The twin helical screw compressor Part 1: Development, applications and competitive position

Abstract

Part 1 of this paper describes the origins, principal developments, characteristics, applications and current competitive position of the twin helical screw compressor. It is now the preferred type in a large range of gas and refrigeration applications previously serviced by the larger piston and smaller centrifugal compressors. Its success has been made possible by two crucial developments: (a) a lubricated variant in which one rotor drives the other without timing gears and (b) the introduction of advanced machine tools capable of mass producing reliably a rotor pair of high efficiency and low maintenance. The technical reasons for its (still growing) success over its rivals are explained, as is the competitive challenge presented by the scroll compressor, which is being produced in ever larger sizes. The paper concludes that if the twin helical screw compressor is to maintain/advance its present dominant position, three things are needed: A designer-friendly computerized model of the working process which is comprehensive, accurate and of general application. Part 2, which follows, addresses this issue. A designer-friendly computerized profile design system not limited to predefined geometric forms and having an optimization facility. Faster, more accurate and cheaper manufacturing methods for rotors.