Pumping system

Abstract

A high pressure pumping system in which a first pump delivers a medium to a discharge port and to a second pump which subsequently delivers the medium to the discharge port.

1 . A liquid pumping system which includes:
 (a) a liquid transfer pump arrangement ( 12 ) which includes a liquid inlet port ( 54 ), a liquid discharge port ( 66 ), a first pump chamber ( 28 ) with a first maximum volume, a first non-return valve ( 56 ) connected to and between the liquid inlet port ( 54 ) and the first pump chamber ( 28 ), a first control device ( 30 ) for pumping liquid from the first pump chamber ( 28 ), a second pump chamber ( 50 ) with a second maximum volume, wherein the second maximum volume is at least half the size of the first maximum volume, the second pump chamber ( 57 ) being connected to the liquid discharge port ( 66 ), a second non-return valve ( 67 ) connected to, and between, the first pump chamber ( 28 ) and the second pump chamber ( 50 ) and a second control device ( 46 ) for pumping liquid from the second pump chamber ( 50 ),   (b) a hydraulic fluid constant flow pump ( 72 ), and   (c) control structure ( 100 ) which, responsive to liquid flow rates from each pump chamber ( 28 ,  50 ), directs hydraulic fluid to the first and second control devices ( 30 ,  46 ) at respective controlled rates whereby, upon actuation of the first and second control devices ( 30 ,  46 ), in a cyclical manner:
 (1) liquid is expelled from the first pump chamber ( 28 ) through the second non-return valve ( 60 ):
 (1.1) at a controlled delivery rate to the liquid discharge port ( 66 ), and 
 (1.2) into the second pump chamber ( 50 ), and, thereafter, 
 
 (2) liquid is directed from the liquid inlet port ( 54 ) through the first non-return valve into the first pump chamber ( 28 ), and liquid is expelled from the second pump chamber ( 50 ) at said controlled delivery rate to the liquid discharge port ( 66 ). 
   
     
     
         2 . A pumping system according to  claim 1  wherein the first pump chamber ( 28 ) is formed by a first cylinder ( 24 ) and a first piston ( 26 ) which is reciprocally movable inside the first cylinder ( 24 ), and the second pump chamber ( 50 ) is formed by a second cylinder ( 40 ) and a second piston ( 46 ) which is reciprocally movable inside the second cylinder ( 40 ). 
     
     
         3 . A pumping system according to  claim 2  wherein, in response to the control structures ( 30 ,  44 ,  33 A,  44 A,  88 ,  90  and  100 ) the first piston ( 26 ) and the second piston ( 42 ) simultaneously execute delivery strokes to provide a pulseless delivery flow from the discharge port ( 66 ) during a pumping cycle. 
     
     
         4 . A pumping system according to  claim 1  wherein each pump chamber ( 28 A,  28 B;  50 A,  50 B) is partly formed by a respective bellows or diaphragm ( 26 A,  26 B;  42 A,  42 B). 
     
     
         5 . A pumping system according to  claim 4  wherein the liquid medium to be pumped is directed into an interior of the bellows, and the hydraulic power medium is directed to a space between a wall of a cylinder and the bellows. 
     
     
         6 . A pumping system according to  claim 4  wherein the hydraulic power medium is directed into an interior of the bellows and the medium to be pumped is then displaced from a space between a wall of a cylinder and the bellows as the bellows is expanded. 
     
     
         7 . A pumping system according to  claim 1  wherein each control device ( 30 ,  44 ,  46 ) comprises a respective piston and cylinder assembly. 
     
     
         8 . A pumping system according to  claim 7  wherein the control devices ( 30 ,  44 ,  98 ,  90  and  100 ) maintain a desired pressure balance between the hydraulic power medium and the medium which is pumped. 
     
     
         9 . A pumping system according to  claim 2  wherein each control device ( 30 ,  44 ,  46 ) comprises a respective piston and cylinder assembly. 
     
     
         10 . A pumping system according to  claim 3  wherein each control device ( 30 ,  44 ,  46 ) comprises a respective piston and cylinder assembly. 
     
     
         11 . A pumping system according to  claim 4  wherein each control device ( 30 ,  44 ,  46 ) comprises a respective piston and cylinder assembly. 
     
     
         12 . Pumping system according to  claim 5  wherein each control device ( 30 ,  44 ,  46 ) comprises a respective piston and cylinder assembly. 
     
     
         13 . A pumping system according to  claim 6  wherein each control device ( 30 ,  44 ,  46 ) comprises a respective piston and cylinder assembly.