tank "freeze"?

[Bobcatter]

I wonder if anyone ever ran across the problem of a tank of gas "freezing" up as referenced on this link:
http://www.newton.dep.anl.gov/askasc...9/gen99600.htm

I guess if it was cold enough, the gas would come out as a liquid. I don't see how it would "freeze" unless there was moisture in the gauge, etc -- somehow.

Just interested in any cold weather stories. Me, I would just wait till it warmed up!

[hankj]

I wonder if anyone ever ran across the problem of a tank of gas "freezing" up as referenced on this link:
http://www.newton.dep.anl.gov/askasc...9/gen99600.htm

I guess if it was cold enough, the gas would come out as a liquid. I don't see how it would "freeze" unless there was moisture in the gauge, etc -- somehow.

Just interested in any cold weather stories. Me, I would just wait till it warmed up!

The "freeze" is not caused by entrapped moisture. High usage rates of propane cause vapor to be produced rapidly in the tank, causing cooling by evaporation.

The intial boling point of propane (the point where vapor is given off) is -44°C. If the cooling effect reduces the temperature to a point below the initial boiling point, no more vapor is produced. The liquid in the tank is really not "frozen", just reduced to a temperature at which it will no longer boil.

Hank

[Sberry]

Freezes the ambient air.

[Joe H]

I run into this problem all the time, even if it's a 100 degree day in july. I fool around with homebuilt jet engines. Some of the bigger ones require so much fuel that a 20 or 50lb tank can't handle it and will freeze up. Sometimes I'll drop the propane tank in a barrel of warm water. That helps some.


As a side note, a tank of CO2 is compressed gas, not even liquified. If you put a cloth bag over the tank valve and crack it open you can fill the bag with dry ice. The cooling effect of expansion is so strong that the CO2 goes directly from being a gas to being a solid.

[Some Creep]

As a side note, a tank of CO2 is compressed gas, not even liquified. If you put a cloth bag over the tank valve and crack it open you can fill the bag with dry ice. The cooling effect of expansion is so strong that the CO2 goes directly from being a gas to being a solid.

Uh, not true. In my paintballing days, our CO2 tanks WERE liquid filled. We had to install expansion tanks and sometimes anti-siphon tubes inside the tanks to keep the liquid from escaping the tank and entering the gun valves and freezing them up. Liquid CO2 does he!! on the elastomers inside the valve and makes the gun go 'phhhtttttt'.
We filled our gun tanks from bulk tanks, so I don't know what to tell you there either.
All that you are doing by capturing the escaping gas in a cloth is consolidating the cold in one place creating ice. You can do the EXACT same thing with compressed air from a standard compressor, just takes longer (AOD pumps have this happen all the time).

[Joe H]

Haha... I knew that.. I don't know what the heck I was thinking when I was typing that. Long day I guess. I've got a 20lb tank I use sometimes for portable air power. Yeah it's definately liquid, lol.

[Pumpkinhead]

You can do the EXACT same thing with compressed air from a standard compressor, just takes longer (AOD pumps have this happen all the time).

Uh, not true, while you MAY create some ice (solid water crystals) with an air compressor, dry ice is a whole different animal. the ice created with an air compressor is water condensed from the atmosphere/released compressed air, dry ice is not condensed CO2, but solid carbon dioxide. CO2 has strange properties, one being it sublimes (changes phase by skipping a phase) going from solid to gas without becoming liquid (get it, dry ice). it also goes from gas to solid in the creation of dry ice.

[TEK]

Uh, not true. In my paintballing days, our CO2 tanks WERE liquid filled. We had to install expansion tanks and sometimes anti-siphon tubes inside the tanks to keep the liquid from escaping the tank and entering the gun valves and freezing them up. Liquid CO2 does he!! on the elastomers inside the valve and makes the gun go 'phhhtttttt'.

Back when I played, I used a Tipmann 68 Special that was designed to run on liquid CO2. Had to buy a special 'clunck' or siphon tube tank just so the gun would run right. That was back in the late '80's so I have no clue what they do now. Still have the gun. It was one of the very first ones built(of that type)

[hankj]

Haha... I knew that.. I don't know what the heck I was thinking when I was typing that. Long day I guess. I've got a 20lb tank I use sometimes for portable air power. Yeah it's definately liquid, lol.

Man, I feel better now! My problem is posting while in a vodka-induced stupor! Never know wht I wrote 'till the next day!

Hank

[Some Creep]

Uh, not true, while you MAY create some ice (solid water crystals) with an air compressor, dry ice is a whole different animal. the ice created with an air compressor is water condensed from the atmosphere/released compressed air, dry ice is not condensed CO2, but solid carbon dioxide. CO2 has strange properties, one being it sublimes (changes phase by skipping a phase) going from solid to gas without becoming liquid (get it, dry ice). it also goes from gas to solid in the creation of dry ice.

Yeah, I know the 'dry' part of the dry ice. I meant the freezing.......

TEK- I used an Autoc_ocker and an Automag. I still have the Automag. I played in tournaments. At one point I played on teams that held the Washington Cup, Idaho Cup, and Montana Cup all in the same year. I got a bunch of trophys.
I ran high-pressure air. They call it running 'nitrogen', but nobody really uses nitrogen because it's expensive and easier to just use compressed air out of a scuba tank. 3000 psi.
Fun times, until I got old and married.....LOL