There are many types of compressors and they are categorized based on different criteria, depending on the need, the appropriate device should be selected from among them. One of the categories is based on the criterion of energy transfer from the device to the fluid and it places compressors in two groups, which are; Dynamic compressors and positive displacement compressors.
Due to the different characteristics of each device, the uses of each one are also different. Dynamic compressors are suitable for low pressures and energy is constantly being injected into the fluid. But in positive displacement compressors, energy transfer is not permanent, but intermittent. The dynamic compressor is divided into two categories: centrifugal and axial flow compressors; And the positive displacement compressor includes two general categories including reciprocating compressors (piston) and rotary compressors.
Dynamic compressor
Dynamic compressors are greatly affected by the external environment. In other words, since there is a constant pressure in these compressors, any change in pressure has a strong effect on the performance of the device and its capacity.
Positive displacement compressor
This type of compressor works with constant flow. One of the simple types of this compressor is the type used in bicycles. Reciprocating or reciprocating compressors are positive displacement compressors, in which pistons are used. These compressors have different single-stage and multi-stage types.
Their design is not such that they work continuously in 24 hours. In addition, its different dimensions have different power; For example, the compressors used in the automotive industry are of smaller types and their power ranges from 5 to 30 horsepower. While larger dimensions with a power of over 1000 horsepower, it is better to be used in larger industries such as petrochemicals. Some types of reciprocating compressors work with oil and some without oil.