Thoughts on this counter flow chiller. The CRAB

[bwilliamson]

I'm thinking of building one of these to use as my chiller. Something about the coil of copper tubing is just too simple for me. I estimate this would cost about $100 in materials. The water lines would run completely through the larger wort lines. You could feed it with whatever temp cold water you want and just recirculate the wort through it until you get down to the temp you want. Then again for $100 you could buy a nice plate chiller. Take all the fun out of building it though.

 

[Indian_villager]

Unless you have some potent pumps you are killing your film coefficients by splitting the flow and reducing the velocities. But then again depending on length and diameter of the tubes you might end up OK by having longer dwell times.

If you intended chilling method is recirc to the boil kettle then dump to fermenter when the temp is reached why not keep it as simple as an immersion coil?

You are making a lot of work for your self.

 

[mendesm]

Dude, if you're doing it for the thrill of building it, go for it.

Indian Villager is spot on the pump/flow issue.

It's a cool drawing though.

The only other thing I can think of is "way too much over engineering"

Cheers!

 

[bwilliamson]

I couldn't agree more about me creating work for myself and over engineering this thing. I just like to make things. As for the flow issues, I have a few Shurflo RV water pumps laying around. They typically move 3-5 gallons per minute at 45 PSI. I figured even if splitting the flow 4 ways and it does slow it down that will be just more time on the cold pipe. Also I originally though the wort was going to run straight through but decided that making the wort turn 90 degrees both in and out of the heat exchanging chamber would get it swirling around much more and help with cooling.

 

[horseinmay]

That's a pretty cool idea, but for efficiency's sake, you may want to rearrange the design. Instead of splitting the flow, and running 4 parallel lines, you should run it in series, making the wort travel through each of the 4 chambers before exiting to your fermenter. This will allow more contact time with the water, and should not be any more pipe, just arranged differently. You would also want to do the same with the water pipes. It would end up functioning the same as a counterflow chiller, but not spiral shaped. Go for it.

 

[bwilliamson]

Good idea. I though of a few different designs but not about making it act as one long tube. Better yet, why not save $$$ on fittings and make a single tube about 6' long.

 

[bwilliamson]

In series both with turns to keep the wort moving around and a stick.

 

[FuzzeWuzze]

In series both with turns to keep the wort moving around and a stick.

At this point you have essentially just created an standard CFC uncoiled in a different shape with the wort having less contact time(where the wort hops water lines).

There's a reason the standard CFC design is so popular, because as you have just demonstrated, its the best engineered solution

 

[bwilliamson]

Yep. I was thinking about this way too hard and it's like trying to reinvent the wheel.

 

[mendesm]

Why not feed 4 cold water pipes in parallel, while the wort flows through just one pipe in series?

This way, every 1/4 of the wort's way, it gets a new batch of cold water bathing over it.

Perhaps, even test what cools beter:

a) wort in inner pipe, water in outer pipe
b) water in inner pipe, wort in outer pipe

My gut feeling says A would be better, but who knows?

 

[bwilliamson]

A test would certainly give results either way. I feel that the wort making 90 degree turns inside the tube would cause more turbulence and mort of the wort would be in contact with the cold pipe rather than the wort just flowing straight through the pipe. The wort on the outside of the hot pipe would be cooled and the inner most part of the flow would still be warm.

 

[Indian_villager]

Depending on what you plan on using as a cold fluid have you thought about using one of these?
http://www.dudadiesel.com/search.php?query=b3-12a

 

[bwilliamson]

I have thought about them but that kind of takes away done of the DIY for me. I was going to use either tap water or the steam beside my house for the cold water source.

 

[Bobby_M]

The tube-in-garden hose design is already a cheap and easy proven solution.

 

[horseinmay]

I have thought about them but that kind of takes away done of the DIY for me. I was going to use either tap water or the steam beside my house for the cold water source.

I would go with the tap water over steam. It's going to cool much faster.