Author Topic: Micro-algae in cooling system  (Read 120 times)

valentina batanova

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Micro-algae in cooling system
« on: June 28, 2017, 10:34:32 am »
Hello,
We had troubles with water chiller, we sent it several times to factory for reparation and worked on tap water (and now also). As a result  I have found that the pipes of both cooling systems (tap and water chiller loop) are covered by thin brown film of microalgue. Now we are purchasing a new water chiller.  How to clean the pipes before connect them with new chiller?
It is possible to use some cleaning component without corrosion of metallic pipes of microprobe (jeol jxa-8230)? or it is necessary to change pipes?
Regards
Valentina

Probeman

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Re: Micro-algae in cooling system
« Reply #1 on: June 28, 2017, 10:48:54 am »
Hello,
We had troubles with water chiller, we sent it several times to factory for reparation and worked on tap water (and now also). As a result  I have found that the pipes of both cooling systems (tap and water chiller loop) are covered by thin brown film of microalgue. Now we are purchasing a new water chiller.  How to clean the pipes before connect them with new chiller?
It is possible to use some cleaning component without corrosion of metallic pipes of microprobe (jeol jxa-8230)? or it is necessary to change pipes?
Regards
Valentina

Hi Valentina,
I have fought this issue for many years until I finally found a solution (no pun intended!). I should mention that all our water cooled instrument chillers are externally cooled by a closed loop "process water" system maintained by the university.  I don't know what "chemical broth" they utilize but I wouldn't want to run it through my EPMA!  However here is my "recipe" for cleaning and preventing algae in the water chiller and instrument:

1. First and foremost, replace all cooling lines, that allow any light in, with opaque metal or rubber lines. Algae needs light to survive, so removing all sources of light in the re-circulating water is of the utmost importance.  We've even added a small hinged coverplate over the flow meter on the Haskris chiller so it is "kept in the dark". Also we added a black rubber flaps over the "roto-meters" on the back of the instrument that blocks all light there.

2. Clean all the lines by running some sort of algaecide through. Our engineer has added some "Y valves" in the cooling lines to allow him to turn off the chiller and run a small pump in a plastic bucket with the cleaning solution. We've used a strong (30%) solution of hydrogen peroxide and also Chloramine-T, but first check with the chiller manufacturer and also JEOL service that these chemicals won't affect any seals.  Both hydrogen peroxide and chloramine-T are very gentle however.

3. Finally using pure RO (reverse osmosis) water, rinse and and replace the water in your instrument and chiller.

Using RO water and no light leaks we can run for years and years without any buildup of algae in our systems.
john
« Last Edit: June 28, 2017, 11:08:41 pm by Probeman »
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valentina batanova

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Re: Micro-algae in cooling system
« Reply #2 on: June 29, 2017, 10:58:05 am »
Thank you John, it is very useful recommendation
will try to follow. To have a darkness ambience in the Lab is practically impossible. Non transparent pipes  are realistic. Now we have non transparent tubes only on one part of the loop: from W.Chiller to microprobe, and transparent  pipes from microprobe to w chiller (the same in case of tap connection). Looks like these transparent parts represent a good the area for microalgae photosynthesis.
Valentina

Owen Neill

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Re: Micro-algae in cooling system
« Reply #3 on: June 29, 2017, 01:17:54 pm »
Hi Valentina,

Haskris recommends adding a small amount of ethylene glycol to the loop as an algae suppressant - I forget the exact proportions, but your manufacturer should have a data sheet that they can provide. I've also found hydrogen peroxide to be a very effective algae killer, although be careful if you use concentrated H2O2, as it will attack nitrile rubber seals if left in the system too long.

JEOL USA distributes a recommended chiller maintenance procedure to prevent algae buildup, which your service manage may be able to provide. Also, duct tape or electrical tape is a great way to make transparent pipes opaque.

Good luck,
OKN