Pumping Systems

Abstract

A system for pumping fluid, including a sequence of two or more positive-displacement sub-systems each having a respective one-way inlet. A respective one-way flow path links each adjacent two of the sub-systems. A one-way outlet from a last of the sub-systems is provided. The system is capable of a mode of operation in which at least some of the sub-systems are substantially in phase with respect to each other to cause the system to draw fluid from more than one of the one-way inlets; and another other mode of operation in which at least some of the sub-systems are substantially in antiphase with respect to each other to increment a pressure of the fluid as the fluid moves along the sequence.

1 . A system, for pumping fluid, comprising:
 a sequence of two or more positive-displacement sub-systems each having a respective one-way inlet;   a respective one-way flow path linking each adjacent two of the sub-systems; and   a one-way outlet from a last of the sub-systems;   the system being configured to operate in at least the following operating modes:   a first mode of operation in which at least some of the sub-systems are substantially in phase with respect to each other to cause the system to draw the fluid from more than one of the one-way inlets; and   one other a second mode of operation in which at least some of the sub-systems are substantially in antiphase with respect to each other to increment a pressure of the fluid as the fluid moves along the sequence.   
     
     
         2 . The system of  claim 1  wherein in the first mode of operation all of the sub-systems are substantially in phase with respect to each other. 
     
     
         3 . The system of  claim 1  wherein in the second mode of operation the sub-systems of each adjacent two of the sub-systems are substantially in antiphase with respect to each other to increment the pressure through each of the sub-systems. 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . The system of  claim 1  wherein at least one of the sub-systems has a variable stroke length. 
     
     
         8 . The system of  claim 7  wherein a ratio, of a stroke length of at least one of the sub-systems to a stroke length of another of the sub-systems downstream of the at least one of the sub-systems, is lower for the first mode than the ratio is for the second mode. 
     
     
         9 . The system of  claim 1  including a control arrangement configured to control at least some of the sub-systems to cause the system to operate in the first mode of operation and the second mode of operation. 
     
     
         10 . The system of  claim 9  wherein the control arrangement is configurable to cause the system to respond to feedback to deliver a target pressure when the system is in at least one of the first mode of operation or the second mode of operation. 
     
     
         11 . The system of  claim 9  wherein the control arrangement is configurable to cause the system to respond to feedback to deliver a target flow rate when the system is in at least one of the first mode of operation or the second mode of operation. 
     
     
         12 . The system of  claim 9 , wherein the control arrangement is configurable to cause the system to respond to feedback, to maximize a delivery of the system whilst maintaining one or more parameters of the system within one or more respective limits, when the system is in at least one of the first mode of operation or the second mode of operation. 
     
     
         13 . The system of  claim 9  wherein the control arrangement is configurable to cause the system to respond to feedback to transition from the first mode of operation to the second mode of operation. 
     
     
         14 . The system of  claim 9  wherein the control arrangement is configurable to cause the system to respond to feedback to equalize at least one parameter of at least one of the sub-systems with a corresponding parameter of at least one other of the sub-systems. 
     
     
         15 . (canceled) 
     
     
         16 . An arrangement, for pumping fluid, comprising:
 a first system as claimed in  claim 1 ;   a second system as claimed in  claim 11 ; and   pumps each of which comprises:
 a respective sub-system of the first system; 
 a respective sub-system of the second system; 
 a respective drive arrangement for driving the respective sub-systems in antiphase to each other. 
   
     
     
         17 . (canceled) 
     
     
         18 . A system, for pumping fluid, comprising:
 a first pumping chamber;   a second pumping chamber;   an outlet path for conveying output of the first pumping chamber and the second pumping chamber;   a control arrangement configured to:   when in a first mode of operation, operate the second pumping chamber substantially in antiphase to the first pumping chamber; and   when in a second mode of operation, operate the second pumping chamber substantially in phase with the first pumping chamber;   a fluid path connecting the first pumping chamber to the second pumping chamber to enable the first pumping chamber to supply power to the second pumping chamber when the second pumping chamber is operated in antiphase to the first pumping chamber; and   a mechanism by which the power is utilized to pump fluid.   
     
     
         19 . The system of  claim 18  including a third pumping chamber and wherein the mechanism comprises a transmission for transmitting the power to the third pumping chamber. 
     
     
         20 . The system of  claim 19  wherein the transmission is a reciprocally driven unit. 
     
     
         21 . The system of  claim 20  wherein the unit includes a screw and the system comprises:
 a nut engaged with the screw; and 
 a drive for rotationally driving the nut. 
 
     
     
         22 . The system of  claim 18  comprising:
 a one-way inlet, and a one-way outlet, associated with the fluid path such that operation of the second pump chamber in phase with the first pumping chamber pumps fluid from the one-way inlet to the one-way outlet. 
 
     
     
         23 . The system of  claim 18  wherein:
 the first pumping chamber and the second pumping chamber each have a respective one-way inlet; 
 the fluid path is a one-way fluid path from the first pumping chamber to the second pumping chamber; and 
 the second pumping chamber has a one-way outlet path. 
 
     
     
         24 . A system, for pumping fluid, comprising:
 a pressure space partly defined by:
 a first movable element; and 
 a second movable element; 
   a one-way inlet and a one-way outlet each associated with the pressure space;   a drive arrangement configured to:
 in a first mode of operation, move the first movable element and the second movable element substantially in phase with respect to each other to pump fluid from the one-way inlet to the one-way outlet; and 
 in a second mode of operation, move the first movable element and the second movable element substantially in antiphase with respect to each other so that the first movable element supplies power to the second movable element; and 
   a mechanism by which the power is utilized to pump fluid.   
     
     
         25 . A system for pumping fluid, comprising:
 two or more positive-displacement sub-systems; and   the system being configured to operate in the following operating modes:
 a first mode of operation, wherein at least some of the sub-systems are substantially in phase with respect to each other; and 
   a second mode of operation, wherein at least some of the sub-systems are substantially in antiphase with respect to each other to build more pressure than in the second mode of operation.   
     
     
         26 . (canceled) 
     
     
         27 . (canceled)