Pulsation Attenuation

Abstract

A system, apparatus, and method for attenuating pulsations in a pumping system. The apparatus includes two pipe loops in fluid communication with a pump. Each of the pipe loops includes two branches with the first branch being longer than the second branch by an amount equal to half of a primary wavelength within a range of wavelengths propagating in a fluid discharged from the pump.

1 . A pulsation attenuation device, comprising:
 a pump having a variable operating speed;   a first loop having an inlet coupled to the pump, an outlet, and two branches therebetween, the first branch being longer than the second branch by an amount equal to half of a first primary wavelength within a range of wavelengths of vibrations propagating in a fluid discharged from the pump; and   a second loop having an inlet coupled to the first loop outlet, an outlet, and two branches therebetween, the first branch being longer than the second branch by an amount equal to half of a second primary wavelength within the range of wavelengths of vibrations propagating in a fluid discharged from the pump, the second primary wavelength being different from the first primary wavelength and not a harmonic of the first primary wavelength.   
     
     
         2 . The pulsation attenuation device of  claim 1 , wherein the pulsation attenuation device is coupled to an inlet of the pump. 
     
     
         3 . A pump pulsation attenuation device to attenuate at least two primary pulsation frequencies that, unattenuated, would cause stress in a system disposed at an outlet of a second outlet junction, comprising:
 a first inlet junction having an inlet through which a fluid flows, the first inlet junction further including a first outlet and a second outlet;   a first conduit having a first end coupled to the first outlet of the first inlet junction, having a first length, and having a second end opposite the first end;   a second conduit having a first end coupled to the second outlet of the first inlet junction, having a second length approximately equal to the first length plus half a first primary wavelength within a range of wavelengths of vibrations propagating in the fluid, which is pumped by the pump, and having a second end opposite the first end;   a first outlet junction having a first inlet coupled to the second end of the first conduit, a second inlet coupled to the second end of the second conduit, and an outlet;   a second inlet junction having an inlet in fluid communication with outlet of the first outlet junction, the second inlet junction further including a first outlet and a second outlet;   a third conduit of a third length having a first end coupled to the first outlet of the second inlet junction, and having a second end opposite the first end;   a fourth conduit of a fourth length approximately equal to the third length plus half a second primary wavelength, the second primary wavelength different from the first primary wavelength, not equal to half the first primary wavelength, not a harmonic of the first primary wavelength, and within the range of wavelengths of vibrations propagating in the fluid pumped by the pump, and the fourth conduit having a second end opposite the first end; and   the second outlet junction having a first inlet coupled to the second end of the third conduit, a second inlet coupled to the second end of the fourth conduit, and the outlet.   
     
     
         4 . The pump pulsation attenuation device of  claim 3 , further comprising an outlet conduit coupled to the outlet of the second outlet junction. 
     
     
         5 . The pump pulsation attenuation device of  claim 3 , further comprising a vessel coupled to the outlet of the second outlet junction. 
     
     
         6 . The pump pulsation attenuation device of  claim 3 , further comprising an inlet conduit in fluid communication with the first inlet junction, the inlet conduit having an area and wherein the first conduit has an area of approximately one-half the inlet conduit area and the second conduit has an area of approximately one-half the inlet conduit area. 
     
     
         7 . The pump pulsation attenuation device of  claim 3 , wherein the pump includes a reciprocating compressor. 
     
     
         8 . The pump pulsation attenuation device of  claim 3 , wherein the pump pulsation attenuation device is in fluid communication with an inlet of the pump. 
     
     
         9 . The pump pulsation attenuation device of  claim 3 , wherein the pump is a reciprocating compressor. 
     
     
         10 . The pump pulsation attenuation device of  claim 3 , wherein the pump is pumping natural gas. 
     
     
         11 . The pump pulsation attenuation device of  claim 3  further comprising an inlet conduit having a first end, a second end coupled to the inlet of the first inlet junction, and a length that improves the pressure at the pump. 
     
     
         12 . A pump pulsation attenuation device, comprising:
 a first conduit of a first length in fluid communication with an outlet of the pump through which fluid discharged from the pump is directed;   a second conduit of a second length longer than the first length through which the fluid discharged from the pump is directed simultaneously with the first conduit;   a third conduit of a third length through which the fluid is sucked into the pump; and   a fourth conduit of a fourth length longer than the third length through which the fluid is sucked into the pump simultaneously with the third conduit.   
     
     
         13 . The pump pulsation attenuation device of  claim 12 , wherein the third length is different than the first length. 
     
     
         14 . The pump pulsation attenuation device of  claim 12 , wherein the second length is approximately equal to the first length plus half a first primary wavelength of a fluid discharged from the pump. 
     
     
         15 . The pump pulsation attenuation device of  claim 12 , wherein the fourth length is approximately equal to the third length plus half a second primary wavelength of a fluid sucked into the pump. 
     
     
         16 . The pump pulsation attenuation device of  claim 12 , wherein the fluid is a gas. 
     
     
         17 . The pump pulsation attenuation device of  claim 12 , wherein the fluid is a liquid. 
     
     
         18 . The pulsation attenuation device of  claim 1 , wherein the second wavelength is not half of the first wavelength. 
     
     
         19 . The pulsation attenuation device of  claim 18 , wherein the two branches of the first loop are of approximately equal cross-sectional area. 
     
     
         20 . The pump pulsation attenuation device of  claim 19 , wherein the pump includes a reciprocating compressor. 
     
     
         21 . The pump pulsation attenuation device of  claim 1 , further comprising an inlet conduit having a first end coupled to the pump and a second end coupled to the first loop inlet. 
     
     
         22 . The pump pulsation attenuation device of  claim 3 , wherein the pump pulsation attenuation device is in fluid communication with an outlet of the pump. 
     
     
         23 . A pulsation attenuation device, comprising:
 A natural gas pump having a variable operating speed;   a first loop having an outlet coupled to the pump, an inlet, and two fixed length branches therebetween, the first branch being longer than the second branch by an amount equal to half of a first primary wavelength within a range of wavelengths of vibrations propagating in a fluid discharged from the pump; and   a second loop having an outlet coupled to the first loop inlet, an inlet, and two fixed length branches therebetween, the first branch being longer than the second branch by an amount equal to half of a second primary wavelength that is different than the first wavelength and is within the range of wavelengths of vibrations propagating in the fluid discharged from the pump.   
     
     
         24 . The pulsation attenuation device of  claim 23 , wherein the second wavelength is not half of the first wavelength. 
     
     
         25 . The pulsation attenuation device of  claim 24 , wherein the two branches of the first loop are of approximately equal cross-sectional area. 
     
     
         26 . The pump pulsation attenuation device of  claim 25 , wherein the pump includes a reciprocating compressor. 
     
     
         27 . The pump pulsation attenuation device of  claim 23 , further comprising an outlet conduit having a first end coupled to the outlet of the first loop and a second end coupled to the pump.