The importance of air cannot but be felt in different fields and even in the biology of life. Apart from its comfort and all air does such an amazing job for us on one way or the other such as what I read here by 
Another amazing article on air is by @real2josh where he dissected air and its properties and also talked about its application in the real world. I wrote about the pneumatic systems some time ago and how it has been used to carry out work for industries and the brains behind how they work.
Earlier today, we were driving along this dirty road where there was this road we pass through that made us regret passing. It was almost a dump or even a dump and while trying to navigate our tire got punctured but luckily for us, there was this technician we call vulcanizers (a wrong word which is popularly used here in Nigeria) and he was not far away we had to bring out the flat tyre and fix it immediately since it was not safe driving.
While he patches up the tyre with all the glues and magic stuff he had in his bag one thing that caught my eye was his air compressor which he used to fill the tyre with air. I had not even noticed why such things have a round cylindrical tank attached or why everything looked so big all my head could fathom was that it was a simple machine but I was wrong. I didn't even know I had seen more air compressors before without knowing what they were.
a small air compressor image by me
Compressed air
syringe with air: image taken by me
Compressed air or air at high pressure as it is known is a very vital part of the world today from the bus doors, transportation, vehicle brakes, to the elevators.
Compressed air requires you taking a large quantity of air and choking it in a little space or storing energy right into the air for usage. Compressed air has a lot of potential energy which can be converted into kinetic energy for work that even 5 men combined cannot do. You are surprised??
Can air really be compressed?
Let us take this simple example or experiment, pick up a syringe and remove the needle such that the needle hub is empty. Draw in a certain amount of air and block the needle hub with your finger such that there is no space for air to leak out.
Now apply a amount of force at the plunger and tell me what you noticed. From what I tried here, as the pressure that is applied on the plunger increases the volume of air decreases. Which means it obeys the boyles law
Where,
P1 V1 = P2 V2
syringe with compressed air after pressure is appliedr: image taken by me
What I am trying to point out here is energy in compressed air, the air released from this syringe can be used to carry out a reasonable amount of work even though that is not its primary function unlike the mechanical pump. This is proof that air can be compressed and it is done using the right amount of power depending on what it is needed for.
The air compressor
The air compressor is that which adds the energy to the air to make the product compressed air. In the case of our analogy above your syringe is the air compressor in this case and it does the work although the pressure or energy it can add to the air is minimal I doubt if it is up to 2psi I didn't measure it though so do not blame me for the figure.
Air compressors are huge instruments in the engineering field and have really changed a lot they are a little different or you can just call them the same as the pneumatic systems. Just that the air compressors may vary in the task they do unlike the pneumatic systems. Produce air at high temperatures for use. They are being used in several fields I remember seeing lots of air compressors at a power plant the tour guide told us they need it to get the engines started, the roadside tyre repairer are another set of people that do use air compressors to fill your vehicle tyre with pressurized air, the even decoration guys use it also to make balloons and fill in these light balloons.
These are just a few of the places where air compressors are used. But we have to know how these air compressors work, what mechanism is behind them which enables them to give more power to the air for this usage.
The mechanisms behind the working air compressor
if you have watched people carry out their event decoration and the way the put air into their balloon well they used their mouth initially before the inflators came to be. Using their mouth to function as a compressor could be tasking and not easy but it does the jo.
According to the example above, would it be too bad to say we pumped air into the balloon?
If I were to wait for an answer I will not continue this post today. Yes, of course, we pumped air into the balloon so this means that there are definitely air pumps but they are not the same as an air compressor. The example we made above was simply an air pump analogy but it still gives the same result as an air compressor. But they cannot be used interchangeably I will explain why in the later part of this article.
The air compressors consist of several parts just like your cylinder engine, so I would not be wrong to say that your air compressor can be compared to your cylinder engine. A typical air compressor has a piston, intake, discharge valve, connecting rod, a crankshaft.
The intake valve of the cylinder opens and allows ambient air come in and closes as the piston moves to compress the air as it does so the outlet valve opens up to the storage and it does so repeatedly and at high speed. This means that the volume of air is reduced as the pressure increases to give the product we called pressurized or compressed air.
This makes the storage full of air that is under pressure or energized air for the purpose of their use. This type is the most common types of the air compressors. Although there are other types that have impellers. Impellers are like blades or vanes that add speed to the fluid or air.
These air compressor cylinders are powered by a mechanical power which may be used with fuel or diesel and connected with a belt drive or chain. Or they could be electrically powered using an electric motor either way they are done to achieve the same result in the energized air.
What differentiates the pump from the air compressors?
The pump and the air compressor are almost the same but are different and sometimes should not be used interchangeably. The air compressor does its job well.
The pump adds speed to liquid (not gas) to its point of delivery at a certain rate while the air compressor adds energy to air to do certain work. The pump can be used for air but liquids should never be used in an air compressor because liquid is not compressible, unlike air.
The lubrication of the air compressor and maintenance are done differently, for instance, there are pumps that are lubricated with oil continuously as they work usually have oil bath while air compressors do not have an oil bath but are lubricated in a special way with long lasting lubrication applied to the bearings. This way, there would be less contaminants while wear is being reduced as the compressors are working. Having an oil bath would lead to constant contamination of the air.
Let us take for instance the painters or furniture makers who make use air compressors to spray a wood or door and there is an oil contaminant in their paint. It will take longer for the paint to dry and might change the color of the result.
Applications of the air compressor
In power generation, compressed air is used in power generation to keep the fuel atomized, it is also used in pneumatic valves.
For divers, if you have watched all those documentaries where divers go down the water for hours to make research on sea creatures they put on a tank in that tank is compressed air. Which is used for the survival of divers.
The application of compressed air is felt in the automobile during the maintenance and service of the engine sometimes in cleaning the most difficult parts they are used also not forgetting their application in the pumping of tyres.
In the military world, submarines make use of compressed air to carry out many activities one of which is the launch of torpedos. In the diving and resurfacing of submarine ships. This is very important in the sub like people call it.
These are just a few of the application I have stated. Earlier I mentioned how they are used in pneumatic systems too for many activities.
Conclusion
Air is everything but compressed air is a super form of air which is used to carry out special activities for mankind.
Air which is compressible can be done by the use of various types of air compressors and the popular one is the reciprocating cylinder used for compression of air although the positive displacement type of air compressors are available.
There is some classification of air compressors due to their pressure there is the low pressure which has a range of 1-150 psi and the medium type of range 151-1000 psi, while the high speed goes above 1000 psi.
These are great pressure no man can produce or hold but air is doing so and can be transformed to a lot of work in little space.
Which means air is great and can be manipulated to mankind's best use. Like I said, I would feel the impact its 9 pm and I am shivering under my blanket as I complete this post on my phone.
I hope you enjoyed reading?
References
My teacher would say knowledge is light and is not just gotten anywhere but from books and experiences. Here are some books I read
If you write STEM (Science, Technology, Engineering, and Mathematics) related posts, consider joining #steemSTEM on steemit chat or discord here. If you are from Nigeria, you may want to include the #stemng tag in your post. You can visit this blog by 
You can also join us at Promo-Mentors, to improve your blogging skills. Join our discord channel and meet awesome mentors who are willing and ready to shape your writing skills.