence to make sure things cool down. Keep in mind this was back in the 90's before we knew we were doing things all wrong. :) Ignorance is bliss, and it worked without over-thinking it.

Agreed, I thought about doing the wire thing to mine when I made it (mine is 3/8 SS core with 3/4 rubber hose jacket). Decided not to because it would have increased the cost, was likely a huge PITA, and most of all it would have forced me to wait longer... I had all the parts but the wire.

In hindsight, I was right - it works as well as I'd every need it to without wire, and putting the hose on to the smooth tube was a PITA. That part is actually how my final length was determined. Shoved hose onto the SS coil until it was pretty much impossible, which was 20' IIRC.
 
@fragged -Thanks for answering the point here is that wire is available as left over from my electric installation I made myself. We live uphill, in de middle of our rubber trees and orchard, 3km away from the next village on solar cells and deep wells... -so it's free so far I'm concerned. I'm using a copper pipe for two reasons, the conductivity is about 20 better than the SS and it's more flexible. One question LBussy did not answer either, what's the size of a batch you can cool down with a 20' or 25' CFC?
 
One question LBussy did not answer either, what's the size of a batch you can cool down with a 20' or 25' CFC?
Not sure if I was clear so I'll re-phrase that part of my answer. You can run any size batch you want through it, the size only matters in that it takes longer to run a larger batch through. I only ever ran my wort through in one pass so there's no pumping/recirculation. The 25' length pretty much guaranteed that the wort coming out was within a couple of degrees of the water going in.
 
Not sure if I was clear so I'll re-phrase that part of my answer. You can run any size batch you want through it, the size only matters in that it takes longer to run a larger batch through. I only ever ran my wort through in one pass so there's no pumping/recirculation. The 25' length pretty much guaranteed that the wort coming out was within a couple of degrees of the water going in.
Thank you, my mistake, I skimmed your first reply too fast, and did not get it correctly. I don't know whether I said so, but my mother tongue is French.
But now I do understand what you mean, in fact my question does not make sense oops. I'll go for 25'
Aeration is also a good idea. In my other activity, I use an aquarium pump and an air stone, here I'll try your drilled racking cane method, it looks like a kind of Venturi effect...
 
it looks like a kind of Venturi effect...
That is it exactly. I've never tested the dissolved oxygen using that method - all I know is it worked before I knew I "had to" use oxygen and a stone. :)

I don't know whether I said so, but my mother tongue is French.
Your English is perfect. Every time I converse with a person in English who speaks a different native language, it reminds and saddens me that our kids are not forced to master a second language.
 
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