How long can Air be Compressed and give off heat?

Let's say I Compress Air so much that it generates Heat. How long can I keep the Air Compressed and still generate Heat?

For Example I Compress Air and it generates 50 Celsius. The Atoms rub on each other while the Pressure is constantly Stable.

And the Compressed Air is Contained in an Metal Surrounding that gives off the Heat. While the Metal Surrounding gives off the Heat at the Normal Air around it.

How long can the Air be Compressed and still give off Heat?

PS: I might not find the Web Page again. It would be nice if you send me the Answer to my Email. emeraldlime (at) hotmail (dot) DE (Where the (at) is the @ Sign, where the (dot) is an . and no Space)(Did that so my Email won't be Found by Automated Email Searches and then used for Spam)

Thank you.

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Bill says...

While I would like to be able all the comments I get with personal emails, two things prevent it. First is that I haven't enough time in the day, and the second is that the answers I provide you may help someone else with the same problem or question, and that's why they are posted on this open site.

Now to your question. We are all trying to conserve energy and recycle products. It is very logical then to try to capture the heat generated by an air compressor, and re-use that heat elsewhere.

In industrial plant environments, compressors commonly run continuously, and they generate a lot of heat. There is a whole industry build up around recycling compressor generated heat.

The heat is a by product of compressing air. The running of the electric motor does as well. In larger compressors, more heat comes from the compression process.

So, as long as your compressor is running it's generating heat through molecular friction, as you point out. When the tank is full and the compressor stops the heat that has been generated migrates into the surrounding area from a high heat source to low ambient.

If your compressor doesn't run for a long time, and assuming no leaks, you will have a tank full of cold compressed air since no more heat is being generated.

Incidentally, it's the natural cooling of the hot compressed air in the air tank that contributes to the water in the tank that you should drain after every use.

Cheers,

Bill