EP0684429B1 - Closed expansion tank for fluid-filled installations - Google Patents

Abstract

The expansion tank (2) has a partition membrane (8) for dividing a liquid compartment (10) and a gas compartment (6). The outside of the expansion tank has a tubular, transparent receptacle (14) at least partly visible from outside and sealed off from the surrounding atmosphere. The receptacle's interior is connected by a passage (16) with the gas compartment and positioned in the bottom third part of the gas compartment. The lengthwise axis of the receptacle is at least 30 degrees from the horizontal. The receptacle consists of a tube closed on one side. The open side is mounted in the wall (4) of the expansion tank on a connecting fitment. A float is contained inside the receptacle. <IMAGE>

Description

The invention relates to a closed expansion vessel for liquid-filled systems according to the generic term of claim 1.

Expansion tanks are mainly used to Volume changes occurring in drinking water and heating systems to balance the liquid or a minimum pressure maintain in the plant. For this, the Expansion vessel on a flexible membrane that its Interior separates into a liquid space that is in contact with the plant in question, and an air or gas space, in which usually a certain form is available. With liquid intake, the air or Gas cushion compresses, and the associated increase in pressure ensures the return of the absorbed liquid to the system in the event of pressure drop or volume decrease.

Separation membranes come in a wide variety of designs and installation methods used. As examples here on the one hand the so-called inverted membranes, which as the actual partition is installed in the expansion tank, and on the other hand the bubble membranes, which are inside the Expansion vessel form a flexible hollow body, listed. An expansion tank with a bladder membrane is described for example in DE-A-29 11 303.

Since expansion vessels must have a long service life, are the separation membranes with the highest quality and for manufactured long life. Nevertheless, in individual cases is a manufactured long life. Nevertheless, in individual cases is a Defect of a separation membrane, a leak or a Break, not to be excluded entirely. Such a defect occurs on, liquid penetrates into the gas space and that Expansion tank becomes inoperable. Moreover, it can due to the non-intended contact between the liquid and the vessel wall of the gas space to form corrosion and consequently the liquid becomes contaminated, which is particularly important for expansion tanks Drinking water has an unfavorable effect.

For these reasons, it is with the known expansion vessels disadvantageous that a membrane defect hardly or can only be determined with great difficulty because of the most expansion tanks, the interior is not possible of the vessel, and a malfunction of the expansion vessel in any other way for the users of the system is not easily recognizable.

The expansion vessel described in DE-A-29 11 303 indeed has a leakage water collecting container arranged on the outside with built-in sight glass, whose Interior is connected to the gas space via a passage; since the background of the sight glass but the dark container interior is any leakage water is very difficult to detect.

It is therefore an object of the invention to provide a closed one To propose expansion vessels of the type described in the introduction, in which a possible penetration of liquid in the gas space is easy and clear to see.

This task is accomplished by the in the characterizing part Features defined by claim 1 solved; preferred Embodiments result from the dependent Claims.

Accordingly, with a closed expansion vessel for liquid-filled systems, especially drinking water and heating systems, with a separating membrane for Separation of liquid space and gas space and one on the Arranged outside of the expansion vessel, opposite the container sealed from the surrounding atmosphere Interior connected to the gas space via a passage the container has a clear area through it which occurs in the container when liquid penetrates Liquid level or one through the liquid level movable display organ against a background is recognizable, at least partially by a translucent Area of the container is formed.

The container is visible against a light background. If the separating membrane now leaks, then when the liquid enters the gas space, also run into the container and can be used immediately from the outside and easily recognized. With a simple optical Review can thus be determined at any time whether the Separation membrane is still intact or possibly a defect having.

The passage is preferably in the lower third provided in the gas space, particularly preferably on the gas space lowest position.

In order to detect any liquid in the According to a preferred embodiment in the interior of the container Float must be included, the exterior of which suitably one has clearly visible contrasting color.

The solution according to the invention enables one surprisingly simple constructive measure, a possible one Penetration of liquid into the gas space from outside in a simple and safe way. The associated additional costs in the production of Expansion tanks are very small, which in view that such vessels are extremely inexpensive these days are offered is critical.

It also proves to be Gas tightness of the expansion tank as very advantageous, that the invention is only a single additional opening in of the vessel wall, the diameter of which is also comparatively high can be kept small. As the form in maintain an expansion tank for a long time Must stay are places that are at increased risk To avoid form pressure loss, if possible to avoid and experience has shown that such positions are all the more effective to seal, the shorter and easier their circumference is. For the same reason, they are also conceivable Measuring devices with electrodes arranged in the gas space disadvantageous, since this leads through conductors in the vessel wall need to be inserted because of the necessary Insulation satisfactory only with considerable effort have it sealed.

Fig. 1 und 2 ein erfindungsgemässes Ausdehnungsgefäss im Schnitt mit an seiner unteren Wand angeordnetem, von aussen einsehbarem Behälter zur Anzeige eines funktionswidrigen Flüssigkeitsaustritts, wobei in Figur 2 schematisch eine undichte Stelle der Trennmembrane und dort austretende Flüssigkeit angedeutet ist, und

Fig. 3 den Behälter in vergrösserter Perspektivdarstellung.

To further explain the invention, an embodiment is described below with reference to the accompanying drawings. Show in the drawings

1 and 2 an expansion vessel according to the invention in section with a container arranged on its lower wall and visible from the outside to indicate a malfunctioning liquid outlet, a leakage point of the separating membrane and liquid escaping there being indicated schematically in FIG. 2, and

Fig. 3 shows the container in an enlarged perspective view.

That which is designated overall by 2 in FIGS. 1 and 2 Expansion tank has one, usually made of steel manufactured, vessel wall 4. This encloses you Gas space 6. In the gas space 6 there is a bubble separation membrane 8 mounted, the interior of which forms a liquid space 10. The liquid chamber 10 is connected to a via a connection 12 - Not shown here - liquid-filled system connected.

On the lower wall section 4.1 of the expansion tank 2 is one designated in its entirety by 14 Container arranged, the structure of which is described in more detail below is described. The interior of the container 14 is from Visible from the outside and via a passage 16 with the gas space 6 of the expansion tank connected. In Figure 2 is illustratively indicated how liquid 18 from a possible leak 20 of the separating membrane 8 in the Gas space 6 penetrates and subsequently through passage 16 runs into the container 14 and can be determined there.

As can be seen in Figure 3, the container 14 is through formed a tube 22 closed on one side, which with its open side in a press fit on a connection fitting 24 is postponed. The tube is transparent and preferably made of plastic and conveniently has one Diameter from about 0.5 to 2 centimeters. The seat of the Tubes on the fitting and their mutual sealing can optionally be secured with a suitable adhesive be. In other embodiments, it would be the tube is of course also possible for the expert to connect with the fitting in another way, for example by screwing and sealing using a sealing ring.

The connection fitting 24 is in the present Embodiment in the lower vessel wall section 4.1 screwed in, an intermediate sealing ring 26 die Seals joint additionally. Alternatively the connection fitting could also be attached to the Weld on the wall or form one piece with the wall.

The longitudinal axis of the container 14 expediently runs vertical. However, it could just as well be oblique to the vertical be aligned, with a certain inclination to the horizontal, preferably at an angle of at least 30 degrees, should be adhered to in the event of any Membrane defect, the inflow of liquid or the escape of the gas present in the container.

According to a preferred embodiment there is a float 28 in the interior of the tube 22, which here has the shape of a sphere. As long as none If there is liquid in the tube, the float lies 28 on the bottom of the tube (in extended Dashed position). However, liquid penetrates on, the float 28 is raised in the direction of arrow A. (dashed position) and shows - from clearly recognizable from the outside - a defect in the separating membrane.

For a clear reading security at all times possible displacement distance of the float 28 preferably so limited that it can be seen from the outside in any case can. For this purpose forms in the embodiment shown the lower edge 30 of the connection fitting 24 an upper Stop for the float 28 because of the float diameter is chosen larger than the inside diameter of the connection fitting. Of course, this would also be the case any other limiting means in question, such as additionally inserted stop elements or a corresponding narrowing of the container cross section.

The container that is visible from the outside must not necessarily be tubular, but could be for example also be spherical or cuboid or have any other suitable shape. Furthermore it would also sufficient if the container is only partially visible would. It would be possible, for example, the back of the container to make opaque what, depending on the circumstances, the cognition ingress of liquid which has penetrated, or to surround the container with an opaque sleeve, that just left a reading window open. And not Finally, the possibility is mentioned, along with one Checking eye also an automatic control to be provided, for example by means of a light barrier or other suitable sensors.

Claims (8)

1. Closed expansion tank (2) for fluid-filled installations, in particular drinking-water and heating installations, having a separation membrane (8) for separating the liquid space (10) and the gas space (6), and having a container (14) which is arranged on the outside of the expansion tank (2), is sealed off in relation to the surrounding atmosphere, and whose interior is connected via a passage (16) to the gas space (6), characterized in that the container (14) has a transparent region through which there is visible a liquid level occurring in the container (14) in the event of liquid ingress or a display member, which can be moved by the liquid level, on a background which is at least partially formed by a light-permeable region of the container (14).
2. Expansion tank according to Patent Claim 1, characterized in that the passage (16) is located in the lower third of the gas space (6) when the expansion tank is aligned in the assembled state.
3. Expansion tank according to Patent Claim 2, characterized in that the passage (16) is arranged at the essentially lowest point of the gas space (6).
4. Expansion tank according to one of Patent Claims 1 to 3, characterized in that the container (14) is tubular, and its longitudinal axis extends in an alignment differing by at least 30 degrees from the horizontal.
5. Expansion tank according to Patent Claim 4, characterized in that the container (14) consists of a small tube (22) which is closed at one end and is mounted by its open end on a connection fitting (24) provided in the wall (4) of the expansion tank.
6. Expansion tank according to one of Patent Claims 1 to 5, characterized in that the container (14) is made of a transparent plastic material.
7. Expansion tank according to one of Patent Claims 1 to 6, characterized in that there is a float (28) in the interior of the container (14).
8. Expansion tank according to Patent Claim 7, characterized in that the possible displacement path of the float (28) is bounded in such a way that it remains in any case in the region of the container (14) which is visible from the outside.

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