DE8913252U1 - Hot water tank - Google Patents

Description

09, Nov 1989

Joh. Vaillant GmbH u. Co.

GM843

Hot water tank

The invention relates to a heatable hot water storage tank with a cold water supply line and a hot water tap line which opens into at least one tap valve leading to a tap, as well as with a storage container from which a portion of the storage water is withdrawn each time the water is tapped in order to prevent the storage water, which increases in volume due to the heating, from dripping at the tap when the storage water is heated up following the tap.

Attempts have already been made in various ways to control the withdrawal of a portion of the stored water during each tapping process.

For example, from DE-OS 14 04 210 a device is known in which, after completion of a tapping process, a predetermined volume of liquid is dispensed from the reservoir.

&psgr; container is sucked out in order to lower the liquid level sufficiently below the overflow.

DE-PS 36 31 178 also shows such a device with a ' two-chamber system and a flexible wall ' which is intended to ensure that a portion of the storage water is sucked out.

Finally, DE-OS 30 40 450 discloses a storage tank whose volume can be changed as required by means of an actuator.

However, all of these devices prove to be too complicated and therefore too expensive for practical use.

The object of the invention is to solve the problem described above by means of a structurally simple and therefore highly practical measure.

According to the invention, this object is achieved in that the volume of the stored water can be reduced by the cold water inlet of the storage tank.

Within the scope of the invention, various possibilities are open for this measure, which can be implemented in practice in a comparatively simple manner with little space expenditure.

According to one embodiment, the volume of stored water can be reduced by a negative pressure generated by the cold water flow.

For this purpose, only a pressure reducer, preferably a venturi nozzle, needs to be arranged in the cold water supply line, in whose negative pressure area an expandable container is connected to the cold water supply line, the variable volume of which is proportional to the pressure prevailing in the container. If cold water now flows in, the result is that there is a negative pressure in the venturi nozzle, the expandable container reduces its volume and only expands to its original, larger volume after the cold water flow has ended, sucking in storage water from the storage container and thereby reducing the storage water volume by a proportion proportional to the cold water flow.

For low-pressure storage, advantageous embodiments can be used in which the storage space itself can change its volume, so that no additional devices need to be accommodated outside the container.

A pressure reducer, preferably a Venturi nozzle, can also be arranged in the cold water supply line of the storage tank, in whose negative pressure area a spring-loaded air inlet valve is arranged.

If negative pressure occurs as a result of cold water flow, this air inlet valve opens and allows air to enter the storage tank, which collects in the area of the tank ceiling and thus reduces the storage water volume.

A retaining plate or an extension of the hot water tap line can act as a retainer for this air. To retain the air during the tapping process, a flap that can be moved in the direction of the hot water flow can be mounted in the area of the hot water tap line connection located in the ceiling of the storage tank.

According to further embodiments of the invention, the temperature of the incoming cold water can also be used to reduce the volume of stored water.

In the case of a hot water tank whose volume can be changed by means of an actuator, this can be advantageously achieved by having this actuator adjust one of its

Contains an expansion body that changes in length depending on the temperature, for example a bimetallic spring, which is directly surrounded by the cold water inlet.

In order to vary the volume of the storage tank itself, its wall can then contain an expandable area between its top and bottom, for example in the form of a bellows, and the bottom can be adjustable in relation to the top by the actuator.

However, it is also possible to arrange a membrane extending over the diameter of the storage tank, preferably in the bottom area, which membrane can be adjusted by the actuator in relation to the ceiling.

Embodiments of the subject matter of the invention are illustrated in the drawings and subsequently explained using the drawing figures.

In detail:

Figure 1 shows a hot water tank with its connections schematically in a side view,

Figure 2 shows a schematic vertical section through a hot water tank of another type,

II··

- 6 Figure 3 a detailed variant of this embodiment,

Figure 4 shows another embodiment also in a schematic vertical section and

Figure 5 shows a modified version of such a memory in the same representation.

According to Figure 1, the storage tank 1 of a pressureless hot water tank 1 is connected to a cold water supply line 3 controlled by a valve 2 and to a hot water tap line leading to at least one tap. A Venturi nozzle 5 is arranged in the cold water supply line 3 as a local pressure reducer, to the negative pressure area of which an expandable container, for example in the form of a bellows 6, is connected, which adapts its volume to the pressure prevailing therein.

changes proportionally.

; If a cold water inflow occurs via the cold water supply line 3 due to a tap at a tap point, this results in a negative pressure in the Venturi nozzle 5, the expandable container 6 reduces its volume accordingly and only expands to its original, larger volume after the cold water inflow has ended, whereby it sucks in storage water from the storage container 1 and thus reduces the volume of the storage water.

For example, the expandable container reduces its volume from level A to level B and expands from level B to level A after the end of the tapping. The difference between the two volumes must correspond to the maximum volume by which the stored water can expand when heated.

In the embodiment of the hot water tank according to Figure 2, a Venturi nozzle 5 is arranged in the cold water supply line 3 as a pressure reducer. In the negative pressure area of this Venturi nozzle 5, there is a spring-loaded air inlet valve 7 in the pipe wall. In this embodiment, the hot water tap line 4 protrudes slightly into the storage tank 1, and in the area of its inlet, a spring-loaded flap 8 is pivotally mounted on an air collecting plate 9.

Figure 3 shows a variant in which the flap 8 is located inside the pipe socket formed by the hot water tap line 4 and closes an opening 10 in the line wall. The air that collects in the area 11 of the top of the container 1 is initially held back by the air collecting plate 9 or the pipe socket with opening 10 and valve so that it does not immediately enter the hot water tap line 4. The flaps 8 are moved in the direction of flow when hot water is discharged.

• · &igr;

and this movement closes another valve located in the pipe socket.

If the cold water supply valve 2 is now closed and the flow of hot water in the hot water tap line 4 is also stopped, the flap 8 falls down and the valve on the air collector plate can open. Now the air held back behind it flows first to the hot water tap. The space thus freed up in the pipe system can absorb the excess storage water caused by thermal expansion. Advantageously, the amount of air accumulating in the ceiling area of the storage tank 1 is proportional to the volume share that arises when the storage water is heated as a result of expansion.

According to the embodiment of Figure 4, the wall of the storage tank 1 comprises an expandable region 12 between its top and bottom, for example in the form of a bellows. The bottom of the storage tank 1 is adjustable in relation to its top by means of an actuator 13 which contains an expansion body which changes its length thermodynamically, namely a bimetallic spring 14, which is immediately flushed with cold water from the cold water outlet 15 of the cold water supply line 3 directed towards it as soon as the valve 2 is opened.

If cold water flows out of the mouth of the cold water outlet 15, which is directed against the bimetal spring 14, during a tapping process, the shortening actuator 13 raises the bottom of the tank and thereby reduces the storage volume. As soon as the cold water supply stops and the storage water is heated, the actuator 13 increases the volume of the storage tank by lowering the bottom to such an extent that it is only partially filled with the storage water and can therefore absorb the excess resulting from thermal expansion.

In the embodiment according to Figure 5, this function of the movable container bottom is taken over by a membrane 16 arranged in the bottom area with a membrane plate 17, which is connected to the lower end of the actuator 13. The membrane 16 is peripherally connected to the container wall and delimits an air-filled space with an air outlet 18.

The function of this embodiment is the same as that of the embodiment of Figure 4.

Claims (3)

Joh. Vaillant GmbH u. Co. GM 843 K: - 1 - 1. Heatable hot water storage tank with a cold water supply line provided with a tap valve and a hot water tap line as well as with a storage tank from which a portion of the storage water is drawn off with each tap in order to avoid dripping of the storage water at the tap point when the storage water is heated up following the tap, the volume of which increases due to the heating, whereby the volume of the stored water can be reduced by the cold water inlet, characterized in that the cold water inlet in the storage tank is connected to a body which changes its length with the temperature of the incoming cold water, for example a bimetal spring (14) is provided and that this reduces the volume of the storage container (1) when it cools down. 2. Heatable hot water storage tank with a cold water supply line provided with a tap valve and a hot water tap line as well as with a storage tank from which a portion of the storage water is drawn off each time water is drawn off in order to prevent dripping of the storage water at the tap point when the storage water is heated up following the drawing off, the volume of which increases due to the heating, whereby the volume of the stored water can be reduced by the cold water inlet, characterized in that a body whose length changes with the temperature of the incoming cold water, for example a bimetal spring (14), is provided for the cold water inlet in the storage tank and that the body whose length changes is connected to a membrane (16) to which a region of the storage tank separated from the volume of the storage tank (1) is connected. 3. Heatable hot water storage tank with a cold water supply line provided with a tap valve and a hot water tap line as well as with a storage tank from which a portion of the storage water is drawn off each time the water is tapped in order to prevent the storage water, which increases in volume due to the heating, from dripping at the tap point when the storage water is heated up following the tap, whereby the volume of the stored water can be reduced by the cold water inlet, characterized in that the tap line (4) connected to the top of the tank ends a certain amount below the top of the tank so that an air space is formed here and that a vent valve (8) is provided which prevents air from flowing out into the tap line (4) when the tap valve is open, while the valve opens after the tap valve (2) is closed.