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How to keep cooling water from going bad

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We are going to recirculate water (to conserve) as our cooling water. How do you keep yours from going bad, without damaging water pumps?

 

Could you ass citric acid or bleach? Any other thoughts?

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if you have the cooling water in contact with stainless alt all, do not use bleach or any chlorine.

Star Sans acid #5, just push the ph to 6 or a hair under and no algae will grow and it will keep your stainless rust free, as well it will be much less harsh on your copper than citric acid.

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15 hours ago, Silk City Distillers said:

Guy who manages cooling systems told me to treat it like a fish tank.

Hope the fish don't get sucked into the hose. :)

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My cooling water tank is an old concrete 35,000 gallons. It was initially filled from the river with a windmill pump that must have sucked small fish or eggs into the tank. There were some quite large fish in there. Then I started circulating warm condenser water I assume they didn't appreciate the heat because they have now vanished. There is now a freshwater plant called azola growing on the surface. The water appearance and smell is now much nicer than when the fish were there.

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Pretty sure he didn't mean to add fish.  I mean, totally cool idea, but I think he meant to keep your cooling system running in a reasonable temp range, keep pumps running to keep the system from becoming stagnant/anoxic.  Nothing worse than letting it go anoxic, and then cooking your bacteria soup with high temps.

 

 

 

 

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years ago we toured a place that had a huge tank filled with exotic water plants as a cooling reservoir , the plants were not only very cool but each one had a job to do to clean and purify the water , very cool addition to a eco friendly tasting room  . we were also in a hotel in montana a few years back that had a moat all thru the lobby and restaurant full of fish , my first thought was that would make a cool cooling system lol . 

tim

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On 11/18/2017 at 5:24 PM, stripedlion said:

how much Star San #5 per gallon?

you will have to follow instructions on the container, I believe they have a chart for rough PH correction.

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They are suggesting a product called Acid #5 by 5-Star. Same company that makes Star-San. I assume you want to use the #5, not the Star San Sanitizer.

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FYI, Acid #5 is a mixture of nitric and phosphoric acids, with some detergent. It is rated for food processing use. It will passivate stainless. Must avoid contact with chlorine containing materials. Especially useful where regular detergent cleaning does not do a good enough job of removing organics, it will neutralize the akaline detergent like citric, but will also further work on any residual organics. While it should passivate stainless, it will continually etch copper or other etchable metals, so I am not so sure it is the best choice for adjusting pH for recirculation systems, unless they are all stainless.

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An open reservoir must either be treated with appropriate chemicals or a minimum of 30% propylene glycol to prevent bacterial growth. Lower than 30% in an open tank will actually feed bacteria.

If you intend on reusing the untreated water for mash batches, then the way to go is the UV.  The UV treats the air gap between the water surface and the top of the tank.  

I am not sure what Indy uses, but it is more common and is the preferred method for cooling tower water outdoor sumps to prevent Legionnaires.

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18 hours ago, MG Thermal Consulting said:

I am not sure what Indy uses, but it is more common and is the preferred method for cooling tower water outdoor sumps to prevent Legionnaires.

We of course have that wonderful system you designed for us. I know about the UV solution as I used is to control grow in my home pond. Legionella, nasty stuff. Surprised it's never been brought up before in the context of recirculating cooling water.  We'll stick with  PG. 

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On 11/19/2017 at 2:33 PM, PeteB said:

My cooling water tank is an old concrete 35,000 gallons. It was initially filled from the river with a windmill pump that must have sucked small fish or eggs into the tank. There were some quite large fish in there. Then I started circulating warm condenser water I assume they didn't appreciate the heat because they have now vanished. There is now a freshwater plant called azola growing on the surface. The water appearance and smell is now much nicer than when the fish were there.

I think you used up all the dissolved oxygen in the water and snuffed out all of the fish.

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Anyone with limited cooling water should consider a continuous stripping still. A properly designed one requires no cooling water and as a bonus they only require about 20% of the energy to run the same volume of wash. 

I think Dehner Distillery has built some. I have but I don't export.

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I read this post with interest as I'm installing a closed circuit cooling system, wherein the cooling water is sent out of the hot condenser through several hundred feet of curly tube located at the bottom of a large pond to cool before coming back through the system.

I've since modified it to take a extra trip through the floor of the tasting room to provide radiant heat, but that's another story. Anyway, I posed the question about keeping the water clean to my friend, a learned doctor and this is what he said...

The cooling water does not need to be sterile. That said, you don’t want a lot of bacteria growing in there because of the “yuk factor”. But bacteria can only grow where there is nutrients. If you put 1 gram of nutrient in a cubic meter of water, it can’t grow more than a gram of bacteria. So the #1 principle is that the cooling water should be clean when you put it in, and the system itself should be clean.
 
I suggest:
1)       fill the system with a TSP/bleach solution. Run the circulating pump for ½  hour. This is to clean out any manufacturing residues from the system
2)       rinse with tap water
3)      fill with RO water (which is sterile and nutrient free).
 
You need to have some documented routine to re-sanitize the cooling system as needed or on some kind of schedule. ? Bi-monthly ? Alternatives could include
1)      repeat of above, but with a “wine equipment sanitizer”
2)      UV treatment on occasion... like an hour a week.
3)      Monitor bacteria growth by plating out cooling water. We will be set up for yeast incubation so we can do bacteria as well.
 
Don’t worry about the stainless steel + bleach paranoia. You wouldn’t want to store bleach solution in a stainless container. But rinsing stainless with a standard sanitizing solution will do no harm at all. Bleach in solution is extremely reactive…. so much so that it is gone in 24 hours.  

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i thunk your over thinking it. we run a hydronic system that heats our house , the distillery and equipment as well as wash water for both . that water is never changed or disinfected even tho the system is open to atmosphere it contains very little oxygen there is never a problem with anything growing in it . i really dont see how a cooling system is any different . its basically a closed to atmosphere system how would anything grow in it , its constantly circulating and plenty hot . we drained our water out of boiler and circulating lines when we moved into new facility and there was nothing growing in it . i personally wouldnt use any bleach in the system not cuz i think it will hurt i jus dont see the point . 

tim 

  

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100% RO water will ruin piping that is not designed to withstand it.  RO water will draw ions from many metals and weakening them.

With medical systems cooling, they either add propylene glycol or have complete stainless steel wetted surfaces.  The chiller must be specified for 100% RO as not all wetted parts of the chiller can be used. Premixed glycol is mixed with RO. 

Chemical or ozone treatment is cheaper, first cost, than designing a cooling system to be compatible.

Most closed loops are not pressurized and have a poly reservoir which because it is non-pressurized, must have an opening to the atmosphere.  The dead air can be treated with ozone, which keeps water clean from biologicals. Of you want to isolate the pressurized and non-pressurized flows, you need to add an isolation heat exchanger, very common in the Northern US where the outdoor chiller is charged with glycol mix for non-freezing and the water reservoir indoors is charged with the process water.

If  you need more details, drop me a line or call.

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Speaking of poly reservoirs.  Clear or light permeable is bad if you want to control algae growth.

You can UV until the cows come home, not going to stop algae from growing on the walls.

Those little green buggers don’t need much in the way of nutrient to grow.  But they do need light.

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