Pulsation Dampener for Gas Compressors Having Selectable Size Choke Openings

Abstract

A gas flow pressure pulsation dampener includes a sealed housing having an inlet port, an outlet port a center section disposed between the inlet port and the outlet port. A choke plate is rotatably disposed in the center section and has a plurality of different size openings disposed circumferentially about the plate. The plate is positioned in the center section so that the openings are placed between the inlet port and the outlet port. The size differences between the openings and the circumferential separation between adjacent openings are selected so that the plate always presents one full opening or parts of two openings between the inlet port and the outlet port. Means for rotating the choke plate are provided to select one of the choke openings to be disposed between the inlet port and the outlet port.

1 . A gas flow pressure pulsation dampener, comprising:
 a sealed housing having an inlet port, an outlet port a center section disposed between the inlet port and the outlet port;   a choke plate rotatably disposed in the center section and having a plurality of different size openings disposed circumferentially about the plate, the plate positioned in the center section so that the openings are placed between the inlet port and the outlet port, the size differences between the openings and the circumferential separation between adjacent openings selected so that the plate always presents one full opening or parts of two openings between the inlet port and the outlet port; and   means for rotating the choke plate to select one of the choke opening to be disposed between the inlet port and the outlet port.   
     
     
         2 . The pressure pulsation dampener of  claim 1  wherein the means for rotating comprises a shaft rotationally fixed to the choke plate. 
     
     
         3 . The pressure pulsation dampener of  claim 2  wherein the means for rotating further comprises:
 a pressure transducer in pressure communication with the outlet port; 
 a controller in signal communication with the pressure transducer; and 
 a motor electrically coupled to the motor, the motor rotationally coupled to a shaft, the shaft coupled to the plate to cause rotation thereof; 
 wherein the controller is configured to detect amplitude of pressure pulses, and in response to the detected amplitude cause the motor to rotate the shaft until the detected amplitude falls below a selected threshold. 
 
     
     
         4 . The pressure pulsation dampener of  claim 2  wherein the shaft is keyed to the plate. 
     
     
         5 . The pressure pulsation dampener of  claim 1  further comprising an indicator plate disposed outside the housing rotationally coupled to the means for rotating, the indicator having indications thereon corresponding to the openings in the choke plate to indicate which choke opening is disposed between the inlet port and the outlet port. 
     
     
         6 . A method for dampening pressure pulses in flowing gas for volume measurement, comprising:
 measuring pressure downstream of a variable opening choke in the flowing gas stream using a pressure transducer that generates an electrical or optical signal in response to pressure;   determining amplitude of pressure variations in the flowing gas from the measured pressure signal;   changing an opening size of the choke until the determined amplitude falls below a selected threshold.   
     
     
         7 . The method of  claim 6  wherein the changing opening size comprises rotating a plate having a plurality of differently sized openings into the flowing gas stream.