Cold Liquor Tank Glycol Usage

[goldstein114]

Finishing up our Brewhouse installation (25 BBL, 4 50 BBL fermenters, 1 50 BBL Bright Tank). We were finally told that our 70 BBL Cold Liquor Tank might need to be mixed with up to 35% Glycol mixture with the water in the tank to allow for the Fermenter Jackets to cool to around 25F. Knowing the prices of Glycol this seems ridiculous as this could be $10,000+ for another unexpected cost.

A few questions:
1) Where does one source Glycol in these quantities?
2) What % mixture are you using or have you used for your Cold Liquor Tanks?
3) Does the Glycol need to be Food Grade (Only used in the Heat Exchange and Fermenter/BBT jacketing)?

[AnthonyB]

Can answer number three at least:

Yes, it needs to be food grade. This has been gone over on Probrewer before, but consider the scenario where one of our tanks develops a crack in the jacket and leaks into the interior of the tank. You don't realize until the tank has been emptied into kegs and beer is being served in accounts or on-premises. In that scenario, you have food grade propylene glycol in the beer and you have some beer you need to pull back from the accounts because it tastes sweet and weird. If in that scenario, you instead had ethylene glycol in the beer, you would have a much bigger problem on your hands.

[brewmatt333]

Wait, your using your cold liquor tank to cool your fermenters? That doesn't sound right. Cold liquor tanks are usually used to provide cold water for knock out, with a glycol chiller being used to chill the fermenters and the cold liquor tank

[goldstein114]

AnthonyB, figured as much, just wanted to be sure I wasn't overplanning as I know larger breweries use products like Ammonia for their chilling which is very very very very non-food safe

Wait, your using your cold liquor tank to cool your fermenters? That doesn't sound right. Cold liquor tanks are usually used to provide cold water for knock out, with a glycol chiller being used to chill the fermenters and the cold liquor tank

Two stage heat exchanger, first with city water, second being the glycol/water mixture. Just confirmed that the fermenters are all piped to the CLT as well, using the glycol/water mixture to chill the jackets.

[brewmatt333]

AnthonyB, figured as much, just wanted to be sure I wasn't overplanning as I know larger breweries use products like Ammonia for their chilling which is very very very very non-food safe



Two stage heat exchanger, first with city water, second being the glycol/water mixture. Just confirmed that the fermenters are all piped to the CLT as well, using the glycol/water mixture to chill the jackets.

So, you have a glycol chiller I assume, and it will only chill a 70bbl jacketed cold liquor tank, which will then be pumped through your fermenter jackets as well as your heat exchanger. Am I reading that correctly? It's a much more convoluted system then it needs to be. And your right, the amount of glycol needed for that system is much more than anyone should ever need. Not only that, but it's probably going to be a whole lot less efficient.

Is there a reason why you can't have your fermenters and brite cooled directly by the glycol chiller rather than the cold liquor tank?

[goldstein114]

So, you have a glycol chiller I assume, and it will only chill a 70bbl jacketed cold liquor tank, which will then be pumped through your fermenter jackets as well as your heat exchanger. Am I reading that correctly? It's a much more convoluted system then it needs to be. And your right, the amount of glycol needed for that system is much more than anyone should ever need. Not only that, but it's probably going to be a whole lot less efficient.

Is there a reason why you can't have your fermenters and brite cooled directly by the glycol chiller rather than the cold liquor tank?

You're correct on all of the assumptions, way it was explained to my boss (and thus to me) was on systems this size a Cold Liquor Tank is used to chill the Fermenters, I've personally only seen Glycol Jacketing, but I'm only the brewer, not the engineer.

The system is pretty much pumped and wired at this point so I'm SOL when it comes to redesigning. As far as I know, Glycol units typically run at a dilution, what I'm trying to figure out is both this dilution as well as what percentage it should be added to the Cold Liquor Tank to keep temps between 4 50 BBL fermenters and 1 50 BBL Bright Tank.

[jbs]

Usually, your cold liquor tank should be filled with water for brewing and cooled by your glycol unit. The cold liquor is used to cool down your wort through the heat exchanger (getting heated up in the process) then piped to your hot liquor tank for continued heating. And then brewing. Your Fermenters and Bright beer tanks should by cooled using your glycol unit. You don't want a 70bbl. glycol reservoir.

[jbs]

redesigning

You're correct on all of the assumptions, way it was explained to my boss (and thus to me) was on systems this size a Cold Liquor Tank is used to chill the Fermenters, I've personally only seen Glycol Jacketing, but I'm only the brewer, not the engineer.

The system is pretty much pumped and wired at this point so I'm SOL when it comes to redesigning. As far as I know, Glycol units typically run at a dilution, what I'm trying to figure out is both this dilution as well as what percentage it should be added to the Cold Liquor Tank to keep temps between 4 50 BBL fermenters and 1 50 BBL Bright Tank.

I suggest going through the work now and redesigning.

[goldstein114]

Usually, your cold liquor tank should be filled with water for brewing and cooled by your glycol unit. The cold liquor is used to cool down your wort through the heat exchanger (getting heated up in the process) then piped to your hot liquor tank for continued heating. And then brewing. Your Fermenters and Bright beer tanks should by cooled using your glycol unit. You don't want a 70bbl. glycol reservoir.

Yeah, I've worked on units like that, if this was standard I'd probably have worked on a system like it or been able to research it, unfortunately life likes to play horrific jokes on me and the design of this system seems to be worse and worse by the day, and I'm left to brew on it. But the "Ice Water" as they describe it is recirculated back to the CLT after the heat exchanger as it should only be used after the tap water cannot chill the wort any further. Mainwaste I can really see here is the extra Glycol needed to dilute the Ice Water tank and the added step to a GRAS process, however having the increased ability to chill the wort could be helpful.

Redesign isn't an option at this point which has been explicitly stated to me, so I get to fill a 70 BBL glycol/water dilution that should stay put for years.

[yap]

here's a link to a chart for glycol ratio from pro refrigeration:

http://www.prochiller.com/reGlycolChart.html

most people (on average) run around 1/3 glycol to 2/3 water by volume...

also remember, it's not just 70 BBL. it's also the fermenter/brite jackets and all the plumbing back and forth that will have to be filled with it too...


good luck. i think you are going to need it with that system. with the amount of glycol you are going to buy, redesign may be cheaper...

[panadero]

For the amount of glycol you will require, you could get a pretty good sized glycol chiller. Try to explain to the powers that be that they have it backwards.
Good luck! I have been - am - there. A 35/65 glycol water mix should get your fermenters down to 32 degrees, the temp of the mix will be 25-28 when not fully in use. I have a ten bbl with only four fermenters on a 5hp chiller, so I am not really sure how this scales up, but prorefrigeration should be able to help with questions, if not solutions. They were great to deal with when we opened a year and a half ago. They sponsor this forum as well, and this forum is the best help you will get for free, and even better than some paid advice.
David

edit - I was sending this when Scott's post came online. What he said!

[Starcat]

Re: JBS

The reply by JBS above is absolutely correct.
Your CLT typically is water that is chilled to generally say 40F and used to assist cooling of wort at the pumpover stage.
Typical heat exchangers have a pass for both glycol off the chiller loop and this PRE-chilled water.
The CLT is NOT on the glycol side of the system, and is not to be confused with a glycol well.

SC

[goldstein114]

Glycol Tank/Ice Water Tank Not CLT

The reply by JBS above is absolutely correct.
Your CLT typically is water that is chilled to generally say 40F and used to assist cooling of wort at the pumpover stage.
Typical heat exchangers have a pass for both glycol off the chiller loop and this PRE-chilled water.
The CLT is NOT on the glycol side of the system, and is not to be confused with a glycol well.

SC

Talked with the Manufacturer and he apologized for his inconsistency in terminology. I was getting confused by him calling it a "Cold Liquor Tank" when this is merely a 70 BBL Ice Water Tank with a Closed Loop to the Glycol Chiller and a Closed Loop to the Fermenters/BBT/Heat Exchanger. 20F was suggested as a temperature to have this tank at, which would require around a 20% Propylene Glycol mixture, around 400 Gallons of glycol.

Now I have to look into Inhibited Propylene Glycol as well, as it is non-corrosive which seems like quite the perk for a solution which should be lasting in tanks/pipes for years.