WO2021014373A1

WO2021014373A1 - Assembly for metering a fluid

Info

Publication number: WO2021014373A1
Application number: PCT/IB2020/056886
Authority: WO
Inventors: Philippe ESTARZIAU
Original assignee: Suez Groupe
Priority date: 2019-07-23
Filing date: 2020-07-22
Publication date: 2021-01-28
Also published as: FR3099246B1; FR3099246A1

Abstract

Assembly for metering a fluid comprising: an electromagnetic static fluid meter, said meter comprising: a measurement chamber through which the fluid can flow; an inlet tube for letting the fluid into said chamber; an outlet tube for letting the fluid out of said chamber; a parasitic current bypass means comprising: a first electrically conductive element connected to the inlet tube and designed to be in electrical contact with the fluid when it flows through the inlet tube; a second electrically conductive element connected to the outlet tube and designed to be in electrical contact with the fluid when it flows through the outlet tube; a third electrically conductive element connecting the first electrically conductive element and the second electrically conductive element.

Description

FLUID METERING KIT

FIELD OF THE INVENTION [0001] The invention relates to an assembly for counting a fluid comprising a static electromagnetic meter for fluid, in particular water. The invention relates more particularly to static counters having a caliber between 15mm and 40mm. When the caliber of the meter is greater than 40mm, we generally no longer speak of a static electromagnetic meter but of an electromagnetic flowmeter.

By static meter, it is understood a meter without moving parts for the measurement of the flow. This includes magnetic sensor counters, called electromagnetic counters, ultrasonic counters and fluid counters also known as vibrating jet counters. The present invention is more particularly concerned with the case of electromagnetic counters.

[0003] Two elements are understood to be in electrical contact in the context of this application when an electric current can flow from one to the other.

[0004] In the context of the present application, the term “measuring chamber of a static electromagnetic meter” will be understood to mean the part of the static meter in which the fluid circulates and the magnetic field is generated so as to perform the measurement. This measuring chamber is connected upstream to a fluid supply pipe and downstream to a fluid outlet pipe.

[0005] The term “element projecting from the internal surface of a tube” in the context of the present application will be understood to mean any element capable of disturbing the lamellar flow of the fluid through said tube. It should be noted that the counting is precise due to the lamellar flow of the fluid through the static meter. The element protrudes when it disturbs the flow of fluid. This induced disturbance depends on the model of the measurement chamber of the static meter and may vary from one manufacturer to another. PREVIOUS STATE OF THE ART

[0006] Static meters with magnetic or electromagnetic sensors operate according to the Faraday principle. When a conductive liquid flows perpendicularly through a magnetic field, a difference in electrical potential is created within the liquid. This potential difference, captured using two electrodes, allows calculation to deduce the speed and then the flow rate of the fluid.

[0007] These measurement technologies are sensitive to stray electric currents. In fact, water connections, particularly those made of metal, are likely to pick up electrical currents, which pass through the water and specifically disturb the potential measurement which is carried out at the level of the electrodes. Parasitic currents can be direct currents (from public transport, for example) or alternating currents, for example, from non-compliant private electrical installations whose earthings are connected to the water pipes. These currents can have other origins, including galvanic currents, stray currents, etc.

[0008] It should be noted, however, that the disorders generated are not such as to call into question the overall quality of the metrology of this type of device. These disorders have been observed thanks to the use of remote reading which allows a reading frequency that can highlight this type of phenomenon. In this case we observe small movements of the index (positive or negative) when there is no physical movement of water in the meter. This phenomenon can for example call into question the accuracy of the detection of blocked meters (due to failure or malicious act).

Figure 1 shows a solution according to the state of the art consisting in hooking a branch cable 1 10 to metal parts in which the water passes by means of collars 120, 121 which trap said metal part and the branch cable 1 10.

This solution requires a long exposure time, an operator having skills in electricity to check the electrical conformity of the installation, requires equipment, and exposes to corrosion in the ambient air the contacts between the cable and the water and therefore degrade the performance of the bypass of parasitic currents over time.

[0011] Thus, there is no suitable solution for static electromagnetic meters allowing the simple realization of a means of bypassing parasitic currents. It should be noted that static electromagnetic meters are deployed en masse over short periods of time by operators with skills limited to plumbing only; unlike flowmeters which are usually installed on a small scale by operators who have electrical skills.

[0012] Thus, there is a need for a solution that does not require:

meticulous and time-consuming cleaning of surfaces to ensure electrical contact between parts of the meter and a means of bypassing stray currents;

operation of verifying the electrical conformity of the means of bypassing parasitic currents by performing electrical measurements, using a multimeter to validate the assembly; of material of the type: collars for attaching a means of bypassing parasitic currents to the meter; electric cable, wire brush for cleaning surfaces, tools for hanging clamps.

SUMMARY OF THE INVENTION [0013] With this in mind, one aspect of the invention relates to a fluid metering assembly comprising:

A static electromagnetic fluid meter, said meter comprising:

a measuring chamber through which the fluid can flow;

a pipe for supplying the fluid to said chamber; a fluid outlet pipe from said chamber; a parasitic current bypass means comprising:

A first electrically conductive element connected to the supply pipe and adapted to be in contact electric with the fluid as it flows through the supply tubing;

A second electrically conductive element connected to the outlet tubing and adapted to be in electrical contact with the fluid as it flows through the outlet tubing;

A third electrically conductive element connecting the first electrically conductive element and the second electrically conductive element.

Preferably, the third electrically conductive element has a useful section greater than or equal to 6mm ² . This useful section value makes it possible to ensure a derivation of 100% of parasitic currents and to prevent some still passing through the water and disturbing the measurement.

[0015] Preferably, the third electrically conductive element is a braid, preferably flat. By nature, it offers a larger contact surface, and can be integrated better if it is decided to place it on the body of the meter so as to protect it more effectively against thefts / attacks of rodents.

[0016] Preferably, the inlet pipe comprises a first connection thread of a fluid inlet pipe; the first electrically conductive element comprises at least part of a first means for clamping the fluid inlet pipe to the first connection thread. Thus, the installation of the parasitic current bypass means (the third electrically conductive element) is done quite simply by screwing / unscrewing the first means of tightening the first connection thread, an operation that can be carried out easily and quickly by an operator, qualified in plumbing, and generally required to perform these operations for installing meters on the network.

[0017] Preferably, at least a portion of the first connection thread comprises a first flat adapted to receive a first end of the third electrically conductive element. This flat is adapted to easily receive the first end of the third electrically conductive element and thus facilitate the installation of the assembly.

Preferably, the outlet pipe comprises a second connection thread of a fluid discharge pipe; the second element electrical conductor comprises at least part of a second means for clamping the fluid discharge pipe to the second connection thread. Thus, the installation of the parasitic current bypass means (the third electrically conductive element) is done quite simply by screwing / unscrewing the first means of tightening the first connection thread, an operation that can be carried out easily and quickly by an operator, qualified in plumbing, and generally required to perform these operations for installing meters on the network.

Preferably, at least a portion of the second connection thread has a second flat adapted to receive a second end of the third electrically conductive element. This flat is adapted to easily receive the second end of the third electrically conductive element and thus facilitate the installation of the assembly.

[0020] Preferably, the first electrically conductive element comprises at least a first part protruding from an internal surface of the supply pipe; and at least a second part in contact with an outer surface of the supply tubing and in electrical contact with the first part. Thus, in this embodiment, the first electrically conductive element is directly integrated into the static meter, which facilitates the installation of the assembly.

[0021] Preferably, the second electrically conductive element comprises at least a third part projecting from an internal surface of the outlet pipe; at least a fourth part in contact with an outer surface of the outlet tubing and in electrical contact with the third part.

[0022] For example, the distance between the central axis of the static meter and the first electrically conductive element is greater than or equal to five times the nominal diameter of the measuring chamber. The central axis of the static meter is defined as the median between the end of the inlet tubing opposite the measuring chamber, and the end of the outlet tubing opposite the measuring chamber . This makes it possible to prevent, when the first electrically conductive element protrudes from an internal surface of the supply pipe, that it disturbs the flow of the fluid in a zone close to the electromagnetic measurement zone. [0023] For example, the distance between the axis of the meter and the second electrically conductive element is greater than or equal to three times the nominal diameter of the measuring chamber. This makes it possible to prevent, when the second electrically conductive element protrudes from an internal surface of the outlet pipe, that it disturbs the flow of the fluid in an area close to the electromagnetic measurement area.

LIST OF FIGURES [0024] Other characteristics will become apparent on reading the detailed description given by way of example and not limiting which follows, made with reference to the accompanying drawings which represent:

Figure 1, an example of a state of the art fluid metering assembly;

FIG. 2, an example of a set for counting a fluid according to a set of embodiments of the invention;

FIGS. 3, 4 and 5, an example of steps in the production of an assembly for counting a fluid, in a set of embodiments of the invention;

Figure 6 shows a prototype of a fluid meter according to a set of embodiments of the invention on a test bench.

DETAILED DESCRIPTION In the following, an exemplary embodiment, shown in FIG. 2, will be described in which the guiding idea consists in creating the electrical bridge from metal clamping elements, which are in contact with water. , and this on each side of the meter. These parts have direct contact.

In this example, the static electromagnetic counter 200 comprises:

a measuring chamber 210;

a supply pipe 220 comprising a first connection thread (not visible in FIG. 2) of a fluid inlet pipe (not visible in FIG. 2) to the meter. The first electrically conductive element 230 is formed by the first means of tightening of the fluid inlet pipe, here a nut. A first flat (not visible in FIG. 2) is formed on an external surface of the first connection thread so as to be able to receive and position a first end of the third conductive element, here a flat copper braid;

an outlet pipe 240 comprising a second connection thread (not visible in Figure 2) of a fluid discharge line (not visible in Figure 2) of the meter. The second electrically conductive element 250 consists of the second means of clamping the fluid inlet pipe. A second flat (not visible in FIG. 2) is formed on an external surface of the second connection thread so as to be able to receive and position a second end of the third conductive element 260, here a flat copper braid.

[0027] This arrangement does not in any way modify the hydraulics of the meter and therefore it does not present the risk of disturbing the measurement. It does not affect the mechanical strength of the meter, or of the metal parts that enclose it. It does not pose a risk to the waterproofing of the meter. Finally, the location chosen means that the installation will not be done on private parts of the connection (in the case of France in particular).

[0028] This solution is necessary in the face of two other possible options:

The integration of terminals inside the meter which may disrupt the measurement hydraulically;

The realization of the bridge on, that is to say by the outside of the metal parts which would make the assembly more difficult and would generate waste of time.

The third electrical conductor element 260 used is preferably a copper braid which must correspond to an earth cable of an equivalent section of 6 mm2 or greater. It was chosen because it is flat (preferably 1.5 mm thick) and will ensure a maximum contact surface with the metal elements. Indeed, the width of the braid as well as the flexibility of the material allows its deformation, facilitates the screwing operation and gives a maximum contact surface on the screw thread of the nut. Figures 3, 4 and 5 below illustrate the steps in the production of an assembly for counting a fluid as described above.

[0031] Figure 3 illustrates a step of creating a flat 310 on the scope of the meter. The first and second connecting threads were filed, leaving the first 2 threads intact. The idea is to create a space in which one can insert the end of the braid, serving as a third conductive element 260, to allow the nut, serving as tightening means, to then come and cover it, and this without harming sealing, both from the water to the outside and from the ambient air to the electrical contact of the meter.

[0032] Figure 4 illustrates the integration of the braid 260 on one of the connection threads in position so as to be able to be clamped by a clamping means as illustrated in Figure 5.

In Figure 5, the braid 260 is placed in the housing created and the nut then traps it by creating the electrical contact and therefore providing a means of bypassing parasitic currents.

Different advantages are obtained:

the braid 260 has the technical effect of deflecting the parasitic currents. It is integrated into the meter, you just have to mount the meter in a completely ordinary way.

The fact of inserting the braid in a housing between the nut and the surface of the meter makes it possible to avoid the external corrosion at the level of the contact because this zone of contact is not under the influence of the ambient air. Thus, the cleaning phase is avoided; there is no difference in operating time on disassembly / assembly operations between an unprotected meter and a protected meter integrated into the metering assembly incorporating a means of bypassing parasitic currents;

the solution can be easily industrialized: the same type of braid can be used for all types of meters. In particular, the same braid is applicable regardless of the diameter of the nuts, and inlet and outlet pipes. The braid model is therefore applicable to all existing meters, which allows the solution to be easily industrialized.

[0035] FIG. 6 represents a prototype of a fluid meter according to a set of embodiments of the invention on a test bench. The sticker 610 represents a photograph of a general view of the fluid meter on the test bench, and the thumbnails 620 and 630 two zooms, respectively on the interface between the braid 260 and the nuts, at the level of the inlet tubing and outlet tubing. The same reference numerals as for Figure 2 were used.

In this example, two tests were carried out:

Leak test at 3.5 bars;

Conductivity test measured at the surface of the nuts that surround the meter.

The tightness tests are good, as shown by the photos shown in Figure 6, no water flow is observed, the original waterproofness of the meter is retained.

Conductivity measurements give <0.1 W, therefore the electrical bridge produced turns out to be a conductor as required.

Preferably, the braid will be placed on the meter to avoid creating a contact surface which will prevent:

That rats come to degrade the sheath of the braid;

Will limit the possibilities of material theft. [0041] The above examples demonstrate the advantages provided by a fluid metering assembly in a set of embodiments of the invention. They are, however, given only by way of example and in no way limit the scope of the invention, defined in the claims below.

Claims

1. Fluid metering assembly comprising:

a static electromagnetic fluid meter (200), said meter comprising:

a measuring chamber (210) through which the fluid can flow;

a pipe (220) for supplying fluid to said chamber;

an outlet tubing (240) for fluid from said chamber;

a parasitic current bypass means comprising:

a first electrically conductive member (230) connected to the inlet tubing and adapted to be in electrical contact with the fluid as it flows through the inlet tubing;

a second electrically conductive member (250) connected to the outlet tubing and adapted to be in electrical contact with the fluid as it flows through the outlet tubing;

a third electrically conductive element (260) connecting the first electrically conductive element and the second electrically conductive element.

2. A fluid metering assembly according to claim 1, wherein the third electrically conductive element has a useful section greater than or equal to 6mm ² .

3. A fluid metering assembly according to one of claims 1 or 2, wherein the third electrically conductive element is a braid, preferably flat.

4. A fluid metering assembly according to one of claims 1 to 3, wherein: the supply pipe comprises a first connection thread of a fluid inlet pipe;

the first electrically conductive element comprises at least part of a first means for clamping the fluid inlet pipe to the first connection thread.

5. A fluid metering assembly according to claim 4, wherein at least a portion of the first connection thread has a first flat (310) adapted to receive a first end of the third electrically conductive element.

6. A fluid metering assembly according to one of claims 1 to 5, in which:

- the outlet tubing has a second connection thread for a fluid discharge line;

- The second electrically conductive element comprises at least part of a second means for clamping the fluid discharge pipe to the second connection thread.

7. A fluid metering assembly according to claim 6, wherein at least a portion of the second connecting thread has a second flat (310) adapted to receive a second end of the third electrically conductive element.

8. A fluid metering assembly according to one of claims 1 to 7, wherein:

- the first electrically conductive element comprises at least a first part protruding from an internal surface of the supply pipe;

- at least a second part in contact with an external surface of the supply pipe and in electrical contact with the first part.

9. A fluid metering assembly according to one of claims 1 to 7, wherein the second electrically conductive element comprises: at least a third portion protruding from an inner surface of the outlet tubing;

at least a fourth part in contact with an outer surface of the outlet tubing and in electrical contact with the third part.

10. A fluid metering assembly according to one of claims 1 to 9, wherein the distance between the central axis of the static meter and the first electrically conductive element is greater than or equal to five times the nominal diameter of the chamber. of measurement.

11. A fluid metering assembly according to one of claims 1 to 10, wherein the distance between the axis of the meter and the second electrically conductive element is greater than or equal to three times the nominal diameter of the measuring chamber. .