Compression Medium
Air is generally used as the compression medium because it is compressible, transparent, easy to transport (non-condensing), harmless, safe, and inexhaustible .
Inert gases are gases that do not chemically react with the environment, and standard compressors can compress inert gases in the same way. Dry nitrogen and carbon dioxide are both inert gases.
"Stage" and "Section"
In positive displacement compressors, after each compression in the working chamber, the gas enters the cooler for cooling, which is called a "stage".
In dynamic compressors, the gas often enters the cooler for cooling after being compressed by the impeller two or more times. Several compression "stages" that undergo cooling are collectively called a "section" .
In Japan, the "stage" of a positive displacement compressor is called a "section". Influenced by this, some regions and some literature in China also refer to the "stage" as a "section". Pressure refers to pressure intensity (P) in the compressor industry. 1 Pa is the force of 1 N acting on a unit area, i.e., 1 Pa = 1 N/m². Pa is the basic unit of pressure. When the pressure value is large, kPa (1 kPa = 1000 Pa) and MPa (1 MPa = 1000000 Pa) can be used.
