The principle of rotary screw air compression is really no different than reciprocating (piston) compression. Both are positive displacement machines that take in a fixed volume of air at atmospheric press.
[pdf] The Variable Frequency Rotary Screw Air Compressor is an energy efficient solution for industrial air compression requirements. The motor output frequency is intelligently matched to air consumption, making it more energy efficient and longer lasting than traditional air compressors.
[pdf] An EU/EPA approved diesel air compressor is a type of air compressor that is powered by a portable air compressor diesel engine and has been certified to meet the stringent emission standards set by the European Union (EU) and the United States Environmental Protection Agency (EPA).
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