Tube in Tube Countercurrent Mash Chiller

Unsensibel

Nice job! Did you already take it for a spin?

CothermanDistilling

saw this and thought I would throw it out there... maybe a 1.5" inside and 2" outside tube modular system? then again.... did we talk about this before?

Smaug

This is what we will have available after walking their floor and will be talking turkey for single and two stage units asap.

TheMechWarrior

I like the look of that Smaug.

CothermanDistilling

yes, but you cannot send mash through that...

Smaug

Yes sorry. I should have posted a new thread.

More like an FYI.....coming soon.

DocPorter

If they make them with a wide enough gap and you grind your grain small enough you may be able to push your mash through something like that.

You'd probably have to take it apart and clean it after every run, so I agree let's see a tube in tube modular system!

Pseudo

@jbierling said: Here's my proof of concept with 40" 2" copper. 3x2x2 copper is $100+ so I thought I might try this approach.

Brilliant man, how did it work out?!

We're currently trying to price something out for ourselves. We asked a manufacturer in China, they suggested the following (which we think is too small):

32mm (1.25") inner pipe, 64mm (2.5") outer pipe, 1200mm (~4') for each tube, 5 tubes in series. But after calculating the surface area of the inner tube, it's only about 0.6m^2 (6.5ft^2) in total - which doesn't seem like enough for a 1200L mash tun.

We'd like to cool in a single pass if possible, so thinking maybe we'll build our own using copper and PVC like @jbierling did. @grim, did you ever get yours built? Maybe you can provide some cooling stats - would be appreciate by the board I'm sure.

Littlechicago

besides a plate cooler, don't over think it. We let our 500 gal mash rest overnight and its 130+ ish after 12 hrs. after straining our corn we use a simple brewers wort chiller. cheap and effective. if you want to be cheap buy some coil copper and add 2 hose barbs or threaded hose ends if you use main water. Lebig type coolers are ok but inefficient for chilling mash.

solarpowerscott

for a mash I would think an immersion chiller would be the best solution.

grim

I got the parts laying around, no time yet. 2 10 foot sections of copper pipe.

CothermanDistilling

@solarpowerscott said: for a mash I would think an immersion chiller would be the best solution.

you would have to circulate the mash, and your efficiency would be much, much lower than counter flow.... the efficiency of a good counterflow is so near 100%, it does not make sense unless you are forced to use an immersion chiller

Anavrin

Just how big are you guys trying to go with this?

I have a 7 plate counterflow chiller, it's about the size of a house brick, and cost about £50, it can easily chill straight from the boiler to the fermenter in one pass, I've used it for many years with my home brew, if I'm not carefull, I can over cool the wort.

I'm sure only a slightly larger version would suit most people's needs.

Here's something similar to what I have.

TheMechWarrior

I suspect these guys are trying to cool ~2,000L in a single pass.

FloridaCracker

Then they can just buy 80 of them.

=))

Anavrin

Going to this sort of expense and size it might only be a cheapish modification to try and aireate the wort as it passes

CothermanDistilling

if you have ever run caustic through a small, homebrew style, non-disassemble-able plate chiller that you thought was clean, you will never use that type of plate chiller again without using caustic every single time....

grim

Overnight passive cooling becomes less effective as batch sizes increase (lower surface area to volume) and ambient temperature goes up (and approaches the mash temp). Years back, I remember leaving out 50l batches in 5c/40f and it still taking about 12 hours to drop down to yeast pitch temps (24c/75f). I can't imagine how much time it would take my mash tun to cool passively in the summer, probably a week. I'm sure with agitation and surface area open to the air, that might take less time, but that leads to the second issue, infection.

Depending on your process, lacto infection is a very real risk, especially if you don't boil, or hold boil temperatures. A 12 hour passive cooling cycle is an ideal situation for lacto to take over. I've seen my own passive cooled batches crash to a pH of high 3 just due to lacto infection, and only in a few hours. Assume your grain is completely covered in lacto.

My batch sizes are large, 2000 liter, and I ferment on-grain, which means plate chillers are simply not possible (at least not the cheap ones).

The "Big Liebig" or "Tube-in-Tube" approach was never intended to be single pass, but recirculating into the mash tun. You would need significantly more than 20 feet to do it in a single pass. Recirc is the only realistic way to reduce hardware costs. You are trading higher operating costs and time for less overall cooling capacity.

grim

Lacto will survive at the lower end of mash/malt drop temps - I've got a study that says 7% of Lacto will survive at temperatures up to 63C/145F. Ideal propagation temperature is 100F with strong activity between 100-120F.

Pseudo

@grim said: The "Big Liebig" or "Tube-in-Tube" approach was never intended to be single pass, but recirculating into the mash tun. You would need significantly more than 20 feet to do it in a single pass. Recirc is the only realistic way to reduce hardware costs. You are trading higher operating costs and time for less overall cooling capacity.

Not sure of the costs where you are, but 2" copper pipe * 12' is about $100 at Home Depot. So each of those pipes gives you about 0.58m^2 (~6.2ft^2) of contact area. It's definitely not perfect, but for $500 (plus additional cost for fittings and PCV piping, of course), that would give me close to 3m^2. Probably configured in 6' rungs, 5 rungs tall, 2 rungs wide.

So a few question that remain:

• Does tube compare 1:1 with the measurements of a plate chiller? So for examples, does 3m^2 of tube give roughly the same efficiency as the same amount of plate? (An 8m^2 plate chiller can definitely be got for well under $2000, for those running off-grain)
• Does anyone know how to roughly calculate the heat transfer coefficient in a practical way to determine how many feet it would take to cool from say, 70°C to 35°C?

DocPorter

The heat transfer will not be the same per unit area. The fluid velocities in a plate chiller are much higher and lead to a higher heat transfer coefficient.

I would use 150 BTU/hr/ft2/°F for a plate chiller and 25 for a tube-in-tube:

Heat Transfer Coefficients in Heat Exchangers

They could be much higher than that, but I like to pick the lower end to be conservative.

grim

My thought was to use TC fittings on the ends of each straight section of pipe, allowing you to inspect and clean straight sections. These straight sections would be connected with stainless TC 180' U fittings, ultimately looping back and forth. Adding in the fittings cost does push the cost up somewhat, also means that if you can get away with the longer 10-12' sections, you'll probably save a lot of money.

My thought was to mount it up on the back wall, higher up, and not taking space on the floor. Much easier than dealing with what will be one hell of a long unit.

I wouldn't solder the long sections together with copper, no way, it would be impossible to clean and inspect.

To get it done in one pass, you can always run it slower, or use colder coolant.

CothermanDistilling

^^^^ zactly!

CothermanDistilling

2m long sections, big boys can put 2 sections end to end before looping back I could see $150/section being a target price... less work than a 2" long condenser, but more material... outside jacket could be really thin...

DocPorter

@CothermanDistilling said: 2m long sections, big boys can put 2 sections end to end before looping back I could see $150/section being a target price... less work than a 2" long condenser, but more material... outside jacket could be really thin...

I'd buy one...

grim

Honestly, you could probably get away with DWV copper, or at the heaviest, type M (aka "the thin stuff").

I don't know that I'd pay for anything more substantial, it's not going to be running pressurized. Even if you were running the shell side using city water, just leave the end open to atmosphere and regulate the supply pressure on the input.

Hell, the thin stuff will have a better heat transfer coefficient too, so it's not like going thinner has a performance downside.

CothermanDistilling

spec the whole thing with really thin stainless, .065 wall or thinner.. and a bit of a swirl embossed into it ;-)

jbierling

I've built and am using mine. This version is four 5 foot sections using 2" DWV copper switching back and forth with stainless 180 TCs. I use it to recirculate until I hid the target temp.

I plan on at least doubling the size when I get more space.

Pseudo

@grim said: These straight sections would be connected with stainless TC 180' U fittings, ultimately looping back and forth.

That was what I had in mind as well on the ends, and good point about that bumping costs - longer rungs would definitely reduce cost - maybe 5 x 12' would be better since we were just planning to mount it on a wall as you mentioned.

@jbierling said: I've built and am using mine. This version is four 5 foot sections using 2" DWV copper switching back and forth with stainless 180 TCs. I use it to recirculate until I hid the target temp.

Have pictures? Would love to see how you rolled it out. Have any numbers as well? How many times are you recirculating, for what mash size, between what temps?

Myles

I know this is a worm for vapour, but something this size would work

Just a big worm condenser.