Mobile control unit for membrane compensation vessels

Abstract

The invention relates to a mobile control unit (1) for diaphragm expansion vessels (MAG) for accommodating a compressed gas cylinder (5), comprising a pressure reducer (10) for reducing the working pressure to approximately 1-8 bar with a connection fitting (2) attached to the underside for accommodating an outlet valve (7) of the compressed gas cylinder (5), an impact-resistant guide sleeve (6) mounted on the underside that guides the compressed gas cylinder (5), an integrated continuously adjustable handwheel for the cylinder-side self-closing outlet valve (7), a self-closing outlet safety valve (4), at least one first high-pressure manometer (9) for indicating the gas pre-pressure, and a second manometer (13) for indicating the discharge pressure in the diaphragm expansion vessel, as well as an integrated pressure relief valve (3) for pressure relief to a defined discharge pressure connected with a pressure relief opening (14).

Description

[0001] The invention relates to a mobile control unit for membrane compensation vessels according to the preamble of claim 1.

[0002] Membrane expansion vessels typically feature flexible rubber membranes that separate a liquid from a gas cushion, thus preventing gas from entering the liquid. Modern heating and solar thermal systems are almost exclusively designed using this type of construction, as it minimizes maintenance requirements.

[0003] The operating principle involves the compression of a gas cushion on the other side of the membrane expansion vessel when a nearly incompressible liquid is heated on one side. Due to the flexible membrane, pressure equalization occurs between the liquid and the gas cushion, as the system pressure at the lowest temperature is higher than the membrane's pre-charge pressure. Therefore, with temperature changes, the relative volume change of the liquid is proportional to the relative pressure change in the system.

[0004] In a properly filled diaphragm expansion vessel, nitrogen and water are balanced when the system is cold and pressurized on the water side. When the system is warm and pressurized on the water side, the nitrogen is compressed by the expansion of the heating water. Correct gas filling is essential for this to work, as an insufficient gas cushion will prevent the expansion vessel from functioning as intended.

[0005] Against this background, it is necessary to check the gas-side filling of the diaphragm expansion vessel at certain time intervals and to restore the required gas pressure, for which so-called vessel fillers are used.

[0006] Aerosol cans are currently commonly used as container fillers. These cans are used by screwing an adapter onto the can's valve and then connecting the filling valve to the expansion vessel. The adapter has a pressure gauge that only displays the pressure in the expansion vessel. For larger quantities, the filling process must be interrupted periodically to check the pressure in the diaphragm expansion vessel. Once the target pressure in the diaphragm expansion vessel is reached, the filling process is complete and the valve on the adapter is closed. The filling valve is then removed from the diaphragm expansion vessel and the adapter is unscrewed from the aerosol can.

[0007] These canned products are suitable for expansion vessels in heating circuits with a pre-charge pressure of up to approximately 2 bar, but generally not for expansion vessels in, for example, domestic hot water and solar thermal systems, which usually operate at a higher pre-charge pressure than 2 bar. The can pressure at room temperature is approximately 3–4 bar, and this pressure is maintained by a propellant gas. A standard container size is 400 ml, which is sufficient for up to two refills on average.

[0008] This practice, however, has several disadvantages. These container filler cans generate a large volume of waste, and the residue remaining in them is problematic. Because the container filler cans do not empty completely depending on the application, up to a quarter of the contents remain in the cans, which also leads to customer complaints.

[0009] Furthermore, a waste problem arises from the fact that only completely empty cans are formally permitted to be disposed of as normal residual waste. Container filler cans that still contain residual gas and other problematic substances are hazardous waste, but in practice, tradespeople often dispose of them as residual waste. This is actually not permitted.

[0010] Due to the low pressure in these expansion vessel canisters, the filling process is relatively lengthy, sometimes taking several minutes to refill the expansion vessel with the required amount of gas. There is also a greenhouse gas issue, which is reduced by newer, more climate-friendly canisters, but these are still not climate-neutral. Furthermore, these more climate-friendly canisters are more expensive and less efficient at filling than their predecessors. Both flammable and non-flammable gas variants are available, but neither is climate-neutral. In both cases, filling the gas is time-consuming, and only up to two refills per canister are possible.

[0011] An optimal solution for filling diaphragm expansion vessels with gas would be the use of nitrogen, as recommended by the manufacturers of these vessels. Nitrogen, being a climate-neutral gas, would also be a particularly environmentally friendly alternative to the gases used in vessel filling cans.

[0012] However, this proves difficult in practice because the nitrogen is in compressed form in the gas cylinder, requiring the connection of a pressure regulator with a manometer to extract the gas. The operating pressure of approximately 300 bar can be continuously adjusted to a working pressure of approximately 6 bar. In practice, this means that filling a diaphragm expansion vessel requires transporting the gas cylinder (weighing, for example, about 16 kg), the pressure regulator, and any additional measuring devices needed to determine the pressure in the expansion vessel, for instance, to a boiler room. This is difficult and time-consuming due to the weight. Connecting these components to the expansion vessel is also a time-consuming process.

[0013] Due to this problem, the use of nitrogen gas cylinders to refill diaphragm expansion vessels is not common practice, as tradespeople prefer the significantly more convenient and quickly deployable vessel filler cans to the described, complex procedure, even though this is more expensive and entails the aforementioned disadvantages. The time factor plays a particularly important role here.

[0014] An improvement in this regard is described in publication DE 10 2018 107 098.5 concerning a vessel filler for diaphragm expansion vessels, which already represents a clear alternative to vessel filler cans and, in particular, addresses aspects of environmental protection. It consists of a pressurized gas cylinder housed in a case with measuring instruments, which can be connected to diaphragm expansion vessels. While this solution is functional, its design and weight make it somewhat unwieldy, indicating a need for improvement.

[0015] Against this background, the object of the present invention is to provide a vessel filler for diaphragm expansion vessels that offers an alternative to the conventional vessel filler cans and structurally complex vessel fillers for diaphragm expansion vessels. It should be a lighter and more easily transportable, yet more compact design that allows the use of nitrogen.

[0016] According to the invention, this is achieved by a mobile control unit for membrane compensation vessels according to the features of claim 1.

[0017] The dependent claims relate to advantageous designs of the control unit for membrane compensation vessels according to the invention.

[0018] This is a device particularly suited to everyday use, as it combines ease of handling and low overall weight with high user-friendliness and robustness.

[0019] The mobile control unit is therefore designed to accommodate a compressed gas cylinder with a capacity of 0.5 l to 1.0 l and a filling pressure of approximately 150 - 200 bar, which meets the everyday requirements for monitoring diaphragm expansion vessels (MAG) in order to service and refill a series of diaphragm expansion vessels (MAG) one after the other with a compressed gas cylinder.

[0020] The compactness, and therefore the low weight and user-friendliness, are achieved by using a pressure reducer as a load-bearing structural element, which serves to reduce the filling pressure of the connected compressed gas cylinder from approx. 150 - 200 bar to a working pressure of approx. 1 - 8 bar, which is useful for setting, for example, a back pressure of 2.6 bar in a diaphragm expansion vessel (MAG).

[0021] This central structural component of the pressure reducer now serves as the support for all other structural components of the mobile control unit. A key inventive element is the impact-resistant guide sleeve attached to and secured on the underside of the pressure reducer. Also located on the underside of the pressure reducer is a connection port for a top-mounted outlet valve of the compressed gas cylinder.

[0022] The impact-resistant guide sleeve now accommodates an upper section of the compressed gas cylinder, which comprises approximately one-third to one-half of the cylinder's height. In this way, the compressed gas cylinder is guided within the sleeve and protected from damage.

[0023] Since the guide sleeve completely encloses the connection fitting on the pressure reducer and the associated top-side outlet valve of the compressed gas cylinder, it is an essential component with regard to the protection of the compressed gas cylinder and thus also occupational safety.

[0024] Against this background, the advantages also arise that the guide sleeve ensures the precise alignment of the compressed gas cylinder's outlet valve with the pressure regulator's connection fitting, simplifying handling and reliably preventing misuse such as misalignment. Consequently, the connection fitting can also be made shorter, as it is relieved of stress by the guide sleeve. The guide sleeve is cylindrical and adapted to the diameter of the compressed gas cylinder for guiding and securing the cylinder to the mobile control unit and for guiding the cylinder's top-mounted outlet valve into the connection fitting.

[0025] To actuate the actuator integrated into the connection fitting for the self-closing outlet valve on the compressed gas cylinder side, an adjustment handle is mounted on the top of the pressure regulator. This handle acts as a continuously adjustable rotary control or handwheel for setting the back pressure in the diaphragm expansion vessel. This adjustment handle continuously directs gas from the compressed gas cylinder through the pressure regulator and a pressure hose to the diaphragm expansion vessel (MAG), with the achieved back pressure in the diaphragm expansion vessel (MAG) being monitored via a pressure gauge.

[0026] Therefore, two pressure gauges are mounted at an angle to the side of the pressure regulator. One is a high-pressure gauge for displaying the gas pressure in the cylinder, and the other is a pressure gauge for displaying the pressure in the expansion vessel when the pressure hose is connected, as described previously. These components are also mounted directly on the pressure regulator as a central, load-bearing element and are connected via appropriate channels to the gas cylinder on one side and to the working pressure side leading to the expansion vessel on the other.

[0027] One of the design enhancements according to the invention is a self-closing outlet safety valve on the pressure regulator that allows gas to flow from the compressed gas cylinder when back pressure is present. The pressure hose to the diaphragm expansion vessel is connected to this valve on the working pressure side, and gas withdrawal is only possible when back pressure is present. This ensures that gas cannot unintentionally flow from this outlet safety valve without a corresponding counter-pressure.

[0028] Another new feature for practical application is a pressure relief valve integrated into the pressure reducer. This valve is suitable for relieving pressure in the diaphragm expansion vessel via the pressure hose to a defined downstream pressure and is connected to a pressure relief port in the pressure reducer. It is conveniently a rotary control located on the pressure reducer, which allows a potentially excessive downstream pressure, for example 3.0 bar, to be reduced back to the target value of, for example, 2.6 bar.

[0029] In practical application, this allows the adjustment handle to be opened further when filling the diaphragm expansion vessel, thus accelerating the gas supply and increasing the back pressure. Should this result in a slightly excessive back pressure, it can be precisely adjusted via the pressure relief valve. This can significantly speed up the process, especially with larger diaphragm expansion vessels.

[0030] A further improvement is an integrated relief valve in the pressure reducer. This valve is pressurized via a channel within the pressure reducer by the downstream pressure (working pressure) through the pressure hose and is designed to release pressure when a defined limit pressure on the working side is exceeded. The relief valve opens when the overpressure on the working side exceeds approximately 8 to 10 bar, releasing the excess pressure to keep it below a defined threshold.

[0031] Depending on the level of overpressure, this relief valve opens more or less, thus releasing more gas as the overpressure increases, for example, due to a malfunction in the adjustment handle or the outlet safety valve of the compressed gas cylinder. This ensures that the overpressure on the working pressure side cannot exceed a certain limit, such as 10 bar, thereby reliably preventing damage to the diaphragm expansion vessel, the pressure hose, or even the mobile control unit itself.

[0032] An advantageous embodiment of the invention provides that the vent opening of the vent valve and the pressure relief opening of the pressure relief valve are arranged on the underside of the pressure reducer and aligned within the guide sleeve. This has the particular advantage that the pressurized gas is guided in a controlled manner and does not escape directly from the side of the pressure reducer. This improves the application with regard to workplace safety.

[0033] In an advantageous design, the gas to be discharged can escape from the guide sleeve, into which it is directed, through at least one, but preferably several, gas outlet openings. These openings are suitably arranged and designed to allow the pressurized gas to escape from the blow-off valve and / or the pressure relief valve within the guide sleeve. For example, several gas outlet openings are arranged side by side in the upper region of the guide sleeve at the transition to the pressure regulator. This causes the gas to be discharged to first exit into the space within the guide sleeve between the top of the pressurized gas cylinder and the pressure regulator, and then to escape through the gas outlet openings located in this area. The mobile control unit for diaphragm expansion vessels according to the invention is explained in more detail below with reference to a figure.

[0034] The figure shows the complete mobile control unit with the central component of a pressure reducer 10 in a perspective view, where the upper end of a compressed gas cylinder 5 is shown inserted into a guide sleeve 6 in dashed lines. It can be seen that an upper outlet valve 7, located on the compressed gas cylinder 5, is aligned with a connection port 2 on the underside of the pressure reducer 10 and inserted into this guide sleeve 6, thus enabling the connection of the compressed gas cylinder 5 to the mobile control unit 1 to be carried out easily and with just a few steps.

[0035] It is also evident that the guide sleeve 6 is dimensioned to completely enclose the upper section of the compressed gas cylinder 8. Thus, the guide sleeve 6 fulfills a crucial aspect of protecting the connection between the compressed gas cylinder 5 and the connection nozzle 2 on the underside of the pressure regulator 10, and the compressed gas cylinder as a whole.

[0036] The pressure reducer 10 is the central component of the present mobile control unit 1, supporting all structural components. The guide sleeve 6 is attached to the underside of the pressure reducer by means of fasteners 17. All other components are therefore arranged on this pressure reducer 10 and connected to each other via channels within the pressure reducer 10.

[0037] The pressure in the compressed gas cylinder 5, connected to the mobile control unit 1 via the connection port 2, can be read on an integrated high-pressure gauge 9. This means that the remaining pressure in the compressed gas cylinder 5 can be read directly on the high-pressure gauge 9 to determine how many operating cycles the remaining pressure in the compressed gas cylinder 5 is sufficient for. This allows the user to determine when the compressed gas cylinder will likely need to be replaced with a new one.

[0038] The display of the second manometer 13, shown frontally in the figure, has a pressure range between 0 and 8 bar and serves to read the working pressure side; that is, it indicates the current back pressure of the diaphragm expansion vessel to be filled. This allows the amount of gas to be added to the diaphragm expansion vessel to restore a target value of, for example, 2.6 bar.

[0039] To achieve this, a pressure hose 12 is connected to an outlet safety valve 4 located laterally on the pressure reducer 10. This is an outlet safety valve 4 in that gas can only be supplied to the diaphragm expansion vessel from this outlet safety valve 4 if a pressure hose 12 is connected and thus there is back pressure at the outlet safety valve 4. If no pressure hose 12 is connected to the outlet safety valve 4 and is under pressure, no gas can flow out.

[0040] Once the pressure hose 12 is connected and linked to the diaphragm expansion vessel, the pressure at the diaphragm expansion vessel is displayed on the second pressure gauge 13, and filling can take place if necessary. For this purpose, an adjusting handle 11 in the form of a rotary knob is turned clockwise, whereby gas from the compressed gas cylinder 5 is supplied through the pressure reducer 10 to the working pressure side at a pressure that depends on the setting of the rotary knob.

[0041] As the adjusting handle 11 is turned further, the background pressure in the diaphragm expansion vessel increases, as can be read on the pressure gauge 13, allowing it to be precisely adjusted to the required back pressure. Once the back pressure is constant, the adjusting handle 11 can be turned back to the closed position, thus preventing any further pressurization. The reading on the pressure gauge 13 should now continuously display the required back pressure.

[0042] In cases where this does not occur immediately, for example, if the outlet valve 7 is opened too far and the pressure in the diaphragm expansion vessel is therefore too high, this can also be adjusted subsequently. For example, if the pressure in the diaphragm expansion vessel reaches a value of, say, 3.0 bar due to the adjusting handle being opened too far, pressure can be released at an integrated pressure relief valve 3 to correctly readjust the pressure in the diaphragm expansion vessel.

[0043] In the enlarged detail shown in the figure, a pressure relief opening 14 is visible on the underside of the pressure reducer 10. This opening communicates with the integrated pressure relief valve 3, allowing pressure to escape through the pressure relief opening 14 via the pressure hose 12 when the integrated pressure relief valve 3 opens. This escaping pressure is then directed into the space of the guide sleeve 6, through which special gas outlet openings 16 are shown. These openings allow gas escaping into the guide sleeve 6 and the space above the pressurized gas cylinder 5 to escape in a controlled manner.

[0044] In the event of a major malfunction, for example of the adjusting handle 11 or the outlet valve 7 on the compressed gas cylinder 5, an overpressure can build up as back pressure, which can be released if a limit, e.g., 8 bar, is exceeded. For this purpose, a relief valve 15, shown only schematically, is also integrated on the underside of the pressure reducer 10. This valve opens automatically when a problematic back pressure of, for example, more than 8 bar is exceeded, thus limiting this problematic overpressure. In the exemplary design shown, this relief valve 15 is located behind the connection fitting 2 and is indicated by dashes as being located behind the connection fitting 2. Reference symbol list

[0045] Mobile control unit (1) Connection piece (2) integrated pressure relief valve (3) Exit safety valve (4) Pressurized gas cylinder (5) Guide sleeve (6) outlet valve (7) upper section of the compressed gas cylinder (8) High-pressure gauge (9) Pressure reducer (10) Adjustment handle (11) pressure hose (12) manometer (13) Pressure release valve (14) blow-off valve (15) Gas outlet openings (16) Fasteners (17)

Claims

1. Mobile control unit (1) for diaphragm expansion vessels (MAG) for accommodating a pressurized gas cylinder (5) with a capacity of 0.5 l to 1.0 l and a filling pressure of approx. 150 - 200 bar, characterized by- a load-bearing structural element of a pressure reducer (10) for reducing the working pressure to approximately 1-8 bar - wherein a connection fitting (2) attached to the underside of the pressure reducer (10) is designed to accommodate a top-side outlet valve (7) of the compressed gas cylinder (5), - an impact-resistant guide sleeve (6) which is fixedly mounted on the underside of the pressure reducer (10) - and which completely encloses the connection fitting (2) and an upper compressed gas cylinder section (8) with the top-side outlet valve (7) and guides the compressed gas cylinder (5), - wherein the connection fitting (2) has an integrated actuator for the cylinder-side self-closing outlet valve (7), - for the actuation of which an adjusting handle (11) for the back pressure is designed as a continuously adjustable handwheel on the top of the pressure reducer (10), - a self-closing,The pressure reducer (10) includes an outlet safety valve (4) that allows gas to escape from the compressed gas cylinder (5) when a back pressure is applied, for connecting a pressure hose (12) on the working pressure side, - at least two pressure gauges (9, 13) arranged at an angle on the side of the pressure reducer (10), designed as a first high-pressure gauge (9) for displaying the gas pre-pressure in the compressed gas cylinder (5) as a cylinder pressure gauge, and a second gauge (13) for displaying the back pressure in the diaphragm expansion vessel when the pressure hose (12) is connected, - and a pressure relief valve (3) integrated in the pressure reducer (10), which is suitable for relieving the pressure in the diaphragm expansion vessel via the pressure hose (12) to a defined back pressure and is connected to a pressure relief opening (14) in the pressure reducer (10).

2. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to claim 1, characterized by the fact thatthe guide sleeve (6) is cylindrically designed and adapted to the diameter of the compressed gas cylinder (5) for guiding and securing the compressed gas cylinder (5) on the mobile control unit (1) and for guiding the top-side outlet valve (7) of the compressed gas cylinder (5) into the connection nozzle (2).

3. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to claim 1 or 2, characterized by the fact that a blow-off valve (15) is integrated into the pressure reducer (10), which is supplied with the working pressure via the pressure hose (12) through a channel running in the pressure reducer (10) and is designed to open for pressure relief when a limit pressure defined on the working pressure side is exceeded.

4. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to claim 3, characterized by the fact thata blow-off outlet opening of the blow-off valve (15) and the pressure release opening (14) of the pressure release valve (3) are arranged on the underside of the pressure reducer (10) and aligned in the guide sleeve (6).

5. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to claim 4, characterized by the fact that the guide sleeve (6) has at least one, but in particular several, gas outlet openings (16) which are arranged and designed to allow the pressurized gas to escape from the blow-off valve (15) and / or the pressure relief valve (3) from the guide sleeve (6).

6. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to one of the preceding claims 3 to 5, characterized by the fact that The blow-off valve (15) is designed to open depending on the level of the overpressure in the event of an overpressure on the working pressure side greater than approximately 8 to 10 bar, keeping the overpressure below a defined threshold value.

7. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to one of the preceding claims, characterized by the fact that the connection nozzle (2) is shortened due to the guiding and securing of the pressurised gas cylinder (5) by the guide sleeve (6).

8. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to one of the preceding claims, characterized by the fact that The adjusting handle (11) is designed to continuously supply gas from the compressed gas cylinder (5) to the diaphragm expansion vessel (MAG) via the pressure hose (12) via the pressure reducer (10), while monitoring the achieved back pressure in the diaphragm expansion vessel (MAG) via the second manometer (13).

9. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to one of the preceding claims, characterized by the fact that the pressure relief valve (3) integrated in the pressure reducer (10) is designed as a stepless rotary control.

10. Mobile control unit (1) for diaphragm expansion vessels (MAG) according to one of the preceding claims, characterized by the fact that - the pressure hose (12) is designed as a cylindrical spiral hose with long-length flexibility, - wherein the diameter as well as the height of the cylindrical winding is dimensioned so that the pressure hose (12) can be received in the guide sleeve (6) without a gas cylinder (5) for transport.

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