| 摘要 |
A multi-stage centrifugal pump (11) is described having a linear series of impellers (19) mounted on a common impeller shaft, with axial thrusts imparted to the shaft by the impellers being balanced by a sealed high-pressure thrust bearing (37) assembly secured to the pump casing (13). The pump is particularly suitable for using in pumping an abrasive fluid. A clean lubricating oil is supplied to the thrust bearing (37) assembly at a pressure slightly greater than that of the abrasive pumped fluid, to ensure that the fluid that migrates across a mechanical seal (43) interposed between the impeller assembly and the thrust bearing assembly is the lubricating oil, not the abrasive pumped fluid. High pressure differentials across a breakdown bushing involving the abrasive pumped fluid, and a resulting wear and erosion of pump components, thereby are avoided. |
