×

Variable speed control for centrifugal pumps

  • US 5,240,380 A
  • Filed: 05/21/1991
  • Issued: 08/31/1993
  • Est. Priority Date: 05/21/1991
  • Status: Expired due to Fees
First Claim
Patent Images

1. A control system for a variable speed centrifugal pump operative throughout a flow range extending from a minimum to a maximum flow rate in which pump pressure as a function of flow rate for a constant speed of operation of the pump has a range of flow rates in which the pump pressure increases as a function of increasing flow rate which is unstable comprising:

  • a sensor in fluid communication with output flow pumped from the pump for sensing only a single operational parameter of the output flow pumped by the pump;

    a variable speed drive for driving the pump at a commanded rotational speed in response to a commanded speed signal; and

    a controller, responsive to the sensed operational parameter, for producing the commanded speed signal as a function of pump flow to vary pump speed from a speed producing the flow rates in which the pump pressure increases as a function of increasing flow rate to the commanded rotational speed to produce pump operation throughout the flow range to produce only flow rates for which pump pressure decreases as a function of increasing flow rate to produce stable pump operation.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×