| 摘要 |
FIELD: fluidics; evacuation systems, for example, in steam turbine condensers. SUBSTANCE: liquid-and-gas ejector has active multi-jet nozzle 1 with central nozzle orifice 2, mixing chamber 3, diffuser 4, inlet chamber 5 with passive medium supply branch pipes 6 which is brought in communication with chamber 3 by means of radial holes 7; all these members are mounted coaxially. Located in mixing chamber 3 coaxially to central nozzle orifice 2 is central body 8 made in form of rod whose one free end is made in form of concave platform 9. Other end of central body 8 is mounted in mixing chamber 8 by means of radial partitions for axial displacement relative to them. Radial partitions have sharp edges 11; they divide mixing chamber 3 at its outlet section into several parallel passages arranged evenly. Mounted inside mixing chamber 3 on its walls between active nozzle 1 and platform 9 of central body 8 is deflecting profiled circular bush 13. Second similar bush 14 is mounted in section between platform 9 and radial partitions 10. Diameter of platform 9 is found from relationships l≅ 0,8d,, where 1 is diameter of platform 9 and d is diameter of imaginary circle closest to center around which peripheral nozzle orifices 15 are located. Central nozzle orifice 2 has lesser diameter as compared with peripheral orifices 15. Mounted concentrically in mixing chamber 3 in section located lengthwise relative to radial partitions is cylindrical wall with sharp edges 17 which forms additional passages. Nozzle peripheral orifices 15 are located in zones bounded by inner contours of cross sections of passages parallel to mixing chamber axis. EFFECT: reduction of length of mixing chamber due to intensification of process of breaking active flow jets; enhanced efficiency due to reduction of losses for friction at lesser length of mixing chamber and reduction of losses of energy due to replacement of normal shock wave at deceleration of supersonic flow by several oblique shock waves; reduction of pressure fluctuations and enhanced reliability. 9 cl, 2 dwg |
