×

APPPARATUS AND METHOD FOR CONTROLLING A CENTRIFUGAL COMPRESSOR

  • US 3,778,695 A
  • Filed: 04/21/1972
  • Issued: 12/11/1973
  • Est. Priority Date: 04/21/1972
  • Status: Expired due to Term
First Claim
Patent Images

1. Apparatus for limiting the current to an electric motor driving a centrifugal compressor to a pre-selected maximum current, comprising, in combination:

  • An adjustable, flow-limiting inlet valve connected to the inlet side of said centrifugal compressor;

    signal generating means connected to the outlet side of said centrifugal compressor for sensing the process pressure in said outlet side and generating a signal proportional to said process pressure;

    control means connected to said signal generating means and responsive to said proportional signal for comparing said proportional signal with a pre-selected process pressure value, said control means generating a control signal representing the deviation of said proportional signal from said pre-selected process pressure value; and

    means responsive to the electrical current delivered to said motor and connected between said control means and said inlet valve, for passing said control signal without deviation to said inlet valve to adjust the inlet valve in response to said control signal so long as said motor current remains below a pre-selected value and modulating said control signal as a function of said motor current above said pre-selected value to adjust said inlet valve in response to said modulated control signal such that the maximum permissible current to said electric motor will not be exceeded.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×