Removing free oxygen from water

[Ouroborus]

I was thinking about water cooling and corrosion. This is a walk-through of my thought process.

 

Oxygen dissolved in water is a source of corrosion. One of the water degasification techniques is to bubble an inert gas through the water to cause the undesired gas (especially oxygen) to be replaced by the inert gas.

 

Wine deteriorates after opening if left in the presence of oxygen. Wine lovers have a device available that allows them to poor wine without letting air enter the bottle, instead filling the space with argon. As a side effect, one can get argon cartridges (similar to CO2 cartridges) for about $4/cartridge.

 

It seems to me that it might be possible to set up a system where any air pockets in a water loop are filled with argon as well as arranging for all the oxygen in the water to be replaced by argon thereby preventing oxygen-induced corrosion.

 

Thoughts?

[ARikozuM]

Complete global saturation. - REference 2017

 

It sounds plausible but then you have other contaminants to worry about such as the equipment and air itself. 

[DrMikeNZ]

Too much effort for negligible benefit.

[Windows7ge]

I like the thought and if true in practice could be a corrosion inhibitor but how to set it up would be complicated. You'd need some type of one way check valve on ends of radiators to fill air gaps with argon without letting water out. Also through evaporation the water will (very very slowly) evaporate through soft tubing which would pull a vacuum leading to air leaking its way into the system. I have this issue where about every 3~4 weeks air starts collecting in my radiators and I have to speed up the pump to get them all to the reservoir. I know it's evaporation because each time its happened the water level gets lower in the reservoir which means air is getting sucked in as the water evaporates.

[Ouroborus]

2 minutes ago, Windows7ge said:

I like the thought and if true in practice could be a corrosion inhibitor but how to set it up would be complicated. You'd need some type of one way check valve on ends of radiators to fill air gaps with argon without letting water out. Also through evaporation the water will (very very slowly) evaporate through soft tubing which would pull a vacuum leading to air leaking its way into the system. I have this issue where about every 3~4 weeks air starts collecting in my radiators and I have to speed up the pump to get them all to the reservoir. I know it's evaporation because each time its happened the water level gets lower in the reservoir which means air is getting sucked in as the water evaporates.

You make some good points. I had envisioned having a gas pocket at the top of the reservoir. This would help with system pressure (gasses compress, liquids don't, relatively). Now that you mention evaporation, such a pocket might be able to perform double duty as a controlled location for gasses to accumulate.

 

There are diaphragm-based pressure valves for controlling pressure on the outlet side of the valve. There are other pressure values for controlling pressure on the inlet side. I think a combination of these could be arranged such that the net pressure in the reservoir sits in a fixed range slightly above local atmospheric.

 

I'm not sure how I might go about topping off such a system, though. Maybe a mechanical switch on the argon injection side that can switch between "normal" and off, with a push-to-flush kind of thing for momentary higher pressure. Then I could turn off the gas, top off the system as normal, turn the gas back on, and flush the gas pocket. I'd have to change out the argon cartridges occasionally, but that can be considered part of system maintenance similar to topping off the loop.

[kb5zue]

Why not raise the system fill point to the highest point possible and then run the pump with the fill point open?  The water will circulate taking the air with it, when the air reaches the highest point, it will escape thru the fill point same as the radiator in your automobile or truck.  The best time to fill the radiator in a vehicle is with the radiator cap removed. As the air escapes, it will be displaced by the fluid in the hoses and radiator(s) at such time allowing the system to be "topped off", and all will be fine.  Yes, oxygen is a corrosive but you must also consider the mechanical parts of the system and the amount of wear they receive over time.  The wearing of the component parts will also release tiny amounts of metals into the system that must also be removed over time.  So, IMHO, the best alternative would be to do a complete flush of the system, say, once ever six months or so.  Good Luck.

[babadoctor]

>running out of oxygen

>in 2017

hahaha, we will have to wait until 2050 for that to happen!!

 

(this is not a joke, the CPP level of CO2 in the atmosphere is 409 right now, we are so fucked)

[ARikozuM]

Just now, babadoctor said:

(this is not a joke, the CPP level of CO2 in the atmosphere is 409 right now, we are so fucked)

Start planting trees, muthaf#ckas!

 

Preferably apple.

[babadoctor]

Just now, ARikozuM said:

Start planting trees, muthaf#ckas!

 

Preferably apple.

*ppm

sorry

[thorsong]

Honestly there really is little you can do. These issues have already been gone through by engineers long ago. 

 If this is something that really concerns you, the only method I see that would be reasonable for long term use in a cooling system would be a gas/liquid membrane.

   Using an inert gas will be a pain and have an ongoing cost associated with it.

  Using a sacrificial piece of metal as a reductant will work but it is also likely that it will contaminate your system with oxidized metal bits.

   The entire system could be run in a vacuum, but that isn't really practical and will reduce the effectiveness the fans in your system down to nothing.

The problem I see running into with a gas liquid membrane would be the flow rate. I don't know that you could push enough H2O through a membrane section in a standard reservoir to keep up with the system's flow rate. You would likely have to run a section of tubing out of the case to a junction that houses a membrane with large enough surface area to compensate for the flow rate. 

[Windows7ge]

34 minutes ago, Ouroborus said:

I'm not sure how I might go about topping off such a system, though.

Argon is heavier than air is it not? Turning off the valves to the argon tanks and just opening a standard fill port shouldn't let any air in (so long as you avoid turbulence) and as you fill it with fluid the argon will be forced out displacing any oxygen that may have seeped in during filling.

 

While you're at it you should theme the computer around the tanks and fittings. Kind of steam punk or mechanical. This way you get something more than a corrosion inhibitor from all this work.