A FLUID PRESSURE DRIVEN PUMPING SYSTEM
TECHNICAL FIELD
This invention relates to a method and apparatus for transferring fluid from a source to a storage or usage point against head pressure and without the need for a power source at the fluid source.
BACKGROUND TO THE INVENTION
There are many situations in which it is necessary to transfer fluid to a higher point from a source where there is no electricity supply and to which there is no easy means of getting a generator. For example, many areas of farmland may have poor access but may offer a good supply of water or require occasional drainage. The cost of providing a permanent electricity supply to such sites is generally prohibitive, whilst transporting heavy equipment to the site may be difficult or impossible.
Conventional pumping systems positioned at the storage or usage site have generally involved compressed air to raise water from a source, or have been unable to overcome a head pressure of greater than 28 feet. Known hydraulic pumps (for example well-bottom pumps) are restricted in their ability to operate efficiently with different supply pressures. Moreover, they do not allow for variation in the ratios of supply to recovered fluid pressure, or supply to recovered fluid volumes.
Thus, it is an object of the present invention to provide a method and apparatus for pumping a fluid from a source to a storage or usage
point which overcomes some of the above mentioned problems, or which at least provides the public with a useful alternative.
Other objects of the present invention will become apparent from the following description which is given by way of example only.
DISCLOSURE OF THE INVENTION
According to one aspect of the present invention there is provided a pump adapted to pump fluid from a source to storage and/ or usage site(s) against a head pressure and without the need for a power source at the fluid source, said pump comprising:
drive means connectable by drive/return lines to a fluid pressure supply and one or more storage and/or usage site(s) remotely positioned from said drive means; valve means intermediate said drive means and said fluid pressure supply and one or more storage/usage site(s), and adapted to permit interconnection of the fluid pressure supply and the one or more storage/usage site(s), alternately, with each end of the drive means to enable a reciprocating drive; control means adapted to control the direction of flow of fluid through the valve means; and driven means interconnected to and driven in a reciprocating manner by said drive means, and having one or more inlet(s) positionable in or interconnectable to a fluid source, and one or more outlet(s) interconnectable
to the one or more storage/usage site(s), remote from said driven means, either separately or via a drive/return line;
and wherein said pump is adapted to enable adjustment of the ratio of a volume of the drive means to a volume of the driven means to enable the recovery of source fluid against different head pressures and/or with different supply fluid pressures.
In a preferred form of pump of the present invention the drive and driven means may comprise cylinders interconnectable in series, and having a common or interconnectable piston rod.
In a further preferred form the drive and driven means may comprise three cylinders in series, interconnectable to the valve means such that the two outer cylinders in combination form the drive means or the driven means, and the central cylinder alone forms the driven means or the drive means, respectively, such that the ratio of drive to driven cylinder volumes may be 2: 1 or 1 :2.
In a further preferred form of pump of the present invention the central cylinder and its associated piston may be replaceable such that a cylinder and piston of different diameter may be positioned between the outer cylinders, enabling further adjustment of the ratio of drive to driven cylinder volumes.
Preferably, control means of a pump of a present invention may comprise a mechanical valve or valves in a fluid line between said fluid pressure supply and said valve means, positioned adjacent an external end of at least one of said outer cylinders and triggered by an extension of said piston rod passing through an end of said outer cylinder(s), said mechanical valve(s) positioned so as to be triggered as pistons approach each end of the cylinders.
Preferably, the valve means may be mechanically operated and positioned adjacent the drive/driven means, remote from the fluid pressure supply.
In a further preferred form, the valve means may be a 4- port valve.
According to a further aspect of the present invention there is provided a method of pumping fluid from a source to storage and/or usage site(s) against a head pressure and without the need for a power source at the fluid source, said method comprising:
providing a fluid pressure supply, alternating the fluid pressure supply to opposite ends of drive means of a pump positioned in or adjacent the fluid source, via valve means,
controlling the operation of the valve means by control means, driving a driven means, in fluid communication with said fluid source, with said drive means to suck fluid from said source and pump it to a storage/usage site remote from said driven means, and enabling adjustment of the ratio of volume of drive to driven means.
In a preferred method of the present invention fluid from the pressure supply means may be kept separate from recovered source fluid.
In another preferred form the method may further comprise positioning both the valve means and the drive means adjacent the fluid source and remote from the pressure supply means.
Other aspects of the present invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 :
Shows a schematic representation of a pump system employing the principles of a pump of the present invention, and showing an outward stroke of the pump.
Fiqure 2:
Shows a schematic representation of the pump system of Figure
1 in a return stroke.
Figure 3:
Shows a schematic representation of one means of adjusting the ratio of the drive to driven cylinder volumes in one embodiment of the present invention.
Figure 4:
Shows a preferred embodiment of drive and driven cylinders in a pump of the present invention.
Figure 5:
Shows a schematic representation of a preferred embodiment of a pump of the present invention.
MODES FOR CARRYING OUT THE INVENTION
Figures 1 and 2 show a pump system, employing the principles of a pump of the present invention. This pump system may comprise a pressure supply means 2, directional control means 3, drive/return lines 4a, 4b, drive cylinder 5, driven cylinder 6 and storage tank 7.
The directional control means 3 may comprise a number of valves 8a, b, c, d, which, in the pump system shown in figures 1 and 2, are electronically controlled. In this system the directional control means 3 is positioned essentially at the top of the system, i.e., at
approximately the same height as the storage tank 7 and supply pump 2. Whilst a similar control means may be employed in a pump of the present invention, the preferred form of directional control means is a system of valves positioned at the bottom of the system controlled mechanically, i.e., substantially at the height of the source of fluid 22.
The drive/return lines 4a, 4b may comprise an outward line 4a and a return line 4b. Essentially, each drive/return line 4a, 4b may interconnect the pressure supply means 2, the drive cylinder 5, the driven cylinder 6 and the storage tank 7. Valves 8a, b, c, d in the directional control means 3 and non-return valves 9a, 9b in branches 10 of the drive/return lines 4a, 4b, enable fluid to pass along each drive line 4a, 4b either between the supply pump 2 and the drive cylinder 5 or between the driven cylinder 6 and the storage tank 7.
A non-return valve 1 1 may be positioned at the entrance to the storage tank 7.
A first chamber 1 2 of the drive cylinder 5 may be interconnected with outward line 4a, whilst a second chamber 1 3 may be interconnected with the return line 4b. The piston 14 has a common piston rod 1 5 with the piston 1 6 of the driven cylinder 6. It will be appreciated that other mechanisms are envisaged by which separate piston rods of the drive and driven cylinders may be coupled.
It will also be appreciated that the pistons of the drive and driven cylinders could be replaced by diaphragms, again with an appropriate means of coupling the diaphragms of each chamber.
The driven cylinder 6 may also have a first 1 7 and a second 1 8 chamber, the first chamber 17 being connected to the outward line 4a and the second chamber 18 to the return line 4b. Non-return valves 9a, 9b in branches 10 of the drive/return lines 4a, 4b allow the passage of fluid out of the driven cylinder 6 only. In addition, each chamber 1 7, 1 8 of the driven cylinder 6 may be connected via an inlet pipe 20 to suction inlet 21 which may be placed in the source of fluid 22. Non-return valves 23 may be positioned to prevent the return of fluid from the driven cylinder 6 to the source of fluid 22.
For the system to operate a supply pressure is required and this is provided by the pressure supply means 2 which may be any form of an existing pump such as a household on demand pump, a specially supplied pump, or simple mains pressure.
The functioning of a pump 1 in the form shown in figures 1 and 2 will now be described having regard first to the outward stroke (as shown Figure 1 ) and then the return stroke (as shown in Figure 2) .
With the valves 8a, 8c of the control means 3 closed, fluid from the pressure supply means 2 passes through valve 8b to outward line 4a and then to the first chamber 1 2 of the drive cylinder 5. The head pressure in the return line 4b acting on the second chamber 1 3 piston
surface 24 of drive cylinder 5 is counteracted by the same head pressure acting on first chamber 1 2 piston surface 25 from the fluid in the outward line 4a. Thus, the additional pressure provided by the pressure supply means 2 will drive piston 14 and rod 1 5 in the direction shown by arrow A of Figure 1 . Fluid will be forced up the return line 4b from the second chamber 1 3 of the drive cylinder 5, via a branch line 26, and also from the second chamber 1 8 of the driven cylinder 6 via a branch line 10. At the same time, fluid from the source 22 will be drawn through the suction inlet 21 via inlet pipe 20 to the first chamber 1 7 of the driven cylinder 6. Fluid forced up the return line 4b passes through open valve 8d and into storage tank 7.
At the end of an outward stroke the valve 8b between the pressure supply means 2 and the outward line 4a is closed, as is the valve 8d between the return line 4b and the storage tank 7. At the same time the valve 8a between the outward line 4a and the storage tank 7 is opened, as is the valve 8c between the pressure supply means 2 and the return line 4b. Thus, in the return stroke, as shown in Figure 2, the additional pressure from the pressure supply means 2 is applied to the drive cylinder 5 via the return line 4b. The pistons 14, 1 6 of the drive 5 and driven 6 cylinders are caused to move in the direction shown by arrow B in Figure 2, and fluid is drawn up into the second chamber 1 8 of the driven cylinder 6 from the source 22 via the suction inlet 21 . Fluid drawn into the driven cylinder 6 during the previous outward stroke is forced through branch 1 0 of the outward line 4a to join the fluid expelled from the first chamber 1 2 of the drive
cylinder 5, passing up the outward line 4a through valve 8a to the storage tank 7.
Referring now to Figure 4. This figure shows a preferred embodiment of the drive and driven cylinders of a pump of the present invention. In one configuration there is a single structure comprising a central driven cylinder 41 with separate drive cylinders 42, 43 at either end of the driven cylinder 41 . The pistons 44a, b, of the cylinders have a common piston rod 45. Again it is envisaged that the cylinders and pistons may be replaced with spherical chambers and diaphragms.
The driven cylinder 41 is connected to the source 22 and may operate in precisely the same manner as in the configurations of Figures 1 and 2.
The drive cylinders 42, 43 also each operate in a manner similar to the drive cylinder of Figures 1 and 2 with the drive lines 46 alternating the supply of pressure to opposite sides of pistons 44a of each drive cylinder 42, 43. Branches of each drive line 46 may be connected to the inlet/outlet 50 of the opposite drive cylinder. Contact of a drive piston 44a with control means 49, which may for example be magnetically operated, would then initiate reversal of the system, to drive the pistons in the opposite direction.
With such a configuration each drive piston 44a may be driven from both sides, alternately. Thus, with pistons 44a, b of common
dimensions there is a 2: 1 ratio of drive to driven displaced volumes of fluid.
It will be appreciated that with rearrangement of connections to the various inlets and outlets to the cylinders, the central cylinder 41 can operate as the drive cylinder and the outer cylinders as driven cylinders. The ratio of drive to driven displaced volumes of fluid then becomes 1 :2, given common dimensions of pistons.
The ratio of diameters of drive to driven cylinders may vary according to the pumping head required and the output pressure available from the pressure supply means 2.
In the preferred embodiment of Figures 4 and 5 the diameter of the central section piston 44b and cylinder 41 may be changed in relation to the diameters of the outer pistons 44a and cylinders 42, 43 to accommodate the available supply pressure and the required output pressures or volumes. This is achieved by the three cylinders being separable and connected by connecting means (not shown), so that the central cylinder 41 may be removed and replaced with a cylinder of different diameter. The central piston 44b would likewise be removed and replaced with a piston of corresponding diameter.
Where the head pressure is low relative to the available pressure supply means a pump of the present invention may be driven via the single central cylinder, which may also have a cylinder and piston of smaller diameter than the driven cylinders. This makes it possible to
use a lower volume of high pressure fluid as the driving medium to move a larger volume of source fluid against a lower head pressure. The reverse configuration may be employed where the supply pressure is low in comparison with the head pressure.
The total output volume of a pump of the present invention is dependent on the pressure and volume capabilities of the pressure supply means 2, as well as the speed of cycle of the drive cylinder(s) as determined by the control means 3.
Where the pressure supply means is provided by the domestic household water supply priority will be maintained for the household supply over the supply to the pump since once a tap is opened in the house the resulting pressure drop will cause the drive cylinder(s) to stop until the pressure rises again.
In the preferred embodiment of the invention shown in Figure 5 the directional control means may comprise a directional control valve 51 positioned adjacent the drive and driven cylinders rather than at the pressure supply means. In this configuration the directional control valve 51 might, for example, be a pneumatic-style multi-port valve having at least 4 ports mounted on or adjacent the drive and driven cylinders. A single pressure line 52 would be connected to a first port
53 of the valve from the pressure supply means, whilst a second port
54 would be connected by a return line or lines 55 to the storage or usage point.
Drive/return lines 46 would connect third 56 and fourth 57 ports of the directional control valve 51 to opposite ends of one or more drive cylinders (depending on whether the one or two drive cylinder configuration is required) . Where there is more than one drive cylinder each line is branched, as in Figures 4 and 5.
Mechanical control valves 58, for example of a roller-type, positioned outside one end of the cylinder arrangement, and operated by an extension 59 of the piston rod 45 passing through that end of the cylinder arrangement, control the change over of the port interconnections in the directional control valve 51 . These mechanical control valves 58 are positioned in a fluid line 61 between the main pressure line 52 and the directional control valve 51 (as shown in Figure 5). The first port 53 is thus alternately connected to the third 56 and fourth 57 ports, and the second port 54 is alternately connected to the fourth 57 and third 56 ports, respectively. An additional mechanical control valve 62 may be connected in series with the other mechanical control valves 58, between those valves 58 and the directional control valve 51 . This additional valve 62 and its fluid line interconnections are shown in Figure 5 in dashed lines.
The outlets from the driven cylinder(s) 41 will always be connected to a retum line 60, which may join the return line 55 carrying supply fluid, or may be separate, depending on whether or not it is necessary to keep the source and supply fluids separate.
Where it is not necessary to recover the fluid from the pressure source, as for example with the use of a natural source such as from a piped waterfall or a used or contaminated fluid supply, then outlets from the drive cylinder may simply discharge the fluid from the pressure source substantially at the level of the fluid source.
Whilst the invention has been described with particular reference to a drive/driven cylinder configuration involving 3 cylinders, it will be appreciated that the invention is not limited to this number, and indeed more cylinders may be positioned in series and with a common or interconnecting piston rod.
It will also be appreciated that a pump of the present invention may be regulated by the inclusion of, for example, ball cock systems at the storage or usage points. For example, a ball cock on the storage tank or on animal troughs would close when the tank or trough was full, increasing back pressure on the drive or driven cylinder and thus stopping the pump until the ball cock opens again.
A plurality of branch lines may be taken off return lines to supply fluid to a number of different points (e.g., a series of animal troughs on farmland). A non-return valve would be preferred in each branch line and a valve means ( e.g. a ball cock) could be provided at each point to regulate the supply of fluid to that point.
Providing the cylinder diameters are kept small, a pump of the present invention, in an alternative embodiment, may be used to raise
th e fluid from a well or bore casing. In such a situation the pump cylinders would be lowered into the well or bore casing.
In an alternative embodiment of the present invention drive 5 and driven 6 cylinders may have the same dimensions, and a ratio between the volume of the cylinders may be created by introducing a lever mechanism interconnecting the two separate piston rods. For example, as shown in Figure 6, drive cylinder 5 may be positioned in a lower part 31 of a steel frame 32, with an end 38 of its piston rod 33 connected to a lower end 34 of a vertically disposed lever 35. The upper end 36 of this lever 35 may be pivoted at a top part 37 of the frame 32. The driven cylinder 6 may be positioned in an opposite side of the frame 32, and its position may be adjusted vertically in relation to the lever 35, again with an end 39 of the piston rod 40 connected to the lever 35.
With this configuration, when the drive cylinder 5 is driven, the lever 35 is caused to pivot to and fro about its pivot point. This movement of the lever 35 is transferred to the piston rod 40 of the driven cylinder. The ratio of the movement of the drive cylinder piston to that of the driven cylinder piston will, therefore, vary according to the vertical position of the driven cylinder in the frame 32. Irrespective of the position of the driven cylinder 6, the forces applying on each piston are essentially unchanged.
Whilst the invention has been described by way of example, and with reference to the preferred embodiments shown in the figures it
will be appreciated that the invention is not limited to these embodiments. Modifications and variations may be made thereto without departing from the scope of the invention as described in the following claims.