System for supplying a cooling and purging air flow to an online monitoring system of a rotary machine

摘要

In one embodiment, a system (10) comprises a sight tube (101) which is inserted into an inspection opening (76) and is set up for optical communication with the interior of a rotary machine (18). The sight tube (101) comprises a window (88) and several openings (96) through which purge air is passed over the window (88). The system (10) also comprises a jacket tube (82) which is arranged around the sight tube (101) and is set up to conduct scavenging air from a first air source to the openings (96) via a first passage (105). , which is formed between an inner surface (107) of the jacket tube (82) and an outer surface (106) of the sight tube (101). The jacket tube (82) has a plurality of outlet openings adapted to direct air for an air curtain around the window (88), and the jacket tube (82) is adapted to direct the air curtain air from a second air source to the outlet openings via a second passage (94) which is formed between an outer surface (95) of the casing tube (82) and an inner surface of the inspection opening (76).