GB2374379A

GB2374379A - Domestic water tank

Info

Publication number: GB2374379A
Application number: GB0206631A
Authority: GB
Inventors: Shaun Hume; Norman John Mckinnell
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-20
Filing date: 2002-03-20
Publication date: 2002-10-16
Anticipated expiration: 2022-03-20
Also published as: GB2374379B; GB0106884D0; GB0206631D0

Abstract

A water tank 24 has at least two inlets 32 and 40 and two outlets 50 and 54, a pipe connecting a first one of said inlets32 to a first one of said outlets 50 through a first check valve 60 and a flow sensor 62, the check valve 60 preventing water flow back to the first inlet, and a pump 64 located to deliver water from the tank through a second check valve 68 to the pipe between the first check valve 60 and the flow sensor 62, the second check valve 68 preventing liquid flow from the pipe to the pump.

Description

IMPROVEMENTS IN AND RELATING TO DOMESTIC WATER INSTALLATIONS This invention is concerned with domestic water installations..

In a normal domestic water installation or system, the water is supplied from the mains to a cold water tank in the house and thence to toilet cisterns and to taps in baths or sinks either directly or indirectly through a hot water tank. All this water is used only once despite the fact that the outflow from appliances such as baths and sinks, commonly known as grey water, is only slightly contaminated and is quite suitable for use in flushing toilets. In addition, rainwater is seldom used at all and then only for watering the garden, and the failure to use rainwater or grey water constitutes a major waste of a natural resource.

It is an object of the present invention to provide domestic water installations that are more economical in their use of mains water.

The present invention is a water tank having at least two inlets and two outlets, a pipe connecting a first one of said inlets to a first one of said outlets through a first check valve and a flow sensor, the check valve preventing water flow back to the first inlet, and a pump located to deliver water from the tank through a second check valve to the pipe between the check valve and the flow sensor, the second check valve preventing liquid flow from the pipe to the pump.

A weir may be located at the second outlet to control the high water level in the tank.

The present invention is also a domestic water installation comprising a tank as defined in either of the last two preceding paragraphs, a cold water tank connected to receive water from

the mains and having an outlet connected to said first inlet, at least one washing appliance having an outlet connected to the first inlet, and at least one toilet cistern connected to the first outlet of the tank.

The present invention is further a valve having a first inlet connectible to a first outlet through a filter, or to a second outlet, means for selecting which outlet is connected to the first inlet, and a second inlet connectible through the filter only to the second outlet when the second outlet is connected to the first inlet.

The present invention is moreover a valve comprising an outer support, a flexible tubular lining in said support, and a member between the lining and the support, the member being pivotally mounted in the support and movable between a first position in which the pasage through the lining is unobstructed and a second position in which the passage is blocked.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which :- Fig. I is a schematic view of a domestic water installation according to the present invention ; Figs. 2A, 2B and 2C illustrate three stages in the operation of a water tank used in the installation shown in Fig. l ; Figs. 3A, 3B and 3C illustrate the operation of a valve used in the installation shown in Fig. l ; Fig. 4 illustrates an arrangement for supplying disinfectant to the water tank of Fig. 2;

Figs. 5A, 5B and 5C illustrate a valve; and Fig. 6 illustrates part of a control mechanism for the valve of Figs. SA to 5C.

Referring now to Fig.!, a domestic water installation according to the present invention comprises a cold water tank 10 located in the loft space 12 of a house, at least one washing appliances such as the bath 14, a plurality of toilets such as 16 and 18 each having an associated cistern 20, a water butt 22, and a water tank 24.

The cold water tank 10 has a mains inlet 26 through which mains water is supplied to the tank. The tank 10 is a type A air break and is used only for the purposes of the installation of the present invention and not for other domestic purposes. An outlet of the tank 10 is connected by a pipe 30 to a first inlet 32 of the tank 24, the pipe 30 also being connected by a pipe 34 to a valve 36 at the outflow of the bath 14.

The tank 24, shown best in Figs. 2A to 2C, is essentially an upright cylinder having on one side at the top three inlets, namely the inlet 32 connected to the pipe 30, an inlet 40 connected by a pipe 42 to the valve 36 at the outflow of the bath, and an inlet 44 connected to the water butt 22 by a pipe 46. The tank 24 has two outlets, the first outlet 50 being connected by a pipe 52 to the cisterns 20, and the second outlet 54 being connected to the main drain 56.

Inside the tank 24, the inlet 32 is connected to the outlet 50 through a first check valve 60 and a flow sensor 62, the check valve preventing the flow of water from the tank back through the inlet 32. At the bottom of the tank is an electric pump 64 whose outlet 66 is connected through a control valve 67 and a second check valve 68 to a point in between the check valve 60

and the flow sensor 62, the second check valve preventing the flow of water back into the pump from its outlet. The flow sensor 62 is connected to the pump to energise it when the flow of water through the sensor exceeds a preset value, provided always that there is sufficient water in the tank 24 to permit operation of the pump. The control valve 67 connects a pair of rotatable spray arms 69 to the pump outlet 66, and is set to open at a higher relief pressure than the check valve 68.

The outlet 54 is associated with a water trap 70 on the inside of the tank which sets the high water level inside the tank, any additional water then entering the tank then overflowing the weir and passing out to the drain 56. A float valve 55 is associated with the water trap and, when dirty water backs up from the drain 56, it is activated to switch off the pump 64 to prevent contaminated water in the tank being used. The pump remains inoperable until it is reset, thus alerting the householder to the need to clean the tank 24. Also, the inlet 44 has a float valve 72 associated with it to prevent water from the butt 22 entering the tank 24 when the tank is full or nearly full.

Finally, at the top of the tank 24 is a reservoir 74 for containing a disinfectant which is slowly supplied through a float valve into the tank through a pipe 76. The reservoir 74 has an inlet accessible from the outside of the tank to allow fresh disinfectant to be added to the reservoir.

The water butt 22 collects rain water from the roof and supplies it to the tank 24 unless the tank is already full and the float valve 72 is closed. The water butt 22 has an overflow 80 which leads into the rainwater drain 82.

The toilets 16 and 18 have their pans connected to the soil pipe 86 which in turn connects with the main drain 56. The soil pipe 86, as seen best in Figs 3A to 3C, is also connected to a second outlet 92 of the valve 36 at the outlet of the bath 14, the first outlet 90 being connected through the pipe 42 to the tank 24 as previously described. The valve 36 has two inlets, the first being connected to the drain hole of the bath while the second, 94, is connected through the pipes 34 and 30 to the cold water tank 10 as previously described. The operation of the valve 36 is controlled by an actuator 98, and the valve incorporates a tubular filter cartridge.

In operation of the installation, the tank 24 receives input water from the water butt 22 and the discharge, through pipe 42, from the washing installations such as the bath 14. Both these sources provide grey water to the tank 24. When a toilet such as 16 is flushed its cistern 20 begins to fill by gravity feed from the cold water tank 10 through th pipe 30, the tank inlet 32, the check valve 60, the flow sensor 62, and the pipe 52. This flow is detected by the flow sensor 62 and if the flow exceeds the preset value, two litres per minute in this embodiment, the pump 64 is energised. The pump pressure opens the check valve 68, and, as it exceeds the pressure in the pipe 30, closes the check valve 60 so that the cistern is refilled by the grey water output of the pump. As the water level in the cistern rises, the float valve in the cistern 20 begins to reduce the flow until it falls below the preset value at which time the flow sensor shuts down the pump.

The check valve 60 can then open, the check valve 68 is closed and the refilling of the cistern is completed with water from the cold water tank 10.

Also, as the flow reduces as the cistern level rises, the pressure at the output of the pump increases to the point at which the control valve 67 opens to allow water to flow into the arms

69 which rotate and spray the inner surface of the tank to clean it, this spraying continuing until the pump is deenergised.

The operation of the valve 36 at the outlet from the bath is important as the washing installations in the house are the major source of grey water. When the bath is to be emptied the actuator 98 is operated, as shown in Fig. 3, to open the first outlet 90 and connect the drainhole of the bath through the filter to the pipe 42 and thence to the tank 24. The filter removes hair and flocculated soap particles and therefore requires to be cleaned regularly. However, as baths are cleaned regularly, often with the use of household cleaning agents, the actuator can change the valve to close the outlet 90 and open the outlet 92 so that water from the bath, as seen in Fig. 3A, is discharged directly to the soil pipe 86. This also triggers a flow of water, as seen in Fig. 3B, from the pipe 34 back through the filter to the soil pipe thus back washing the filter. This back flow is terminated after ten seconds though the direct connection to the soil pipe will remain until the actuator is again used to restore the valve to its recycle configuration.

It is necessary that when the actuator 98 opens one outlet 90 or 92 it also closes the other outlet, and a preferred form of valve 120 used in achieving this is illustrated in Figs. 5A to 5C.

The valve 120 consists of a flexible lining 122, preferably an stretchable elastomer, in a pipe 124 and a member 125 located between the lining 122 and the pipe 124. The member 125 is, in this embodiment where the pipe 124 has a circular cross-section, is an annulus and is pivotally mounted in the pipe by spindles 128 at the top and at the bottom which extend through to the exterior of the pipe. In the position illustrated in Fig 5A flow through the pipe is not obstructed, but clockwise rotation of the member 125 on the spindle squeezes the lining 122 as seen in Fig. 5B, and eventually blocks the flow of water through the valve, as seen in Fig. 5C, when the lining

is sealed twice upon itself, once at each side of the member 125. It should be noted that the pipe 124 in the region of the lining serves only as an external support for the lining, and that the rotation of the member is preferably slightly more than 180 to provide an over centre action making accidental opening of the valve more difficult. It should also be noted that rotation of the member 125 stretches the lining so that lining resiliently biases the member 125 anticlockwise to the open position.

By providing two such valves 120, one in each of two pipes leading respectively to the outlets 90 and 92, and interconnecting their spindles so that when one valve is open the other is shut, then a simple method of controlling the flow from the drain of the bath to the outlets is achieved. A suitable mechanical connection, for example through a system of cables and pulleys, to the actuator 98 then allows the actuator to control the operation of the valves.

Part of such a mechanical control system for two valves 120 is shown in Fig. 6. A circular member 130 is rotatable about an axis 132 by the actuator and is connected to the valves 120 by respective cables 134 and 136. In the position shown, following rotation of the member 30 to its clockwise end position, the valve connected to the cable 134 is fully closed and the valve connected to the cable 136 is fully open. Anticlockwise rotation of the member 130 from the position shown in Fig. 6 initially pulls both the cables 134 and 136 to close the valve connected to the cable 134 even more tightly and to begin to close the valve connected to the cable 136. As the connection between the cable 134 and the member 130 passes the top dead centre position the cable begins to relax allowing its valve to open under the resilient bias of its lining until it is eventually fully open. The cable 136, as its connection to the member 130 approaches top dead centre, is pulled to close its valve. As the connection of the cable passes top dead centre the

resilient bias of its valve, pulling on the cable, brings the connection past top dead centre to a stable position the mirror image of that shown in Fig. 6.

In a modification of the embodiment described, the float valve associated with the disinfectant reservoir is replaced by a preferred arrangement diagrammatically illustrated in Fig.

4. A U-tube 100 is located in the tank 24 and one limb 102 of the U-tube is located in an inverted container 104 which is open at the bottom, closed at the top, and contains a volume of air. The topofthelimb 102 isabovethespill level set bythewatertrap40. Theotherlimb 106oftheU- tube is located to receive disinfectant from the airtight reservoir 74 through a tube 108 which just enters the mouth of the limb 106, the mouth being located at or just above the spill level 110.

When the tank 24 is full to the spill level, the limb 106 of the U-tube is full of disinfectant and, because the end of the tube 108 is below the level of the disinfectant in the limb 106, no disinfectant can leave the reservoir. At this time, as the air in the container 104 is under pressure, the level of the disinfectant in the limb 102 is quite low.

When water is pumped out of the tank 24, the water level falls and lowers the pressure of the air in the container 104 allowing the disinfectant to rise in the limb 102 and thus fall in the limb 106. This allows disinfectant to leave the reservoir and enter the limb 106 until the level of the disinfectant is above the end of the 108. Thereafter, when water enters the tank 24 to raise its water level, the increasing air pressure in the container 104 forces down the disinfectant in the limb 104 causing disinfectant in the limb 106 to over flow into the water in the tank, this process continuing until the tank is again full. It should be noted that the volume of disinfectant added

to the tank is directly related to the fresh volume of water added thus maintaining at all times the desired concentration of disinfectant in the water in the tank.

In a further modification of the embodiment described, the actuator 98, pipe 35 and valve 36 associated with the bath are removed and the bath outlet is connected only to the pipe 42. At the water tank 24, in this modified embodiment, the pipe 42 is connected to a diverter valve (not illustrated) which has a first outlet connected into the water tank and a second outlet connected to the main drain 56. The operation of the diverter valve is controlled by a switch, preferably located at the bath, so that bather has the option of allowing the bath water to into the tank 24 or to the main drain.

Claims

CLAIMS 1. A water tank having at least two inlets and two outlets, a pipe connecting a first one of said inlets to a first one of said outlets through a first check valve and a flow sensor, the check valve preventing water flow back to the first inlet, and a pump located to deliver water from the tank through a second check valve to the pipe between the check valve and the flow sensor, the second check valve preventing liquid flow from the pipe to the pump.
2. A water tank as claimed in claim 1, in which a weir is located at the second outlet to control the high water level in the tank.
3. A water tank as claimed in claim 1 or claim 2, including a pipe between the pump and the second check valve, a control valve in said pipe set to open at a higher relief pressure than the second check valve, and a pair of rotatable spray arms connected to the pump outlet through the control valve when it is open.
4. A water tank as claimed in any preceding claim, in which the tank has a third inlet having a float valve associated with it to close the input when the water level in the tank exceeds a preset limit.
5. A water tank as claimed in any preceding claim, including an associated tank connected with the water tank through means for supplying liquid from the output of the associated tank to the main tank after the water level in the main tank drops below a preset level.
6. A water tank as claimed in claim 5, in which said means comprises a U-tube having one

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limb connected to the output of the associated tank and the other limb located inside a container which is open at the bottom and closed at the top.
7. A water tank substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
8. A domestic water installation comprising a tank as claimed in any preceding claim, a cold water tank connected to receive water from the mains and having an outlet connected to said first inlet, at least one washing appliance having an outlet connected to the second inlet, and at least one toilet cistern connected to the first outlet of the tank.
9. A domestic water installation as claimed in claim 8 when dependent on claim 4,, including means for supplying rainwater to the third inlet..
10. A valve having a first inlet connectible to a first outlet through a filter, or to a second outlet, means for selecting which outlet is connected to the first inlet, and a second inlet connectible through the filter only to the second outlet when the second outlet is connected to the first inlet.
11. A valve comprising an outer support, a flexible tubular lining in said support, and a member between the lining and the support, the member being pivotally mounted in the support and movable between a first position in which the passage through the lining is unobstructed and a second position in which the passage is blocked.