Cooling Jackets for Plastic Conicals?

Seem to be a lot of threads about DIY plastic connicals.

They got me to thinking: I have seen designs for cooling jackets for SS connicals, but none for plastic. By "cooling jacket", I mean a coil of tubing that encloses part of the body of the connical, that is fed with a chilled liquid. The flow of liquid is controlled by a thermostat, with the probe in the wort, and the whole thing is covered by insulation.

Is something like this worth thinking about with a plastic connical, or am I missing something?

 

I wonder if you could simply purchase 2 hoppers of different size? Then build it so there is an inner and outer hopper.

 

Another option might be to hang a stainless coil from the lid.

 

I was thinking of adding a coil to the inside through the side wall... similar to this...



I wonder if the tempeture gradient would be enough to get the wort to "stir itself" and stay uniformly cooled?

 

At least initially, the yeast should handle that.

 

So, I've been thinking of doing this as well. The main downside is the poor thermal transfer between plastic. However, I'm thinking if its covered in coils and then insulated, you can overcome the slow transfer.

As a starter, I'm planning on buying a roll of PEX tubing and wrapping it around a plastic conical and then insulating heavily. I think a cold enough liquid will allow enough transfer to overcome the poor material choice. If it doesn't work, at least PEX isn't expensive. I'm imagining this conical will be in a room that is already relatively cool (not over 75 for example), so I don't expect it to take much to drop it another 10 degrees or so.

 

Probably be simpler to just use a cheap CL fridge.

The liquid cooling is just SO COOL, though.

 

Pun intended?

I agree with just using a fridge from CL. Maybe build a fermentation chiller? I'll be using my chiller for my conical.

Plastic is cheaper but won't allow a cooling jacket cuz plastic is an insulator not a conductor. There's always a tradeoff...

 

After looking at this project for a couple months, I came to the same conclusion. Pick up a small used fridge, add a new temp controller you're done. No hoses, connections or pumps to deal with every time you ferment new batch. Probably more efficient as well.

 

True, but at some point, that's no longer practical. What if your conical is 110 gallons?! Or if you need 4 of them and each of them are 110 gallons?

Just sayin...

 

Yes the temperature gradient will cause motion - not that you'll need it. It the thermal input will also move through the wort simply because heat energy seeks cooler material. And you don't really care about it being a slow process because it's going to sit there for maybe weeks. Time is on your side. No agitation needed.

You can do that inside the poly chamber and it'll work excellently.
Out side not so much because plastic is a crappy convector.


Just one caveat: Be careful about cold flow when installing bulkhead fittings. Use O rings and don't over tighten.
And sanitation: Because of all the introduced stuff (threads, O rings, yadda yadda) you will need to be able to take it apart and clean it whenever you set up for a brew. Just resign yourself to that one extra task.
But, clean and snug, It should work very well.

In fact any one owning a conical that is not jacketed (poor babies) might want to take a long hard look at this elegant and simple idea.

I've seen SST conicals wrapped in copper pipe. I never saw any one soldering the pipe to the conical which they ought to do to get good convection. I'm guessing that people just can't bring themselves to solder to the it expensive conical.


On the poly conical I reccommend that you use a metal strip about 3/16 to 1/4 thick and no less than an inch preferably 1.5 - 2" wide and put one on at least on the outside running up and down to connect physically the two inlet and outlet ports.
This will provide stability and strength which the poly fermenter does not have and prevent stress cracking from the tension and stress that you will (of a certainty) be putting on the plastic. I'd think about getting a lengh of Stainless and poutting a 1.25" wide strip insode the fermenter to sandwich the bulkhead fittings into a unitary structure with the fermenter.

I used to build a lot of different vessels large and small from plastics and I can see that the stresses of that sort of thing will be an issue.

Drill the holes not with a common 2 flute twist drill, but with a Forstner bit or a hole saw or better yet (best actually) a Plunge router in a holding jig, having pre-drilled a little pilot hole to remove the center material o the router bit doesn't dither on the center (most router bits that size are not center cutting).

It is important when drilling plastic to get as clean a cut as possible cutting at a speed that generates as little heat as possible (or use coolant) because the act of machining will set up stresses in the polymer which can easily propagate and grow into bona fide cracks.

HDPE is pretty good about tolerating machining.
I believe most poly conicals are HDPE.
They should be UHDPE but no one would pay for that.

 

Hmm... interesting... thanks for the insight. I am still tossing the idea around. For now I have been keeping my conical in a closet that remains at 68-70 degrees all the time. It has been working great for ales. The cooling would be for lagering, and a more constant ale fermentation. I just can see building a chamber larger enough to fit a 5 gallon conical, 15 gallon conical and several carboys.