Nitrogen in tires????

I fill my tires at a gas station that also uses air tools (air wrenches, etc.). I think some of these systems have filters that let the water condense. When air is compressed to 150 psi, the relative humidity goes up by a facter of 11. The filters can remove most of the water, effectively drying the air to a certain degree.

So, if you fill your tires at a gas station that uses an air filter on its compressed air, you should end up with much less moisture in your tires than one that has a compressor that doesn't have filtered air (like the ones where there is a compressor that is turned on when you put in the quarters).

Jeff

It's true. If you do a google search for "ideal gas laws" you can learn the physics behind it.

Jeff

A lot of old time gas station had water separators on their compressors, but there are not many old time gas stations left. For that matter there are not many gas stations that provide "free" air these days. I know of two in my immediate area. Neither has a water separator on the compressor. I have a couple of compressors on my farm. None of my compressors have a water separator -although I do occasionally bleed the tank (water accumulates in the tank). I am not very good at this and as a result, I've lost a couple of tank because of internal rust over the last 30 years. A little water vapor in the compressed air doesn't have much of an effect on air tools (impact guns, ratchets, air hammers) but it can ruin a paint job if you are using a spray gun (guess how I know...). Still, for road use, the amount of water vapor in the air used to fill tires is trivial and not worth worrying about. If it bothers you, be sure to fill your tires when it is really cold outside...

Ed

Just a technical note: Nitrogen is not an inert gas. Inert gases include helium, argon, neon and xeon. They are elements that don't react with anything. Nitrogen does react with oxygen (that's why it from nitrogen oxides in your engine), hydrogen (making ammonia) and other things (which is important for proteins, DNA, RNA in your body, all of which have nitrogen in them).

So nitrogen isn't an inert gas. Granted, it doesn't burn like oxygen and methane gases, but it is not inert, either.

Jeff

Perhaps you might want to search 'latent heat of compression' and what happens to water VAPOR that is compressed, then comment

mike

Why would I?

I understand this. I have taken college courses in chemistry and physics as well as graduate courses in science.

As air is compressed, it heats up. If you don't believe me, just feel the bottom of an-old fashioned hand pump after you pump up a tire (even a bike tire). It is hot, because of the compressed air.

But, by the time the compressed air is running through the air pipes and hose, it is near ambient temperature again.

So what you have to say is not relevant, unless the water has a way of escaping between the compressor inlet and where the air enters the tire.

Jeff

You might want to search 'oxygen.' If you do you will discover oxygen does NOT burn.

You can prove it to yourself. Turn off the oxygen, on a burning oxy-acetylene torch, and observe what happens. Then turn off the acetylene, on a burning oxy-acetylene torch, and observe what happens. ;)

mike

Apparently you failed the course, if you do not understand what happens to the moisture in the heat of the air compressed LOL

mike

I should have said "reacts."

Well, smart guy, why don't tell us what happens to the moisture? Tell us, where it goes.

Jeff

Do you own home work, I get paid when I teach an engineering class.

mike

Close.

mike

In other words, you are acting like an butthole who can't back his claims.

And I give you the benefit of the doubt when I say "acting."

Jeff

No. "So nitrogen isn't an inert gas. Granted, it doesn't react like oxygen and methane gases, but it is not inert, either." is totally accurate. My reference forth is any high-school chemistry book.

Get a clue, if you can.

Jeff

Try again. One can mix oxygen with a fuel but it still will not burn. Search a bit more, WBMS. ;)

mike

What is your problem? I made it very clear that I was wrong. I also said that reacted is the correct word. I am correct that I was wrong, and I am correct that reacted is a correct word.

I also corrected the sentence below to: So nitrogen isn't an inert gas. Granted, it doesn't react like oxygen and methane gases, but it is not inert, either.

And added: so you can tell exactly what I changed.

Do you wonder why people call you a "moron?" This should give you a clue. I don't think it will, but it should. Ask a third grader.

Jeff

"Mike Hunter" wrote in message news:K_Cdnd2CNbXzdoranZ2dnUVZ snipped-for-privacy@ptd.net...

You are splitting hairs Mike. The definition of "burn" is not nearly as precise as you are trying to suggest.....

Main Entry: burn Function: verb Inflected Form(s): burned 'b?rnd, 'b?rnt\ or burnt 'b?rnt\; burn·ing Etymology: Middle English birnen, from Old English byrnan, v.i., bærnan, v.t.; akin to Old High German brinnan to burn Date: before 12th century intransitive verb1 a: to consume fuel and give off heat, light, and gases b: to undergo combustion; also : to undergo nuclear fission or nuclear fusion c: to contain a fire d: to give off light : shine, glow 2 a: to be hot b: to produce or undergo discomfort or pain c: to become emotionally excited or agitated: as (1): to yearn ardently (2): to be or become very angry or disgusted 3 a: to undergo alteration or destruction by the action of fire or heat b: to die in the electric chair4: to force or make a way by or as if by burning 5: to suffer sunburn transitive verb1 a: to cause to undergo combustion; especially : to destroy by fire b: to use as fuel c: to use up : consume 2 a: to transform by exposure to heat or fire b: to produce by burning c: to record digital data or music on (an optical disk) using a laser ; also : to record (data or music) in this way 3 a: to injure or damage by or as if by exposure to fire, heat, or radiation : scorch b: to execute by burning ; also : electrocute4 a: irritate, annoy -often used with up b: to subject to misfortune, mistreatment, or deception -often used in passive c: to beat or score on

In a strict chemistry definition, burning is the act of a fuel (like carbon or hydrogen or whatever) combining with oxidizer (usually oxygen) and giving off heat. In a way rusting is burning iron. None of the elements involved in a chemical fire (the oxidizer,usually oxygen or the fuel) is changed into another element. Neither component truly burns, in the sense that they are transformed into something else. They are combined into a new substance (water, CO, CO2, etc), but the elements are still the same, just bound together in a molecule. And you don't have to have oxygen to burn something. Titan II rockets combined hydrazine (fuel) and nitrogen tetroxide (oxidizer) to create on heck of a fire. If that wasn't burning, I don't know what it would be called.

Anyhow, pure oxygen won't burn, but neither will pure gasoline. Mix the two in the proper way and you get fire - i.e., you are burning the fuel. The act of combining oxygen and fuel is burning. You can't have one without the other, so I don't see why you have to be so picky when someone says "it doesn't burn like oxygen and methane gases." If you combine oxygen and methane gas, you can easily get a fire (i.e., something is burning). I think must people knew what he meant.

Ed

There is not a simple answer. To figure out what happens to the water vapor when you compress "wet" air you would need to know the initial relative humidity, temperature, and pressure and the "new" temperature and pressure after the air has been compressed. With this information and a set of steam tables you should be able to figure out the new conditions inside the air tank (or tire). However, for sure, when you compress air and then allow it to cool back to the original temperature, it will hold less water vapor. Whether you actually get liquid water in your tank or tire depends on the final temperature and pressure of the compressed air and how much vapor there was in the original uncompressed air.

Ed

You obviously were never firefighter, if that is what you believe. Oxygen may well react with gasoline but to 'burn' it needs an ignition source. Would the gasoline that reacted with oxygen, in a carburetor, given off heat or have burn under any of your definitions? ;)

mike