Glycol Contamination

[Barrie66]

To All,
Due to an internal failure to a small copper heat exchanger, seawater contaminated the glycol coolant. It formed a heavy sludge which completely gummed up the cooling system. The propylene glycol used was a reddish color. At this stage we haven't been able to disconnect the heat exchanger to investigate the internals. However, we will probably replace it with cupro nickel at a later stage. Also is the glycol mixture we are using correct? We need to inhibit corrosion.
Thanks in anticipation

 

[MikeHalloran]

So far as I understand it, neither propylene glycol nor ethylene glycol play any role in inhibiting corrosion.

Commercial glycol coolants contain _other_ stuff, I don't know what, for that purpose, and it's plainly consumed in doing its job, so periodic flushing and replacement is recommended.

We can't evaluate whether the mixture you are using is correct for your application, because you haven't told us what the mixture is, and you haven't told us the application. Even the best of us here are not _that_ good.



Mike Halloran
Pembroke Pines, FL, USA

 

[IRstuff]

It matters not, since the corrosion inbitors in PG and EG are usually proprietary. EG, in particular, will corrode aluminum and other metals.

You need to discuss this with your supplier and identify if they have a corrosion inhibitor or whether you need to find an after-market inhibitor.

TTFN

 

[Barrie66]

Sorry guys.
We are an OEM providing hypochlorite generators. This particular application is on board a fishing vessel in the Bering Sea. The heat exchanger is a commercially available shell and tube, specifically for seawater applications. The coolant is recirculated through the heat exchanger to cool the silicon controlled rectifier (SCR). The flow rate is very low assisted by a 130W 1/2" pump.
The PG used was obtained at the local auto parts store and we assumed that it contained corrosion inhibitors.
The unit has been operating less than 3 months and after cleaning out the copper water ways in the SCRs there doesn't appear to be any corrosion. It seems that the seawater contamination caused the PG to gum up.
My question is whether propylene glycol is the correct coolant for this type of applicaton.

 

[EdStainless]

At what temp? The glycols get very thick when they are cold. There are other things to use. There is a good product called EnviroCool.

But back you your situation. I presume that you bought commercial anti-freeze. That you first flushed the system to make sure that there was no oil or other residue in it. And then filled it with a 50/50 mixture. Right?

This product should work fine if your system is clean and you dilute it with clean water.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[IRstuff]

Most commercial antifreezes are designed for specific material environments in automobile engines, so there might be some incompatibility with your materials. You shuold check with the supplier.

TTFN