APPAREIL ROTATIF A DEUX ETAGES FORMANT POMPE CENTRIFUGE OU TURBINE DE DETENTE

L'invention concerne un appareil rotatif formant à la fois une pompe centrifuge et une turbine de détente. Elle se rapporte à un appareil comprenant un boîtier 34, des entrées 12 et des sorties 30, une volute 14 dans chaque étage, des plaques 38 d'extrémité et un arbre 15 portant des roues centrifuges 20. Les deux étages sont montés dos à dos. La pompe permet la circulation de suspensions très corrosives. Application au pompage des suspensions de charbon. A two-stage, high-pressure centrifugal slurry pump comprises a pump housing 34, and inlets 12 outlets 30 which are located through the periphery of the pump. In each stage, pre-rotation vanes 16 are located along the interior wall of the pump housing and convey slurry from the inlet 12 to the impeller 20 while reducing the relative velocity at the impeller inlet and primarily at the impeller inlet tip 18. The face-to-face impellers 20 are located on the pump shaft 56 and transmit the slurry to vaneless radial diffusers 24 from which the slurry is conveyed into a fold-over volute 28. A replaceable cutwater is interposed between the diffuser and the volute to channel slurry into the volute and slurry seals 46 are coaxially located along the pump shaft between the impellers and end plates 38 to prevent leakage. Although the stages can be connected in parallel, or pump independently, an external connection 32 connects them in series. By reversing the flow, the pump discharge outlet 30 of each stage becomes a turbine intake, the fold- over volute 28 becomes a converging scroll, the radial vaneless diffuser 24 becomes the radial vaneless turbine inlet nozzle, the pre-rotation vanes 16 become flow straightening guide vanes and the pump inlet volute 14 becomes the turbine radial discharge scroll.