GB1343246A - Gas compressors - Google Patents

Abstract

1343246 Centrifugal compressors; turbines INGERSOLL-RAND CO 14 June 1972 [2 July 1971] 27812/72 Headings F1C F1G and FIT A gas compressor has at least a first compressing stage 16 with at least three separate inlets in parallel for admission of gas to the stage in a common direction, at least two of the inlets being at least partially confined within another of the inlets. The first stage 16 comprises an inlet housing 36 having a port 38 through which ambient air flows to a compressor rotor 40 before passing through passageway 42 to intercooler 22, demisters 26, 26' and second compressing stage 18. The latter has a rotor 48 which, together with rotor 40, is driven by a motor (32) Fig. 1 (not shown) via shaft 58 and gearing 56. The air leaving rotor 48 flows through discharge passage-way 50 to a consumer 52, the discharge pressure being detected by sensor 86 which controls valve 80 to recycle some of the discharge air back to first stage 16 should consumer demand fall. Respective outlets of valve 80 are connected to passageways 74, 76 each of which communicates through a pair of hollow struts 64 with one or other of the chambers defined by partition 66 disposed within a hollow centre body 62 mounted in housing 36. The respective chambers define two further inlets to rotor 40 via nozzle ring 92, turbine rotor 60 and flow straightening vanes 96. Thus according to the position of plunger 82 of valve 80 discharge air may be recycled back to compressor rotor 40 through one or both of passageways 74, 76 and then turbine 60, the latter assisting drive of compressor 40 to prevent surge. The temperature of the recycled air is maintained sufficiently high to prevent icing of first stage 16, the temperature control being effected by a sensor 116 which acts on valve 114 to vary cooling water flow through inter-cooler 22 and thus maintain the air temperature leaving the inter-cooler constant. The first and second stage compressor housings 36, 46 respectively are mounted side by side in a common casing 30 from which they can each be slidably removed. The respective rotor assemblies can then also be removed.