Centrifuge types, classification operation

The compressor or blower installation in a typical refinery or chemical process unit is not out-of-doors completely. Some form of shelter often is provided, ranging from only a roof to a completely closed building. When process equipment such as a centrifugal gas compressor, which is not hazardous in normal operation, is present in the shelter, the hazard classification depends on the extent to that which the shelter restricts ventilation. The extent of the shelter provided determines the area classification and the type of motor enclosure that should be applied. 

There are two basic types of compressors (1) centrifugal and (2) positive displacement. Both of these major classifications can be further divided into sub-types, depending on their operating characteristics. This section provides an overview of the more common centrifugal and positive-displacement compressors. 

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