WO2007019648A1

WO2007019648A1 - Liquid conservation device and liquid system incorporating conservation device

Info

Publication number: WO2007019648A1
Application number: PCT/AU2006/001198
Authority: WO
Inventors: Brian Terrence Driscoll; Lindy Honeychurch
Original assignee: Water Miser (Aust) Pty Ltd
Priority date: 2005-08-18
Filing date: 2006-08-18
Publication date: 2007-02-22

Abstract

There is provided a water conservation device (1) including a housing (2) having an inlet (3) and a primary outlet (4) defining therebetween a primary flow passage (5). A secondary outlet (8) terminates a secondary flow passage (9) that extends from an intermediate point (10) on the primary flow passage (5). A shuttle valve (12) is longitudinally moveable in a shuttle valve chamber defined in the passage (5) between a normal operating position where it shuts off the secondary flow passage (9) and a diverting position where it closes off a downstream portion (13) of the flow passage (5) and opens the secondary flow passage (9). The shuttle valve (12) includes a wax thermostat element (15) which acts against spring (16) designed to yield when the valve (12) moves between the normal operating and the diverting positions and spring (17) designed only to yield at much higher loadings to avoid damage to components of the valve (12).

Description

LIQUID CONSERVATION DEVICE AND LIQUID SYSTEM INCORPORATING

CONSERVATION DEVICE

FIELD QF THE INVENTION

This invention relates to a liquid conservation device. The invention also extends to a tap assembly and a liquid conservation system including the conservation device. The invention also extends to method of conserving water using the device.

This invention relates particularly but not exclusively to a water conservation device for fitting to a domestic hot water outlet so as to divert water that is below a specified design temperature away from the outlet so it is not passed through the hot water outlet. Water is only returned to the hot water outlet once it reaches its design temperature. It will be convenient to hereinafter describe this invention with reference to this example application. The invention also extends to a hot water system including the device.

However it is to be clearly understood that the invention is capable of broader application. For example the invention may be applied to a water system that provides cold water at a design temperature, eg cold water for drinking. In this case the device will be used to divert an initial volume of water that is above the design temperature away from a discharge tap and then recycle it back to the cooling device so that it can be reused.

Further the invention can be applied to liquids other than water. For example it may be applied to drinks other than water including alcoholic beverages and also drinks like coffee and tea. The primary requirement for the invention to find application is that the substance must be a liquid and it must be desired for the liquid to be supplied in a certain condition. Generally this condition will mean supplying the liquid at a certain temperature. However the Applicant does not exclude diverting an initial volume of liquid until some other condition has been reached, for example a certain concentration of a component in the liquid, a certain pH or salinity, or even a certain viscosity.

Applicant envisages that the application of this invention could potentially be so wide that it is not possible at this time to provide a closed list of the possible uses of the invention.

BACKGROUND TO THE INVENTION

In a domestic environment a hot water supply, for example a storage hot water system (HWS), is typically situated spaced away from one or more hot water taps while water in the storage tank is kept at a design temperature, such as by one or more heating elements, gas burner or heat exchanger such as a solar heat exchanger. Water that is held in the water lines in between use of the hot water supply is not heated or even insulated and thus cools rapidly to ambient. As a result when the hot water tap is turned on the initial water flow from the tap is cold. Typically a user might let this water flow directly to a drain and only commence use of the water passing out of the tap once it warms up sufficiently. This therefore leads to a loss of clean water down the drain.

An example domestic hot water system is shown in Fig 1. The hot water is fed from a hot water tank through hot water lines to a plurality of taps. Often one or more of these taps will be taps with a central mixer where water from each of the taps is fed into a central mixer and a single stream of water issues from the mixer. These mixer taps are a common feature in many if not all homes. Other taps will include the usual pillar taps.

Clearly therefore it would be advantageous if a way of saving the water drained waiting for a tap to run hot could be devised. This is particularly so in recent times in Australia where extended drought and population increase have placed water supplies under increasing demand pressure. Water restrictions are in place in many regions. It would be particularly advantageous if a way could be devised of diverting this initial volume of cold water into a secondary system until the water warmed up and there after directing the water supply through the hot water tap.

It would be particularly advantageous if a said device for doing this was able to use the tap to shut off and open the flow of water through the device. This would obviate the need for a second valve to perform this function and would considerably simplify the device.

SUMMARY OF THE INVENTION

According to one aspect of this invention there is provided a liquid conservation device, comprising: a housing defining an inlet and a primary outlet with a primary flow passage extending from said inlet to said primary outlet, the housing also defining a secondary outlet spaced from said primary outlet and a secondary flow passage extending from said secondary outlet to an intermediate point on said primary flow passage where it is in fluid communication with said primary flow passage; valve means in said primary flow passage having a normal operating position in which it shuts off the secondary flow passage and opens a primary flow passage from the inlet to the primary outlet, and a diverting position in which it closes off the primary flow passage downstream of the secondary flow passage and opens the secondary flow passage to the inlet; control means for moving the valve means between said normal operating position and said diverting position in response to a measured condition of the liquid in proximity to the valve means; whereby when liquid flows through the inlet its condition is measured and if it does not meet certain predetermined criteria then it is caused to flow through the secondary flow passage, and when said criteria are met the valve means moves to the normal operating position permitting liquid to flow through the primary flow passage downstream of the valve means and out through the primary outlet. The liquid may be water or any other liquid having an initial flow condition that transitions into a useful flow condition. The invention will be further described with reference to the liquid being the water comprising a hot water supply system. The predetermined criteria may comprise the temperature of the liquid. For example, in domestic water mixing systems the predetermined criteria may be a maximum temperature whereby the system prevents scalding by diverting retained hot water. However, the invention is exemplified by, and is described hereinafter with reference to, the predetermined criteria being a minimum temperature of the water. The temperature criteria may require the water to be above a predetermined temperature at which it is suitable for use as hot water in a hot water system. Typically the predetermined temperature might be 35 to about 50 degrees Celsius. The device may be used on a hot water tap for diverting and then recovering an initial volume of water that is not at the required temperature through the secondary outlet.

Thus when liquid is initially caused to flow through the device the primary valve control means tends to its diverting position if the liquid is not at its design or predetermined temperature and is diverted through the secondary flow passage. When the liquid approaches its design temperature the primary valve means move towards its normal operating position directing liquid through the primary flow passage downstream of the primary valve and out through the primary outlet. The tap can then be used for normal use.

The valve means may comprise a shuttle valve, eg with a movable shuttle valve element, received within a shuttle valve chamber, eg defined by the primary flow passage, and the shuttle valve may be translationally displaced within the shuttle valve chamber between said normal operating position and said diverting position.

The valve chamber may have a substantially elongate circular cylindrical configuration and the shuttle valve may be displaced to and fro in a longitudinal direction. The shuttle valve may further include a shuttle valve guide means operatively coupled to the shuttle valve element that complements the valve chamber to guide to and fro movement of the shuttle valve in the chamber.

The shuttle valve may include resilient biasing means for biasing the valve element into the diverting position. Thus when the predetermined temperature criteria are met the temperature sensitive control means dominates the biasing means and moves the valve element to the normal operating position.

The temperature sensitive control means may include an element that undergoes a change in length as a result of a change in temperature. For example the element may lengthen when warmed and contract when cooled.

One example thermostat element is a wax element. However it is to be clearly understood that other forms of elements can also be used.

The thermostat element may be coupled to a shuttle element of said valve means such that expansion of the thermal element moves the shuttle element, towards the normal operating position, and contraction of the thermostat element moves the shuttle valve element to the diverting position.

The wax element may be received within the shuttle element and move with it as a single unit.

By appropriate calibration of the thermostat element, the shuttle valve can be set such that it is fully and completely positioned in the normal operating position once the liquid passing though the shuttle valve has reached its predetermined minimum temperature.

The device may include a non-return valve adjacent the inlet for resisting the flow of liquid in a reverse direction from the primary flow passage out through the inlet. The non-return valve may include a valve closure in the form of a ball, resiliency biased into engagement with a valve seat. The resilient biasing means may be in the form of a helical coil spring loaded under compression.

The device may include a further non-return valve adjacent the secondary outlet for resisting liquid flow in a reverse direction from outside the housing in though the secondary outlet. This further non-return valve may be the same as the nonreturn valve described above positioned adjacent the inlet.

The device may include a yet further non-return valve adjacent the primary outlet for resisting liquid flow in a reverse direction from outside the housing in though the primary outlet. This further non-return valve may be the same as the nonreturn valve described above positioned adjacent the inlet.

The portion of the primary flow passage downstream of the valve means may be located in a diametrically opposed relation to the secondary flow passage relative to the shuttle valve and both said passages may extend outwardly away from the valve means transverse to the axis of movement or longitudinal axis of the shuttle valve.

The device may be adapted to be inserted between the control handle and spindle of a tap and the spout of a tap. The tap might be a pillar tap. Alternatively the tap might be a mixer tap. This way the control handle and spindle can be used to shut off and open flow through the device.

According to another aspect of this invention there is provided a tap assembly for providing liquid to a user, eg in a domestic environment, the tap assembly comprising: a conduit defining a flow path from an upstream end to a downstream end of the tap assembly; a tap handle and tap closure mounted on the conduit for shutting off and opening flow of liquid through the flow path; a device according to the first aspect of the invention described above operatively coupled to the conduit in line therewith downstream of said tap handle and closure; a spout formation defining an outlet through which liquid issues from the tap mounted on the conduit in line there with downstream of the device; whereby the flow of liquid through the tap is opened and shut off by the control handle at the upstream end of the conduit and then passes through the device where it is either diverted or passed out through the spout.

The liquid may be water, eg for use in a domestic environment.

The opening and closing of the tap which is positioned upstream of the device acts to open and close the flow of liquid through the device. Thus the device does not require a further or secondary valve to close off the flow of water through the secondary channel when the tap is switched off. This has the effect of considerably simplifying the structure of the device.

The tap assembly may be a mixer tap and the spout formation may be a mixer.

The tap handle may comprise a tap handle that you rotate and the closure may be a spindle. Alternatively it may be a lifting handle formation.

The tap of the tap assembly may be a hot tap. The tap assembly may include a further tap, eg a cold tap, operatively coupled to the mixer in the same way as the hot tap in parallel with the hot tap.

The mixer may permit a user to vary the proportion of hot and cold water mixed into the stream issuing from the mixer, eg by adjusting the extent to which two taps are opened. The mixer may further have means for varying the amount of water that issues from its spout. Alternatively the tap assembly may be a pillar tap in which case the closure is a spindle and the spout formation is simply the normal curved spout through which the water issues.

Typically where the tap assembly is a pillar tap the hot tap is alone and is not coupled in parallel to a cold water tap like with the mixer tap assembly.

The tap handle and spindle may be that found on a conventional tap that is rotated in clockwise fashion to close and anti clockwise to open.

The device may include any one or more of the optional or preferred features of the first aspect of the invention described above.

The tap assembly may further include a recycle conduit operatively coupled to the secondary outlet of the device.

The tap assembly may further include non return valves associated with each of the primary inlet, and the primary and secondary outlets. The non return valves may be located on the conduits associated with the respective inlets and outlets.

According to another aspect of this invention there is provided a liquid system including a tap assembly as described above according to the second aspect of the invention operatively coupled to a supply conduit which in turn is operatively coupled to a liquid supply, wherein the device is positioned downstream of the tap handle such that opening and closing of the tap shuts off and opens the flow of liquid through the device.

The liquid supply may be a hot water supply, eg including a hot water tank having hot water. The secondary outlet of the device may be coupled to a tank, eg a recycle tank, so that water that is passed through the secondary outlet is collected in the tank.

The invention also extends to a method of conserving liquid, eg water, by diverting an initial volume of liquid from a tap and then collecting it for use again using the device described above according to the first aspect of the invention, wherein the device is positioned downstream of the tap.

According to yet another aspect of this invention there is provided a water conservation device for use in a domestic hot water system, the device comprising: a housing defining an inlet and a primary outlet with a primary flow passage extending from said inlet to said primary outlet, the housing also defining a secondary outlet spaced from said primary outlet and a secondary flow passage extending from said secondary outlet to an intermediate point on said primary flow passage where it is in fluid communication with said primary flow passage; valve means in said primary flow passage having a normal operating position in which it shuts off the secondary flow passage and opens the primary flow passage from the inlet to primary outlet, and a diverting position in which it closes off the primary flow passage downstream of the secondary flow passage and opens the secondary flow passage to the inlet; temperature sensitive control means for moving the valve means to said normal operating position when the temperature of the water passing through the valve means rises above a predetermined temperature; whereby the temperature of the liquid is measured when it flows through the valve means and if it is below a certain predetermined temperature then it is caused to flow through the secondary flow passage, and when the temperature of the liquid increases towards said predetermined temperature then the valve means moves to the normal operating position permitting the water to flow through the primary flow passage downstream of the valve means and out through the primary outlet. The device may have any one or more of the preferred or optional features of the device described above according to the first aspect of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A water conservation device and tap assembly in accordance with this invention may manifest itself in a variety of forms. It will be convenient to hereinafter describe in detail one preferred embodiment of the invention with reference to the accompanying drawings. The purpose of providing this specific description is to instruct persons having an interest in the subject matter of the invention how to carry the invention into practical effect. In the drawings:

Fig 1 is a schematic flow sheet of a known domestic hot water system including a mixer tap comprising hot and cold water taps and a central mixer and also a pillar tap;

Fig 2 is a sectional front view of a water conservation device in accordance with the invention in a diverting position with water being diverted through a secondary outlet; Fig 3 is a sectional front view of the device of Fig 2 in a normal operating position with water from the hot tap being directed through the primary outlet;

Fig 4 is a schematic sectional view of the liquid conservation device of Fig 2 coupled to a mixer tap assembly with a central mixer;

Fig 5 is a sectional side view of the device and an associated hot water tap that is a pillar tap in the diverting position;

Fig 6 is a sectional side view of the device and associated tap of Fig 5 in the normal operating position; and

Fig 7 is a schematic flow sheet of a domestic hot water system incorporating the liquid conservation device of Fig 4. Fig 1 refers to a domestic hot water system of a type that is already known. It has been described in the background to the invention and will not be described further in the detailed description.

In Figs 2 and 3, reference numeral 1 refers to a water conservation device in accordance with the invention.

The device 1 comprises broadly a housing 2 defining an inlet 3 and a primary outlet 4 with a primary flow passage 5 extending from said inlet 3 to said primary outlet 4. The housing 2 also defines a secondary outlet 8 spaced from said primary outlet 4 and a secondary flow passage 9 that extends from an intermediate point 10 on the primary flow passage 5 to the secondary outlet 8.

The secondary flow passage 9 opens into and is in fluid communication with the primary flow passage 5 at the point 10 where they meet. Broadly therefore the primary flow passage 5 may be divided into an upstream portion 11 that is positioned upstream of the point 10 and a downstream portion 13 that is positioned downstream of the point 10.

The device 1 also includes a valve means in the form of a shuttle valve 12 received within the primary flow passage 5 near the point 10. The housing 2 and particularly the flow passage 5 defined therein is modified in this region to define a shuttle valve chamber.

The valve 12 is longitudinally moveable in the shuttle valve chamber between a normal operating position shown in Figs 3 and 6 where it shuts off the secondary flow passage 9 and a diverting position shown in Figs 2 and 5 where it closes off the downstream portion 13 of the flow passage 5 and opens the secondary flow passage 9.

The shuttle valve 12 comprises broadly a valve element 19 that is configured to close off the secondary flow passage 9 when in the operating position and close off the downstream portion 13 of the primary flow passage 5 when in the diverting position. The valve 12 also includes a valve guide 14 for guiding the shuttle valve element 12 back and forth between its two positions in the shuttle valve chamber. The guide 14 has a guide surface that complements the chamber guide surfaces whereby to effect smooth and consistent to and fro movement of the shuttle valve 12. The shuttle valve 12 also includes temperature sensitive control means in the form of a thermostat element 15 that undergoes a change in length as a result of a change in the temperature of the liquid passing there through. The valve element 19 and the valve guide 14 are both directly coupled to the temperature sensitive element 15 such that they move to and fro directly together with the element 15.

The valve 12 also includes means for loading the valve element 19 in the chamber under some compression. These loading means comprise springs 16 and 17 at each end of the valve 12. The one spring 16 is designed to yield when the valve 12 moves between the normal operating and the diverting positions. The other spring 17 is designed only to yield at much higher loadings, eg to avoid damage to components of the valve 12. For example this might occur if the temperature of the water rises above its design temperature causing additional lengthening of the element 15 over and above that required to move the element 19 from the diverting to the operating positions. This additional length needs to be accommodated somewhere and the spring 17 provides this ability. The valve 12 also includes a removable cover 18 that can be removed to provide access to the components within the valve 12 to enable them to be serviced and replaced.

In the illustrated embodiment the thermostat element is a wax element 15 which has been found to be very suitable for this purpose. However it is to be clearly understood that many other thermostat elements could be equally used.

In use a device 1 may be mounted in line with a tap handle and spindle (tap) and say a mixer with a spout (mixer) through which the water issues. A typical starting position of operation of the device 1 is when water flow through the device 1 has been switched off for some time and the water in the passages and the housing 2 has cooled back to ambient temperature.

In this situation the temperature to which the temperature sensitive element 15 on the valve 12 is exposed to is below design temperature. Thus the valve 12 will be in the diverting position and the secondary flow passage 9 will be open and the downstream portion 13 of the passage 5 will be closed. This diverting condition is shown in Fig 2.

As a result when water is first caused to flow through the inlet 3 and into the passage 5 it will be diverted through the passage 9 and out through the outlet 8. This water is thus diverted into a recycle conduit and does not flow out of the outlet 4 which typically leads to a said tap.

When the water warms up it progressively causes the thermostat element 15 to expand and lengthen. This in turn causes the shuttle valve 12 to move from the diverting position towards the normal operating position. This progressively closes off the secondary passage 9 and opens the downstream portion 13 of the flow passage. Once the predetermined design temperature of, eg 35-40⁰C, has been reached the shuttle valve 12 will have moved fully into the normal operating position. This will cause all water flowing through the valve 12 to flow through the downstream portion 13 of the primary flow passage 5 and out through the outlet 4 and shut off flow through the secondary flow passage 9.

Substantially all of the water that issues from the primary outlet 4 will be hot water at or about the design temperature and suitable for use. It is not preceded by a period of cold water. Instead the initial volume of cold water is diverted through the passage 9 and out through the outlet 8. The water from the tap is then used in the normal way by the user for whatever purpose they require. When the tap is switched off it shuts off the flow of water through the device 1 because it is upstream of the device 1. Initially after this flow has been shut off, the valve remains in its normal operating position.

However the water that occupies the flow passage 5 and the hot water line upstream of the device 1 will be held statically in the lines until the tap is next opened for use. As the water is no longer being actively heated it will cool over time and gradually move back to ambient temperature or the temperature of the air around the device and also the temperature of the housing.

If the tap remains shut off for a protracted period the temperature sensing element 15 will contract and progressively move the shuttle valve 12 from the Fig 1 position to the Fig 2 diverting position where it opens the secondary flow passage 9 and closes off the downstream portion 13 of the primary flow passage 5. This returns the valve element 19 to the diverting position shown in Fig 2 and the various components will remain in this position until the device is next used. The cycle can then be repeated when the tap is next open for use.

Thus if the tap is turned on again shortly after it was switched off, the water and housing would not have cooled much, and the valve would not yet have moved back to its diverting position. As a result there will not be an initial volume of water that is diverted. This is a useful feature because it means that water is not diverted unless it is cold and this improves the efficiency and convenience of the device.

Another possible scenario is that the tap is re-opened after an intermediate period of time has elapsed. That is the tap and any water within it has cooled down to some extent but not completely. In this situation the valve will be in an intermediate position between the diverting and normal operating positions and will pass some water through to the tap but not all of it. Some will be diverted into the flow passage 9. In this scenario the valve may move back to the normal operating position more quickly then if the water was cold. Fig 4 shows the device of Figs 2 and 3 coupled up to a bridge tap assembly with a central mixer. In Fig 4 reference numeral 50 will be used to refer generally to the bridge tap assembly.

The tap assembly 50 comprises hot and cold taps 51 and 52 and a mixer 55 for receiving water from one or both of the taps. The mixer 55 has a mixer inlet 56 through which water enters the mixer 55 and a mixer outlet 57 through which water is discharged from the tap assembly 50 in use. The tap assembly 50 also includes a hot water conduit 60 from the hot water tap 51 to the mixer inlet 56 and a cold water conduit 62 from the cold water tap 52 to the mixer inlet 56.

The mixer 55 has means for varying the amount of water that issues there from. The amount of water issuing from the tap can be varied by the angle to which the mixer is lifted or turned. By varying the extent to which each of the hot and cold water taps is opened a user is able to broadly control the temperature of the water that issues from the mixer 55. As the structure and function of mixers would be well known to persons skilled in the art and do not form part of the invention they will not be described in further detail in this specification.

The taps 51, 52 are typically mounted on a counter spaced laterally apart from each other and the mixer 55 is positioned approximately centrally between them. In the illustrated embodiment the hot water conduit 60 merges with the cold water conduit 62 shortly before the mixer 55 by means of a tee junction.

A said water conservation device 1 as described above for Figs 2 and 3 is coupled in line with the hot water conduit 60 such that water passing from the tap 51 to the mixer 55 passes through the primary inlet 3 and out through the primary outlet 4.

The secondary outlet 8 is coupled to a recycle conduit 65 for recycling water that is passed out of this outlet 8. Typically this might lead to a recycle tank or else back into the hot water system. In use the hot and cold taps 51 and 52 are controlled by a user in the usual way. If a user desires hot water they just switch the hot tap on first.

This water then flows through the hot conduit 60 into the inlet 3 of the device 1. If the temperature of the water is below a predetermined temperature, eg 35 to 45 degrees Celsius, then the shuttle valve 12 is positioned towards the diverting position and this directs water through the secondary flow passage 9 and out through the secondary outlet 8.

Once the water heats up to its design or predetermined temperature then the shuttle valve 12 moves towards the normal operating position and this causes water to flow through the primary outlet 4 and into the mixer 55. The user can then use the tap in the normal way for their usual activities. They achieve the desired water temperature by opening each of the hot and cold taps the appropriate amount. When they are finished they switch the taps 51 , 52 off in the usual way.

Thus the device 1 fitted in line with a hot water tap 51 in a bridge tap with a mixer 55 enables an initial volume of cold water to be diverted and then recycled. The fact that the device 1 is downstream of the tap 51 means that you don't need to have an automatic valve to close off the secondary passage 9 when the tap is closed. This considerably simplifies the operation of the device and associated tap.

Figs 5 and 6 show the device of Figs 2 and 3 coupled up to a conventional pillar tap. As this is similar to the mixer tap of Fig 4 the same reference numerals will be used to describe the same components unless otherwise indicated.

In summary the device 1 is coupled in line with the flow path defined by the pillar tap assembly 50 (pillar tap) including its associated conduits. The tap spindle and control handle 51 is positioned upstream of the device 1 and the spout 57 or outlet of the tap 50 is positioned downstream of the device 1. This way the tap 50 can be used to open and shut off the flow of water through the device 1 and it is not necessary to have a secondary valve to perform this function.

In use when the tap 50 is opened water flows past the tap spindle 51 and into the device 1. If the water is below the predetermined temperature then it is diverted through the secondary outlet 8 of the device 1 and not through the tap 50. This is shown in Fig 5. If and when the water reaches the predetermined temperature the valve 12 closes off the secondary passage 9 arid opens the primary flow passage 5 and the water can flow through the spout 57 of the pillar tap 50 and out through the outlet. This is shown in Fig 6.

Fig 7 shows the tap assembly including conservation device integrated into a domestic hot water system.

A water supply 100 collects water for domestic use. In the illustrated embodiment the supply 100 is provided by tank 101 collecting rain water and the like. At the same time the supply could equally be provided by domestic mains supply of municipal water.

Water can be drawn from the supply 101 and fed into a water heater 102. This comprises a tank of water which is heated, eg by electricity or gas, to a predetermined temperature of about 35-40⁰C. The tank typically will have a capacity of several hundred litres.

This water is then drawn off the hot water tank 102 by means of hot water supply lines 103. The lines 103 branch at various points and terminate in hot water taps for use in various points in the house. These taps come in various forms. Some such taps are simple pillar taps. Others are so called mixer taps where hot and cold taps connected in parallel feed water into a central mixer from where the water is dispensed. A said mixer tap is shown in Fig 7 and is illustrated by the reference numeral 50.

While a pillar tap has not been shown in the drawings the invention could be applied equally to a pillar tap.

The tap assembly 50 comprises hot and cold taps feeding water into a central mixer downstream of the taps and includes a device 1 as described above with reference to Figs 2 and 3. A recycle conduit 108 is operatively coupled to the secondary outlet 8 of the device 1.

In use when the hot water tap is switched on water passes from the tank 101 into the device 1 before it enters the mixer 55. If the water entering the device 1 and particularly the inlet 3 thereof is below design temperature then it is diverted through the secondary outlet 8 of the device 1 into a recycle tank 108 from where it can be reused.

When the hot water coming directly from the hot water tank 103 enters the device 1 the valve 12 is moved to the normal operating temperature by extension of the temperature control element. This causes the water to be cut off from the passage 9 and instead to be directed through the primary outlet 4 and into the mixer 55. From there it is used in the usual way for the usual hot water use.

Thus the device and the tap assembly enables the initial volume of water passing through the hot water tap which is cold to be diverted and passed into the recycle tank from where it can be reused.

An advantage of the device described above with reference to Fig 7 is that it can be used to save liquid, eg water, which would otherwise pass down a drain. This liquid can then be gainfully used in other applications or recycled to a clean liquid supply. This has the potential to substantially reduce the wastage of clean or potable liquid. An advantage of the system is that it operates automatically and does not require user intervention. It will automatically divert the liquid to the secondary outlet and only send it out through the tap when it is at the right temperature. It requires absolutely no input from a user.

An advantage of this conservation device is that it is fairly simple and requires in essence only one valve namely a temperature sensitive valve. These valves have proven ability and are reliable and require only little maintenance. Specifically it does not require a second valve for shutting off and opening the flow of water through the device. The elegance of this invention resides in utilising the existing tap to open and shut the flow of water through the device by positioning the device downstream of the tap. This enables the structure of the device to be considerably simplified.

A further advantage of the device described above is that it will be able to be manufactured and supplied to the market at a reasonable cost.

A yet further advantage of the invention is that it can be retrofitted to existing hot water lines in houses. For example the device can be easily integrated into a bridge tap with a mixer. It is simply coupled in line with the hot water line downstream of the hot water tap. Conveniently the device might be received in a cupboard or the like or may be mounted on the wall.

It will of course be realised that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as defined in the claims appended hereto.

Claims

1. A liquid conservation device, comprising: a housing defining an inlet and a primary outlet with a primary flow passage extending from said inlet to said primary outlet, the housing also defining a secondary outlet spaced from said primary outlet and a secondary flow passage extending from said secondary outlet to an intermediate point on said primary flow passage where it is in fluid communication with said primary flow passage; valve means in said primary flow passage having a normal operating position in which it shuts off the secondary flow passage and opens a primary flow passage from the inlet to the primary outlet, and a diverting position in which it closes off the primary flow passage downstream of the secondary flow passage and opens the secondary flow passage to the inlet; control means for moving the valve means between said normal operating position and said diverting position in response to a measured condition of the liquid in proximity to the valve means; whereby when liquid flows through the inlet its condition is measured and if it does not meet certain predetermined criteria then it is caused to flow through the secondary flow passage, and when said criteria are met the valve means moves to the normal operating position permitting liquid to flow through the primary flow passage downstream of the valve means and out through the primary outlet.

2. A liquid conservation device according to claim 1 , wherein the liquid is selected from liquids that in use have an initial flow condition that transition into a useful flow condition.

3. A liquid conservation device according to claim 2, wherein the liquid is the water comprising a hot water supply system.

4. A liquid conservation device according to any one of the preceding claims, wherein the predetermined criteria comprises the temperature of the liquid.

5. A liquid conservation device according to claim 4, wherein the predetermined criteria in a domestic hot water mixing system is a maximum temperature.

6. A liquid conservation device according to claim 4, wherein the liquid is water in a hot water reticulation system and the predetermined criteria is a minimum temperature of the water.

7. A liquid conservation device according to claim 6, wherein the hot water reticulation system is a domestic hot water system.

8. A liquid conservation device according to claim 7, wherein the minimum temperature is selected to be in the range of from 35 to about 50 degrees Celsius.

9. A liquid conservation device according to any one of the preceding claims, wherein flow from the secondary outlet is recovered for reuse or recycling to the liquid source.

10. A liquid conservation device according to any one of the preceding claims, wherein the valve means comprises a shuttle valve having a movable shuttle valve element, received within a shuttle valve chamber defined by the primary flow passage, and the shuttle valve is translationally displaced within the shuttle valve chamber between said normal operating position and said diverting position.

11. A liquid conservation device according to claim 10, wherein the shuttle valve includes resilient biasing means for biasing the valve element into the diverting position, and wherein as the predetermined criterion is met the control means dominates the biasing means and moves the valve element to the normal operating position.

12. A liquid conservation device according to any one of the preceding claims, wherein said criterion is minimum temperature and wherein the control means includes an element that undergoes a change in length as a result of a change in temperature.

13. A liquid conservation device according to claim 12, wherein said control means includes a wax element thermostat.

14. A liquid conservation device according to claim 13, wherein the thermostat element is coupled to a shuttle element of said valve means such that expansion of the thermal element moves the shuttle element, towards the normal operating position, and contraction of the thermostat element moves the shuttle valve element to the diverting position.

15. A liquid conservation device according to claim 14, wherein the wax element is received within the shuttle element and moves with it as a single unit.

16. A liquid conservation device according to any one of the preceding claims, wherein there is provided a non-return valve adjacent the inlet for resisting the flow of liquid in a reverse direction from the primary flow passage out through the inlet.

17. A liquid conservation device according to claim 16, wherein there is provided a further non-return valve adjacent the secondary outlet for resisting liquid flow in a reverse direction from outside the housing in though the secondary outlet.

18. A liquid conservation device according to claim 16 or claim 17, wherein there is provided a yet further non-return valve adjacent the primary outlet for resisting liquid flow in a reverse direction from outside the housing in though the primary outlet.

19. A liquid conservation device according to any one of the preceding claims, wherein the device is adapted to be inserted between the control handle and spindle of a tap and the spout of a tap.

20. A liquid conservation device according to claim 19, wherein the tap is a pillar tap.

21. A liquid conservation device according to claim 19, wherein the tap is a mixer tap.

22. A tap assembly comprising: a conduit defining a flow path from an upstream end to a downstream end of the tap assembly; a tap handle and tap closure mounted on the conduit for shutting off and opening flow of liquid through the flow path; a device according to any one of claims 1 to 21 operatively coupled to the conduit in line therewith downstream of said tap handle and closure; a spout formation defining an outlet through which liquid issues from the tap mounted on the conduit in line there with downstream of the device; whereby the flow of liquid through the tap is opened and shut off by the control handle at the upstream end of the conduit and then passes through the device where it is either diverted or passed out through the spout.

23. A tap assembly according to claim 22, wherein the assembly is a mixer tap and the spout formation is a mixer.

24. A liquid system including a tap assembly according to any one of claims 22 or 23 and operatively coupled to a supply conduit which in turn is operatively coupled to a liquid supply, wherein the device is positioned downstream of the tap handle such that opening and closing of the tap shuts off and opens the flow of liquid through the device.

25. A liquid system according to claim 24, wherein the liquid supply is a hot water supply including a hot water tank having hot water therein.

26. A liquid system according to claim 25, wherein the secondary outlet of the device is coupled to a recycle tank, so that water that is passed through the secondary outlet is collected in the recycle tank.

27. A method of conserving liquid by diverting an initial volume of liquid from a tap and then collecting it for use again using a liquid conservation device according to any one of claims 1 to 21, wherein the device is positioned downstream of the tap.

28. A water conservation device for use in a domestic hot water system, the device comprising: a housing defining an inlet and a primary outlet with a primary flow passage extending from said inlet to said primary outlet, the housing also defining a secondary outlet spaced from said primary outlet and a secondary flow passage extending from said secondary outlet to an intermediate point on said primary flow passage where it is in fluid communication with said primary flow passage; valve means in said primary flow passage having a normal operating position in which it shuts off the secondary flow passage and opens the primary flow passage from the inlet to primary outlet, and a diverting position in which it closes off the primary flow passage downstream of the secondary flow passage and opens the secondary flow passage to the inlet; temperature sensitive control means for moving the valve means to said normal operating position when the temperature of the water passing through the valve means rises above a predetermined temperature; whereby the temperature of the liquid is measured when it flows through the valve means and if it is below a certain predetermined temperature then it is caused to flow through the secondary flow passage, and when the temperature of the liquid increases towards said predetermined temperature then the valve means moves to the normal operating position permitting the water to flow through the primary flow passage downstream of the valve means and out through the primary outlet.