| 摘要 |
<p>1,130,347. Centrifugal pumps; priming pumps. HUDSON ENGINEERING CO. Dec. 8, 1965 [Dec. 16, 1964], No.52126/65. Headings F1A and F1C. In a priming system for a pump, e. g. a multistage centrifugal pump 11, Fig. 1, a priming valve 3 is positioned outside the conduit 4, preferably on a removable section 6, to facilitate replacement and maintenance of the valve. An inspection window 7 permits access to the valve. In the event of loss of prime of the pump, the valve is opened to permit liquid in the conduit to be recirculated back to the suction well 5. The well has an inlet 2 which may instead be at the top of the well. The valve is actuated by a spring- biased piston (41), Figs. 2 to 5 (not shown), or a diaphragm, controlled by a pressure representative of the velocity of flow in the conduit 4 either downstream of or intermediate the pump stages. The pressure is sensed by a funnelshaped sensor (56) or a Venturi-shaped sensor (62), or by pitot tubes (94) arranged within a Venturi (80). A passage 15 having a check valve 16 allows air to pass from the well to the conduit during priming.</p> |
