WO2014020606A1

WO2014020606A1 - A method and system for controlling liquid flow

Info

Publication number: WO2014020606A1
Application number: PCT/IL2013/050652
Authority: WO
Inventors: Eitan Furst
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-07-31
Filing date: 2013-07-31
Publication date: 2014-02-06
Anticipated expiration: 2015-01-31

Description

A METHOD AND SYSTEM FOR CONTROLLING LIQUID FLOW

FIELD OF THE INVENTION

The present invention relates to controlling liquid flow, in general and, in particular, to a method and system for controlling flow of hot water or other hot liquid.

BACKGROUND OF THE INVENTION

A typical conventional water flow system is illustrated in Fig. 1. Many conventional water flow systems today include a hot water source 2, such as a boiler, solar heater, that are used to provide a user with hot water. These systems also include hot water pipes 3 which connect the hot water source 2 to a dispensing device 5, e.g. a shower or sink faucet, bidet, etc., not located close to the point of use. Typically, these systems also include a cold water pipe 4 connecting a main source of water 1 to the dispensing device. When dispensing device 5 is open, water flows from hot water source 2 through pipe 3 and out of spout 7 under gravitational force or under pressure. When dispensing device 5 is then closed, pipe 3 remains filled with hot or warm water that did not reach spout 7 while the dispensing device 5 was open. It will be appreciated that, in this conventional water flow system, in order for a user to receive hot water from the spout, the leftover water at lower temperature remaining in the water pipes must first be drained from the pipes and replaced by the hot water from the tank. Therefore, the next time the user opens the dispensing device 5, the remaining cooled water inside pipe 3 flows out, first, before it is replaced with fresh hot water from the hot water source 2. Since the pipe 3 from the hot water source to the dispensing device is typically quite long, it contains a large quantity of water which will go to waste before the user receives water of a desired temperature. This is especially the case in apartment and multi- story buildings, where all the water tanks (or other water source) are positioned on the roof or another location outside the apartment. Thus, in such conventional water systems, very large quantities of low temperature water in the pipes go to waste, and the user often must wait a long time for the hot water to arrive at the spout. In addition, there is a waste of energy, since the non-used water was heated but then cooled off inside the pipes, and more energy must be applied in order to heat the incoming cold water.

Accordingly, there is a long felt need for a more efficient and water- saving hot water system, and it would be very desirable to have such a flow system that provides hot water with substantially no delay, while saving energy.

SUMMARY OF THE INVENTION

The present invention relates to a method and system for controlling the water or other liquid flow in pipes in locations where the source of liquid is disposed at a distance from the point of use. In particular, when referring to hot water pipes, in order to prevent the waste of water that was heated but not dispensed, a valve is closed to stop the hot water flow shortly before the user has finished using the water (showering, washing dishes, etc.). The user then continues to use the heated water until it stops flowing from the pipe, at which time he or she turns off the faucet. In this way, the pipes are drained in such a way that the drained liquid can be used, and no heated water is wasted, as all the heated water in the pipes is used.

There is provided according to the present invention a method for controlling liquid flow. The method includes opening a controllable control valve disposed in a liquid pipe permitting liquid to flow through the liquid pipe from a source of liquid to a liquid outlet valve, opening the liquid outlet valve, selectably closing the control valve, stopping inflow of liquid through the valve to the liquid pipe, and draining the liquid from the liquid pipe below the control valve through the liquid outlet valve.

According to some embodiments of the invention, the step of draining includes maintaining the liquid outlet valve open, and the method further includes closing the liquid outlet valve when the liquid pipe between the control valve and the liquid outlet is drained of liquid.

According to some embodiments, the step of draining further includes introducing air into the liquid pipe below the control valve.

There is further provided, according to the invention, a system for controlling liquid flow including a source of liquid, and a liquid outlet with a liquid outlet valve, the system further including a controllable control valve disposed in a liquid pipe, the pipe extending between the source of liquid and the liquid outlet, the control valve controlling flow of liquid from the liquid source into the liquid pipe, and a control switch for actuating switching of the control valve between two states: a first when the control valve is closed; and a second, when the control valve is open. In order to take advantage of gravitation to empty the pipe, the liquid outlet is disposed lower than the source of liquid or, at least, lower than the control valve.

According to preferred embodiments of the invention, the system further includes a venting valve, disposed in the liquid pipe below the control valve, for introducing air into the liquid pipe when the control valve is closed.

According to some embodiments, each of the controllable control valve and the venting valve includes switching circuitry, actuated by the control switch, for causing the control valve to open when the venting valve is closed, and to cause the control valve to close when the venting valve is open.

According to other embodiments, the system further includes a valve controller coupled to the control switch and actuated thereby, and including switching circuitry coupled to the controllable control valve and to the venting valve for causing them to switch states when actuated by the control switch.

According to further embodiments, the valve controller further includes a device for determining when a pre-set quantity of liquid has passed through the control valve and automatically actuating the switching circuitry to close the control valve and open the venting valve when the pre-set quantity of liquid has passed through the control valve.

In some embodiments the venting valve is a controllable valve controlled by the control switch. In other embodiments, the venting valve can be a check valve or other one-way valve. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further understood and appreciated from the following detailed description taken in conjunction with the drawings in which:

Fig. 1 is a schematic illustration of a conventional prior art water flow system; Fig. 2 is a schematic illustration of a water flow system constructed and operative in accordance with one embodiment of the present invention;

Fig. 3 shows an enlarged detailed view of a control box, suitable for use in the system of Fig. 2;

Fig. 4 is a schematic illustration of a water flow system constructed and operative in accordance with another embodiment of the present invention; and

Fig. 5 is a schematic illustration of an electric valve controller, according to an alternative embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a method and system for controlling the water or other liquid flow in pipes, reducing wasted water and wasted energy. The invention is particularly useful in locations where the source of liquid is located a relatively long distance from the point of use, which typically results in a large amount of standing liquid in the pipes. This water tends to cool by exchanging heat with the environment, to temperatures below what users desire, particularly in cold countries. According to the present invention, substantially the heated water is drained from the pipe and used by the user, before the water outlet is closed. This is accomplished by closing a control valve disposed in the pipe between the liquid source and the liquid outlet valve, shortly before the user has finished using the hot water. Closing the valve prevents the flow of liquid from the liquid source into the pipe. At the same time, the user holds open the faucet or dispensing valve at the liquid outlet so as to use the heated water flowing out and emptying the pipe of all the heated water. According to some embodiments, the liquid outlet is disposed lower than the source of liquid, to take advantage of the gravitational force. The system is also operative when the control valves are disposed relatively close to the liquid source and the control valves (not necessarily the liquid source) are higher than the liquid outlet. However, the source can be lower than the outlet and the liquid can be lifted to the valves by means of the water system pressure or a pump.

This method and system will be described herein with regard to heated water flow, by way of non-limiting example only, for which they are particularly suited, in order to quickly and efficiently provide a user with hot water from a source of hot water and, at the same time, prevent waste of water while the user waits for heated water to arrive at the outlet.

This is accomplished by introducing a controllable valve into the pipe carrying hot water from the source of hot water, e.g. a hot water tank or boiler, to a hot water dispensing valve, for example, a faucet in a shower. Preferably, the valve is electrically operated. This valve, hereinafter: a control valve, controls the flow of liquid from the source into the pipe. The control valve can be reversibly switched between a normally closed state, wherein the control valve prevents the flow of hot water from the source of hot water to the dispensing valve, stopping the flow of hot water through the pipe, and an open state, wherein the control valve allows the flow of hot water from the source of hot water to the dispensing valve. Thus, the water pipe, essentially, can be divided into three pipe sections: a first pipe section which connects the water source to the control valve; a second section of pipe, which connects the control valve to the venting valve; and a third section of pipe, which connects the second section from the venting valve to a dispensing device. When the control valve is closed, the second pipe section is sealed off from the first pipe section. This means that no liquid flows from the liquid source to the second pipe section, and any liquid already in the second and third pipe sections flows out through the liquid outlet valve or dispensing device, typically by gravity, as long as the dispensing device is open.

The system further includes a control switch operated by the user, first to reversibly switch the control valve from the normally closed state to the open state, and then to switch the control valve from the open state back to the closed state. The control switch preferably is disposed adjacent the dispensing device, for easy access by the user. For use in a shower stall or other environment where the user may be wet while turning on and off the switch, the switch preferably will be disposed in an adjacent wall with a waterproof covering and/or suitably insulated to prevent entry of water into the contacts and creating an electric shock to the user, as known.

A control wire electrically may connect the control switch to the control valve. Alternatively, a wireless control system can be utilized, or a pneumatic actuating button coupled to an electric switch. According to another embodiment, the valve can be moved between the two states manually. Preferably, the control valve is a solenoid operated valve. According to a preferred embodiment, the control valve is disposed in a control box for protection against unintentional actuation or damage, but providing ease of access, when necessary. In this way, little to no water remains in the second and third pipe sections once the dispensing valve has been closed. When a user wants to take a shower, for example, one can quickly receive hot water soon after opening the dispensing valve, since the second and third pipe sections of the hot water pipe are free of water and the hot water from the hot water source arrives directly at the dispensing valve without mixing with lower temperature water standing in the pipe, as it is the case in conventional hot water systems. In addition, there is little or no waste of water while waiting for cold water to be drained out of the hot water pipe, prior to use.

However, when heated water pipe empties, a vacuum builds up inside the pipe that can slow or prevent the emptying of the pipe. According to some embodiments of the invention, emptying of the pipe can be facilitated by introducing a second valve, a venting valve, in sequence into the pipe, which introduces ambient or pressurized air to the pipe section, thereby lowering the vacuum formed in the pipe to a point where it has a minimal effect on dispensing of the water.

According to some embodiments, the venting valve can be a one-way valve or a check valve preventing the outflow of water through the valve. When a certain level of vacuum is reached inside the pipe, the one-way valve will open, introducing air into the pipe and facilitating the outflow of water from the pipe.

Alternatively, the venting valve can also be a controllable valve, that can be reversibly switched between a normally open state, wherein the venting valve permits ambient air to enter the pipe, and a closed state, wherein the venting valve blocks the flow of ambient air into the pipe. In this case, the same control switch that actuates the control valve to open can, at the same time, actuate the venting valve close, and vice versa.

If desired, the same arrangement of a control valve, with or without a venting valve, can be introduced into the pipe leading cold water from a source of cold water, e.g., the main water conduit system, to the water dispensing device, for example, the dispensing valve or faucet in a shower. It will be appreciated that the liquid and venting valves arrangement can be limited to a hot water pipe only. However, providing the same arrangement for the cold water pipe helps to avoid an unbalanced change in water pressure when the hot water is drained during use, when the control valve is switched to the closed state.

Referring now to Fig. 2, there is shown a system 10 for controlling liquid flow according to some embodiments of the present invention. System 10 will be described with relation to a shower or sink in a bath room, for which it is particularly suited. System 10 includes a source 22 of hot liquid, here shown as a hot water tank or solar boiler, disposed higher than a liquid outlet, here illustrated as a dispensing device 25 (a shower faucet) with spout 27. A hot water pipe 30 couples the hot water source 22 to the dispensing device 25, and a cold water pipe 40 couples a cold water inlet 15 to the dispensing device 25. A controllable control valve (not shown) is disposed in liquid pipe 30, the control valve controlling flow of liquid through the pipe. A venting valve (not shown) is also disposed in the liquid pipe 30, below the control valve, introducing air to the liquid pipe when the control valve is closed.

In the embodiment illustrated in Fig. 2, the control valve and the venting valve are housed in a control box 6. A control switch 14 is provided for controlling the valves in the control box by actuating switching of the control valve between closed and open states and, of the venting valve, in embodiments wherein it is a controllable electronic valve, between open and closed states.

One embodiment of a suitable control box 6 is shown in detail in Fig. 3. As can be seen, control box 6 holds at least one, and possibly two control valves 8. A first control valve 8 is disposed in hot water pipe 30. A second control valve 8', if desired, is disposed in cold water pipe 40. Control switch 14 is electrically coupled to the valves in the control box, as via a control wire 16. Water pipes 30 and 40 have three sections: pipe sections 23, 24 coupled to the hot and cold water sources, respectively, pipe sections 31 and 41 extending between the control valves and the venting valves, and pipe sections 33, 44 leading to the dispensing device.

In the embodiment of Fig 3, control valves 8, 8' are in a normally closed state, wherein they block the flow of water from pipe sections 23 and 24 to pipe sections 31 and 41, respectively. Venting valves 9, 9' are in a normally open state, wherein ambient air is introduced into the lower pipe sections 33, 34. Venting valves 9, 9' facilitate the draining of pipe sections 31, 41, and 33, 44 when control valves 8, 8' are closed and dispensing valve 25 is open, by allowing ambient air to enter pipe sections 31 and 41. Thus, when dispensing valve 25 is closed by the user when no more water flows out through the dispensing valve, pipe sections 31, 41, and 33, 44 have been drained of water by gravitation and have been filled with air that entered through the venting valves. Alternatively, pressurized air can be introduced through venting valves 9, 9' to urge the liquid in the pipes to drain out the outlet valve.

Preferably, as illustrated in Fig. 3, an electric valve controller 18 is provided, coupled to control switch 14, for controlling the valves. Valve controller 18 includes switching circuitry and is electrically coupled to the valves, as via wires 20, and to control switch 14, as via control wire 16. When control switch 14 is activated, valve controller 18 causes control valves 8, 8' to switch to the open state and venting valves 9, 9' to switch to the closed state. And when control switch 14 is turned off, valve controller 18 causes control valves 8, 8' to switch to the closed state and venting valves 9, 9' to switch to the open state. Alternatively, a separate control switch 14 can be provided for direct actuation of each valve, in which case, valve controller 18 is not required. In this case, the user must actuate both control switches, in order to switch both the control valves and the venting valves to the desired states. According to yet another embodiment, instead of a valve controller 18, the switching circuitry can be an integral part of the liquid and venting valves, themselves, or of the outlet valve or faucet.

In order to take advantage of gravity to empty the pipe, it will be appreciated that the control valve must be located higher than the liquid outlet valve. This will also work if the liquid source is lower than the outlet, when the system's water pressure is sufficient or a pump mechanism is provided. One example of such a system 50 is illustrated schematically in Fig. 4. System 50 includes a liquid source 52, a control box 54 holding at least one control valve (not shown) and, possibly, at least one venting valve (not shown). The valves in control box 54 are connected to the liquid outlet valve 56, here illustrated as a shower faucet. The operation of the systems of Figs. 2-4 is as follows. When a user wants to receive hot water from the hot water source 22 to a liquid outlet valve 25, the user turns on the control switch 14, which causes control valve 8 to open, permitting liquid to flow through the liquid pipe from the source of liquid to the liquid outlet valve. When the user opens liquid outlet valve 25, hot water flows from the hot water source 22 through pipe section 23 of pipe 30 to pipe sections 31 and 33, respectively, and out through spout 27, as in a conventional water flow system. However, since the pipe sections 31 and 33 below control valve 8 were drained of water after the previous use and contain only air, fresh hot water flowing from hot water source 22 reaches spout 27 rapidly and with only a minor reduction in temperature. Thus, the user is provided, almost immediately, with hot water without the need to wait for a relatively large amount of water at a low temperature to be drained from the pipes, before the water at spout 27 reaches a desired high temperature.

Shortly before the user is about to finish using water from the water system, the user turns off the control switch 14 which, in turn, causes the control valve 8 to close. Closing the control valve 8 blocks the flow of water from pipe section 23 to pipe section 31. This, in turn, permits draining of pipe sections 31 and 33 though spout 27 by gravity, as long as dispensing valve 25 remains open. The user can leave dispensing valve 25 open and continue to use the water remaining in the pipes until no water exits spout 27, to ensure that no more water is left in these pipe sections. After use of the system, only pipe section 23 is filled with hot water. Below the closed control valve 8, pipe sections 31 and 33 are filled with ambient air, only.

It will be appreciated that the closer the valves are to the water source, the more effective the system will be, as the empty pipe portions below the control valve are longer, in a given length of pipe. It will be appreciated that the same method can be implemented in the cold water pipe, in order to balance the change in water pressure when the hot water is drained during use, when the control valve is switched to the closed state.

In an embodiment where there is a venting valve, the operation of the system will be as follows. When a user wants to receive hot water from the hot water source 22 to a dispensing or liquid outlet valve, the user turns on the control switch 14, which causes control valve 8 to open and also causes venting valve 9 to close. When the user opens dispensing valve 25, water flows from the hot water source 22 through pipe section 23 of pipe 30 to pipe sections 31 and 33.

Shortly before the user is about to finish using water from the water system, the user turns off the control switch 14 which, in turn, causes the control valves 8 to close and causes venting valve 9 to open. Closing the control valve 8 blocks the flow of water from pipe section 23 to pipe section 31. Opening venting valve 9 introduces ambient or pressurized air to pipe sections 31 and 33. This, in turn, aids draining of pipe sections 31 and 33 though spout 27 by gravitation, as long as dispensing valve 25 remains open. The user can leave dispensing valve 25 open and continue to use the water remaining in the pipes until no water exits spout 27, to ensure that no more water is left in these pipe sections.

It will be appreciated that if the venting valve is a check valve that operates on vacuum, there is no need for the control switch to operate the venting valve. Rather, the venting valve operates as a function of the pressure in the pipe. This embodiment provides a simplified system, as no controller is required to open and close the venting valves.

It will be appreciated that, while control valves 8, 8' and venting valves 9, 9' are described herein above as electrically activated solenoid valves, alternatively, they may be any other suitable controllable valves, e.g., manual, mechanical, electrical, hydraulically operated, or any other controllable valves.

According to another embodiment of the invention, there is no separate actuator for the control valve. Rather, the dispensing valve, itself, is an electrical faucet which is configured so that turning on the faucet automatically actuates the control valve, to permit the flow of liquid from the source. If there is an electrically controllable venting valve, the faucet will activate the controller to actuate both the valves. Otherwise, operation is the same as described above with a separate actuator.

In the case of automatic actuation, or in any of the embodiments described above, valve controller 18 may include a device for automatically closing the control valve 8 at a pre- set time shortly before the user typically finishes use, so as to provide enough time to drain the water from the pipes through use. This device can be a timer or a flow sensor or any other device for determining a quantity of liquid passing through the control valve. Fig. 5 is a schematic illustration of an electric valve controller 18' including a device for determining liquid quantity 60 having a switch for activating and deactivating valve 8. When the control switch 14 is activated, the device for determining liquid quantity 60 is turned on, as via wire 16', and, in turn, switches the control valve 8 to the open state, as via wire 64 or using wireless communication. When a pre-selected amount of time has passed or a pre-set quantity of water has passed through the control valve, the liquid quantity determining device 60 automatically switches the control valve back to the closed state, without requiring the user to actuate the control switch 14. The user may then continue to use the water flow until the pipes are drained of water.

If there is also a controlled venting valve, the device for determining liquid quantity 60 is coupled to switching circuitry 62 that activates valves 8 and 9, as via wire 20' or using wireless communication, ensuring that, when control valve 8 is in one state, then venting valve 9 is switched to the opposite state.

It will be appreciated that the present invention saves energy, since substantially all the heated water is used, and energy is not wasted heating water that remains in the pipes.

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. It will further be appreciated that the invention is not limited to what has been described hereinabove merely by way of example. Rather, the invention is limited solely by the claims which follow.

Claims

1. A method for controlling liquid flow, the method comprising:

opening a controllable control valve disposed in a liquid pipe permitting liquid to flow through said liquid pipe from a source of liquid to a liquid outlet valve; opening the liquid outlet valve;

selectably closing said control valve, stopping inflow of liquid through said valve to said liquid pipe; and

draining the liquid from the liquid pipe below the control valve through the liquid outlet valve.

2. The method according to claim 1, wherein:

the step of draining includes maintaining the liquid outlet valve open, and the method further includes closing the liquid outlet valve when said liquid pipe between said control valve and said liquid outlet is drained of liquid.

3. The method according to claim 1, wherein said step of draining includes draining in such a way that the drained liquid can be used, thereby preventing waste of liquid

4. The method according to claim 1 or claim 2, wherein said step of draining further includes introducing air into the liquid pipe below said control valve.

5. The method according to claim 4, further comprising introducing air into the liquid pipe when said control valve is closed and no liquid flows from the liquid source to the liquid pipe, and stopping inflow of air into said liquid pipe when said control valve is open and liquid flows from the liquid source to the liquid pipe.

6. The method according to claim 1, wherein said step of opening a control valve includes activating a control switch to actuate switching of said control valve between two states: a first when said control valve is closed; and a second, when said control valve is open.

7. A system for controlling liquid flow including a source of liquid, and a liquid outlet with a liquid outlet valve, the system further comprising:

a controllable control valve disposed in a liquid pipe, said pipe extending between the source of liquid and the liquid outlet, said control valve controlling flow of liquid from the liquid source into said liquid pipe;

a control switch for actuating switching of said control valve between two states: a first when said control valve is closed; and a second, when said control valve is open.

8. The system according to claim 7, further comprising a venting valve, disposed in said liquid pipe below said control valve, for introducing air into said liquid pipe when said control valve is closed.

9. The system according to claim 8, wherein each of said controllable control valve and said venting valve comprises switching circuitry, actuated by the control switch, for causing the control valve to open when the venting valve is closed, and to cause the control valve to close when the venting valve is open.

10. The system according to claim 8, further comprising a valve controller coupled to said control switch and actuated thereby, and including switching circuitry coupled to said controllable control valve and to said venting valve for causing them to switch states when actuated by the control switch.

11. The system according to claim 10, wherein said valve controller further comprises a device for determining when a pre-set quantity of liquid has passed through the control valve and automatically actuating the switching circuitry to close the control valve and open the venting valve when said pre- set quantity of liquid has passed through the control valve.

12. The system according to any one of claims 7-9, wherein said control switch includes a device for determining when a pre-set quantity of liquid has passed through the control valve and automatically closing the control valve when said preset quantity of liquid has passed through the control valve.

13. The system according to either claim 11 or 12, wherein said device is selected from the group including a timer and a flow meter.

14. The system according to claim 8, wherein said venting valve is selected from the group including a solenoid valve, a check valve and a one-way valve.