| 摘要 |
<p>A multi-stage pump includes a pump head having at least two compression stages disposed in series With espect to the direction of flow of fluid through the pump, and a reverse fluid bypass circuit including a fluid passageway through which fluid flowing between upstream and downstream ones of the compression stages can he circulated back upstream of the upstream compression stage. The reverse fluid bypass circuit may restrict or stop the flow of fluid through the fluid passageway as long as the pressure differential across the fluid passage is below a. predetermined value. To this end, the reverse fluid bypass circuit may be configured to restrict the flow of fluid while the fluid is in its transitional or molecular flow regime, and allow the flow of fluid while the fluid is in its viscous flow regime.</p> |
