Counter-Flow Chiller build - User Builds Discussions on Home Brew Forums

C_B

I finally decided to build a pipe in pipe counter flow chiller when I saw Lakewood's heat exchanger.
I like this design for a couple of reasons...
No concern about hop material or possibly break material as with a plate style heat exchanger
I can use this to heat the wort by running hot water through it unlike a typical rubber hose around a copper pipe counter flow chiller.
Here is a picture of the parts. Not included, (2) 10' sticks of 1/2" copper and (2) 10' sticks of 3/4" copper pipe.

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This is how I laid out the fittings. I decided to go with 3/4"x1/2"x3/4" tees on all but the wort and water connections so that I could use the excess 3/4" pipe for those little connections.

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I popped 7/8" holes in a 2x6 to hold it all together. Hindsight, that made assembly a pain. To do over again I would do something after the fact to tie it all together.

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Here's where the whole project got a little sidetracked. The fitting on the left is unaltered, the right has been filed. See that little stop in there? Yeah it ruin my day. I tried to make a little jig (block of wood with a hole) and drive the fitting on. One worked like that. The next one crushed the pipe in. So I bought a 10" course round bastard file and went to town. That worked like a charm and took maybe 2-3 minutes per fitting. During this I noticed a large variance in the size of that stop between each individual piece.

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monkeys

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Here is a really bad picture of it all sweated together.

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All hooked up.

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A little different angle. A close up of that tiny little hose would show it almost kinked. The shorter the better in this case. A longer hose wanted to kink worse.

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Finally pumpin'!

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This was the pump output. I even had two of those Kendt Disconnects inline. I'm not too worried about those now.

C_B

A few notes about the build...

The blocks of wood really tied the unit together. Nicely. I can pick it up with one hand and I'm not afraid of putting too much pressure on the fittings. It did make it a bit tricky to put together, not impossible.
I cut the 1/2" in half (5' length) and build the rest of the chiller around that dimension to minimize waste. I also left 5/8" of the inner 1/2" pipe sticking past the fitting in case I want to change the return design at a later date.
With the hoses on the end I love the accessibility of pulling those off and running a brush or something through the wort tube if I'm feeling extra OCD.
One other important factor with this design... All of the sweat fittings are contacting chilling water, not wort. So If you're unsure about your soldering skills, the only leaks you can cause are from chilling water, out. No chance of contaminating wort with chilling water.

C_B

Thoughts on cleaning it the first time? I put five gallons of water in the kettle and added a half scoop of OxyClean. The turned on the pump and heat. I recirced at least 15 minutes until it was nearly boiling. Then after testing it I rinsed with cold water.

Jayrizzle

Is there a PVC fitting that will cover a standard copper pipe size with out leaking really bad? I want to make a shotty one for cheap.

C_B

5 gallons or 210* water to 180 in 1 minute.
Then to 160 at the 2 minute mark.
then 120 around 4 minutes.
Total chill time to get 5 gallons from 210* to 80* (that's when I stopped caring) >>>>> 8.5 minutes.

This was with both the wort and chilling water running full bore. In the future I'll throttle back the wort to reduce turbulent flow in the kettle and run the chilling water wide open until I'm under 170. Then throttle back the chilling water to minimize water usage.

C_B

Dr_Jerryrigger said:
Is there a PVC fitting that will cover a standard copper pipe size with out leaking really bad? I want to make a shotty one for cheap.

You could use pvc no problem. With tees and all that. I want the option of running near boiling water through the jacket to heat the wort also.

Jayrizzle

Yeah, I made a shitty little one out of all copper it was nice how it was copper.

Thym

nice build. i like the wood block stays.

jeepinjeepin

Dr_Jerryrigger said:
Is there a PVC fitting that will cover a standard copper pipe size with out leaking really bad? I want to make a shotty one for cheap.

With a threaded adapter, yes. PVC pipe->slip/thread PVC coupler->thread/slip copper fitting.

Jayrizzle

jeepinjeepin said:

Dr_Jerryrigger said:
Is there a PVC fitting that will cover a standard copper pipe size with out leaking really bad? I want to make a shotty one for cheap.
With a threaded adapter, yes. PVC pipe->slip/thread PVC coupler->thread/slip copper fitting.

Right good call. I don't feel it's worth the 15% savings the more I think about it.

C_B

Lakewood said:
nice build. i like the wood block stays.

Oh right, a note about these... from the mock up to the final soldering I managed to not pay attention to these. So now the whole thing has a slight twist to it. Cosmetic, but annoying.

Thym

C_B said:

Lakewood said:
nice build. i like the wood block stays.

Oh right, a note about these... from the mock up to the final soldering I managed to not pay attention to these. So now the whole thing has a slight twist to it. Cosmetic, but annoying.

No big deal. We always knew you were a little warped anyway.

Jayrizzle

So based on testing, do you think it would work as well if it was a little shorter? And if so how short?

On another note, though a sani nightmare, it would seem that you'd get more cooling if the wort was in the jacket as the air would eat some. Just a thought.

C_B

Dr_Jerryrigger said:
So based on testing, do you think it would work as well if it was a little shorter? And if so how short?

On another note, though a sani nightmare, it would seem that you'd get more cooling if the wort was in the jacket as the air would eat some. Just a thought.

I thought about that and agree with you. Sanitation is why I didn't do it. All the fittings in there would provide a heck of a place for nasties to grow. I think a better bet would be a smaller inner pipe. but jumping down to 3/8 adding fittings, so I didn't do it.

I think it would work fine shorter. Just work slower. You probably have good cold ground water? That would help take those last couple degrees off. If you use it as a one pass chiller rather than recirc you could get away with 10' with cold water and a slow drain. But that's mearly a guess.
It took 30* off 5 gallons in 60 seconds.

Jayrizzle

C_B said:

Dr_Jerryrigger said:
So based on testing, do you think it would work as well if it was a little shorter? And if so how short?

On another note, though a sani nightmare, it would seem that you'd get more cooling if the wort was in the jacket as the air would eat some. Just a thought.

I thought about that and agree with you. Sanitation is why I didn't do it. All the fittings in there would provide a heck of a place for nasties to grow. I think a better bet would be a smaller inner pipe. but jumping down to 3/8 adding fittings, so I didn't do it.

I think it would work fine shorter. Just work slower. You probably have good cold ground water? That would help take those last couple degrees off. If you use it as a one pass chiller rather than recirc you could get away with 10' with cold water and a slow drain. But that's mearly a guess.
It took 30* off 5 gallons in 60 seconds.

Did you touch the cooling jacket enough to get an idea of where it got super hot?

C_B

Dr_Jerryrigger said:

C_B said:

Dr_Jerryrigger said:
So based on testing, do you think it would work as well if it was a little shorter? And if so how short?

On another note, though a sani nightmare, it would seem that you'd get more cooling if the wort was in the jacket as the air would eat some. Just a thought.

I thought about that and agree with you. Sanitation is why I didn't do it. All the fittings in there would provide a heck of a place for nasties to grow. I think a better bet would be a smaller inner pipe. but jumping down to 3/8 adding fittings, so I didn't do it.

I think it would work fine shorter. Just work slower. You probably have good cold ground water? That would help take those last couple degrees off. If you use it as a one pass chiller rather than recirc you could get away with 10' with cold water and a slow drain. But that's mearly a guess.
It took 30* off 5 gallons in 60 seconds.

Did you touch the cooling jacket enough to get an idea of where it got super hot?

It didn't really. I ran both the pump and the hydrant balls out. Next step it to make it more efficient.

Thym

The only way to make this design really efficient is to reduce the volume of each flow chamber while maintaining the same surface area. But that's really hard since there isn't a good way to use up the outer bit of the jacket cross section. The cooling performance is dependant on the speed of the flow across the heat exchange surface (inner pipe wall) and given a constant cross section, the speed is dependant on the flow rate. A shorter design will make it less efficient.

C_B

Lakewood said:
The only way to make this design really efficient is to reduce the volume of each flow chamber while maintaining the same surface area.

Plate chiller.

Jayrizzle

C_B said:

Lakewood said:
The only way to make this design really efficient is to reduce the volume of each flow chamber while maintaining the same surface area.

Plate chiller.

Or reducing the flow with a valve.

Thym

Dr_Jerryrigger said:

C_B said:

Lakewood said:
The only way to make this design really efficient is to reduce the volume of each flow chamber while maintaining the same surface area.

Plate chiller.

Or reducing the flow with a valve.

No, that actually reduces the efficiency, since the flow velocity is reduced. Better to flow fast for a long distance.

Thym

C_B said:

Lakewood said:
The only way to make this design really efficient is to reduce the volume of each flow chamber while maintaining the same surface area.

Plate chiller.

You could run the concentric pipes through a roller to flatten them out starting a few inches in from either end. Seems like it would work well. I haven't tried it though.

Jayrizzle

Lakewood said:

Dr_Jerryrigger said:

C_B said:

Lakewood said:
The only way to make this design really efficient is to reduce the volume of each flow chamber while maintaining the same surface area.

Plate chiller.

Or reducing the flow with a valve.

No, that actually reduces the efficiency, since the flow velocity is reduced. Better to flow fast for a long distance.

This is true. The ideal chiller would be infantly long, with infanant surface area, and a flow rate moving the speed of sound.

But my reality is 57F water that's baicaly free, and copper and space that's not.

T(s)+(T(o)-T(s))e^(-kt) =T(t)

So you don't get much from chilling 200F wort with 199F water.The "k" value is quite important and in this system is a product of surface area and turbunace and flow rate. With the counter flow you have coolant heating and providing less effect the further you go.

For my uses I feel jamming a 2' tube with stainless scrubbies and letting it flow slow with lots of coolant it the best option... Or maybe it should be 6 feet....

Thym

fill the chilling water portion with the scrubbies, that will help the cooling water pull heat out. put a small rod or capped tube inside the the inner wort tube. and you'll get pretty good efficiency.

C_B

Lakewood said:
fill the chilling water portion with the scrubbies, that will help the cooling water pull heat out. put a small rod or capped tube inside the the inner wort tube. and you'll get pretty good efficiency.

I thought about running a 3/8 pipe through the middle and running cooling water through it also. That would eliminate the access to the wort chamber with a brush. And it would cost enough more in pipe and fittings that I could just buy a good 40 plate extra long chiller. So I didn't. But that would definitely boost efficiency.

Thym

C_B said:

Lakewood said:
fill the chilling water portion with the scrubbies, that will help the cooling water pull heat out. put a small rod or capped tube inside the the inner wort tube. and you'll get pretty good efficiency.

I thought about running a 3/8 pipe through the middle and running cooling water through it also. That would eliminate the access to the wort chamber with a brush. And it would cost enough more in pipe and fittings that I could just buy a good 40 plate extra long chiller. So I didn't. But that would definitely boost efficiency.

make it removable, and use something cheap

Jayrizzle

Lakewood said:
fill the chilling water portion with the scrubbies, that will help the cooling water pull heat out. put a small rod or capped tube inside the the inner wort tube. and you'll get pretty good efficiency.

That would increase efficiency, but may reduce flow rate of coolant, which is free so not the place I need maximize efficiency. Two water inputs and expelling points would be more efficient in terms of copper used.

C_B

Dr_Jerryrigger said:

Lakewood said:
fill the chilling water portion with the scrubbies, that will help the cooling water pull heat out. put a small rod or capped tube inside the the inner wort tube. and you'll get pretty good efficiency.

That would increase efficiency, but may reduce flow rate of coolant, which is free so not the place I need maximize efficiency. Two water inputs and expelling points would be more efficient in terms of copper used.

If the capped pipe or rod in inside the wort tube it won't impact coolant flow rate.

Jayrizzle

C_B said:

Dr_Jerryrigger said:

Lakewood said:
fill the chilling water portion with the scrubbies, that will help the cooling water pull heat out. put a small rod or capped tube inside the the inner wort tube. and you'll get pretty good efficiency.

That would increase efficiency, but may reduce flow rate of coolant, which is free so not the place I need maximize efficiency. Two water inputs and expelling points would be more efficient in terms of copper used.

If the capped pipe or rod in inside the wort tube it won't impact coolant flow rate.

Yes, that is true.

C_B

So now that I have it hooked up correctly utilizing the entire chiller I tested it again today while cleaning it. 10 gallons of boiling water down to 180* in about 60 seconds. Overall chill time was about 15 minutes. That was pulling off the bottom and dumping it back in the top. No whirlepool action to speak of so I'm not sure how accurate the thermometer at the bottom was.
With the pump valve about half open and the water valve all the way open the wort discharge side of the chiller was warm to the touch at the start. I think I was knocking it down to around 90* from the start.

Jayrizzle

What was the cooling water draining at?

Thym

C_B said:
So now that I have it hooked up correctly utilizing the entire chiller I tested it again today while cleaning it. 10 gallons of boiling water down to 180* in about 60 seconds. Overall chill time was about 15 minutes. That was pulling off the bottom and dumping it back in the top. No whirlepool action to speak of so I'm not sure how accurate the thermometer at the bottom was.
With the pump valve about half open and the water valve all the way open the wort discharge side of the chiller was warm to the touch at the start. I think I was knocking it down to around 90* from the start.

Sounds about right.

C_B

Dr_Jerryrigger said:
What was the cooling water draining at?

Flow rate? Whatever my well pump pumps.
Temp? At first, hot hot. Then just warm enough I don't want hold the outlet pipe for more than a second.

Jayrizzle

C_B said:

Dr_Jerryrigger said:
What was the cooling water draining at?

Flow rate? Whatever my well pump pumps.
Temp? At first, hot hot. Then just warm enough I don't want hold the outlet pipe for more than a second.

So about the same as the water going into it?

C_B

Dr_Jerryrigger said:

C_B said:

Dr_Jerryrigger said:
What was the cooling water draining at?

Flow rate? Whatever my well pump pumps.
Temp? At first, hot hot. Then just warm enough I don't want hold the outlet pipe for more than a second.

So about the same as the water going into it?

The temp? No. It was hot. I'm guessing at least 150 to start. Then probably 130. 120-130 for a while. It was steaming coming out of the hose most of the time.

Jayrizzle

Oh sorry, the temp of the coolant coming out was about the temp of the kettle water going in.

C_B

Dr_Jerryrigger said:
Oh sorry, the temp of the coolant coming out was about the temp of the kettle water going in.

Ah. Right. Now I understand the question. I was running the violent water full on. So there was a difference I'm sure. The coolant water exiting was hot, but not quite that hot.