Using a convoluted counterflow chiller as a heat exchanger in a HERMS?

Anyone have any thoughts on how well this would work?

I'm imagining recirculating temperature controlled water through the outer tube, and sweet wort through the inner tube. A PID controller controls a heating element in the hot liquor tank; the PID's thermocouple measuring the temperature of the sweet wort as it leaves the heat exchanger.

Wouldn't just be easier to put the coil in the hot liquor tank and regulate that temperature?

Double_D said:

Wouldn't just be easier to put the coil in the hot liquor tank and regulate that temperature?

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Of course, this was my first thought. However, ideally I'd like my hot liquor tank to double as my boil kettle, and I'm already going to have a hop screen and heating element in there; having to deal with the coil too makes me worry that things will get a bit crowded.

Additionally, I'm going to have the counterflow chiller set up anyway, so it'd just be a simple matter of turning a few three-way valves to switch from heating to cooling modes.

Really, what I'm describing seems like it's the same thing; I'm just proposing taking the coil out of the hot liquor tank and bringing the hot water to the coil.

I've gone back and forth on this for my own build. I initially thought to do exactly what you have described, and it should work just fine in theory.

My present instinct is to simplify things and just use a tall false bottom (buffer the grain) and go the direct fire RIMS route.

I use a herms coil mounted in my HLT/BK. I use propane, so I dont have a heating element, but its not too crowded. When I tx the wort back into it for the boil, the HERMS coil becomes an immersion cooler.

Pumping hot water through a counterflow should work in theory. You may have to increase your heating water several degrees above target. Id play with test runs using plain water instead of wort and seeing how well you can regulate the temperature before Id try it on a real batch of beer.

geniz said:

I use propane, so I dont have a heating element, but its not too crowded.

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Interesting. So you turn the gas on and off to regulate the temperature? Or do you simply stop recirculating the sweet wort when the temperature gets too warm?

geniz said:

Pumping hot water through a counterflow should work in theory. You may have to increase your heating water several degrees above target. Id play with test runs using plain water instead of wort and seeing how well you can regulate the temperature before Id try it on a real batch of beer.

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This was my thinking as well. Although the more I think about it, the more I think that this approach might have better heat transfer properties than the standard setup. With a convoluted counterflow chiller, not only do you have the turbulence of the sweet wort speeding up heat transfer, but you're constantly moving "fresh" water past the sweet wort, vs. merely circulating it in the hot liquor tank (although circulating the hot water in the HLT is probably the same thing).

Yes, I turn the gas on and off to regulate the temperature. I keep the BK/HLT a few degrees hotter than my target temperature. I use a igloo cooler as my MT, so technically, I really shouldn't have to recirculate to maintain my temps, but my system is a 2 vessel Brutus 20-like system and I recirculate to increase my efficiency.

With the HLT system, you have to stir the water in the HLT to avoid temp stratification around the coil. Using the counterflow chiller should eliminate this problem.

Looking forward to seeing how this progresses

kylekestell said:

. However, ideally I'd like my hot liquor tank to double as my boil kettle

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so your brew set up will just consist of a boil kettle and a mash tun? What will you lauter into when your mash is done and your HLT/BK is full of hot liquor for sparge?

I have done it before. Works surprisingly well. You need to keep your temp a couple degrees over your target.

That's the thinking, yeah. It seems wasteful to require a third tank when I really only need two. I don't have a ton of space and I'm a minimalist by nature, so I'm trying to keep this build as simple as possible.

But you're right, I need some kind of tank to hold the first runnings while I sparge. However, I figure that this doesn't need to be on the same level as my HLT/boil kettle and my mash tun. I usually do a mash out infusion to raise my mash water volume to half of my total runnings (equal first and second runnings), so this third "holding tank" only needs to be 50% the volume of my other two keggles, yeah?

I have an old 5gal corny that doesn't hold pressure anymore. It'd be a tight fit, but it might work.

EDIT: I usually just do 5 gal batches, but I'd like to option of doing 10gal for when I'm expecting a crowd.

For reference, here's what I'm thinking:

I did this for a while, It worked great and was very responsive. I just got paranoid that I was going to get some grain from the mash left over in the coil that would contact the wort after the boil and contaminate a batch. Though I did use this method several times with out incident.

I recirculates Star san in reverse through the coil after the mash, then allowed the boiled wort into the coil with out turning on the cooling water for a couple QT's...but i still worried. I felt more comfortable having my pre-boil equipment separated from my post bol equipment.

You could also make a small dedicated heat exchanger, say a 20QT pot with an element and a coil, or look into a RIMS.

kylekestell said:

That's the thinking, yeah. It seems wasteful to require a third tank when I really only need two. I don't have a ton of space and I'm a minimalist by nature, so I'm trying to keep this build as simple as possible.

But you're right, I need some kind of tank to hold the first runnings while I sparge. However, I figure that this doesn't need to be on the same level as my HLT/boil kettle and my mash tun. I usually do a mash out infusion to raise my mash water volume to half of my total runnings (equal first and second runnings), so this third "holding tank" only needs to be 50% the volume of my other two keggles, yeah?

I have an old 5gal corny that doesn't hold pressure anymore. It'd be a tight fit, but it might work.

EDIT: I usually just do 5 gal batches, but I'd like to option of doing 10gal for when I'm expecting a crowd.

Click to expand...

Sounds like it would work for batch sparging. But in my humble opinion, I would suggest using the old corny for your HLT and lautering into your bk. you could also nix the mash out and simply increase your strike water for a thinner mash (would help to increase fermentable sugars in the wort as well). Then you could heat your sparge water while you mash, transfer into the corny, lauter into the bk and sparge.

I tried to do a two vessel system when I first started, I couldn't find a way to make it work easily, it ended up being a mess on brew day. I quickly bought a dedicated HLT.

OK. You guys have convinced me.

Between the potential sanitation issue, and having to add a third tank to store the first runnings (not to mention the more complex plumbing required in a two-tank setup), I might as well just add a third keggle and go with a more traditional design. I think I'm understanding why the vast majority of the systems I see are three-tank with the more traditional coil in the HLT.

An extra keggle and heating element adds <$150 to the project; I'll probably save at least that much with the simplified plumbing.

I've been doing this with my convoluted counterflow heat exchanger. It works great. Sanitation has never been an issue for me. I didn't want to spend the money for ANOTHER copper coil to install in my HLT. I also use my HLT to ferment in. The idea of having a permenate coil installed sounded annoying to me. Cleaning it seems hard. Also consider that you will have to add 2 more coupler ports to the HLT to mount the coil.

To clean the heat exchanger between mashing and wort chilling, you can recirculate wort through the coil right after you stop boiling. The wort will be over 170 so you are in the pasteurization range. Recirculate the wort through the coil for 5 - 10 minutes before turning on the cold water if you're paranoid about it. If you do have three vessels, you can pump some very hot/almost boiling water through the coil from the HLT after you have mashed. I've never had a sanitation problem.

The best way I've found to control it is to turn the HLT pump on and off. This removes the heat source from the coil. I leave the pump for the Mash Tun on to help clear the wort up. It gives you more control because you are going tom 170~180 HLT water for heat in the coil to nothing. By trying to control the HLT water temp and run both pumps non-stop, you are actually loosing some level of control. In theory, the HLT could be boiling while you mash, but you don't need it to be that hot. I try to set mine 5 or 10 degrees above the sparge temp while mashing. When you are ready to sparge, you should be close to temp in the HLT.

Another nice thing about the setup is you can use a small vessel for the HLT. You will want enough water in it that when you are finished with the mash, you can sparge with the HLT. However, a bigger HLT has more thermal mass and will work better for the heat exchanger.

kylekestell said:

That's the thinking, yeah. It seems wasteful to require a third tank when I really only need two. I don't have a ton of space and I'm a minimalist by nature, so I'm trying to keep this build as simple as possible.

But you're right, I need some kind of tank to hold the first runnings while I sparge. However, I figure that this doesn't need to be on the same level as my HLT/boil kettle and my mash tun. I usually do a mash out infusion to raise my mash water volume to half of my total runnings (equal first and second runnings), so this third "holding tank" only needs to be 50% the volume of my other two keggles, yeah?

I have an old 5gal corny that doesn't hold pressure anymore. It'd be a tight fit, but it might work.

EDIT: I usually just do 5 gal batches, but I'd like to option of doing 10gal for when I'm expecting a crowd.

Click to expand...

Really, if you dont do "Big" beers, and you can live with 70% efficiency, you dont need a third holding tank.

You have two options. First, do a full volume mash like BIAB. If you continuously recirculate, your efficiencies should be in the 70s. If your mash tun can't handle full volume mashes, mash in the traditional sense and then sparge while recirculating. i.e.. start off with the proper amount of sparge water in your HLT/BK and recirculate this into your mash tun. You will eventually be sparing with wort, and the SG of your wort in the HLT/BK and MT will be the same. At that point, you just drain the MT into the HLT/BK and boil normally. That what I do. It works well. I can do it with one burner and one pump. This is basically a simplified Brutus 20 system

If you decide to do a big beer, or ar worried about efficiencies, just drain your MT into fermentation pail(s) and batch sparge as normal. Then dump your runoffs into the BK and boil away. You have flexibility with this system to do efficient one burner, one pump brews.

Whether you recirculate thru a HERMS coil or thru a counterflow is really a matter of economics/convenience. Its basically the same type of system, just whether or not your exchanger is in a tank or not.

For what its worth, Im still playing with my system. Sometimes I recirculate, sometimes I don't. I get the best efficiencies if I continuously recirculate. If I am doing a 5 gal batch, I mash with full volume like BIAB. If I do a 10 gal batch, I do a traditional mash and recirculate the rest of the sparge volume after the mash is compete. But as my system evolves my techniques will evolve. I do love the simplicity of a two vessel system.

I use a converted 5 gallon water cooler for my hlt, and it makes sparging and lautering quite simple. I get roughly 76% efficiency with my system, and I'm pretty pleased with that.

Eventually I want to set it up as a herms build, with the heat exchanger in the hlt, and using the sparge water to raise the mash temps. This will also allow me to use the hlt/heat exchanger as a pre-chiller for my plate chiller at the end of the boil. But that's farther down the road for me, I don't have a need for step mashing at the moment.

What great answers. Thanks everybody! This is certainly a lot to think about. It's fantastic how many different ways there are to brew beer.

First, do a full volume mash like BIAB. If you continuously recirculate, your efficiencies should be in the 70s.

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I'm currently getting about 75% efficiency in my rubbermade cooler mash tun with a batch sparge, so dropping down to 70% (although I've read that you can get up to 80% with BIAB) while vastly simplifying the process seems like a fine compromise. I've actually done a number of no-sparge beers and I've always appreciated its simplicity (the beer has been good too).

I didn't want to spend the money for ANOTHER copper coil to install in my HLT. I also use my HLT to ferment in. The idea of having a permenate coil installed sounded annoying to me. Cleaning it seems hard. Also consider that you will have to add 2 more coupler ports to the HLT to mount the coil.

Click to expand...

This was my thinking originally. Just seems like too many holes in the HLT and too much junk inside.

After spending the last hour sketching out different setups and reading the replies here, I'm now leaning toward my original plan, a two 15gal keggle setup with the counterflow chiller as a heat exchanger.

OK. More pictures. Thoughts?

1. Heating the mash water



2. Dough in



3. Mash



4. Boil



5. Chill



(Red is water, blue is wort. Except in the last picture. I goofed that one up.)

Looks good! the only thing I do differently is in step 1, I pump the "mash water" thru my MT as it heats to preheat my MT

I know I am a couple of years late to this thread, but I was thinking about this exact same approach. My only concern not previously addressed is what to do about the brass fittings on the counterflow chiller (water in/out ports). For chilling, this is no problem, but when running hot water from the HLT through the chiller, wouldn't you want a stainless steel fitting to avoid contaminating your future sparge water with (small amounts of) lead? I had planned on buying a counterflow chiller and removing the brass in favor of a stainless steel connection of some sort.

I am glad to hear that it works well at least. I also have 2 kettles (a 10 and a 20 gallon) and I thought it would make more sense to have the heat exchange coil outside the kettles.

Thanks,
Paul

Lead concerns....From the brass?
I believe, that you can "pickle" the brass and alleviate those concerns.

From the solder, where used?

Lead free solder, for drinking water systems.

Thanks for the tip on pickling the brass. I may give that a shot. I found this article which explained it a bit more: http://powersbrewery.com/pickling-brass/

It has been found that pickling brass has no effect on lead leaching, in some cases even increasing it.

Interesting. Do you have the source article?


Sent from my iPhone using Home Brew

Do a google image search.

Source?
http://homedistiller.org/forum/viewtopic.php?f=33&t=20910
http://www.artisan-distiller.net/phpBB3/viewtopic.php?f=20&t=4205

I've been thinking about a similar idea. Sorry, I don't have a drawing.

The idea is to combine HERMS and RIMS equipment. Instead of an HLT with a heating element in it, just use a small 1 gallon pot with an inlet and outlet.

Water pot --> RIMS --> CFC --> water pot

MLT---------------------> CFC --> MLT


This way, you have the smallest inertia due to the water possible because you are using so little, which should increase the mash ramp rates. Get the gentle heating of a HERMS system with the responsiveness of a RIMS system.

I currently have a traditional HERMS system and kal-type panel, but in the coming year or two I'm looking to down-size a little. I might give this idea a shot, as I already have everything except the RIMS tube.