GB2496640A - Flushing apparatus and method for a water system of a building - Google Patents

Abstract

The invention relates to an apparatus and method of flushing water contained in a water system of a building to reduce the likelihood of bacterial infection. The apparatus and or method may also prevent water pipes and tanks from freezing and bursting during cold weather. The apparatus or method preferably comprises a flush valve 20 and actuator 22, a drain pipe 21, sensors 24, 25, 26, 28 & 29 and a controller 23 which opens and closes the flushing valve 21 according to signals received from the sensors. The sensors monitor the air and water temperature and if the temperature is such that bacteria may form or the system is about to freeze, it will flush the water system. The length of the flush and the volume of the water flushed can be manually or automatically adjusted or programmed as required to suit the threat. The apparatus and method may also monitor the water for the actual level of harmful Bacteria cells and if need be administer set doses of chemical disinfectants. It may also send alerts by text that the system requires maintenance.

Description

FLUSHING APPARATUS AND METHOD

This invention relates to both apparatus for and a method of flushing water contained in a building water system.

This invention is primarily concerned with water systems installed in domestic dwellings but is also concerned with water systems for buildings in general and would be applicable, for example, to a water system in a small shop or office, or even larger business premises. Hereinafter, reference will be made exclusively to domestic water systems as installed in a dwelling but the invention is not to be regarded as limited thereto.

A typical domestic water system has an incoming water pipe connected to a communal water main, that incoming pipe being fitted with a stopcock so that water supplied to the dwelling may be shut off, if needed. Traditionally, the incoming pipe directly feeds at least one tap which is usually at the kitchen sink, with the rest of the domestic supply being fed from a storage tank having a ball valve and supplied with water from the incoming pipe. The storage tank is often sited in the roof space and gravity-feeds the other outlets in the dwelling, but the storage tank could be at or below ground level, with water being pumped to the various outlets. Ideally, such a storage tank has a tightly-fitting cover, to stop insects, rodents, birds or other debris falling into the tank and contaminating the water supplied therefrom.

More recently, dwellings are being fitted with closed mains water pressure systems where no storage tank is employed. Rather all of the domestic demand is met from the incoming pipe but with an accumulator to smooth the supply to the various taps and accommodate pressure variations.

In an installation where there is a roof or other storage tank, if the water is left static for an extended period, various microbes can start to multiply. This is especially so in the case of a roof tank, for during the summer months the temperature in the root space may rise significantly. Generally, there is not a problem if the temperature of the static water is less than 20°C but in the summer months in the United Kingdom, the temperature in a roof space can remain above 20°C for an extended period of time, giving an opportunity for the rapid multiplication of bacteria if water is not drawn from the roof tank on a frequent basis. There can also be problems arising in the pipes of the water system unless water flows through each pipe again on a frequent basis. If a tap or other outlet such as a shower head is used only infrequently, bacteria, and in particular, the bacteria which causes Legionnaires' disease can start to multiply and lead to significant health problems when water is subsequently drawn from that tap or outlet.

The problem discussed above in relation to the pipes of a water system can equally occur with a closed mains water pressure system if the temperature is above 20°C for an extended period and no water is drawn from the system for an extended period.

Yet another problem associated with domestic water systems can arise in the winter months, if water is left static in the various pipes of the installation.

Though most of the pipes of the installation are within the dwelling, some may be in the root space or in an outside wall and so the water therein can freeze and burst those pipes. Even the pipes within the dwelling can burst consequent upon water in those pipes freezing, in the event that the heating in the dwelling is turned off for an extended period during the winter months. This problem rarely arises if water flows frequently through those pipes since the incoming mains water is normally at a temperature significantly above freezing.

This invention stems from investigations into ways of reducing the likelihood of bacterial infection in the pipes of a domestic water system. As a result of those investigations, it also has become apparent that the invention can also be used, in its preferred aspects, to reduce the likelihood of pipes bursting consequent upon water freezing therewithin, in the event that the building is left without heating and without water being drawn from the system for an extended period during the winter months, such as may occur if the occupants are away on holiday.

Accordingly, one aspect of this invention provides apparatus for flushing water contained in a water system installed in a building and including pipes for conducting water to various water outlets, a connection to an incoming mains water supply and a drain arrangement, the apparatus comprising a flushing valve connected to a pipe remote from the incoming mains water supply connection and having an outlet arranged to supply water to the drain arrangement, an electrically-operated actuator for the flushing valve, a controller for the actuator, and at least one sensor connected to the controller which sensor is arranged to sense at least one of water flow in the system and the temperature of the system, and the controller is arranged to cause opening of the flushing valve in response to a received sensor output.

According to a second and closely related aspect of this invention, there is provided a method of flushing water contained in a water system installed in a building and including pipes for conducting water to various water outlets, a connection to an incoming mains water supply, a drain arrangement, and a flushing valve connected to a pipe remote from the incoming mains water supply connection and having an outlet arranged to supply water to the drain arrangement, in which method at least one of water flow through a pipe of the water system and the temperature of the system is sensed, and a controller causes operation of the flushing valve in response to a received sensor output.

Most preferably, in implementing this invention, more than one flushing valve is provided, and typically there may be three or four such valves, though in any particular installation, a different number of valves may be required. The or each flushing valve should be installed in a pipe of the water system at a location removed as far as possible from the incoming mains water supply pipe, so that opening of the flushing valve maximises the flow of water through the system from the incoming pipe. The or each flushing valve should be installed adjacent an outlet from the water system; this has the advantage that there is likely to be easy access for the flushing valve to the drain arrangement but more importantly, the provision of a flushing valve in this way minimises the volume of static water in a pipe, when the flushing valve is opened.

It will be appreciated that with this invention, in the event that a sensor provides an output to the controller indicating that the multiplication of bacteria is likely, then the controller opens the or each flushing valve in order to allow water to flow through the system. The sensor may simply detect temperature, such that if the temperature rises to a specified upper value, an appropriate output is supplied to the controller. In the alternative, the sensor may detect water flow in a pipe of the system and it there has been no flow for a pre-set period, then an appropriate output is supplied to the controller. Of course, sensors may be provided for both temperature and water flow and the controller responds to open the or each flushing valve only if the temperature is above the specified value and there has been no flow for the pre-set period.

Further, the apparatus may be arranged to reduce the likelihood of water freezing in the pipes, by furnishing one or more temperature sensors which provide an output to the controller in the event that the sensed temperature falls below a specified minimum value. Typically, the controller may be arranged to open the or each flushing valve if the detected temperature falls to 1°C, but the controller may be set to open the or each valve if the temperature falls to 3°C.

The incoming mains water temperature rarely falls below 5°C and more usually is several degrees higher than that. Thus, flushing the system with water from the mains supply at, say, 8°C will remove the likelihood of freezing until the water in the domestic pipes again falls to below 3°C, at which point the system may be flushed once more with warmer water from the mains supply.

The sensor may be fitted to a pipe so as to detect the temperature of the water in the pipe, though it would be possible to have a sensor sensing air temperature in the vicinity of a pipe. Preferably, the apparatus has more than one sensor arranged to detect the temperature at different locations within the water system where pipes are likely to be subjected to lower temperatures, such as in an external wall or in the roof space. Where there is more than one sensor, each sensor should be connected back to the controller which may act on the basis of the lowest detected temperature. Conveniently, the temperature sensors are connected to the controller by wireless links, to facilitate the installation of the apparatus to an existing water system.

The controller may be adjustable to open the flushing valve for a given time, depending upon the total volume of the water system. It may not be necessary to replace all of the water in the system, but rather just to ensure the likelihood of bacterial multiplication is reduced, or during the winter months to secure a flow of warmer water into and through the system, in order to raise the temperature sufficiently to obviate the likelihood of freezing. In the latter case, another possibility could be to monitor the temperature of the outflow of water from the flushing valve to the drain arrangement, the controller closing the flushing valve when the outflow temperature has risen to a sufficient extent to render freezing of the pipes unlikely.

The apparatus may include one or more heaters which are energised by the controller when freezing conditions have been detected. Such a heater could be a space heater installed for example in the roof space of a dwelling, to reduce the likelihood of freezing when the external air temperature has fallen to below 0°C. Alternatively, a low-powered water heater could be provided in a roof tank to raise the temperature of the water in that tank, when the detected temperature in the vicinity of that tank has fallen sufficiently for freezing to be likely. Then, flushing the system with the water from the roof tank will raise the temperature of the water in other parts of the system.

An alarm arrangement may be connected to the controller, so that an alarm will be sounded or perhaps transmitted to a remote location, indicating that the flushing valve has been opened. This could give a warning that the multiplication of bacteria or that freezing in the pipes is likely. The operation of the alarm could be adjusted so that a warning is given only if the temperature continues to rise or fall (depending on the intended use of the apparatus) following operation of the flushing valve. Suitable action could then be taken for example by an engineer, such as turning off the stopcock associated with the incoming water pipe and then draining down the entire water system in the case of freezing conditions, or of flushing through the entire system with a bactericide in the case of relatively high temperatures being encountered.

Further to reduce the likelihood of bacterial infection, the controller may be programmed to cause flushing of the system irrespective of the detected temperature, if the dwelling is uninhabited for an extended period, resulting in the water in the pipes remaining static. For example, the controller may be programmed to allow flushing of the system once a week or perhaps once a month, depending upon the season of the year, with the aim of reducing the likelihood of various microbes developing within static water in the pipes or a tank.

The apparatus described above may be modified to include a dispenser for an anti-microbial agent which, when operated, releases the agent into the water in the system. The dispenser may be operated by the controller, to release the agent whenever the system is to be flushed to prevent the development of microbes. Conveniently, and particularly since the problems associated with the growth of microbes often occurs in roof tanks, the agent may be released directly into the roof tank. Then, on opening of the flushing valve the agent will be flushed through the system so disinfecting the pipes.

By way of example only, one specific embodiment of domestic water system flushing apparatus and incorporating several of the features of this invention, as well as a method of operation for that apparatus, will now be described in detail, reference being made to the accompanying drawing.

In the drawing, there is shown an incoming water pipe 10 of a domestic dwelling (not shown), the pipe being fitted with a stopcock 11 and being connected underground to an external water main for example provided in the road outside the dwelling. From the stopcock 11, water is fed to a roof tank 12 provided with a ball valve 13 to maintain the water level in the tank. An outlet pipe 14 supplies water to taps 15 arranged at sinks 16 in the dwelling, each sink having a drain pipe 17 leading to the usual drainage arrangements for the dwelling. The pipe from the stopcock 11 is usually arranged also to feed a kitchen tap 18 so that the water supplied to the kitchen does not pass through the roof tank 12.

As described, the domestic water system is entirely conventional. In this invention, a flushing valve 20 is fitted into the pipes leading to the taps 15, to be disposed closely adjacent the respective tap. The flushing valve has a drain pipe 21 which, in the case of the upper flushing valve shown in the drawing leads to the associated sink 16, but in the case of the lower flushing valve leads directly to the drainage arrangements of the dwelling. In both cases, when the flushing valves are opened, water may flow from the roof tank 12 through the pipes 14 and 21 leading to the taps, that water being diverted to waste by the valves. As the water is drained from the tank 12, it is replenished from the incoming water pipe 10.

Each flushing valve 20 has an actuathr 22 comprising an electric motor, powered by a controller 23 by way of signal lines Si. The controller receives signals from sensors disposed at appropriate places in the system. Sensor 24 senses the temperature of the water coming into the dwelling through the stopcock ii, sensor 25 senses the temperature of the water in the roof tank 12 and sensor 26 senses the temperature of water ri the pipe 21 leading from the lower flushing valve 20 to the drain. These sensors supply temperature signals Ti, 12 and T3 to the controller 23. Sensors 28 and 29 are flow sensors arranged to detect flow of water in the pipes in which those sensors are installed and supply respective flow signals Fl and F2 to the controller 23.

The controller 23 is programmed to cause opening of the flushing valves in the event that the temperature sensed by sensors 24 or 25 falls to 1°C.

The controller may be programmed to maintain open the flushing valves for a pre-set period of time, or in the alternative to maintain open the flushing valves for a sufficiently long period for the temperature of the water drained by the lower flushing valve 20 to rise typically to above 5°C. Sensor 24 may give an indication of the temperature rise which might be expected on replenishing the roof tank 12. If the incoming water is very cold, then only a smaller temperature rise in the roof tank can be expected and the flushing valves may then be closed. If the incoming water is warmer, then a greater temperature rise in the roof tank can be expected before the valves should be closed.

In addition to the temperature sensors, the flow sensors 28 and 29 detect when water is flowing through the pipes in which those sensors are installed.

The controller 23 is also programmed to respond to a situation where there has been no flow through the pipes for a pre-set period, and then to open the flushing valves when that situation occurs. The pre-set period may be adjusted depending upon the sensed temperature -for example, if the temperature in the roof tank 12 is above 20°C, the growth of bacteria is more likely than if the temperature is much lower. Thus, flushing may occur daily with temperatures above 20°C and less frequently with lower temperatures.

An alarm arrangement includes an audible alarm 30 connected to the controller 23, to give a warning whenever appropriate, to an inhabitant of the dwelling. For example, an audible alarm may be given when the detected temperature in the system has fallen to 3°C, or if the temperature at the root tank has risen to such an extent that bacterial growth is likely. A warning may also be given it flushing is in progress. The kind ot warning given may depend upon the event detected -for example by different tones or by intermittent or continuous operation of the alarm.

The controller 23 itself may include one or more visual indicators (not shown) which may display the operation ot the apparatus and also whether the flushing valves 20 have been opened in an attempt to minimise the likelihood of bacterial growth or freezing. Further, the controller 23 may trigger a remote warning through a link 31, for example using the GRFS system and mobile telephone technology or perhaps using a landline to a remote indicator.

The controller 23 may include an input device (not shown) allowing programming and also an output device (not shown) to assist with programming. At its simplest, the input device may comprise a plurality ot switches or jumpers, with the output device comprising seven-segment displays. An alternative is tor the controller to have a port allowing the connection thereto of a computer, allowing programming directly from the computer with the computer display serving to indicate the programmed parameters.

In one mode of operation intended to protect against freezing of the water in the pipes or the root tank, a warning (either audible or remote) may be given in the event that the lowest detected temperature has fallen to 3°C. If no action is taken by an inhabitant ot the dwelling or an engineer, and the alarm has not been reset, the controller may initiate the flushing ot the system when the temperature has fallen to perhaps to 1°C. In a further modification of the system, the stopcock 11 could be fitted with a power-operated actuator (not shown) driven by the controller 23 and then, if despite operation of the flushing valve, the temperature continues to fall, the stopcock 11 could be driven to close and so provide protection against flooding should subsequent freezing burst a pipe.

The controller 23 may include a self-contained battery for powering the various functions but preferably the battery is rechargeable and has a charger connected to the domestic mains supply. In the event of a failure in the power supply arrangement, an audible warning may be given or the remote warning arrangement may be triggered, for as long as the battery lasts.

Also as shown in the drawing, the apparatus may include a dispenser 32 for a microbial agent, arranged with an outlet pipe 33 disposed to feed the agent into the roof tank 12. The dispenser is triggered by a signal S2 supplied by the controller 23, to discharge a pre-set dose of the agent into the tank 12. The controller may include a switch (not shown) which when operated causes the dispenser to release a pre-set dose into the roof tank. In the alternative, the controller may supply the signal S2 for releasing the dose at pre-set intervals, such as once a day, once a week or perhaps once a month, depending upon the environmental conditions and the likelihood of contamination. Further, when the dispenser 32 is triggered, the controller 23 may serve to cause flushing of the water system, by opening the flushing valves 20, so that water from the roof tank 12 and dosed with the agent will be flushed through the pipes to the valves.

The alarm arrangement including the audible alarm 30 and the remote link 31 may be activated in order to show that a flushing cycle including the microbial agent is in operation and further to indicate if for any reason the flushing cycle has not operated correctly, so possibly leaving water in the system having a high microbial agent content. In this case, an inhabitant may be warned that the system should be flushed once more prior to consumption of the water. The microbial agent flush may be associated with the flushing to prevent freezing as described hereinbefore or may be entirely separately operated, as required. -10-

Claims (1)

1. <claim-text>CLAIMS1. Apparatus for flushing water contained in a water system installed in a building and including pipes for conducting water to various water outlets, a connection to an incoming mains water supply and a drain arrangement, the apparatus comprising a flushing valve connected to a pipe remote from the incoming mains water supply connection and having an outlet arranged to supply water to the drain arrangement, an electrically-operated actuator for the flushing valve, a controller for the actuator, and at least one sensor connected to the controller which sensor is arranged to sense at least one of water flow in the system and the temperature of the system, and the controller is arranged to cause opening of the flushing valve in response to a received sensor output.</claim-text> <claim-text>2. Apparatus as claimed in claim 1, wherein the at least one sensor is arranged to sense the flow of water in a pipe of the system.</claim-text> <claim-text>3. Apparatus as claimed in claim 2, wherein a plurality of sensors is provided to sense the flow of water in several different pipes of the water system and each of those pipes has a flushing valve associated therewith downstream of the sensor, the controller acting on inputs received from all of the sensors.</claim-text> <claim-text>4. Apparatus as claimed in claim 2 or claim 3, wherein the controller is arranged to cause opening of a flushing valve when the sensor associated therewith does not detect water flow in the pipe for a pre-programmed time.</claim-text> <claim-text>5. Apparatus as claimed in claim 4 and in which there is a further sensor arranged to detect temperature in the water system, wherein the pre-programmed time is dependent upon the temperature sensed by said further sensor.</claim-text> <claim-text>6. Apparatus as claimed in claim 1, wherein the sensor is arranged to sense temperature at least at one location in the system.</claim-text> <claim-text>7. Apparatus as claimed in claim 6, wherein a plurality of sensors is provided to sense temperature at several physically spaced locations in the system, the controller acting on inputs received from all of the sensors.</claim-text> <claim-text>8. Apparatus as claimed in any of the preceding claims, wherein the controller is arranged to cause opening of the flushing valve when the sensed temperature exceeds a pre-determined upper value.</claim-text> <claim-text>9. Apparatus as claimed in claim 6 or claim 7, wherein the controller is arranged to cause opening of the flushing valve when the sensed temperature falls below a pro-determined minimum value.</claim-text> <claim-text>10. Apparatus as claimed in claim 9, wherein the controller includes an output for controlling the operation of one or more heaters associated with the water system.</claim-text> <claim-text>11. Apparatus as claimed in claim 10, wherein at least one of the heaters comprises a space heater arranged to supply heat to a space within which at least a part of the water system is installed.</claim-text> <claim-text>12. Apparatus as claimed in claim 10 or claim 11, wherein at least one of the heaters comprises a water heater arranged to supply heat to water in the water system or to replenishing water for the water system, whereby opening of said flushing valve allows warmer water to flow in the system.13. Apparatus as claimed in any of claims 6 to 12 and in which the water system includes an electrically-operated stopcock in the incoming water pipe, wherein the controller has an output for driving the stopcock to the closed setting in the event the sensed temperature falls below a pre-set minimum value.</claim-text> <claim-text>13. Apparatus as claimed in any of the preceding claims, wherein the controller is arranged to maintain open the flushing valve for a pre-set period following the opening thereof.</claim-text> <claim-text>14. Apparatus as claimed in any of the preceding claims and including a dispenser for an anti-microbial agent, the dispenser being arranged to release microbial agent into water in the water system and the controller being arranged to control operation of the dispenser.</claim-text> <claim-text>15. Apparatus as claimed in claim 14, wherein the controller is arranged to cause the dispenser to operate whenever the flushing valve is opened or shortly before the opening of the flushing valve.</claim-text> <claim-text>16. Apparatus as claimed in claim 14, wherein the controller is arranged to cause the dispenser to operate irrespective of opening of the flushing valve.</claim-text> <claim-text>17. Apparatus as claimed in any of the preceding claims and including an air blower arranged when operating to drive air into stored water in the water system, the controller being arranged to control operation of the air blower.</claim-text> <claim-text>18. Apparatus as claimed in claim 17, wherein the controller is arranged to cause the air blower to operate whenever the flushing valve is open so that aerated water is flushed through the pipes of the water system.</claim-text> <claim-text>19. Apparatus as claimed in any of the preceding claims and including an ultra-violet sterilisation unit arranged so that water being flushed through the pipes is sterilised thereby, the controller being arranged to control operation of the ultra-violet sterilisation unit.</claim-text> <claim-text>20. Apparatus as claimed in claim 19, wherein the controller is arranged to cause operation of the ultra-violet sterilisation unit whenever the flushing valve is open so that sterilised water is flushed through the pipes of the water system.</claim-text> <claim-text>21. Apparatus as claimed in any of the preceding claims, wherein there is a diverter valve associated with the flushing valve and arranged to divert at least some of the some of the flow through the flushing valve back to a storage tank forming a part of the water system.</claim-text> <claim-text>22. Apparatus as claimed in any of claims 1 to 20, wherein there is a circulating pump and at least one flow control valve associated therewith, whereby operation of the pump and the at least one flow control valve causes circulation of water through the pipes of the water system.</claim-text> <claim-text>23. Apparatus as claimed in any of the preceding claims, wherein the control unit includes means for recording data concerning the operation of the various components of the apparatus, and means for accessing the recorded data.</claim-text> <claim-text>24. Apparatus as claimed in any of the preceding claims, wherein the control unit includes alarm means for giving a visual, audible or other alarm signal in the event that flushing is required or if a fault condition is detected.26. Apparatus as claimed in claim 1 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. -13-27. A method of flushing water contained in a water system installed in a building and including pipes for conducting water to various water outlets, a connection to an incoming mains water supply, a drain arrangement, and a flushing valve connected to a pipe remote from the incoming mains water supply connection and having an outlet arranged to supply water to the drain arrangement, in which method at east one of water flow through a pipe of the water system and the temperature of the system is sensed, and a controller causes operation of the flushing valve in response to a received sensor output.28. A method as claimed in claim 27, wherein a dispenser for an anti-microbial agent is triggered by the controller to release microbial agent into water in the water system, and the flushing valve is opened either with the dispensing of the agent or shortly thereafter, to flush the agent through the water system.29. A method of flushing water contained in a water system installed in a building and substantially as hereinbefore described with reference to and the accompanying drawings.</claim-text>