WO1999066211A1

WO1999066211A1 - Hydraulic valve assembly

Info

Publication number: WO1999066211A1
Application number: PCT/AU1999/000483
Authority: WO
Inventors: John Oswald William Bamford
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-06-17
Filing date: 1999-06-16
Publication date: 1999-12-23
Anticipated expiration: 2000-12-17

Abstract

A hydraulic ram valve assembly has a chamber (30) with an inlet port (31) for communicating with an elevated source of fluid and a waste port (33). A waste valve housing (35) extends upwardly from and communicates with the waste port (33). The waste valve housing (35) has an outlet (36) at an upper end thereof. A waste valve element (6) is disposed in the waste valve housing (35) between the waste port (33) and a first waste valve seat (37) defined by the waste valve housing outlet (36). A waste pipe (10) extends upwardly from and communicates with the waste valve housing outlet (35). A replaceable elongate member (7) is disposed in the waste pipe (10) and extends into the waste valve housing (35). The elongate member (7) is vertically displaceable within the waste pipe (10) independently of the waste valve element (6).

Description

HYDRAULIC VALVE ASSEMBLY

Field of the Invention

The current invention relates to a hydraulic valve assembly, and in particular relates to a hydraulic ram type valve assembly which is operated by the flow of a fluid, so that its operation converts part of the energy of the fluid into useful work.

Background to the Invention

Various methods of pumping water are known. However, for remote applications common electrically powered pumps are unsuitable where electricity is not available, and other traditional pumping equipment is unsuitable where the cost of installation, maintenance and operation is prohibitive.

Another method of pumping water which does not rely on electrical power and expensive equipment utilises the energy of water flowing from a small head of pressure to pump some of that water to a higher head of pressure above the source of the water. Water can be pumped in this manner utilising what is known as a hydraulic ram pump. The hydraulic ram pump makes use of the fundamental relationship between the change of velocity and the change of pressure of a fluid. Put simply, if the flow of fluid in a pipe is suddenly stopped, there will be a sudden increase in pressure. This is manifested in what is known as "water hammer" in household water pipes. It is this sudden increase in pressure created in an hydraulic ram pump which enables it to drive a portion of fluid to a high pressure or head.

Hydraulic ram pumps however, lack flexibility in that they can not be readily adjusted for different pumping tasks delivering water to different heads of pressure at different flow rates, or for different input flow rates operating them. As a result, a large head of pressure required to be pumped to may not be achievable with a given hydraulic ram pump. Alternatively, for situations where water is only required to be pumped to a small head of pressure, the power produced by the hydraulic ram pump may be excessive such that a delivery flow rate much larger than that required is produced, with an associated large amount of water being wasted in producing that power. Current hydraulic ram pumps also lack flexibility in that they are not typically configured to provide work output other than by the pumping of water.

Object of the Invention

It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. Summary of the Invention

In one broad form the present invention provides an hydraulic ram valve assembly comprising: a chamber having an inlet port for communicating with an elevated source of fluid and a waste port, a waste valve housing extending upwardly from and communicating with said waste port, said waste valve housing having an outlet at an upper end thereof, a waste valve element disposed in said waste valve housing, said waste valve element being displaceable within said waste valve housing between said waste port and a first waste valve seat defined by said waste valve housing outlet, a waste pipe extending upwardly from and communicating with said waste valve housing outlet, a replaceable elongate member disposed in said waste pipe and extending into said waste valve housing, said elongate member being vertically displaceable within said waste pipe independently of said waste valve element.

Preferably said waste port defines a second waste valve seat. Preferably said elongate member is a tube.

The tube may be provided with at least one transverse hole towards a lower end thereof. Alternatively said elongate member is a solid rod.

Preferably said waste valve element is a ball.

Alternatively said waste valve element is a poppet type valve element. The elongate member may be provided with a collar towards an upper end thereof for engaging an upper end of said waste pipe so as to limit displacement of said elongate member.

The hydraulic ram valve assembly may be configured as a hydraulic ram pump and further comprise: a delivery port provided in said chamber, and a one-way delivery valve element cooperable with a delivery valve seat defined by said delivery port for enabling flow of fluid from said chamber through said delivery port.

In one embodiment, the chamber may be provided with a one-way air inlet valve for ingestion of air into said chamber when pressure therein falls below atmospheric pressure. In such an embodiment said hydraulic ram valve assembly may further comprise an upwardly extending air vessel communicating with said delivery port downstream thereof.

Alternatively said hydraulic ram valve assembly may further comprise a pressure cell communicating with said delivery port downstream thereof. Additionally or alternatively to being configured as a hydraulic ram pump, the hydraulic ram valve assembly may be configured to produce useful mechanical work.

In such a configuration, said elongate member may be connected to a load for converting reciprocating motion of said elongate member during operation of said hydraulic ram valve assembly into useful work.

Alternatively, said chamber may be communicated with a cylinder housing a reciprocating piston for converting pressure fluctuations in said chamber during operation of said hydraulic ram valve assembly into useful work.

Typically, said reciprocating piston will be spring biased toward said chamber.

Brief Description of the Drawings

Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic cross-sectional front elevation view of a water pumping installation including a hydraulic ram valve assembly. FIG. 2 is a cross-sectional front elevation view of a hydraulic ram valve assembly.

FIG. 3 is a cross-sectional front elevation view of a hydraulic ram valve assembly similar to that of FIG. 2, modified to allow the addition of air into the cycle of operation. FIG. 4 is a cross-sectional front elevation view of a hydraulic ram valve assembly similar to that of FIG. 2, modified to provide a mechanical output.

FIG. 4a is a cross sectional front elevation view of the hydraulic ram valve assembly of Figure 4 modified to provide only a mechanical output.

FIG. 5 is a cross-sectional front elevation view of a hydraulic ram valve assembly similar to that of FIG. 2, modified to vary the operating characteristics thereof.

FIG. 6 is a cross-sectional front elevation view of a hydraulic ram valve assembly similar to that of FIG. 2 with a modified waste valve element.

FIG. 7 is a cross-sectional front elevation view of a hydraulic ram valve assembly similar to that of FIG. 4, with an alternate modification to provide a mechanical output.

Detailed Description of the Preferred Embodiments

Referring to Figure 1, a water pumping installation is depicted utilising the hydraulic ram valve assembly 1 according to a preferred embodiment to pump water. Water from the source 2, which is at a height above the hydraulic ram valve assembly

1 , flows through an inlet pipe 3 to the hydraulic ram valve assembly at a low head (or pressure). The energy in this water flow is used by the hydraulic ram valve assembly 1 to pump some of the water through the delivery pipe 4 to a greater head (or pressure). Water going into the delivery pipe 4 can therefore be raised, for example, into a storage tank 5 higher than the source of water 2. This basic set up and principle of operation of the pumping installation is generally the same as that of known hydraulic ram installations.

Figure 2 depicts a preferred embodiment of the hydraulic ram valve assembly 1 configured to work as a hydraulic ram pump. The hydraulic ram valve assembly 1 has a chamber 30 with an inlet port 31 for communicating with the elevated source of fluid via the inlet pipe 3, a delivery port 32 communicating with the delivery pipe 4 and a waste port 33.

A one-way delivery valve element 8 is cooperable with a delivery valve seat 34 defined by the delivery port 32 for enabling flow of fluid from the chamber 30 through the delivery port 32, whilst preventing flow back into the chamber 30 through the delivery port 32. Here the delivery valve element is in the form of a ball 8, which seals against the end of a nipple 9 forming the delivery port 32 and delivery valve seat 34. Other typical forms of one-way delivery valve, however, are envisaged including one way flapper and poppet valves. If the hydraulic ram valve assembly 1 is not configured as a pump, the delivery port 32, delivery valve element 8 and associated features need not be employed, as will be discussed below. A waste valve housing 35 extends upwardly from and communicates with the waste port 33. The waste valve housing 35 has an outlet 36 at the upper end thereof. A waste valve element 6 is disposed in the waste valve housing 35 and is displaceable within the waste valve housing 35 between the waste port 33 and a first waste valve seat 37 defined by the waste valve housing outlet 36. Here the waste valve element 6 is in the form of a ball 6 which seals against a bush 11 forming the waste valve housing outlet 36 and the first waste valve seat 37. Other suitable forms of waste valve element 6 are envisaged, so long as the waste valve element is displaceable between the waste port 33 and waste valve housing outlet 36. Such a suitable alternative waste valve element would be a poppet valve element 106 as depicted in Figure 6. A waste pipe 10 extends upwardly from and communicates with the waste valve housing outlet 36. Here the waste pipe 10 is secured to the waste valve housing 35 via the bush 11 , enabling ready removal of the waste pipe 10, however it is envisaged that the waste pipe 10 could be integrally formed with, or fixedly secured to the waste valve housing 35. A replaceable elongate member 7, here in the form of a tube, is disposed in the waste pipe 10 and extends into the waste valve housing 35. The elongate member 7 is vertically displaceable within the waste pipe 10, and here rests on the waste valve ball 6. The elongate member 7 can here be accessed for replacement by removing the waste pipe 10 from the bush 11. In embodiments where the waste pipe 10 is integrally formed with, or fixedly secured, to the valve housing 35, the elongate member 7 can be removed by a tool constructed for this purpose. Provision of the waste pipe 10 and replaceable elongate member 7 allows the operating characteristics of the hydraulic ram valve assembly 1 to be controlled through replacement of the elongate member 7 with a different elongate member 7, as is discussed below.

During operation of the hydraulic ram valve assembly 1 , the waste valve ball 6 and elongate member 7 will both move up and down. The waste valve ball 6 and elongate member 7 are not connected to each other, and do not always remain in contact with each other during all parts of each operating cycle. In normal operation of the hydraulic ram valve assembly 1 , one cycle of operation can be regarded at starting when the waste valve ball 6 is at its lowest point, at the waste port 33, and no water is passing through the hydraulic ram valve assembly. At this moment, the elongate member 7 will be at or close to the lowest point to which it can go within the hydraulic ram valve assembly, and will be in contact with or close to waste valve ball 6.

At the start of the cycle of operation being described, delivery valve ball 8 will be seated on the delivery valve seat 34 sealing the delivery port 32 against any backflow of water into the chamber 30.

As the operating cycle commences, the inlet water pressure of water flowing into the chamber 30 through the inlet port 31 will lift the waste valve ball 6 slightly so that water starts to flow past the waste valve ball 6, through the waste valve housing 35 and up the waste pipe 10 to exit the hydraulic ram valve assembly 1. At this point in the operating cycle, water will not flow past the delivery valve ball 8. This is because water pressure in the delivery pipe 4, created by the head of water in the delivery pipe 4 which has not as yet reached the storage tank 5, will act on the top of the delivery valve ball 8 to urge it against the delivery valve seat 34, making it easier for water flowing into the chamber 30 through the inlet port 31 to flow past the waste valve ball 6.

As water flows past the waste valve ball 6, the velocity of the water increases the force that is available to lift the waste valve ball 6. This raises the waste valve ball 6 further, and increases the area through which water can flow. The consequent increased flow of water further increases the lifting force, so that the waste valve ball 6 is further raised with another increase in the flow of water. The result of this is that the waste valve ball 6 and elongate member 7 are progressively raised, with an increasing flow of water to waste from the top of the waste pipe 10.

As the waste valve ball 6 is lifted vertically, it will lift elongate member 7 with it. The waste valve ball 6 can only rise vertically until it reaches the first waste valve seat 37 formed by the bush 11. The elongate member 7 is not stopped by the bush 11 as is the waste valve ball 6, and when the upwards velocity is sufficient the elongate member 7 will lose contact with the waste valve ball 6 and continue upwards for a further distance within the waste pipe 10.

When the waste valve ball 6 reaches and seals against the first waste valve seat 37, the flow of water through the chamber 30 and the waste valve housing 35 will be stopped very suddenly. This causes the water pressure below the waste valve ball 6 to increase very suddenly. For a short while, the pressure below the waste valve ball 6 will be higher than the static inlet pressure at the inlet port 31 that corresponds to the head of water from the water source 2 driving the hydraulic ram valve assembly 1. This higher pressure will act upon the underneath of the delivery valve ball 8, and cause it to unseat from the delivery valve seat 34 to briefly open the delivery port 32 so that water flows into the delivery pipe 4 until the pressure on top of and below the delivery valve ball 8 are nearly equal. It is therefore possible to lift water through the delivery pipe 4 to a greater height than the height of the water source 2 driving the hydraulic ram valve assembly. When a flow of water is stopped suddenly as just described, the initial effect is the sudden pressure increase already referred to. Depending on the nature of the inlet pipe 3 and the means whereby the flow of water was suddenly stopped, there can be a subsequent effect so that the pressure then falls below atmospheric pressure near to where the water flow was suddenly stopped. This effect occurs in the chamber 30 of the hydraulic ram valve assembly 1.

As the cycle of operation continues, the water pressure in the chamber 30, below the waste valve ball 6 and the delivery valve ball 8, will therefore decrease. When the pressure below the delivery valve ball 8 is less than the pressure in the delivery pipe 4, the delivery valve ball 8 will seat on the delivery valve seat 34 to seal the delivery port 32 and prevent water flowing back from the delivery pipe 4. As the pressure below the waste valve ball 6 further decreases, the waste valve ball 6 will unseat and fall away from the first waste valve seat 37 and drop through the waste valve housing 35 towards the waste port at the top of the nipple 12. The pressure at which the waste valve ball 6 begins to drop is influenced by its mass, the mass of the elongate member 7, whether or not the elongate member 7 had left contact with the waste valve ball 6, and the weight of water trapped in the waste pipe 10 above the waste valve ball 6. The point at which the waste valve ball 6 will fall away from the first waste valve seat 37 is also influenced by the degree to which the pressure in the chamber 30 falls below atmospheric pressure. At this point in the cycle, the waste valve ball 6 and the delivery valve ball 8 will both be in their lowest positions. However, the pressure in the chamber 30 can still continue to fall, so that it will go below atmospheric pressure if it has not already reached such a level. With the waste valve ball 6 resting on the nipple 12 at the waste port 33 and the delivery valve ball 8 seated on the delivery valve seat 34, the water pressure below in the chamber 30 will start to increase as water flows again from the inlet pipe 3 through the inlet port 31. This becomes the start of another cycle of operation. Once started the operation is self-sustaining, so that in this example water continues to be pumped from a low head to a higher head.

The above description of the operation of the hydraulic ram valve assembly 1 is for a normal operating cycle, when there is a pressure or head of water in the delivery pipe 4. When operation is first commenced with no water in the delivery pipe 4, it may be necessary to operate the hydraulic ram valve assembly 1 manually for a few cycles to build up sufficient pressure in the delivery pipe 4 to make operation self sustaining. Pushing the elongate member 7 down, and then releasing it can do this.

The time for each cycle of operation of the hydraulic ram valve assembly 1 can vary greatly depending on the individual design and the circumstances of operation. However, to give some indication of the nature of self-sustaining operation, some hydraulic ram valve assemblies in the role of pumping water will operate at about 60 cycles of operation a minute.

The hydraulic ram valve assembly 1 is capable of pumping water or other fluids to high pressures. However, the amount and pressure of the fluid going into the hydraulic ram valve assembly 1 determine the amount of useful work that can be achieved. As a consequence, the amount of useful fluid going into the delivery pipe will be reduced where there is an increase in height or pressure to which the useful fluid must go.

The pressure or head to which water from a fixed source can be pumped by the hydraulic ram valve assembly 1 is dependant on the flow rate of water through the inlet port 31 into the chamber 30 and out the waste port 33 to waste at the point in the cycle of operation where the waste valve ball 6 lifts to reach and seal against the first waste valve seat 37, suddenly stopping the flow of water through the chamber 30. An increase in the flow rate to waste will provide an increase in the delivery power of the hydraulic ram valve assembly, providing an increased potential pressure or head to which water can be pumped. If the potential pressure is greater than that needed to deliver the required amount of water against the head of water and pipe friction losses in the full delivery pipe 4, the excess power will provide an increased flow rate through the delivery port 32 and delivery pipe 4. In situations where a high flow delivery flow rate is not desired, however, this excess power will be wasted, and the extra water going to waste delivering the excess pressure will be wasted. In other circumstances, it may be desirable to increase the delivery flow rate whilst still pumping the water to the same head. Provision of the replaceable elongate member 7 provides a simple means by which to adjust the delivery power of the hydraulic ram 1 to suit a given situation where water is to be pumped to a given head at a given flow rate. Replacing the elongate member 7 with another elongate member of greater mass, and / or replacing the waste valve ball 6 with a waste ball valve of greater mass will increase the force needed to lift the waste ball valve 6 through the waste valve housing 35 to seat against the first waste valve seat 37. Provision of this greater lifting force will require a greater flow of water through the chamber 30 to act on the waste valve ball 6. A greater power output is hence produced, albeit with a greater waste of water through the waste pipe 10.

The increased flow of water through the chamber 30 at the point of sudden flow stoppage to give greater delivery power can also be provided by increasing the flow path area through the waste pipe 10. This will reduce the restriction to flow through the waste pipe 10 which in turn will result in a larger flow being required to develop a sufficient pressure differential to lift the waste valve ball 6 against the first waste valve seat 37. Increasing the flow path area can be achieved by replacing the elongate member 7 with another elongate member of reduced diameter area so as to increase the flow path between the elongate member 7 and the waste pipe 10.

Increasing the diameter of the waste pipe 10 will have a similar effect. The elongate member 7 is typically a hollow tube 7 so as to provide an additional flow path within the tube 7 for flow of water to waste. Water can enter the hollow of the tube 7 when (and if) the tube 7 lifts from the waste valve ball 6, at the junction of the tube 7 and the waste valve ball 6 if a seal is not created between the two, or through transverse holes which are typically provided toward the lower end of the tube 7 to communicate with the hollow interior of the tube. Increasing the number of holes in the tube 7 will increase the flow path into the hollow interior of the tube reducing the waste flow restriction and providing for increased power output. A single tube can thus be modified with the provision of extra holes, or a series of alternate tubes provided to fine tune the hydraulic ram valve assembly for the input conditions and output requirements.

It has been found, however, that a point is reached where the provision of further holes or further increasing the clearance between the elongate member 7 and the waste pipe 10 will prevent the waste valve ball 6 from lifting at all such that the hydraulic ram valve assembly 1 will not operate. It is also believed that the proportion of waste water flowing within the tube 7 as opposed to through the space between the tube 7 and the waste pipe 10 effects the operating characteristics of the hydraulic ram valve assembly 1.

Whilst a hollow tube is preferred, the elongate member 7 could also be a solid rod, with adjustment being provided through variation in diameter and mass of replacement rods. Changing the length of the elongate member 7 will also have some effect on the power output of the hydraulic ram valve assembly 1 , with a shorter elongate member 7 resulting in a reduced flow path restriction toward the top of the waste pipe 10 which may be sufficient to increase the waste flow rate required to lift the waste valve ball 6.

Figure 5 depicts a further modification of the hydraulic ram valve assembly 1 which can be used to control its operating characteristics. The elongate member / tube 23 is here provided with a collar 24 towards an upper end thereof for engaging an upper end of the waste pipe 10. The collar 24 is able to support the weight of the elongate member 23 when necessary in the operation of the hydraulic valve. The upper end of the waste pipe 10 is provided with a socket 25 which is attached using screw threads, so that the distance from the top of the waste valve ball 6 to the top of the socket 25 can be adjusted by rotating the socket 25. A lock nut 26 is used to retain the socket 25 in the desired position. By a means such as the elongate member 23 and the socket 25 , it is possible to control the downward movement of the elongate member 23 so that its lower end does not go below a set distance relative to the waste valve ball 6. Referring to Figure 5, the adjustment of the socket 25 as shown gives a space 27 between the waste valve ball 6 and the tube 23 when they are both in their lowest position. The availability of an adjustment such as this makes it possible to preset the space 27 that exists between the waste valve ball 6 and the tube 23 at the start of the cycle of operation of the hydraulic ram valve assembly 1.

For given conditions of operation, as the space 27 is increased in a particular hydraulic ram valve assembly 1, the waste flow path is increased enabling more water to flow through the hollow of the tube 23 and thereby increase the total waste water flow rate so as to increase the delivery power output of the hydraulic ram valve assembly 1 in a similar manner to as discussed above.

A further possible modification involves the use of a gate valve or other means of controlling the flow of fluid placed at the top of the waste pipe 10 to replace the socket 25 depicted in Figure 5. In this way the amount of fluid going to waste can be adjusted to a suitable amount.

It is also possible to provide other paths for fluid going to waste, for example, by holes through the side of the waste pipe 10. Alternative pipe connections (not shown) can be used near the base of the waste pipe 10 so that more precise control of waste fluid flows is possible.

While the hydraulic ram valve assembly 1 and associated parts shown in Figure 2 are constructed from a number of individual components, most of which are standard fittings and which enable simple assembly and disassembly for internal access, it is possible to combine all the functions within a more integrated and specialised housing. However, the operating principles remain the same, and the construction shown in Figure 2 is merely one preferred arrangement of components.

The various parts of the hydraulic ram valve assembly 1 and associated components can be made of metal, plastic or other suitable materials, provided the strength and durability is satisfactory for the application in which the hydraulic ram valve assembly 1 is used.

The arrangement shown in Figure 2 is a relatively simple example of the operation of the hydraulic ram valve assembly. By the addition of other components and the use of alternative components, it is possible to improve the suitability of the hydraulic ram valve assembly for particular applications or in particular circumstances.

Figure 3 depicts a modified version of the hydraulic ram valve assembly again arranged to work as a water pump, but configured to add air into the cycle of operation and to then make use of this air. The chamber 30 is provided with a one-way air inlet valve for ingestion of air into the chamber 30 when pressure in the chamber falls below atmospheric pressure. The plug 14 depicted in Figure 2 is replaced with a bush 15, elbow 16, air inlet valve ball 17, and bush 18. The bush 18 forms an air inlet valve seat 38 against which the air inlet valve ball 17 seals to form the one-way air inlet valve. Other known forms of one-way valve could also be utilised. An upwardly extending air vessel 19 is also provided, communicating with the delivery port 32 on the downstream side thereof. The air vessel 19 replaces the plug 13 depicted in the embodiment of Figure 2.

As described above, in operation of the hydraulic ram valve assembly 1, the pressure in the chamber 30 below the delivery valve ball 8 will fall below atmospheric pressure during one part of the cycle of operation. When this occurs, the atmospheric air pressure below the air inlet valve ball 17 will be greater than the pressure above it in the chamber 30. The greater air pressure below the air inlet valve ball 17 will lift it from the air inlet valve seat 38 and allow air to go upward and past the air inlet valve ball 17 into the fluid above the air inlet valve ball 17 in the chamber 30. To minimise the pressure within the chamber 30 so as to maximise the ingestion of air, it is preferred that the nipple 12 forms a second waste valve seat at the waste port 33, sealing the waste port 33 when the waste valve ball 6 is in its lowermost position against the nipple 12. This seal will help create a vacuum in the chamber 30 and prevent water in the waste pipe 10 being drawn back into the chamber 30 rather than air through the air inlet valve. When the pressure above the air inlet valve ball 17 returns to greater then atmospheric pressure during other parts of the cycle of operation, the air inlet valve ball

17 will remain seated on the air inlet valve seat 38 to prevent the exit of water.

Air entering through the operation of the air inlet valve ball 17 will rise as bubbles in the water that is pumped through the delivery port 32 by operation of the hydraulic ram valve assembly 1. Air going through the delivery port 32 past the delivery valve ball 8 will then either go upwardly into the air vessel 19, or remain with the water going into the delivery pipe 4. By this means the air vessel will partly or wholly fill with air, and be replenished as necessary with additional air. Apart from fluctuations arising from the cycle of operation, the air in the air vessel 19 will be at a pressure corresponding to the water pressure immediately downstream of the delivery port 32.

The presence of air under pressure such as in the air vessel 19 can provide various benefits. Useful fluid can only go past the delivery valve ball 8 when the pressure in the chamber 30 is greater than the pressure downstream of the delivery port 32 in the delivery pipe 4. In the absence of the air vessel 19 or equivalent, fluid flowing through the delivery port 32 going past the delivery valve ball 8 must overcome both the pressure above the delivery valve ball 8 and the inertia of the column of fluid in the delivery pipe 4. As discussed above in connection with the embodiment of Figure 2, the amount of fluid that can be pumped for a given hydraulic ram valve assembly will decrease as the delivery pressure increases.

The presence of the air vessel 19 or an equivalent evens out the pressure fluctuations that would otherwise exist, and in so doing reduces the average pressure against which the hydraulic ram valve assembly 1 operates. This in turn increases the amount of useful fluid which can be delivered through the delivery pipe 4.

Another way to even out the pressure fluctuations is to use a pressure cell that can be pre-charged with air to a particular pressure. These are already widely used in a variety of pumping applications. Such pressure cells have a flexible diaphragm within a container, so that air under pressure on one side of the diaphragm is separated from water on the other side of the diaphragm. Although not shown in Figure 3, such a pressure cell could be installed in place of the air vessel 19. Where such a pressure cell is used, it would depend on the circumstances of operation as to whether the addition of air into the cycle of operation is desirable. The ability of the hydraulic ram valve assembly 1 to introduce air into the cycle of operation provides another way for this invention to do useful work. In the example of the hydraulic ram valve assembly 1 depicted in Figure 3, after the air vessel

19 has reached normal operating conditions, there is a surplus of air that will go up the delivery pipe 4 with the useful fluid. While the additional components are not shown in Figure 3, it is therefore possible to take away air under pressure from the level where the air vessel 19 is attached to the tee 20 above the delivery port 32.

As examples of this, and depending on the circumstances of operation, a length of piping to deliver air or an air storage reservoir could be attached to the top of the tee

20 instead of the air vessel 19. In these examples, if the capacity of the piping or of the air storage reservoir were sufficient they would also act as alternatives to the air vessel 19. Such an arrangement of the hydraulic ram valve assembly 1 would enable it to provide useful work as an air compressor.

While it is possible for the hydraulic ram valve assembly 1 to simultaneously carry out useful work in more than one way, such as pumping water and compressing air at the same time, this may not always give the best use of the invention. To the extent that multiple uses are not completely compatible, the hydraulic ram valve assembly 1 can be constructed to provide the best efficiency for the most important use.

Figure 4 depicts a variation of the hydraulic ram valve assembly 1 which has been configured to provide a mechanical output as well as to pump water. Here an alternative elongate member 21 projects above the top of the waste pipe 10 where it is connected to a load 22 for converting reciprocating motion of the elongate member during operation of the hydraulic ram valve assembly 1 into useful work. Here the load is indicated by a mass 22 shown attached to the top of elongate member 21. The mass 5 22 will be driven up and down as the elongate member is raised and lowered during the cycle of operation. A practical application would involve other devices using the forces available as elongate member 21 goes up and down.

Rather than using some of the available energy to pump water and some to provide a mechanical output, a mechanical work output only can be provided byo removing the delivery port 32, delivery valve ball 8 and associated components at the right of the hydraulic valve assembly 1 as depicted in Figure 4a. The nipple 9 forming the delivery port 32 of the pump configuration is replaced by a plug 9a as depicted in Figure 4a.

A further embodiment utilising an alternate configuration to produce5 mechanical output is depicted in Figure 7. In this embodiment, the chamber 30 is communicated with a cylinder 39 housing a reciprocating piston 40 for converting pressure fluctuations in the chamber during operation of the hydraulic ram valve assembly 1 into useful work. Here the cylinder is attached to the inlet pipe 3 slightly upstream of the chamber 30 where the chamber 30 pressure fluctuations will still dictate0 pressure in the cylinder 39. The reciprocating piston 40 is spring biased toward the chamber 30 by spring 41 and is connected by a connecting rod 42, which will reciprocate with the pressure fluctuations during the cycle of operation, to a load.

Again the delivery port 32 and associated delivery valve ball 8 can be eliminated, such as by replacement of the nipple 9 with a plug, to provide only a mechanical output in5 the same way as described above with reference to Figure 4a.

To the extent that other simultaneous uses for pumping or compressing air are not completely compatible, the hydraulic ram valve assembly 1 can be constructed to provide the best efficiency for mechanical output where that is the most important use, as described above. While much of the description of the invention has used water as the example of the operating fluid, the invention is also applicable to other fluids in circumstances where the hydraulic ram valve assembly 1 would be of use.

Claims

1. An hydraulic ram valve assembly comprising: a chamber having an inlet port for communicating with an elevated source of fluid and a waste port, a waste valve housing extending upwardly from and communicating with said waste port, said waste valve housing having an outlet at an upper end thereof, a waste valve element disposed in said waste valve housing, said waste valve element being displaceable within said waste valve housing between said waste port and a first waste valve seat defined by said waste valve housing outlet, a waste pipe extending upwardly from and communicating with said waste valve housing outlet, a replaceable elongate member disposed in said waste pipe and extending into said waste valve housing, said elongate member being vertically displaceable within said waste pipe independently of said waste valve element.

2. The hydraulic ram valve assembly of claim 1 wherein said waste port defines a second waste valve seat.

3. The hydraulic ram valve assembly of either of claims 1 and 2 wherein said elongate member is a tube.

4. The hydraulic ram valve assembly of claim 3 wherein the tube is provided with at least one transverse hole towards a lower end thereof.

5. The hydraulic ram valve assembly of either of claims 1 and 2 wherein said elongate member is a solid rod.

6. The hydraulic ram valve assembly of any one of claims 1 to 5 wherein said waste valve element is a ball.

7. The hydraulic ram valve assembly of any one of claims 1 to 5 wherein said waste valve element is a poppet type valve element.

8. The hydraulic ram valve assembly of any one of claims 1 to 7 wherein the elongate member is provided with a collar towards an upper end thereof for engaging an upper end of said waste pipe so as to limit displacement of said elongate member.

9. The hydraulic ram valve assembly of any one of claims 1 to 8 and configured as a hydraulic ram pump and further comprising: a delivery port provided in said chamber, and a one-way delivery valve element cooperable with a delivery valve seat defined by said delivery port for enabling flow of fluid from said chamber through said delivery port.

10. The hydraulic ram valve assembly of claim 9 wherein said chamber is provided with a one-way air inlet valve for ingestion of air into said chamber when pressure therein falls below atmospheric pressure.

11. The hydraulic ram valve assembly of claim 10 further comprising an upwardly extending air vessel communicating with said delivery port downstream thereof.

12. The hydraulic ram valve assembly of claim 9 further comprising a pressure cell communicating with said delivery port downstream thereof.

13. The hydraulic ram valve assembly of any one of claims 1 to 12 and configured to produce useful mechanical work.

14. The hydraulic ram valve assembly of claim 13 wherein said elongate member is connected to a load for converting reciprocating motion of said elongate member during operation of said hydraulic ram valve assembly into useful work.

15. The hydraulic ram valve assembly of claim 13 wherein said chamber is communicated with a cylinder housing a reciprocating piston for converting pressure fluctuations in said chamber during operation of said hydraulic ram valve assembly into useful work.

16. The hydraulic ram valve assembly of claim 15 wherein said reciprocating piston is spring biased toward said chamber.