DE3001989A1 - Expansion vessel with membrane divider - probes low water level by electrode and high level by membrane-operated pressure switch - Google Patents

Abstract

Expansion vessel has a gas space and membrane divided water space and water level sensor to control the compressor or safety fittings. The low water level is taken by an electrode (117) and high level by a membrane (9) operated pressure switch (119) in the vessel top walling (1,5). It is also possible to use membrane actuated switched for both high and low levels. The vessel pref. has a water inlet flange (8,11) at the base, the membrane clipped between these and the electrode suspended from the cover plate (10) over the top flange (7).

Description

PATENT LAWYERS MEINKE AND DABRINGHAUS

REPRESENTATIVE AT THE EUROPEAN PATENT OFFICE · REPRESENTATIVES BEF = ORE EPO · MANDATAIRES AGREES PRES L OEB

DIPL-ING. J. MEINKE
DIPL-ING. W. DABRINGHAUS

4600 DORTMUND 1, 18th

WESTENHELLWEG 67

TELEPHONE (02 31) 14 5810
TELEGRAM DOPAT Dortmund TELEX 822 7328 pat d

FILE NO .: 79/3504

Applicant: Winkelmann & Pannhoff GmbH, Schmalbachstraße 2,

Awls

Designation: "Expansion vessel, especially for closed

Heating and cooling systems "

Addendum to patent (patent application P 29 10 722.0-16)

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The invention is directed to an expansion vessel for closed heating and cooling systems with a gas space and a water space separated by a membrane and a device for measuring a low and a maximum water level within the vessel as well as a control that can be acted upon by a device for a compressor and / or for additionally provided safety devices, in particular according to the patent (Patent application P 29 10 722.0-16).

Such expansion vessels are used to hold the expansion water ₃ produced in heating or cooling systems, such systems usually being compressor-controlled, since the pressure within the overall system should only be subject to very slight fluctuations. During the heating phase, such an amount of air is released from the gas space that corresponds to the amount of water flowing in. For example, if the heating water cools down again, the volume of water in the expansion tank is reduced and the compressor pumps the required amount of air back into the gas space.

When operating such systems it can happen, e.g. if leakage water has to be refilled, that the expansion vessel Is filled with water beyond the desired amount, or that the system is not properly maintained so much water escapes from the overall system that the

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expansion vessel below a predetermined amount Filling water is emptied. In order to avoid damage that can occur at both level extremes, such Pressure expansion vessels are provided with level indicators or electrical measuring and control devices that emit optical, acoustic or other signals at the corresponding extreme water levels.

In a known expansion vessel of this type, the gas space is arranged within the expansion vessel so that the outer metal wall of the vessel is wetted. A water level measurement is taken over by electrodes attached to the container wall, which are due to the wetting or missing Wetting forward the corresponding information to a controller. Disadvantage of the known expansion tank is that wetting of the metallic container wall can lead to corrosion phenomena, so that relatively frequent inspections of the vessels may be necessary.

In order to avoid this, it is already known to arrange the water space inside the vessel in such a way that it is separated from the gas space is enclosed, i.e. the metallic container walls are only exposed to air, but not to water. However, this eliminates the possibility of checking the level in the water space directly through electrodes in the container wall to eat.

It is known (leaflet from the company Stücklin & Cie., Basel,

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Switzerland) to measure the filling quantity of such a pressure expansion vessel based on the vessel weight, i.e. at the known vessel, a pressure gauge is arranged under a leg that is calibrated accordingly and with a maximum load an excess of the filling quantity and a minimum load an undershooting of the filling quantity is able to report. The disadvantage of the known vessel is that it is on a perfectly horizontal plane must, which experience has shown is very difficult to reach in basement and boiler rooms and, on the other hand, the device must be flexibly connected to all supply lines, a rigid connection, for example a pipe connection, would make an advertisement impossible.

It is the task of the _invention, just like the task of the

Main application P 29 10 722.0-16 (patent.), A

To create a solution with which a reliable level measurement is possible without taking into account any special features of the installation or assembly needs and without the risk of corrosion of the container by water wetting is given.

In the case of an expansion vessel of the type mentioned at the outset, this object is achieved according to the invention by that for measuring the low water level in the lower area and for measuring the maximum water level in the upper area Area of the pressure expansion vessel each

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.;. ":. 3001389

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gene of the membrane surrounding the water space actuatable switching element is provided.

From DE-OS 21 51 905 a membrane-controlled monitoring device is known that an impermissible expansion and thus the risk of destruction of the separating membrane between gas and water space should be avoided, i.e. it is a transverse stretched in the expansion tank Separating membrane that cannot prevent part of the container from corroding. For the purpose of safeguarding against destruction, it is provided here that the membrane is a spring-loaded one Switching pin is applied when it is in the area of its limit strain on a spring-loaded Switch pin applies, which is arranged displaceably in a recess in the vessel housing and then the gas supply to the expansion tank stops. A high and low tide Stand monitoring is not possible with the known device.

In an advantageous embodiment, the invention provides that the switching elements are designed as pressure switches that can be actuated by the membrane, with further according to the invention it can be provided that the pressure switch in the upper or lower container dome on a Place with a large radius of curvature are arranged, the latter measure having the particular advantage that not just the assembly of the pressure switch in practice

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is simplified, but also an impermissible kink the diaphragm when switching is avoided, which could occur if the diaphragm moves during the switching process apply to an area with a very small radius of curvature would have to.

In a further embodiment it can be provided according to the invention that in the upper or lower area of the pressure expansion vessel several switching elements linked in terms of circuitry are provided. The arrangement of several Switching elements for monitoring the respective fill level has the advantage that, for example, in the case of an inexact installation position of the expansion tank, the contents of which can be optimally used, namely if a switch is installed Indicates a lack of water, but two of e.g. three equally spaced switches indicate or indicate that the water level is still low. vice versa, so that an electrical compensation circuit enables optimal utilization of the vessel is.

The invention is explained in more detail below with reference to the drawing, for example. This shows in the only one Figure is a section through an expansion tank according to the invention.

The illustrated, generally designated 1 pressure expansion vessel consists essentially of a container body 2, which is supported on footrests 3, for example in a heating

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room is set up. The container body is in conventionally from a cylindrical part 4 and an upper end dome 5 and a lower end dome 6 educated. The two end domes 5 and 6 are with flange parts 7 or 8 equipped for clamping a membrane, for example made of rubber, or other deformations allowable material are used, the clamping pressure being provided by an end plate 10 in the case of the upper flange part 7 and in the case of the lower flange part 8 by a counter flange 11 by means of a not shown Tensioning screws is applied. The counter flange 11 can be provided with a pipe bend 12, the water inlet 13 forms.

The interior of the container body 2 is divided into a water space 14 and a gas space 15 by the membrane 9. The water space Ik is connected to the water inlet 13 of a heating or cooling system (not shown in detail) via the pipe bend 12, while the gas space 15 is acted upon by a compressor, which is only indicated schematically at 16.

A pressure switch 17 with a switching element 18 is arranged on the lower vessel dome 6, against which the membrane 9 rests when the water space Ik is filled. A pressure switch 19 is arranged on the upper end dome 5, the activatable switching element 20 of which, like the switching element 18, protrudes into the gas space 15 and from the membrane 9

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can be acted upon. The two switching elements 17 and 19 are only hinted at in terms of their circuitry reproduced control 21 connected, which takes over all necessary control functions of the system, so for example the control of the compressor, which is not shown in the figure.

The operation of the expansion vessel is as follows: In normal operation, for example, the The water space 14 is half filled, so that the switching element 18 of the pressure switch 17 is switched by the membrane 9 and therefore does not have to indicate a lack of water. In the gas space 15 is due to the activity of the compressor 16 a certain counter pressure has been built up, which is reflected in the use of the device in heating and cooling systems Can judge according to various criteria, for example the building height or the like. However, this is not important .

By operating the heater, the heating water is heated and thus expands, so that the water space 14 in addition a volume of water is applied to it, which, if a gas air release valve is switched accordingly, causes that this opens in order to keep the pressure in the gas space 15 practically constant. If the water now cools down, so a corresponding volume of water is withdrawn from the water space 14, so that the pressure in the gas space 15 drops and the

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Compressor pumps air back into the gas space in order to maintain the operating pressure of the system.

If, for example, too large an amount of water is introduced into the water space 14 when the system is started up, then the membrane 9 expands until it finally actuates the pressure switch 19, which controls the "vessel overfilled ". For example, the heating can be switched off by such a control in order to prevent a further rise in the water temperature and thus a further expansion of the water volume or other measures can be taken.

The other extreme is that ζ.Β, through leaks So much water can have escaped from the system in the system that the membrane moves away from the lower switching element 17 or its switching element 18 lifts off due to the inherent stress, so that, for example, the necessary compressor control the pressure within the gas space 15 can no longer be maintained. In this case this reports Switching element to the controller 21 "water shortage", which in turn lead, for example, to the entire system being switched off or but acoustic, optical or other signals can trigger the operator of the system on this lack of water to point out.

Of course, the embodiment described is not limited to the possibilities shown in the figure.

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restricts. As a heating or cooling circuit fluid, for example In addition to water, a water / prostate protection agent mixture, oil, a liquid refrigerant or the like can be provided, just as a gas / gas combination is conceivable. Media such as those used in solar technology can also be used, for example are used.

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Claims (4)

Expectations : (1./ Expansion vessel for closed heating and cooling systems with a gas space and a water space controlled by a membrane and a device for Measurement of a low and a maximum water level inside the vessel as well as with one above a device loadable control for a compressor and / or for additionally provided safety devices, in particular according to patent (patent application P 29 10 722.0-16) characterized in that for measuring the low water level in the lower area (6) and for measuring the maximum water level in the upper area (5) of the pressure expansion vessel (1) one each by placing the one surrounding the water space Membrane (9) actuatable switching element (17 or 19) is provided. 2. Expansion vessel according to claim 1, characterized in that the switching elements can be actuated as from the membrane (9) Pressure switch / 17 or 19) are formed. 3 · Expansion vessel according to claim 2, characterized in that the pressure switches (17 or 19) are in the upper or lower Container dome (5 or 6) are arranged at a point with a large radius of curvature. 4. Expansion vessel according to one of the preceding claims, characterized in that in the upper or lower Area (5 or 6) of the pressure expansion vessel (1) several 13U03Ö / 0B87 BAD ORjQiNAL rere circuit-wise linked switching elements (1? or 19) are provided. 130030/0587