MULTISTAGE COMPRESSORS FOR PET BOTTLE BLOWING PROCESSES

摘要

A multistage reciprocating air compressor (10) for compressing air to an elevated pressure level discharge (29) with an intermediate pressure level discharge (30, 30') for use in blow moulding of PET bottles and similar products, having a first, second and third reciprocating piston stages (11, 21, 26), including respective inlet unloading means (16,17; 34; 25), with first, second and third actuating means (31, 32, 33) operable in response to respective sensed discharge pressure levels from the discharges to actuate inlet unloading means (16,17; 34, 25). The elevated pressure level discharge (29) being from said third stage and said intermediate pressure level discharge (30, 30') being from an interstage region between at least one of said first and second stages (11, 21 ) or said second and third stages (21,26).