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Liquid oxygen as a cooling agent?

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June 25, 2010 7:14:48 PM

Hello,
What about putting LN2 enclosed in a hard plastic like polycarbonate to use as a cooling agent?
a b K Overclocking
June 25, 2010 7:41:25 PM

LN2 is liquid Nitrogen, LOX = oxygen

Any small leak of O2 can create a large fire hazard and is not a recommended coolant.

?? Not sure how brittle liquid gas would make a polycarbonate. At work we use insulated stainless steel
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a b K Overclocking
June 25, 2010 8:15:35 PM

Same thing with LN2:

At atmospheric pressure, liquid nitrogen boils at 77 K (−196 °C; −321 °F) so can you image putting a heat source to it when it's in a sealed container, yep same explosion.

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a b K Overclocking
June 25, 2010 8:24:58 PM

RJR
You are correct and since you covered the pressure problems of both when heated: I was commenting on "If a small leak occured". O2 will create a much greater fire hazzard than Nitrogen. Nitrogen (small leak) is more a concern due to displacing the Oxygen and creates a breathing Problem. The old saying you have to have Oxygen for a fire is not totally true as Nitrogen will also combine with some other elements (ie H2) with explosive results.
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a b K Overclocking
June 25, 2010 9:26:59 PM

Now THIS is rocket science!
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a b K Overclocking
June 26, 2010 5:29:05 AM

Why do you possibly want to use a polycarbonate container, can't metal pressure tanks hold the stuff just fine? You do know LN2 is only cold when it is allowed to expand. Holding up the container to the CPU won't make it cold at all.

As for liquid oxygen, I don't think you can even get your hands on it since it is highly reactive. Can rust metals extremely quickly. Also highly explosive. Oxygen in such concentration and pressure is in danger of reacting with hydrogen in the air potentially casuing an explosion. Also breating excess oxygen is bad for your body, it can oxidize the metals within your body. Divers and hospitals never use pure oxygen, but a mix.

Polycarbonate is not an ideal material for a pressure tank. If you want something virtually indestructable and can hold a much greater PSI, look into carbon fiber tanks. Though they are more expensive.
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June 26, 2010 11:31:41 AM

LN2, LOX, and in fact any liquid that is in gas form at STP (Standard Temp/Pressure, 25ºC/1 atmosphere) will expand VIOLENTLY when it is stuffed into a container and heat is applied - and in the case of LOX will present a serious oxidation and fire hazard.

Carbon fiber alone will not work easily for a high-pressure storage tank. It will need reinforcing bands on the walls and additional strengthening at the seams, or you will need to source a tank purpose-made for high pressures. Polycarbonates also will not work, if only because the container walls will need to be extremely thick to contain such pressures.

Normally when LN2 is used for overclock cooling, they stick it into a deep copper cylinder with a closed bottom, which in turn rests upon the CPU. The LN2 that has taken in the heat expands and rises out of the tube, and more LN2 is poured in. This is a system that was developed purely for setting records, not day to day use. LOX (and any other gas) would use the same method.

LN2 was used in certain Cray machines several years back, and they used a compression recirculation system - exactly the same principle as a fridge, only designed to handle higher pressures and temperatures. This cooling strategy has been seen in PCs before, known as 'phase change' cooling. It is called that because the working 'fluid' changes phase from liquid to gas, and back again. This is about the only method you would be able to use for a high pressure gas system that recirculates the gas.

Hope this helps.
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June 27, 2010 5:27:02 AM

a safer solution to using LOX or LN2 is dry ice =D i use LOX at work and ive heard rumors of a small gumball sized piece of frozen LOX rolling around after he was done servicing the aircraft and desided it be fun to smash it with his boot. well...his foot exploded and had to be amputated. bad joojoo

LN2...what everyone said above

with dry ice that stuff is already like -78c??? get everything you need in order to cool your PC as you would if you were using LN2 but instead put dry ice into the cylinder. after you've filled the cylinder with the desired amount of dry ice fill it with acetone to improve contact between dried ice and copper tube.

this vid is pretty decent in showing u what is used
http://www.youtube.com/watch?v=Swo6TmyDnGc&feature=rela...
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June 27, 2010 5:39:18 PM

rofl_my_waffle said:


As for liquid oxygen, I don't think you can even get your hands on it since it is highly reactive. Can rust metals extremely quickly. Also highly explosive. Oxygen in such concentration and pressure is in danger of reacting with hydrogen in the air potentially casuing an explosion. Also breating excess oxygen is bad for your body, it can oxidize the metals within your body. Divers and hospitals never use pure oxygen, but a mix.


The statement about LOX interacting with Hydrogen in the air and causing an explosion is laughable. I work around LOX every night and we vent it directly into the air with no issues. And thats pressurized LOX by the way. The danger is going to be with it's interaction with petroleum based products. Thats when LOX becomes volitale.

Also the fact that it is HIGHLY flamable makes it unwanted for anything besides rocket fuel and aviator breathing.

Stick with Liquid Nitrogen. It's no flamable and much safer than LOX. Of course it's just as cold so burns can still happen.
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a b K Overclocking
June 28, 2010 12:55:03 PM

cmcghee358 said:
The statement about LOX interacting with Hydrogen in the air and causing an explosion is laughable. I work around LOX every night and we vent it directly into the air with no issues. And thats pressurized LOX by the way. The danger is going to be with it's interaction with petroleum based products. Thats when LOX becomes volitale.

Also the fact that it is HIGHLY flamable makes it unwanted for anything besides rocket fuel and aviator breathing.

Stick with Liquid Nitrogen. It's no flamable and much safer than LOX. Of course it's just as cold so burns can still happen.



{Puts on "Old Guy Hat"}

I spent 7 years in Naval Aviation - This guy knows what he's talking about. Bolded line for emphasis.


OP: Put this one in the "Dumb Idea" box, and forget about it.
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a b K Overclocking
June 28, 2010 1:06:10 PM

+1 ^ (added For both prevous posts)
H2 in the air is less than 1%. And yes mixing Oxygen with petroleum can be rather exposive. Oxygen + gasoline is more explosive than dynamite. Since O2 is an oxidizing agent it depends on the rate of oxidation, if that produces enough heat then a fire will result. An example, sodium placed in water will release H2 and enough heat to ignite the H2. Add a spark or small flame to a O2 enriched enviorment and and even steel wool will burn.

As for N2, when combined with H2 yield a "flame" that produces NH3 just like O2 + H2 yields water. BUT in the atmosphere H2 is a very smal percentage. Worked with a system that "cracked" NH3 to give H2 and N2, the h2 was used to fill meteorlogical balloons.
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June 28, 2010 3:07:22 PM

This is also coming from my 13 years working on F-16s that use 5 Liter LOX bottles(which use a vaccuum layer for insulation btw)

We also use Liquid Nitrogen.

So what we learned today. LOX will blow up. Liquid Nitrogen isn't combustable(which is why we service tires with it) and just as cold. If you are trying an extreme freeze cooling system, never use LOX.
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June 28, 2010 3:10:30 PM

rofl_my_waffle said:


As for liquid oxygen, I don't think you can even get your hands on it since it is highly reactive. Can rust metals extremely quickly. Also highly explosive. Oxygen in such concentration and pressure is in danger of reacting with hydrogen in the air potentially casuing an explosion. Also breating excess oxygen is bad for your body, it can oxidize the metals within your body. Divers and hospitals never use pure oxygen, but a mix.


Also lol, 100% oxygen is used quite regularly depending on the situation. Pilot's use it when the outside air is contaminated with things like Hydrazine or noxious smoke. Also doctors will dial up the oxygen dosage based on how much the patient is absorbing.

Is all of this fanciful pondering or do you have any basis of fact?
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a b K Overclocking
June 28, 2010 4:11:29 PM

Don't know if still available, use to be able to by small bottles for use in welding. Walmart use to carry, but haven't seen lately.

cmcghee358. Lox use to be attached to Ground Power (AGE). Where I worked for my first 4 yrs in USAF. Then switched to Meteorlogical carrer field - Taught ML539 which "cracked" Amminia (NH3). and current work at NASA where we use N2 for cooling thermo-vac camber and boil-off is used on Instrument to reduce Humidity.

Take care
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June 28, 2010 4:35:52 PM

Cool beans!
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July 5, 2010 1:28:01 AM

rofl_my_waffle said:
Why do you possibly want to use a polycarbonate container, can't metal pressure tanks hold the stuff just fine? You do know LN2 is only cold when it is allowed to expand. Holding up the container to the CPU won't make it cold at all.

As for liquid oxygen, I don't think you can even get your hands on it since it is highly reactive. Can rust metals extremely quickly. Also highly explosive. Oxygen in such concentration and pressure is in danger of reacting with hydrogen in the air potentially casuing an explosion. Also breating excess oxygen is bad for your body, it can oxidize the metals within your body. Divers and hospitals never use pure oxygen, but a mix.

Polycarbonate is not an ideal material for a pressure tank. If you want something virtually indestructable and can hold a much greater PSI, look into carbon fiber tanks. Though they are more expensive.



I don't want metal, I want plastic! I'm not trying to have a pressure tank, I'm trying to use it for cooling liquids. Polycarbonate is the hardest plastic I know of that could hold up except for maybe plexi? I'm not looking for a big tank, I'm looking for a small container.

That's not totally true. Divers use 100% pure O2 for emergency purposes as do hospitals. When divers are diving under pressure, it's a normal air mixture of 79% nitrogen, 21% oxygen even though there are some small percentages of gasses in there. I'm a scuba diving instructor and O2 Instructor. You have to be certified to use 100% oxygen.

Thanks though.
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July 5, 2010 1:34:18 AM

i4yue said:
a safer solution to using LOX or LN2 is dry ice =D i use LOX at work and ive heard rumors of a small gumball sized piece of frozen LOX rolling around after he was done servicing the aircraft and desided it be fun to smash it with his boot. well...his foot exploded and had to be amputated. bad joojoo

LN2...what everyone said above

with dry ice that stuff is already like -78c??? get everything you need in order to cool your PC as you would if you were using LN2 but instead put dry ice into the cylinder. after you've filled the cylinder with the desired amount of dry ice fill it with acetone to improve contact between dried ice and copper tube.

this vid is pretty decent in showing u what is used
http://www.youtube.com/watch?v=Swo6TmyDnGc&feature=rela...



The thing is, how long could dry ice last for? No more than a week, I would think? Thanks

Yeah, We used to put LOX in a plastic water bottle, close the lid, and chuck it at the hangars...

good times, good times! Makes one hell of a boom!!!
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July 5, 2010 1:36:04 AM

cmcghee358 said:
The statement about LOX interacting with Hydrogen in the air and causing an explosion is laughable. I work around LOX every night and we vent it directly into the air with no issues. And thats pressurized LOX by the way. The danger is going to be with it's interaction with petroleum based products. Thats when LOX becomes volitale.

Also the fact that it is HIGHLY flamable makes it unwanted for anything besides rocket fuel and aviator breathing.

Stick with Liquid Nitrogen. It's no flamable and much safer than LOX. Of course it's just as cold so burns can still happen.



That's what I need...something that will stay cold! I never mentioned LOX, that was the first person. I've been talking about LN2 the whole time. Thanks
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July 5, 2010 1:53:04 AM

cmcghee358 said:
This is also coming from my 13 years working on F-16s that use 5 Liter LOX bottles(which use a vaccuum layer for insulation btw)

We also use Liquid Nitrogen.

So what we learned today. LOX will blow up. Liquid Nitrogen isn't combustable(which is why we service tires with it) and just as cold. If you are trying an extreme freeze cooling system, never use LOX.



Where were you stationed?
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July 5, 2010 4:16:09 PM

Luke AFB AZ 98-02
Osan AB Republic of Korea 02-03
Luke AFB AZ 03-Present
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July 5, 2010 4:22:46 PM

maybe we have met on a TDY before? I've been to both on TDY's
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July 5, 2010 4:23:16 PM

What do you do?
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July 5, 2010 4:26:39 PM

I WAS a 16 crew chief. Spangdahlem 3 years, Kadena 4 years
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July 5, 2010 4:33:27 PM

Check your messages. And being an F-16 crew chief you shoulda known better than to imagine using LOX as a CPU cooler. lol
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July 5, 2010 4:37:10 PM

ha ha...I never said I wanted to use LOX, I said LN2. Someone else said LOX.
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July 5, 2010 4:38:02 PM

You should consult your thread title sir.
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a c 224 K Overclocking
July 6, 2010 4:20:33 AM

This topic has been closed by 4ryan6
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