DIY convoluted copper

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Vesku

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I've been destroying a lot of copper tube, but finally got my tool working:

IMG_20121101_3348.JPG


Gutted:

IMG_20121031_3345.JPG


CFC:

IMG_20121101_3360.JPG


Double copper test (ugly):

IMG_20121106_3394.JPG


Test plot, 3.5L/min flow for hot water, 10L/min for the cool (12C):

con%2520cfc%2520proto.jpg


I used 15mm copper for the copper/pvc-CFC and some imperial about the same size for the double copper CFC.

The tool is just a hole in 2X4 and adjustable bearing. Annealed copper works better, but "hard" copper can be used too. It needs re-annealing after the grooves are made to be able to make the coil.

For the next one (a shorter one for my CFC-HERMS), I'll try to "twist" the outer copper as well (except the bends). And it will have a shape of something like this:
220px-Mike_oldfield_tubular_bells_album_cover.jpg
 
I made this for the double copper:

IMG_20121208_3552.JPG


Here's some of the "twisting tools":

IMG_20121208_3555.JPG
 
Looks awesome!

Now, please forgive some ignorant questions. I can't really see the twisting tools very well. It sounds like you made grooves in the tube and then twisted? Can you go into more detail on the process? Thanks!
 
I want to you guys to think too ;) Everything is made so easy nowadays with the google and all ;)

It's basically a thread die, a very dull one. Drill a hole that has two angles. One angle is for the angle that the bearing is against the copper and other for how fast it moves when you roll it on the tube. I'll took a video clip next time I'm doing something (may take some time as I'm totally out of money. I've to wait until the scrapyard has some copper...)

I don't know how the real tools work, but I would guess the process is the same. I don't think that the tube is actually twisted at all, just "grooved".
 
Thanks, that clears up alot.

I'm not very tool savy and wouldn't have known to look up thread die, but when I first saw it I thought it looked a bit like it was gone over with a dull pipe cutter on a diagonal somehow.

It's really clever and a very professional looking result.

I'm sure everyone would appreciate a video demonstration.

Nice work!
 
+1 one to JsGuitar.

Your craftmanship and ingenuity are amazing. Looking forward to more!

Dan
 
I`ve just notice this thread and was interested in having a go at producing a homemade convoluted tube, just wondered if anyone else has been sucessful in copying the idea.

More experiments to follow :)
 
You make it all look easy! Great video. Thanks for sharing. I really had no clue what the method was when you posted the pics of your equipment. What angle is the hole in the board cut?
 
+1, You're clearly an expert at this now! I also couldn't imagine how you were doing it before, so this helps.

I'm sure you don't want to take your tool apart for pictures, but if you're ever up for it I'd like to see what the thread die looks like that you're using.

I've enjoyed your recent contributions, thanks!
 
There's a skateboard bearing that is "leaning" against the tube. I just screw it against the tube with the threaded rod with handle on it's end. Pretty simple thing really.

I made a few test holes to get the angles right. I 1st just had a knife blade against the tube to mark how fast it moves forward when rolled. I used a router to make the "machining" of the tool. No idea what the angles are though. Easy&cheap to test, if the material for the tool frame is wood. And if a proper tool is machined, it should be easy enough to figure out the angles when doing the CAD drawing.
 
I like plots too :) I found this one that I though I already deleted. It shows better how the CFC with the outer PVC hose performed:

convoluted%2520CFC-take%25202.jpg


The in going water was about 78C. 1st I ran it with with free flow 2.5L/min. Without any cooling water the temperature (blue line) drops a couple of degrees.
Next I opened the cooling water tap (12C). The output drop fast to about 16C.
Then I used pump to force the to be cooled water trough the CFC. The flow was about 11.5L/min and out coming water 34C.
I'm looking forward to see how fast I can cool my next patch as I'm using the new whirlpool kettle and this cooler. It should be pretty darn fast cooling for my 5 gal patch. 5 minutes?!!?

The blue line is output. The red one is the input. Others are just there to make the plot harder to read.
 
I like your teaching style Vesku ;)

Seriously, when you design a space capsule brewery, I want to know about it!

:mug:

I've a new idea for instant step mashes ( > 40F/min ), but that may need zero gravity to work ... so maybe the space rocket is the next step :D
 
Not with same diameter (15mm) tube. I was able to find note's of ½" CFC with 19mm PVC. This was about 2 times longer than the convoluted. My notes say:
"Cooling efficiency when using cooling water at 12C, with approx. 7.5L/min flow:
- water in 82.5C
- water out 20.9C
- gravity fed free flow 3.5L/min"
 
I like plots too :) I found this one that I though I already deleted. It shows better how the CFC with the outer PVC hose performed:

convoluted%2520CFC-take%25202.jpg


The in going water was about 78C. 1st I ran it with with free flow 2.5L/min. Without any cooling water the temperature (blue line) drops a couple of degrees.
Next I opened the cooling water tap (12C). The output drop fast to about 16C.
Then I used pump to force the to be cooled water trough the CFC. The flow was about 11.5L/min and out coming water 34C.
I'm looking forward to see how fast I can cool my next patch as I'm using the new whirlpool kettle and this cooler. It should be pretty darn fast cooling for my 5 gal patch. 5 minutes?!!?

The blue line is output. The red one is the input. Others are just there to make the plot harder to read.

Vesku, I'm having trouble reading this graph...at what time did it drop a couple of degrees and then the faster drop? I don't really see those unless the temp drop,is when the line goes up? Sorry if I'm being dense here...
 

Vesku,

the video seems to be no longer available. I may be interested to give this a try and would appreciate a chance to see the video if possible. The tool description is suggestive but I do not yet have a clear idea how to make one. Any kind of a quick sketch to help clarify would be greatly appreciated.

Also, can you commend on the wall thickness of the copper tubing you convoluted?

And lastly, do you think there is any hope of this technique working on 0.02" thin-wall stainless tubing?

thanks,

-fafrd
 
I am also hoping to do something like this but cant seem to make my jig work based on the written description. Any ideas on how to make this work?

Anyone?
 
I am also hoping to do something like this but cant seem to make my jig work based on the written description. Any ideas on how to make this work?

Anyone?

Seconding this request. Also interested to know if those who have done this think it would work on thin-wall (0.02") stainless tubing...

-fafrd
 
Convoluted tubing is only needed if you aren't flowing fast enough to create turbulent flow . If you aren't creating turbulent flow, it's because your tubing is larger than needed for the flow rate (Reynolds number, or some crap like that). Going down a size can sometimes give superior performance to a larger round tube, and longer smaller tubing will accomplish the same thing as shorter larger convoluted tubing. When just looking at price, more of the smaller tubing is usually a cheaper solution, even if you convolute the tubing yourself.
 
So just to be clear, you are saying that using a smaller, longer inner tube can create enough turbulence? Or are you saying to size down the outer tubing of the CFC to create turbulence of the coolant?

Sorry to be so thick headed I just want to understand the concept you are describing so I can build the best possible apparatus.

Thanks in advance.
 
So just to be clear, you are saying that using a smaller, longer inner tube can create enough turbulence? Or are you saying to size down the outer tubing of the CFC to create turbulence of the coolant?

Sorry to be so thick headed I just want to understand the concept you are describing so I can build the best possible apparatus.

Thanks in advance.
Nothing wrong with asking, as this is fairly counter-intuitive, like many things.

A benefit of convolutions is to provide turbulence/mixing vs. laminar flow (it also provides minor benefit of a bit higher surface area/cross section ratio- circular tube is perfectly minimized in this regard). The turbulence of both the inner and outer liquid is important. The outer liquid, in this case, is not (usually) constrained to some maximum flow, so getting turbulence there is not (usually) an issue. The inner liquid may be flow constrained by the desired output temp (for single pass cooling). If this flow is insufficient to create turbulence, a smaller diameter tube that provides turbulence at that flow can perform better than the larger non-turbulent flow tube. It may even work at the same length, but the length may also need to be increased to meet the desired temp. That's the theory anyway. There are too many scenarios to describe when larger non-turb beats smaller turb, or vice-versa. I am just giving the rationale behind convoluted tubing, and the alternatives.

The amount of flow to get turbulence isn't that high, especially for circular spirals. I don't have any guidance to provide regarding optimal tubing size, but there have been threads on in it. Or, if you are good at math, there are the Reynolds equations to make some theoretical calcs.

The whole CFC/PC fascination is kind of lost on me, though, especially when recircing to the kettle and/or prechilling is required. I always saw them as only well suited to cases where tap water was cold enough to provide single pass cooling to ferm temps, and you either had a conical, or didn't care about all the cold break getting in your fermenter. Personally, I am an IC believer. Ease of use and simplicity trumps optimized performance in my world.
 
Thanks for the info. I am gathering all the data I can before building mine. I was thinking of going with a smaller inner tube anyway as EVERYBODY I have spoken to seems to throttle back on the wort going through theirs which a) reduces turbulence and b) reduces surface contact with the inner tubbing.

I agree with not quite getting the benefit of recirculating if a single pass would make you reach pitching temp. It means more things touching your wort as it is cooled which risks infection. It also means you still have to transfer your chilled wort into your fermenting vessel after it is cooled instead of transferring it while cooling it. And since I do a secondary fermentation, I would leave all the cold break behind with the yeast/trub at that point. While cold break in the fermentation tank doesn't hurt the beer, some say it actually helps fermentation (I can't back that claim up though).

The CFC advantage to me is that I switch batch sizes often. I have tried using a smaller IC that was designed for 5 gallon batches on a 10 gallon batch which barely worked (took forever). And when I tried a bigger IC designed for 10 gallon batches about 35-40% of the coils sat above the top of wort in a 5 gallon batch...which didn't hurt the cooling but since I couldn't submerge all of it during the boil it opened it up to infection as an unboiled item was in my wort. Yes, you can sanitize it before placing it in the wort (or try spooning boiling wort over the exposed coils, I guess), which is an extra step (your are sanitizing you transfer lines with an IC anyway, just like you would sanitize a CFC)

A CFC seems to be the right solution for doing any batch size and seems easiest to protect against infections.

As far as pre-chillers go, if your tap water is warm you really have to use it one with either style of apparatus to get down to the temps you may want.
 
I wanted to make a whirlpool kettle that I could use to cool the wort as well. To get the whirlpool going small diameter tubing is not an option. I had some 15mm soft copper handy and came out with an idea how to make the grooves ... it's boring to go the easy way ;) I've noticed that, if I think too much beforehand, so many problems will arise that I just end up drinking beer and doing nothing :)

I only had a couple of goes with the kettle, before I had to sell my gear, but it worked really nice. I cooled 5 gal patch from boiling in about 5 minutes even with relatively warm tap water that we have during the summer. I also wanted to try hopping during the whirlpool and cooling (sort of poor man's hopback variation). I think that the aroma of the beers was stronger, but it all maybe just my imagination too.
 
I agree with not quite getting the benefit of recirculating if a single pass would make you reach pitching temp.
I was talking more about guys who use multipass because a single pass won't do it, which is the case in much of the south. Might as well use an IC in those cases.

It means more things touching your wort as it is cooled which risks infection. It also means you still have to transfer your chilled wort into your fermenting vessel after it is cooled instead of transferring it while cooling it. And since I do a secondary fermentation, I would leave all the cold break behind with the yeast/trub at that point. While cold break in the fermentation tank doesn't hurt the beer, some say it actually helps fermentation (I can't back that claim up though).
Everything is fairly sanitary post boil in the chill path if recircing a CFC.
RE: Cold break- It is supposed to have some benefits for the growth phase, but after that it's supposed to get ejected. This is why brewers, and homebrew conical owners, do a trub dump after 24-48 hours. Taste some beer decanted off the trub pile left after you rack to secondary. I have done it, and it is not pleasant. I doubt the trub pile has some magic property that prevents that flavor from spreading into the rest of the beer.

The CFC advantage to me is that I switch batch sizes often. I have tried using a smaller IC that was designed for 5 gallon batches on a 10 gallon batch which barely worked (took forever).
Thats not fair. A CFC should take exactly twice as long for a 10G vs. 5G. If your IC performance was so poor, your CFC shouldn't have been that great either using the same tap temp. Were you agitating the wort with the IC? It makes a massive difference.

And when I tried a bigger IC designed for 10 gallon batches about 35-40% of the coils sat above the top of wort in a 5 gallon batch...which didn't hurt the cooling but since I couldn't submerge all of it during the boil it opened it up to infection as an unboiled item was in my wort. Yes, you can sanitize it before placing it in the wort (or try spooning boiling wort over the exposed coils, I guess), which is an extra step (your are sanitizing you transfer lines with an IC anyway, just like you would sanitize a CFC)
But how do you know whether your CFC is actually clean. FUD!

A CFC seems to be the right solution for doing any batch size and seems easiest to protect against infections.
An oversized CFC can provide better cooling for smaller batches than an oversized IC (that doesn't submerge completely).
Easiest to protect against infections is more than stretch. See FUD above.

As far as pre-chillers go, if your tap water is warm you really have to use it one with either style of apparatus to get down to the temps you may want.
Yes, but with an IC all you do is run with tap water 'til it plateaus, then switch to an ice bath recirc for the last bit until you hit your temp. It does require a pump of some kind, but nothing fancy.
With a CFC single pass, you have to pre-chill the input somehow, and maintain a fairly precise input temp, or your output temp will go all over the place unless you sit there adjusting throughput. It's not as simple thing to do.
 
I was talking more about guys who use multipass because a single pass won't do it, which is the case in much of the south. Might as well use an IC in those cases.

Or use a prechiller. We have warm tap water in CA and the CFC's I have seen in use get it in one pass. But if you are running into the problem you describe and don't have a PC, then yes, you have to recirc. But that has yet to be a problem for the ones I have seen even in hot summers in CA.

Everything is fairly sanitary post boil in the chill path if recircing a CFC.

But in a single pass you aren't recircing, so you have to sanitize it...just like you would sanitize your transfer lines using an IC. No additional steps. device vs device...so far


Thats not fair. A CFC should take exactly twice as long for a 10G vs. 5G.

Fair? Fair has nothing to do with it...it's a reality. When I have used a 5 gallon IC on a 10 gallon batch, yes, IT DID TAKE TWICE AS LONG. Which is too long. And of course I agitated the wort using the IC. However, by having to stand over 10 gallons of recently boiling wort with my hand half way in the kettle stirring steaming wort for almost 30 minutes worrying the whole time that I might drop a bead of sweat or lint from my shirt or any myriad other contaminants into my wort, I am not sure I wasn't the one that was being agitated. So much for your simplicity trumping all theory.

So either I have to preform that lame task or have two IC's, one for each batch size, actually you still have to agitate with each size. Pure simplicity is sanitizing a CFC the same way you would you transfer lines and turn on a ball valve to transfer/chill your wort. Instead you are claiming that standing over your wort for even 15 minutes to agitate it (and yourself), not to mention greater risk contamination is somehow more simple? FUD

If your IC performance was so poor, your CFC shouldn't have been that great either using the same tap temp.
Sorry that just isn't correct. I have used my IC for years, many years, and my friend converted me to CFC's in one single demo. He let me borrow his CFC and in my brewing enviro it chilled in a single pass. I was able to transfer/chill my wort in under ten minutes. With my IC had to chill for 15 then transfer. (I know not a true apples to apples comparison but it was actually later in the summer so the CFC had a theoretical disadvantage but worked better)

But how do you know whether your CFC is actually clean. FUD!
Sigh. The point I was making was that it was fewer steps to insure sanitation in a CFC. I can counter with how do you know your transfer lines are actually clean? Comparing those two parts is equal. And if you are recircing your boiling wort thru your transfer lines to sanitize and still manually agitating your wort with your IC...I dont see it being any simpler, at all. Doing a sanitation flush on a CFC is easier than manually agitating wort with an IC for 15 minutes. For me at least.


Easiest to protect against infections is more than stretch. See FUD above.
Agree to disagree. You are chilling your wort by standing over it and agitating hoping nothing migrates into the wort during the agitation...then transferring through sanitized lines. I know, I did it for a decade and a half that way. A CFC meanwhile is just doing the transfer step. The line is routed thru the CFC and therefore is closed. Boiling wort transfered chilled into your fermenter.

Yes, but with an IC all you do is run with tap water 'til it plateaus, then switch to an ice bath recirc for the last bit until you hit your temp. It does require a pump of some kind, but nothing fancy.
With a CFC single pass, you have to pre-chill the input somehow, and maintain a fairly precise input temp, or your output temp will go all over the place unless you sit there adjusting throughput. It's not as simple thing to do.
FUD overload...how is using tap water then switching to a pumped ice bath easier than placing a pre-chiller inline with your coolant water and forgetting about it. On really hot days I am planning to place my old IC (which already has hose fittings) in a bucket of ice and running my coolant water from the hose thru the IC (in the ice bath) and then through the cold side of my CFC. How is that any harder than switching inputs mid cooldown and then pumping water into it. To do it the way you are describing (which I have done) requires a pump (a second pump if you are also recircing your wort) as well as the ice vessel. Again, your simplicity point is losing footing. Not to mention that if you are returning the water to the ice bath, that has absorbed thermal energy from a run though the IC, the ice bath with begin to warm up. You will be wasting that resource before some of it is even used.

Then again, if it works for you...cheers.
 
Latest try, I haven't had a change to test it yet to see how efficient it is, but I'm sure it's OK for CF-HERMS. Nice and compact with the straight pipe's. I'll make a longer one for cooling, I think I'll make it in a shape of a triangle or a cube and use 180 capillary angles instead of bending the inner pipe...

IMG_20130902_5860.JPG
IMG_20130902_5865.JPG
 
Vesku said:
Latest try, I haven't had a change to test it yet to see how efficient it is, but I'm sure it's OK for CF-HERMS. Nice and compact with the straight pipe's. I'll make a longer one for cooling, I think I'll make it in a shape of a triangle or a cube and use 180 capillary angles instead of bending the inner pipe...

So are both the inner and outer pipes convoluted?
 
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