Rotary screw type compressors are the popular kind that is in mass production. Whenever you pass by a factory or manufacturing plant, you can bet the process is being driven with this type of air compressor.
The rotary screw compressor’s working principal
Rotary screw compressors have two rotors that are located within the housing that interlocks. The ambient air that extends into the compressor comes from the inlet valve. The air is then trapped between two rotors. From there, the screws turn, and this increases the pressure of the air by lowering its volume. Some rotary screw compressors do consist of only the one screw. This type is often used in the industrial world as they need the power of two screws for large-scale productions. The screw compressors have an assembly that consists of the rotors and housing to be at the air end. The air end is where the incoming ambient air gets compressed.
Oil or non-oil screw air compressors?
Some screw air compressors use oil, and some don’t. All air compressors will need to filter out the oil that is found in the ambient air. In the compressors that are using oil, will have a motor that controls the male rotor, which is what will turn and drive the female side rotor. The oil creates a film that sits between the rotors and acts as a sealant and coolant for the chamber.
In a compressor that doesn’t need oil, there isn’t anything to drive the compression process. From here, the two rotaries within the oil-free compressors are instead controlled by gears. Without any oil to serve as a sealant, these compressors are not capable of reaching very high levels of pressure. The toil free compressors are not as efficient and will run hooter due to having no oil to cool the machine down.
Due to these limitations, the industrial screw air compressors are often confined to specific uses.
The air serves as a different function apart from the compression of the air; this is where the oil gets compressed in the air. After the air ending stage has finished, the new compressed air will pass into the sump part orf separator tank where the oil is then extracted out of the air.
It is the spinning motion the forcefully shakes to the oil particles from the compressed air to allow the latter to be pure once it has reached the endpoint.
It will depend on the temperature of
the separated oil, whether a thermostatic valve treats the oil as it should.
The purpose of this is to prevent the oil from getting too cold or too hot. If
oil gets too hot, it will end up wearing down the machinery inside; if too cold
it won’t separate properly.
Air cannot go through the system until there is enough pressure for it to become self-lubricated. If the oil ends up with too much water, the end with the air will not be able to function correctly.
In the rotary screw compressors that have a stationary blade, there will be a driving shaft that contains an eccentrically mounted roller that is inside the pump chamber. In the chamber, there is a blade that divides the outlet from the inlet valves. The blade itself becomes sandwiched by the interior body of the compressor and the roller surface.
As the roller moves around the blade will go up and down to match the rotary motion. The compressor has three moving parts the blade, roller and shaft. Each moving part will be lubricated. In the cylinder, the pressure is compressed to high temperature along with the vapours of low temperature. This is only made possible with the motion of the roller.