GASTURBINE

A gas turbine engine comprising a number of annular wall sectors which form a complete circular wall defining a hot gas passage is provided with a cooling system incorporating a plurality of hollow impingement vessels disposed in a circular array within an annular chamber behind the wall. Cooling fluid is routed to the self-contained impingement pressure vessels which are provided with perforations to disperse the cooling fluid into impingement upon the wall. Unlike prior systems, the impingement vessels are not physically attached to the band but, rather, are supported by a structural frame which partially defines the annular chamber and, in the preferred embodiment, also supports the wall sectors. Since the impingement vessel, and not the backside of the wall, is the pressure vessel for the pressurized cooling fluid, leakage between adjacent wall sectors is greatly reduced with no loss in cooling effectiveness when compared to conventional cooling systems. Thus, turbine cycle performance is improved.