Manifold for liquid tank and water purification system

Abstract

The present invention relates to a manifold for a liquid tank, preferably for use in a water purification system, and to a water purification system provided with the manifold.

Description

Technical Field

[0001] The present invention relates to a manifold for a liquid tank, preferably for use in a water purification system, and to a water purification system provided with such a manifold. Background Art

[0002] In a water purification system, measuring the tank liquid level is mandatory. This information is mainly used to start the tank filling sequence when the liquid tank is empty and to stop the tank filling sequence when the tank is full.

[0003] Many standard sensor technologies are available on the market. One of the most commonly used technologies for liquid level measurement is pressure sensor technology because it is inexpensive, accurate, reliable, mature, and readily available on the market.

[0004] The biggest drawback of pressure sensor technology is the measurement itself, because 1 cm of water represents 1 mbar of static pressure. In a typical pressure sensor, this is associated with a very small signal that may be difficult to read, especially when the tank is being filled or emptied.

[0005] The pressure drop generated by the water flow is generally much greater than 1 mbar. If not taken into account and compensated for, this pressure drop interferes with the signal, and the liquid level cannot be read by the system, i.e., when the tank is being filled, the liquid level appears higher than it actually is, and when the tank is being emptied, the liquid level appears lower than it actually is.

[0006] For example, if the pressure drop due to the water flow from or into the liquid tank is about 4 mbar, then when the tank is being emptied, the water level in the tank is underestimated by 4 cm.

[0007] Typically, the water level in the liquid tank to be measured in a water purification system is between 0 cm and 30 cm (corresponding to between 0 mbar and 30 mbar) for a small system, and between 0 cm and 150 cm (corresponding to between 0 mbar and 150 mbar) for a large system. For effective operation, the liquid level measurement should measure the tank liquid level with an accuracy better than 1 cm (1 mbar).

[0008] To take this phenomenon into account when using this type of liquid level sensor technology, it is known to use two different and separate water flow channels or water connectors on the tank, one for filling or emptying the tank and one for measuring the static pressure. Thus, the water flow pressure drop does not affect the pressure sensor that measures the water height based on the static pressure.

[0009] Figure 1Conceptual diagram showing an example of a manifold 1 for a liquid tank 2 according to the prior art. The (second) flow channel 8 downstream of the connector A is a connector for a pressure sensor 5. In this flow channel, water only flows when the tank is attached to the manifold, but does not flow when the tank is filled or emptied and thus there is no pressure drop. The (first) flow channel 9 downstream of the connector B is a connector for emptying or filling the tank. In the (first) flow channel 9, the expected typical water flow rate is about 2 liters per minute and the pressure drop is greater than 50 mbar.

[0010] The high water flow rate in the (first) flow channel 9 downstream of the connector B generates a pressure drop that is not detected by the sensor 5 in the (second) flow channel 8 downstream of the connector A, making the pressure measurement stable and reliable. However, this solution has the following disadvantages: the water around the pressure sensor 5 is never updated, which generally can stimulate bacterial growth and water pollution.

[0011] In the case of using a transparent and removable tank, this problem is more prominent because the user can see the system / tank flow connectors through the tank or when the tank is pulled out. The potential bacterial growth visible in these parts of the tank can cause a lack of confidence in the water purification device.

[0012] The object to be solved is to provide a manifold for a liquid tank, preferably for use in a water purification system, and a water purification system provided with such a manifold that avoids or at least reduces water pollution. Summary of the Invention

[0013] To solve the problems described above, the present invention provides a manifold for a liquid tank having the features of claim 1 and a water purification system having the features of claim 12. Preferred embodiments of the manifold for a liquid tank are defined in the dependent claims.

[0014] In particular, the present invention provides a manifold for a liquid tank, the manifold comprising: a first flow channel for filling liquid into and / or discharging liquid from the tank; a second flow channel for guiding the liquid in the tank to a pressure sensor mounted in the manifold to allow measurement of the static pressure in the liquid tank; and a third flow channel connecting the first flow channel and the second flow channel, wherein the third flow channel is configured and arranged to replace the stagnant liquid in the second flow channel when the liquid is filled into and / or discharged from the tank through the first flow channel.

[0015] Preferably, the manifold is configured to removably receive the liquid tank and comprises: a first connector for releasably communicating the first flow channel to a mating first tank connector of the liquid tank; and a second connector for releasably communicating the second flow channel to a mating second tank connector of the liquid tank.

[0016] Preferably, the manifold includes a liquid tank configured to be removably received on the manifold, and the liquid tank includes: a first valve arranged to automatically open when a first connector of the manifold is connected to a mating first tank connector; and a second valve arranged to automatically open when a second connector of the manifold is connected to a mating second tank connector.

[0017] Preferably, the manifold includes a liquid tank such that the volume of the liquid tank communicates with the first flow channel and the second flow channel.

[0018] Preferably, the manifold includes a valve for selectively opening / closing the communication between the first flow channel and a flow path downstream of the first flow channel.

[0019] Preferably, the third flow channel is connected to the first flow channel upstream of the valve.

[0020] Preferably, the second flow channel has a volume of 1 mL or less.

[0021] Preferably, the third flow channel is sized to provide a flow rate through the third flow channel between 0.02 L / h and 5 L / h.

[0022] Preferably, the third flow channel is sized to provide a pressure drop of 1 mbar or less when the liquid is filled into the tank and / or discharged from the tank through the first flow channel.

[0023] Preferably, the first flow channel is sized to provide a flow rate of at most 2.0 L / min, preferably at most 1.6 L / min.

[0024] Preferably, the pressure sensor installed in the manifold is configured to allow measurement of the static pressure in the liquid tank between 0 mbar and 150 mbar, preferably between 0 mbar and 30 mbar. Description of the Drawings

[0025] Figure 1 Conceptual schematic diagram showing an exemplary manifold for a liquid tank according to the prior art.

[0026] Figure 2 Conceptual schematic diagram showing an exemplary manifold for a liquid tank according to the present invention.

[0027] Note that throughout the drawings, the reference numeral "W" is used to indicate volumes (such as but not limited to tank 2, first flow channel 9, second flow channel 8, and third flow channel 10) that are partially or substantially completely filled with liquid, preferably water, when the present manifold is in use. Alternatively, when the manifold is not in use, these volumes may be partially or substantially completely filled with air. Thus, the liquid (e.g., water) is not necessarily considered an integral part of the manifold itself. Detailed implementation manners

[0028] In particular, the present invention also provides a water purification system including a manifold according to the present invention.

[0029] The manifold for a liquid tank of the present invention provides the following advantages: during operation, i.e., when the liquid is filled into the tank and / or discharged from the tank, the stagnant liquid around the pressure sensor is replaced, thus avoiding stimulating bacterial growth and water pollution.

[0030] Now, with reference to the accompanying exemplary schematic diagrams Figure 1 and Figure 2 the present invention will be described in detail based on a preferred exemplary embodiment.

[0031] Now, the manifold of the present invention for a liquid tank, preferably for a water purification system, will be described in conjunction with the exemplary embodiment shown in Figure 2 As for the basic layout, the manifold 1 for a liquid tank 2 according to the present invention is similar to the manifolds in the prior art described in conjunction with

[0032] Therefore, the manifold 1 according to the present invention includes connectors A and B for communicating the liquid tank 2 with the channels of the manifold 1, particularly the first flow channel 9 and the second flow channel 8. The first flow channel 9 is used to fill the liquid into the tank 2 and / or discharge the liquid from the tank 2, and the second flow channel 8 is used to guide the liquid in the tank 2 to a pressure sensor 5 installed in the manifold 1 so as to allow measurement of the static pressure in the liquid tank 2. The pressure sensor 5 is installed in a part of the manifold 1 communicating with the second flow channel 8 such that the liquid pressure acts on the sensitive component of the sensor. Figure 1

[0033] The manifold 1 according to the exemplary embodiment further includes a third flow channel 10 connecting the first flow channel 9 and the second flow channel 8 to each other, wherein the third flow channel 10 is configured and arranged to replace the stagnant liquid in the second flow channel 8 when the liquid is filled into the tank 2 and / or discharged from the tank 2 through the first flow channel 9. To facilitate the replacement of the liquid in the second flow channel 8, i.e., to minimize the dead volume in the second flow channel 8, the third flow channel 10 is preferably connected to the second flow channel 8 at a position closely adjacent to the pressure sensor 5.

[0034] ​The present invention is an improvement of the solution described in the introduction of the specification and is based on maintaining two separate or different hydraulic flows from the tank into the manifold through flow channels, but providing a third flow channel between the two flows. The purpose of the third flow channel 10 is to provide a controlled water flow through the second flow channel 8 via the first flow channel 9, the controlled water flow being sufficient to replace at least part of the water volume in the second flow channel 8 each time the tank 2 is filled or emptied, but small enough to generate only a minimal pressure drop. Preferably, the pressure drop generated by discharging the liquid from the second flow channel 8 through the third flow channel 10 is 1 mbar or less.

[0035] The size of the third flow channel 10 should be selected depending on the flow rate to be achieved through the channel and the pressure drop generated by the water flow on the first flow channel. In a typical water purification system for laboratory use as described herein for the present invention, the equivalent diameter for the third flow channel may be about 0.8 mm.

[0036] The manifold 1 is configured to removably receive the liquid tank 2, and as is known in the prior art, the manifold 1 includes a first connector 4 for releasably connecting the first flow channel 9 to a mating first tank connector 14 of the liquid tank 2 and a second connector 3 for releasably connecting the second flow channel 8 to a mating second tank connector 13 of the liquid tank 2 (the connectors are schematically shown in the drawings as they may correspond to existing and well-known types of connectors for fluid communication; thus, the connectors may desirably include seals to avoid liquid spillage in the connected state).

[0037] Although not shown, the liquid tank may be integrally fixed with the manifold. In this case, connectors and valves may not be required.

[0038] The liquid tank 2 in the detachable variant includes a first valve 14a and a second valve 13a, the first valve 14a being arranged to automatically open when the first connector 4 of the manifold 1 is connected to the mating first tank connector 14, and the second valve 13a being arranged to automatically open when the second connector 3 of the manifold 1 is connected to the mating second tank connector 13. The valves may also be integrated in the manifold 1 such that they operate automatically when the connection between the corresponding connectors is established. Thus, when there is no tank, the channels in the manifold are closed to the environment.

[0039] In both the detachable variant and the integrated variant, the manifold 1 may include a valve 6 for selectively opening / closing the communication of the first flow channel 9 with the flow path downstream of the first flow channel 9, the flow path leading to an outlet or a distributor or downstream water treatment equipment. In addition, the first flow channel 9 is sized to provide a flow rate of at most about 2 liters per minute (L / min) and preferably at most 1.6 L / min.

[0040] As shown, the third flow channel 10 is connected upstream of the valve 6 to the first flow channel 9.

[0041] In the manifold of a typical water purification system for laboratory use, the second flow channel 8 leading from the second connector 3 to the pressure sensor 5 preferably has a volume of 1 mL or less. Further, in the manifold of a typical water purification system for laboratory use, the third flow channel 10 is preferably dimensioned to provide a flow rate through the third flow channel 10 between 0.02 L / h and 5 L / h.

[0042] For use in such a system, the third flow channel 10 is dimensioned to provide a pressure drop of 1 mbar or less when liquid is filled into and / or discharged from the tank 2 through the first flow channel 9, in order to achieve the desired accuracy of the measurement of the liquid level in the tank.

[0043] Further, for use in such a system, the pressure sensor 5 mounted in the manifold 1 at the downstream end of the second flow channel 8 is configured to allow measurement of the static pressure in the liquid tank 2 between 0 mbar and 150 mbar, preferably between 0 mbar and 30 mbar.

Claims

1. A manifold (1) for a liquid tank (2), comprising: A first flow channel (9) for filling the liquid into the tank (2) and / or discharging the liquid from the tank (2); A second flow channel (8) for guiding the liquid in the tank (2) to a pressure sensor (5) installed in the manifold (1) to allow measurement of the static pressure in the liquid tank (2); And A third flow channel (10) connecting the first flow channel (9) and the second flow channel (8), Wherein the third flow channel (10) is configured and arranged to replace the liquid stagnant in the second flow channel (8) when the liquid is filled into the tank (2) and / or discharged from the tank (2) through the first flow channel (9).

2. The manifold (1) according to claim 1, wherein, The manifold (1) is configured to removably receive the liquid tank (2), and includes: a first connector (4) for releasably communicating the first flow channel (9) to a mating first tank connector (14) of the liquid tank (2); and a second connector (3) for releasably communicating the second flow channel (8) to a mating second tank connector (13) of the liquid tank (2).

3. The manifold (1) according to claim 2, wherein, The manifold (1) includes a liquid tank (2) configured to be removably received on the manifold (1), and the liquid tank (2) includes: a first valve (14a) arranged to automatically open when the first connector (4) of the manifold (1) is connected to the mating first tank connector (14); and a second valve (13a) arranged to automatically open when the second connector (3) of the manifold (1) is connected to the mating second tank connector (13).

4. The manifold (1) according to any one or more of claims 1 to 3, wherein, The manifold (1) includes the liquid tank (2) such that the volume of the liquid tank (2) communicates with the first flow channel (9) and the second flow channel (8).

5. The manifold (1) according to any one of claims 1 to 4, wherein, The manifold (1) includes a valve (6) for selectively opening / closing the communication between the first flow channel (9) and the flow path downstream of the first flow channel (9).

6. The manifold (1) according to claim 5, wherein, The third flow channel (10) is connected to the first flow channel (9) upstream of the valve (6).

7. The manifold (1) according to any one of claims 1 to 6, wherein The second flow channel (8) has a volume of 1 mL or less.

8. The manifold (1) according to any one of claims 1 to 7, wherein, The third flow channel (10) is sized to provide a flow rate through the third flow channel (10) between 0.02 L / h and 5 L / h.

9. The manifold (1) according to any one of claims 1 to 8, wherein, The third flow channel (10) is sized to provide a pressure drop of 1 mbar or less when the liquid is filled into the tank (2) and / or discharged from the tank (2) through the first flow channel (9).

10. The manifold (1) according to any one of claims 1 to 9, wherein, The first flow channel (9) is sized to provide a flow rate of at most 2.0 L / min, preferably at most 1.6 L / min.

11. The manifold (1) according to any one of claims 1 to 10, wherein, The pressure sensor (5) installed in the manifold (1) is configured to allow measurement of the static pressure in the liquid tank (2) between 0 mbar and 150 mbar, preferably between 0 mbar and 30 mbar.

12. A water purification system comprising a manifold (1) according to any one of claims 1 to 11.

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