Mixer for cooling and sealing air system of turbomachinery

A system is provided for directing air from plural compressor ports to provide cooling and/or sealing air to an associated turbine site. A first flow from a pressure stage of the compressor has a first pressure and temperature. A second flow from another pressure stage of the compressor has a second pressure and temperature. The first and second pressures/temperatures are different. An ejector has two inlets for receiving the first and second flows, and output for combining the first and second flows into a third flow. The pressure and temperature of the third flow are different from the first and second pressures and temperatures. A bypass line is connected between the first flow and the third flow, and provides a bypass flow. A mixer combines the bypass flow and the third flow into a fourth flow. The fourth flow has a pressure and temperature intermediate the pressure and temperature of the bypass flow and the third flow. The mixer comprises inner and outer sections. The inner section is generally cylindrical in cross section and has a plurality of holes therein. The angle between the direction of the bypass flow and the direction of the third flow, when the bypass flow meets the third flow in the mixer, is less than about 90 degrees.