Page 156 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

Be st Practice 3 .7 Compressor Best Practices

Fig 3.7.1 Dry twin screw compressor
(Courtesy of Man/GHH)

Fig 3.7.2 Oil injected twin screw
compressor (Courtesy of Kobelco-Kobe Steel
Ltd.)

is rapidly becoming the type of choice in gas turbine fuel gas
Screw compressors exhibit the following advantages over other booster applications, which require medium flows, pressure
positive displacement compressor types: ratios and the ability to handle varying gas densities. As the
Constant inlet volume flow characteristics and advantages of screw compressors become
Can meet variable process differential pressure requirements
Can handle varying density and dirty gases more widely appreciated, their use in all types of applications
Pulsation free will increase.
Valves, unloaders and volume pockets not required The objective of this chapter is to familiarize the reader
Mechanical seals used, packing not required with the design, principle of operation, application and
High reliability (close to centrifugal types) condition monitoring of the different types of screw com-
Small ‘footprint’
pressors available. Figure 3.7.4 defines the objectives of this
Low installed cost
chapter.
Throughout this section, the reader must remember that all
Fig 3.7.3 Screw compressor advantages screw compressors are positive displacement compressors.
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