Application and Design of Integrally Geared Compressors

Abstract

Tutorial 7: Integrally geared compressors (IGC’s) are common in plant/instrument air service as well as air separation applications, and continue to gain acceptance over a wide range of other applications. An IGC can achieve high efficiencies but is subject to complicated mechanical interactions. As a result of the mechanical complexity: design engineers, application engineers, and even end users of IGCs benefit from a diverse and in-depth knowledge of all of the engineering principles applied to arrive at an efficient machine with robust operating characteristics. This paper emphasizes the practical aspects of sizing and selection criteria for an integrally geared compressor for a range of applications and promotes a thorough understanding of practical limits of this type of compressor. Underlying aerodynamic principles are reinforced and limiting design aspects such as: gear tooth loading, lateral rotordynamics, bearing surface speed and loads, low- and highcycle fatigue of impeller blades are all iterated to find compromises to meet the demands of each application. Understanding the application and applying appropriate design limits is essential to meeting ever more challenging installation requirements.