EP0916909A1 - Economiser for water heater - Google Patents

Abstract

The incoming cold water feed (3) is controlled by a solenoid-operated valve (72,71) connected electrically (76) to the pressure measuring unit (73). This has a pressure connection (77) to the water heater (1), a mains connection (75) and a visual pressure indicator (74). The unit closes the valve (71) if the pressure rises above a preset level, say 3.5 bars, keeping it closed till pressure falls below a lower value, e.g. 2 bars, e.g. because hot water is drawn off (4). The safety valve (21) is set to open well above this operating range e.g. at 7 bars. In a variant, the pressure measuring unit is placed in the draw-off connection (4).

Description

The present invention relates to a water saving device for water heaters.

It has been found that such operation could lead to excessive water consumption, of the order of several hundred liters per month without the water heater being used for water supply hot. This is due in particular to the fact that the water distribution circuits cold in agglomerations whose development was important, have seen their distribution pressure increased so that they can supply in diameter pipes restrict the amount of water needed to the supply of all families. So now it's common to find pressures in the urban network distribution of the order of 6 to 7 bars therefore very close to the pressure of the safety group (2) valve (21), which promotes this phenomenon of water consumption.

In an alternative embodiment of the devices of the prior art to overcome the disadvantages of these security groups (2) related to increasing supply pressures for cold water pipes, the installers recommended placing upstream of the safety group (2) a pressure reducer (6). However, this pressure reducer (6) did not prevent the oscillatory phenomenon.

The object of the invention is therefore to limit this phenomenon.

This object is achieved by the fact that the water saving device for storage water heaters protected against overpressure by a safety group with pressure limiting valve internal of the water heater is characterized in that means for measuring the pressure are arranged either between the limiting valve and the circuit entering the water heater, or leaving the water heater, means for controlling the opening of the cold water supply circuit of the water heater are triggered following detection by the means of measurement of the pressure, of the crossing of a determined pressure threshold.

According to another particularity, the measurement means are a pressure switch adjustable in a pressure range determined between 2 and 3.5 bars.

According to another particular feature, the pressure switch is mounted on the security group, which security group includes a siphon connected to an evacuation pipe.

According to another particular feature, the hot water pipe at the outlet of the water heater is connected to a mixing valve supplied with cold water by a pipe, the hot water supply circuit comprising between the mixing valve and water heater a non-return valve.

According to another particular feature, the opening control means and closing the cold water inlet pipe are arranged at the entry of the safety group downstream of the check valve of the safety group security.

According to another particular feature, the control means are constituted by a solenoid valve electrically connected by a connection with a pressure switch control output.

According to another particular feature, the pressure switch comprises an actuation button which controls the solenoid valve to make this solenoid valve play the role of the shut-off valve of the group of security.

La figure 1 représente une vue schématique du dispositif économiseur selon l'invention ;

la figure 2 représente une vue schématique d'un autre mode de réalisation du dispositif économiseur selon l'invention ;

la figure 3 représente une vue schématique des dispositifs de l'art antérieur.

Other features and advantages of the present invention will appear more clearly on reading the description below made with reference to the appended drawings in which:

FIG. 1 represents a schematic view of the economizer device according to the invention;

FIG. 2 represents a schematic view of another embodiment of the economizer device according to the invention;

FIG. 3 represents a schematic view of the devices of the prior art.

FIG. 3 represents the prior art constituted by a water heater (1) supplied with cold water by a pipe (3) to which a security group (2). This safety group (2) includes a shut-off valve (22), a non-return valve (23) which prevents water from the water heater (1) from return to the cold water pipe (3) and a safety valve (21) which limits the pressure inside the water heater to 7 bars. This safety valve (21) when opened releases steam into a siphon (24) and excess water is collected by a pipe evacuation (5).

The disadvantage of this prior art is that cold water arrives and fills the water heater (1). The electrical resistance or the water heater the water heater will raise the water temperature and gradually the pressure in the water heater and the pipes especially when the user does not consume hot water. When this pressure rises around 7 bars, the safety valve (21) opens and the water under pressure is discharged through the pipe (5). The water level in the water heater lowered, the non-return valve (23) opens and water cold enters the water heater. We thus manage to maintain a cycle oscillatory in which the water heater operates continuously, evacuates water heated under pressure in the direction of the evacuation pipe, instead of distributing it through the hot water distribution pipe (4).

The economizer is achieved by one of two modes of realization of figure 1 or 2. Thereafter in the description one does not redescribe not the elements of the safety group (2) of the prior art but these are part of the circuit of the invention. In Figure 1 a solenoid valve (71) controlled by an electromagnet (72) is mounted on the pipe supply (3) of cold water to a storage water heater (1). The electromagnet (72) is connected by an electrical connection (76) to a contactor gauge (73) whose trigger threshold can be set between 2 minimum bars and maximum 3.5 bars. This pressure switch (73) is linked to the hot water distribution circuit by a pressure (77) and supplied with electrical energy by a power outlet (75). The contactor also includes an indicating device (74) used to indicate the circuit pressure. The pressure switch (73) generates an electrical signal on the link (76) when the preset threshold pressure is exceeded. This electrical signal controlled by the electromagnet (72) closing the valve (71). The electrical signal is maintained by the pressure switch as long as the pressure does not drop below a second threshold set for example at 2 bars. Below this value, the supply of the solenoid valve is interrupted and the valve (71) is open, allowing cold water to be supplied to the water heater (1).

As the hot water temperature rises, the pressure rises reaching the pre-set threshold, for example, 3.5 bar and the contactor pressure gauge (73) controls the closing of the solenoid valve (71) thereby interrupting the cold water supply to the water heater tank. Of this way if the pressure continues to increase by heating the water, this increase in pressure cannot trigger an evacuation significant water through the safety valve (21). Even if some quantity of water is evacuated, the filling of the water heater circuit will only be not performed as long as the pressure remains above 3.5 bar. The solenoid valve (71) is closed and interrupts the cold water supply circuit. As soon as the hot water distribution circuit (4) is used, water is consumed and, the pressure in the water heater decreases. This pressure goes down in below a lower threshold set, for example, at 2 bars which causes opening by the control line (76) of the solenoid valve (71). The water heater can then fill up normally and will be able to fill with cold water until the water pressure reaches the fixed limit value and the pressure switch which will interrupt again the water supply circuit.

We understand that by the device of the invention we thus arrive at limit the risk of water leaking through the group's safety valve (21) security (2). Similarly, the invention can be used in the version where the water heater has its hot water supply line (4) of the installation connected to a mixing valve (42). The mixer (42) is supplied with the other side in cold water through a pipe (31) and distributes water mixed by the pipe (34). Such a connection in the prior art could also cause cold water consumption in allowing the filling of the water heater through the mixing valve (42). For avoid this phenomenon, in addition to adapting the device of the invention, places a non-return valve (41, figure 2) at the inlet of the mixer, which prevents the circulation of water from the mixer (42) to the water heater (1).

In the variant of FIG. 2, the pressure switch (73) is connected to the hot water outlet pipe (4) of the water heater and controls the solenoid valve (71, 72) which is connected as before upstream of the safety group (2) on the cold water supply circuit (3).

Thus, the invention has been described for storage water heaters, especially electric but can also be used on other types storage water heaters such as gas, fuel or other combustibles.

In an alternative embodiment, the pressure switch (73) can be provided with a manual actuation button, intended to trigger supplying the link (76) and closing the valve (72). This mode of realization eliminates the need for the stop valve (22) normally provided in the safety group.

Other modifications within the reach of those skilled in the art make also part of the spirit of the invention.

Claims (7)

Water saving device for water heaters (1) to accumulation protected against overpressure, by a safety group (2) comprising a valve (21) for limiting the internal pressure of the water heater (1) characterized in that means (73) for measuring the pressure are arranged either between the limiting valve (21) and the circuit (3) water inlet into the water heater, or outlet (4) of the water heater and means (76, 71, 70) for controlling the opening of the circuit cold water supply to the water heater are triggered following the detection, by means of pressure measurement, of the crossing of a pressure threshold determined. Water saving device for water heaters according to claim 1, characterized in that the measuring means are a pressure switch (73) adjustable in a pressure range determined between 2 and 3.5 bars. Water saving device for water heaters according to claim 2, characterized in that the pressure switch (73) is mounted on the security group (2), which security group includes a siphon (24) connects to a drain pipe (5). Water saving device for water heaters according to one of the previous claims, characterized in that the water pipe (4) hot at the outlet of the water heater (1) is connected to a mixing valve (42) supplied with cold water via a pipe (31), the hot water supply circuit (4) comprising between the mixer (42) and the water heater (1) a check valve back (41). Water saving device for water heaters according to one of the previous claims, characterized in that the means for control (71, 72) for opening and closing the inlet pipe cold water (3) are arranged at the entrance to the safety group (2) downstream of the safety group check valve (23) (2). Water saving device for water heaters according to claim 5, characterized in that the control means are constituted by an electrically connected solenoid valve (71, 72). Water saving device for water heaters according to one of the previous claims, characterized in that the contactor pressure gauge has an actuation button which allows control the solenoid valve (71, 72) so as to play this solenoid valve the role of the stop valve (22) of the safety group (2) by a connection (76) with a control output of the pressure switch (73).

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