What are compressors?
Compressors are machines built to increase the pressure of fluids, mainly those that can be compressed like gases. One of the most used gases is air since it allows many functions to be performed such as: handling of pneumatic actuators, blowing of bottles and bags, in pneumatic tools, to inflate objects, etc.
These machines are classified by their way of operation and we can find two categories each with its different types of compressors.
This type is characterized by having a compression chamber in which the volume of the gas is decreased, when it reaches the maximum compression value given by the design, expels it into the system.
Dynamic or turbochargers
Dynamic compressors are characterized by the fact that they use molecular acceleration as a working principle to compress the gas, it is sucked by an impeller that accelerates it, and then sends it to a diffuser ring that stops the gas and generates a pressure in the gas for later be released to the outside.
Positive displacement compressors
Within this category we can find two sub-classifications: the alternative or oscillating piston and the rotary ones.
Reciprocating or swing piston compressors
Piston or reciprocating compressor
The operation of this compressor is quite easy to understand since it has a crankshaft powered by an electric motor that makes the piston move, when it makes its downward stroke the system absorbs the gas, and then compresses it when the stroke is upward. This process is repeated as many times as necessary and when the pressure reaches its maximum level, a sensor deactivates the motor to reduce electrical consumption. Read more…
This type is characterized in that the air is not in contact with the mechanical parts of the compressor, since it has a diaphragm where the air is concentrated. The compression method is done through a piston that pushes the diaphragm to pressurize the concentrated air.
These are characterized by having a continuous and rotary compression system, within this type we can find screw, vane, scroll type and roots.
Its operation is based on the rotation of two helical screws, one male and the other female, which rotate together to drag the gases into the holes that form along the screws. These gaps become smaller as the gas advances to exert a greater force and thus be compressed.
The operation of this compressor is based on the orbital movement of two rotors in the form of a spiral, one fixed and the other mobile, which is placed with 180º of phase.
This type of compressor has an internal rotor that is placed eccentrically to the motor shaft (it is placed on one side of the circle and not in the center) and, as its name implies, it has blades integrated into the rotor, which at when turning, they exert pressure in the air on the holes generated by its construction.
Roots or lobe compressor
This compressor is characterized by having two rotors connected by a set of gears to rotate at the same time but in opposite directions in order to be able to propel the air at a higher pressure than the initial one.
Compressors in this category are used for high flow rates and we can find two different types, axial and radial centrifugal compressors.
Axial centrifugal compressor
The operation of this type practically resembles that of a fan, since it rotates a turbine to suck air and generate greater pressure at its outlet. This flow is generated in the axial direction or better said perpendicular to the axis of rotation.
Radial centrifugal compressor
It is practically the same operating principle as the axial compressor, except that it is constructed in a different way to generate the pressure radially or rather to the same direction as the direction of rotation of the shaft rotation.