Air Compressors and How They Work
The practice of workshops using a central power source for driving tools isn’t new. Over the years, what’s changed though, is the use of air compressors in place of the belts and shafts that were driven mechanically to route power around the workspace. The underlying physics remains the same, i.e., when a certain volume of gas increases within an enclosure, the pressure increases, thereby producing power. Modern day air compressors are compact, portable and efficient, and are available in a variety of designs and configurations to suit different operational requirements. So, be it at the gas stations round the corner, or major manufacturing plants, air compressors can be found in a wide range of situations today.
The Basics of Air CompressorsIf you’re new to the world of air compressors, knowing how they work can be advantageous. And, the best place to begin is by understanding the underlying mechanism. Air Compressor’s work on the Boyle’s Law, which states that the temperature of gas being constant, its volume and pressure are inversely proportional.
The equation derived from the Boyle’s Law is pV=C.Therefore, temperature being constant, the volume decreases as pressure increases, and vice versa. The following graphic from NASA should provide more clarity:
Components of an Air CompressorThe air compressor comprises of four basic components, namely:
- Electric motor, which powers the compressor pump by driving a pulley and two belts. The power is transferred from the motor to the pump via a crankshaft and a flywheel. A magnetic starter is also installed here to prevent damage to motor due to thermal overload.
- Compressor pump, which compresses the incoming air, and then discharges it into the receiver. In case of two stage compressors, the air usually needs to pass through two cylinders. First, a low-pressure, larger cylinder, and then a higher pressure smaller cylinder.
- Receiver tank, which stores the compressed air, and the receiver valve which prevents the air from flowing back into the air compressor pump.
- Pressure switch, which shuts down the motor when the compressed air reaches the receiver tank’s factory-set limit.
- Air dryers and after-coolers, to cool the hot compressed air, and prevent the system from overheating and consequent damage.
- Air filtration and moisture removal pipelines, which need to be installed for draining out the condensed moisture from the air compressor system before it reaches the tool.
- Air lubricator for use in tools that require lubrication. Be careful not to use them for those that don’t, since you can risk contamination.
- Pressure gauge, which measures and regulates the air pressure to tools. They require being installed in drop lines for each tool.
- Shut-off valves need to be installed in each drop line so as to isolate the accessories from the air compressor for servicing purposes.