It is really remarkable that the very air that we breathe can also be harnessed to help humans in other various ways.
From ensuring safer travel in tires through dealing with dust to powering tools that help us create and advance, air in its compressed form has been a real boon to humanity ever since the industrial revolution.
Air compressors play an instrumental role in using and controlling that power to our advantage.
If you’ve wondered how your own model does such a good job of powering your tools, read on and find out exactly how air compressors work.
The nitty gritty
In the simplest possible terms, air compressors take the air in their tank and increase its pressure by decreasing its volume – the initial amount of air stays the same but due to the higher pressure it is under it doesn’t take up as much space as it did initially.
To accomplish this, most compressors use reciprocating piston technology.
Every compressor ha a cylinder with inlet and discharge valves that appear at opposite sides of its top end. Air is sucked in through the inlet valve and compressed inside a piston.
Once the desired pressure is reached, the compressed air can then be released through the discharge valve.
The piston’s movement creates a vacuum that causes air to be sucked inside the cylinder through the intake valve. Once the piston starts moving in the opposite direction, the air already inside is pushed towards the discharge valve, all the while keeping the intake valve tightly sealed. The more this process is applied, the higher the pressure generated.
Compressors you encounter most in everyday use, regardless if they are static or portable, rely on a number of compartments that reduce the space it takes up. This is called positive displacement.
Even though technically you only need a motor and a pump to achieve compression, the usefulness of such a machine is greatly enhanced with a built-in air tank.
This allows for a certain amount of air to be pressurized and then stored at a given pressure for later use, and is the staple when operating a vast array of different pneumatic tools whose continuous operation relies on a steady supply of air.
Of course, the pistons and associated parts need to be lubricated in some way. In this respect, compressors can be divided into 2 categories – those that use oil and those that do not.
In the former, oil splashes into the cylinder and onto other components, causing smooth, uninterrupted operation.
It isn’t supposed to escape the cylinder, but air compressed in such machines has trace elements of it more often than not. This can actually be beneficial for some tools that require periodic oil treatment to work properly.
For others, such as sanders, where even the smallest amounts of oil are unwanted, oil-free, long-lasting lubrication is called for. This decreases maintenance, but the compressors that use it tend to be noisier and more stress is applied to their motors.
Now that you have an elementary grasp on how they work, you’ll be able to choose a good air compressor with more confidence.