Counter flow HERMS

Hi,

Has anyone used a counterflow chiller (e.g. chillzilla) in a RIMS setup using a low wattage element to heat the water (not the wort obviously) instead of putting a coil inside a kettle and using a bigger element as in a traditional HERMS?

I would like to move from my RIMS system to a HERMS system bu it seems to me it would be a lot more efficient heating the one or two gallons of water around a coil instead of heating 15 gallons inside a keggle.

I really don't think you would have to have a 15gallon full kettle for a HERMS system. If you are brewing 10gallon batches I would think you might need 10gallons in the HLT at the most.

I suppose you could use less water volume by having less in the HLT and then pumping it through the counterflow chiller and then back into the HLT. However, this would require you to have two pumps. One pumping the HLT water and the other pumping the wort. On the other hand you could then get away without having something to stir the HLT.

As far as efficiency you might gain some efficiency from there being less heat loss from a smaller water volume in the HLT. However, at some point you would still have to heat the same volume of water up as a typical HERMS system for the sparge water. So your efficiency gain would then become very little.

At least thats my take on it. I have never used a HERMS just my crappy setup so somebody with more experience can take this if they want.

Picture of Chillzilla
Chillzillas

There are a few people on here who use a CFC or plate chiller as a HEX for their mash. I think you're right about better efficiency if you mean faster temperature ramps heating a small water tank for the CFC on the non-wort side compared to the entire volume in the HLT.

I'm building a system with a small (3-ish) gallon pot with a heating element and mechanical stirrer for the HERMS coil. The reason I'm doing that instead of just running the water over an element and through a CFC is the additional pump. I want to hard plumb my system and reconfiguring (or additional valves) would be a pain.

Here's my system's design https://www.homebrewtalk.com/f11/another-herms-designed-clock-135250/.

Scut_Monkey said:

I really don't think you would have to have a 15gallon full kettle for a HERMS system. If you are brewing 10gallon batches I would think you might need 10gallons in the HLT at the most.

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If you are brewing with a normal HERMS (Coil in the HLT) you have to put enough water in thye HLT to cover the coil. Your assumption is not correct. The efficiency would come in because it would be a closed system. Less water would be used. The water would be heated and recycled through the CFC.

Sawdustguy said:

If you are brewing with a normal HERMS (Coil in the HLT) you have to put enough water in thye HLT to cover the coil. Your assumption is not correct. The efficiency would come in because it would be a closed system. Less water would be used. The water would be heated and recycled through the CFC.

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I'm kind of confused. I feel like this is very similar to what I said. Can you clarify how I was incorrect.

Scut_Monkey said:

I really don't think you would have to have a 15gallon full kettle for a HERMS system. If you are brewing 10gallon batches I would think you might need 10gallons in the HLT at the most.

I suppose you could use less water volume by having less in the HLT and then pumping it through the counterflow chiller and then back into the HLT. However, this would require you to have two pumps. One pumping the HLT water and the other pumping the wort. On the other hand you could then get away without having something to stir the HLT.

As far as efficiency you might gain some efficiency from there being less heat loss from a smaller water volume in the HLT. However, at some point you would still have to heat the same volume of water up as a typical HERMS system for the sparge water. So your efficiency gain would then become very little.

At least thats my take on it. I have never used a HERMS just my crappy setup so somebody with more experience can take this if they want.

Picture of Chillzilla
Chillzillas

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You said, "I really don't think you would have to have a 15gallon full kettle for a HERMS system. If you are brewing 10gallon batches I would think you might need 10gallons in the HLT at the most." What if you were brewing 5 gallons? You would still have to have enough water in a conventional HERMS to submerse the coil. If the coil is 20" long you would have to fill the HLT with 20 inches of water no matter how much you are brewing. With the CFC HERMS coil you only have recirculate the amount of water in the CFC coil (about a gallon or two). So if you were making a 5 gallon batch maybe you would need 7 gallons instead of filling the HLT with enough water to cover the HERMS coil. While it may be true that you need another pump, you would use less water and expend less energy than heating a HLT with enough water to cover the HERMS coil.

Sawdustguy said:

While it may be true that you need another pump, you would use less water and expend less energy than heating a HLT with enough water to cover the HERMS coil.

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That was exactly my thought... it seems it would be a lot quicker and use less energy to ramp the 1 gallon in steps that heating 10-16 gallons (or whatever amount). Of course, you would still need an element of sufficient size to make up for the HEX loss to the mash.

In any case, while you would in fact need two pumps, you would not need to stir. I think I am going to try this. What material do you think is appropriate for the outer layer of the HERMS coil - other than a regular hose? Maybe I could put the counterflow unit into a home depot bucket (heater unit outside) and fill the bucket using expandable foam.

How are you planning to heat the sparge water? This is one area that really has not been addressed. One of the advantages of a regular HERMS system is that at the end of the recirculation you have a HLT with the sparge water already heated or very close to the sparge temp.

I understand that a counterflow chiller will be more efficient during the recirculation. However, you then have to heat up all of the sparge water anyways. So in essence the large volume of water that you heat up for an immersion chiller type HERMS is not ALL wasted energy.

I am not shooting your idea down as I do believe that it could work. Just adding to the discussion is all. For instance you need to keep the large volume of water in the HLT from lossing heat over an hour with a regular herms. Your system would not have this level of heat loss adding to it's efficiency. Also, like it was already mentioned you might be heating up more water than needed to cover an immersion chiller with a regular type HERMS.

JVD_X said:

Maybe I could put the counterflow unit into a home depot bucket (heater unit outside) and fill the bucket using expandable foam.

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This seems like a good idea to reduce heat loss from the CFC to the ambient air. Perhaps you could spray the foam into a bag and use that to encapsulate the CFC. This way if you need to work on the chiller you can then remove the bags. The spray foam is very sticky and would make working on the chiller a pita.

Scut_Monkey said:

How are you planning to heat the sparge water? This is one area that really has not been addressed. One of the advantages of a regular HERMS system is that at the end of the recirculation you have a HLT with the sparge water already heated or very close to the sparge temp.

I understand that a counterflow chiller will be more efficient during the recirculation. However, you then have to heat up all of the sparge water anyways. So in essence the large volume of water that you heat up for an immersion chiller type HERMS is not ALL wasted energy.

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True... in my model I heat my sparge water much earlier and put it into a cooler until it comes down to 170... then start the sparge. My main issue is reducing the amount of power required to effectively implement HERMS because I simply don't have enough amps to support anything over 1500 watts of element.

I have other reasons for switching from RIMS to HERMS.

Scut_Monkey said:

I understand that a counterflow chiller will be more efficient during the recirculation. However, you then have to heat up all of the sparge water anyways. So in essence the large volume of water that you heat up for an immersion chiller type HERMS is not ALL wasted energy.

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Wrong!!!!! Did you read my previous post? Suppose you were using a coil that was 14 inches (normal for a Herms coil made of 1/2" tubing) in height and you were making a batch that was 5 gallons. To make 5 gallons you only need about 7.5 gallons of water (12 quarts for the mash and the rest for the sparge). The 7.5 gallons fills the keggle only half way. To cover the HERMS Coil you need to fill the keggle with a lot more than 7.5 gallons. You would only need a gallon of water to fill the CFC and circulate it. Kapish? To cover the HERMS coil you would need at least 12 gallons of water in the keggle to cover it. The savings in energy of not having to heat another 4 to 5 gallons of water is greater than powering a pump or two.

Ok, for some reason I got kicked off on this suddenly (probably because I told my stubborn ass I couldn't do it). I think I've come up with a design that is roughly equivalent to my "small tank HERMS."

How do you embed attachments?

And finally, cooling.

EDIT: Ok, the design needs one more valve at the top of the HEX to stop sparge/strike water from going down the recirc/whirlpool/cooling path. No, I'm not fixing it. I'm going home.

And I never actually figured out how to embed it, it just happened!

GearBeer,

This is exactly what I am planning, minus the HLT.

I found a posting on the Northern Brewer forum by Kaiser on cold water sparging - so I don't think that I would need an HLT at all.

Also - I was thinking I could use another fluid in the HEX besides water like Propylene Glycol.

JVD,

If you're not going to have a HLT, how are you planning on heating your strike water? In the boil kettle?

I looked up Kaiser's experiment, it looks promising for batch sparging. However, the prospect of setting up a recirculating mash (HERMS or RIMS) system and batch sparging doesn't make much sense to me. The introduction to the cold sparging experiment included a well founded concern about fly sparging with cold water.

Especially in batch sparging where there is no concern about channeling through the grain bed.

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That said, it may still be possible to eliminate the HLT by choosing a larger heating element capable of significantly warming the incoming tap water (perhaps even to strike temperatures). I would certainly want to do some experimenting before I committed to such a design, though.

What is the motivation behind introducing propylene glycol to your brewing system?

GearBeer said:

However, the prospect of setting up a recirculating mash (HERMS or RIMS) system and batch sparging doesn't make much sense to me. ?

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Why? I have a RIMS and Batch Sparge just fine. As a matter of fact I get efficiencies of 85% when Batch Sparging with my RIMS. My system is pretty much a clone of the Brew Magic System with some added features.

I currently heat my strike water in my mashtun by RIM recirculation.

Sawdustguy said:

Wrong!!!!! Did you read my previous post? Suppose you were using a coil that was 14 inches (normal for a Herms coil made of 1/2" tubing) in height and you were making a batch that was 5 gallons. To make 5 gallons you only need about 7.5 gallons of water (12 quarts for the mash and the rest for the sparge). The 7.5 gallons fills the keggle only half way. To cover the HERMS Coil you need to fill the keggle with a lot more than 7.5 gallons. You would only need a gallon of water to fill the CFC and circulate it. Kapish? To cover the HERMS coil you would need at least 12 gallons of water in the keggle to cover it. The savings in energy of not having to heat another 4 to 5 gallons of water is greater than powering a pump or two.

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I did read your post and I'm in agreement with it. You need to read my entire post as I clearly reiterate your point.

Scut_Monkey said:

I am not shooting your idea down as I do believe that it could work. Just adding to the discussion is all. For instance you need to keep the large volume of water in the HLT from lossing heat over an hour with a regular herms. Your system would not have this level of heat loss adding to it's efficiency. Also, like it was already mentioned you might be heating up more water than needed to cover an immersion chiller with a regular type HERMS.

Click to expand...

Sawdustguy said:

Why? I have a RIMS and Batch Sparge just fine. As a matter of fact I get efficiencies of 85% when Batch Sparging with my RIMS. My system is pretty much a clone of the Brew Magic System with some added features.

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Yeah, I agree. They're completely separate processes. One doesn't depend on the other. If you've got a single tier stand you can herms/rims/direct-fire and batch sparge with a single pump. Fly sparging requires a second pump, which is one of the reasons I stick to batch sparges.

Scut_Monkey said:

I did read your post and I'm in agreement with it. You need to read my entire post as I clearly reiterate your point.

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Sorry, you are right, we agree. I missed that.......mia culpa.

Lil' Sparky said:

Yeah, I agree. They're completely separate processes. One doesn't depend on the other. If you've got a single tier stand you can herms/rims/direct-fire and batch sparge with a single pump. Fly sparging requires a second pump, which is one of the reasons I stick to batch sparges.

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Fly sparging doesn't require any pump whatsoever if you are using gravity feed. However, I fly sparge with just one pump while I gravity feed into the kettle.

Yeah, I understand the gravity/pump trade-off. I could fly sparge without any pump when I had my 3-tier stand, but that really wasn't the point.

My post was in response to GearBeer saying that if you use HERMS/RIMS, then it doesn't make sense to batch sparge. I was trying to explain one of the many reasons I batch sparge, even though I recirculate my mash. Whether you recirculate your mash or not really has no bearing on how you decide to sparge.

Let me explain my comment.

You've been recircing for an hour, producing a very nice grain bed. Only to stir it up?

I don't see any problem with batch sparging with a RIMS/HERMS system when a recipe calls for it (i.e. a barleywine or a RIS) but it seems to me that you'd scrap one of the major advantages of the system by batch sparging regularly.

Well first, recipes never dictate your sparge method.

Now let's address the clarity concern. Yes, I stir the mash when you add a batch sparge infusion. I immediately set the mlt to recirculate and in < 5 mins the wort is crystal clear and I switch the output to the kettle. A lot of batch spargers let their mash sit for a few mins after adding/stirring their sparge before they vorlauf, so I'm not really taking any extra time. I assure you I have no clarity problems. You can read a book through a pint of beer.

You may think fly is easier/better. That's always up for debate and not really what we're talking about. I've done both. I happen to batch sparge with my system now. Sure you switch a few more hoses, but I'm done sparging in 1/2 the time. Plus I'd need an extra pump for my stand if I fly sparged.

I just wanted to point out that your assumptions don't match up with my experience.

Cheers! :beer:

Lil' Sparky said:

Well first, recipes never dictate your sparge method.

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The recipe won't directly dictate your sparge method. However, if you're trying to brew a 1.120 barleywine, then you're probably going to want to do a single infusion for the barleywine and batch sparge for a small beer. It's simply not practical to completely sparge the grain and boil it down to your final volume and original gravity when doing a big beer. You'd end up with a pretty carmalized beer.

If your system only has one pump I can understand batch sparging. I overgeneralized my statement, it wasn't intended to apply to those with only one pump. I have elected to design a system with two pumps (thanks Forrest!), so I will generally be fly sparging unless brewing a high gravity beer.

thread theft! thread theft!

I can't decide if I want to build my own counterflow or just buy a chillzilla. If I build my own regular garden hose probably won't work well given the temps. What do ya'll think?

I think... Chillzilla = expensive!

You could use silicon instead. It would last a long time, but it's expensive, too.

GearBeer said:

If your system only has one pump I can understand batch sparging. I overgeneralized my statement, it wasn't intended to apply to those with only one pump. I have elected to design a system with two pumps (thanks Forrest!), so I will generally be fly sparging unless brewing a high gravity beer.

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[nitpick]
I'd say I require only 1 pump because I decided to batch sparge. Similarly, you require 2 pumps because you decided to fly sparge. Not necessarily the other way around.

The "batch sparge" method you referred to is commonly referred to as partigyle. Not really the same thing, but I understood what you were talking about.
[/nitpick]

I'm sure you'll be happy with your system!

I designed a DIY tube-in-shell counterflow Heat Exchanger awhile back. I used 1/4" copper which was too small, but I'm thinking of doing it again and using 1/2" copper. It's a little unwieldy, but it'd be just fine for installing on a brew stand. I'm thinking of soldering some 10 gauge copper to the outside of the tube, both to center the tube and to create turbulence in the cooling/heating water.

Here are a couple pictures of the one that was too small. I'm going to try to make it work for my 5 gallon KISS rig (when it's at home).



EDIT: Check out my newest 2-pot flow diagram (2 posts): https://www.homebrewtalk.com/f11/another-herms-designed-clock-135250/index2.html#post1552751

Gearbeer! Funny.

What was your experience? Do you see any efficiency in that design? I saw a similar design on a sight for making alt-fuels but they wrapped it in insulation.

I think you missed it (posting while I was editing) I have a new 2 pot flow diagram: https://www.homebrewtalk.com/f11/another-herms-designed-clock-135250/index2.html#post1552751.

I think the heat exchanger is a pretty good design, if I don't say so myself. It's similar to common industrial and research counterflow heat exchangers. It has several advantages over the soft copper in garden hose design (tube stays centered in the shell and copper shell won't break down like the hose) and one glaring disadvantage (it's long and requires a clear mounting point).

Gearhead,

I was thinking that instead of using convoluted tubing from morebeer I could use a design similar to yours with the exception that the innner tubing could be modified in some way to introduce turbulence into the wort flow.

Anyone have ideas on how to introduce turbulence into the flow? I was thinking about splitting the wort tubing into sections joined by a coupler with some kind of crimp in it. Or maybe some springs inserted into the tube.

The easiest way would be to flow the wort quickly. You will have turbulent flow in that tube without any further additions. That convoluted tubing is just a convoluted way to get more money IMO

I'm not sure I follow what you're saying about splitting the wort tubing into sections...

The reason I didn't do anything to the inside of the shell is that anything there could potentially harbor bacteria. Of course, with the design integrated into the whole brew rig it can be sanitized with boiling wort, which wasn't an option when I designed it.

A spring that fits tightly in the tube wouldn't be a bad option, it could be removed for cleaning.

I don't know if anything on the inside is necessary. It would be interesting to see a comparison of cooling data. I think the turbulence created when the wort turns around would be enough.

Here's a thread you guys might be interested in. https://www.homebrewtalk.com/f11/plate-chiller-herms-58747/

Korndog uses a plate chiller for his HEX.

I've seen a couple plate chiller HERMS setups. I'm not very fond of plate chillers. They pack a lot of surface area into a small space, but they seem pricey and I worry about their propensity to clog/trap debris.

I'm not trying to talk anybody into anything. I just thought there might be some valuable info in there for the OP, who was wondering about doing a CFC-based HERMS. Korndog (and I think another guy) have had success with that design.

I like my plate chiller, but I'd have to be really confident in my lauter design to use it for HERMS. My FB lets a little too much debris through for me to go that route. The guys in that thread seem to be OK with the amount of grain material that is getting in there.

GearBeer said:

I'm not sure I follow what you're saying about splitting the wort tubing into sections...

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Something like the pic below...

Boerderij_Kabouter said:

The easiest way would be to flow the wort quickly. You will have turbulent flow in that tube without any further additions. That convoluted tubing is just a convoluted way to get more money IMO

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I hear ya. Do you think there is enough? Maybe add something around the outside of the wort tube?

Lil' Sparky - I already have a therminator but I don't trust it. I am concerned that little grains might clog it.

GearBeer said:

I'm thinking of soldering some 10 gauge copper to the outside of the tube, both to center the tube and to create turbulence in the cooling/heating water.

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Along the lines of what BK was saying, I'm not sure it's necessary, but this is what I was thinking.

Sparky,

I appreciate the info. It looks like they went to great lengths to reduce their particle size and quantity. It gets a little crazy when they get into the steam stuff!