阅读说明：本技术 电磁流量计上的夹具 (Clamp on electromagnetic flowmeter ) 是由 S·达斯古普塔 V·卡里瓦拉 于 2018-12-19 设计创作，主要内容包括：本发明提供了一种用于操作电磁流量计的方法,该电磁流量计能够被安装到流管的表面上,以用于测量在流管中流动的流体的流量。该方法包括：对线圈进行激励,以便获得与流管中的流体的电磁相互作用,从而导致漏电流；通过向电极施加电势差来提供电流以补偿流管中的所得漏电流,所述电极附接到电磁流量计的壳体并且与流管接触；检测其中流动的所得电流在阈值范围内的状况；以及基于所施加的电势差的值,确定流管中的流量的测量值。(The present invention provides a method for operating an electromagnetic flow meter that can be mounted to a surface of a flow tube for measuring a flow rate of a fluid flowing in the flow tube. The method comprises the following steps: energizing the coil to obtain electromagnetic interaction with the fluid in the flow tube, resulting in leakage current; providing a current to compensate for a resulting leakage current in a flow tube by applying a potential difference to an electrode attached to a housing of an electromagnetic flowmeter and in contact with the flow tube; detecting a condition in which a resulting current flowing is within a threshold range; and determining a measure of flow in the flow tube based on the value of the applied potential difference.)

1. A method for operating an electromagnetic flow meter (100), the electromagnetic flow meter (100) being mountable onto a surface of a flow tube for measuring a flow rate of a fluid flowing in the flow tube, the method comprising:

energizing a coil (220) to obtain an electromagnetic interaction with the fluid in the flow tube (200) resulting in a leakage current in the flow tube (200) due to the electromagnetic interaction in the flow tube (200);

providing a current to compensate for a resulting leakage current in the flow tube (200) by applying a potential difference to a pair of electrodes (230), the pair of electrodes (230) attached to a housing of the electromagnetic flowmeter (100) and in contact with the flow tube (200);

detecting, with a processing unit, a condition in which a resulting current flowing in the flow tube (200) is within a threshold range; and

determining, with the processing unit, a measure of the flow in the flow tube (200) based on the values of the applied potential differences.

2. The method of claim 1, wherein the resulting current flowing in the pipe within a threshold range has a value of zero.

3. An electromagnetic flow meter (100), the electromagnetic flow meter (100) being mountable onto a surface of a flow tube (200) for measuring a flow rate of a fluid flowing in the flow tube (200), the electromagnetic flow meter (100) comprising:

a housing having a support (250) secured to the flow tube (200), wherein a coil (220) is attached to an inner surface of the support (250), wherein the coil (220) is electrically energized to generate an electromagnetic field for interacting with the fluid flowing through the flow tube (200) and causing a circulating leakage current in the flow tube (200);

a control circuit having:

a controllable voltage source for supplying a potential difference onto a pair of electrodes (230), wherein the pair of electrodes (230) is attached to the housing and in contact with the flow tube (200) to provide a compensation current for the cyclic leakage current in the flow tube (200);

a current sensing component for measuring a current flowing in the flow tube (200); and

a processing unit for detecting a condition in which the measured current is within a threshold range and for measuring flow in the flow tube proportional to the applied potential difference with the controllable voltage source.

4. The electromagnetic flowmeter of claim 3 wherein the controllable voltage source is at least one of a DC source or an AC source.

5. An electromagnetic flowmeter as claimed in claim 3 comprising a display for indicating the determined flow rate of fluid in the flow tube.

6. The electromagnetic flow meter of claim 3, wherein the current sensing component is an ammeter.

7. The electromagnetic flowmeter of claim 3, transmitting the determined flow rate of fluid in the flow tube to a remote control center of the electromagnetic flowmeter for storage and analysis.

Technical Field

The present invention relates to the field of electromagnetic flow meters, and more particularly to a method of operating a clamp on an electromagnetic flow meter.

Background

Measuring the flow of fluid through a conduit or pipe can be done in a number of ways, including using an electromagnetic flow meter. A typical electromagnetic flowmeter operates according to faraday's law of electromagnetic induction. An electromagnetic field is applied within a flow tube having a fluid flow with a certain level of conductivity. The electromotive force (EMF) induced by the interaction of the electromagnetic field with the fluid molecules (ions in the fluid) is measured using electrodes provided at the side walls of the flow meter conduit. The measured EMF is proportional to the flow rate and is therefore used to measure the flow rate.

EM flow meters are widely used for measuring fluid flow rates and are typically installed in a fluid path together with a main pipe carrying the fluid and in which it is required to measure the flow of the fluid. This arrangement for installation requires bolting (bolting) of the EM flowmeter flange to a flange provided in the main pipe. The EM flow meter is installed between main pipes through which the flow of fluid is to be measured. Pre-installation of such EM flow meters between sections of a main pipe involves planning to install the flow meter along with installation of the main pipe, or later installing the flow meter by cutting the main pipe, which adds complexity, invasiveness and causes inconvenience.

In order to improve the benefits of convenience, especially in scenarios where the EM flowmeter is to be installed in the main pipeline at a later point in time, there is a need for an electromagnetic flowmeter that can be easily installed.

Disclosure of Invention

The above-mentioned deficiencies, disadvantages and problems are addressed herein and will be understood by reading and understanding the following specification.

The present invention provides a method for operating an electromagnetic flow meter mountable to a surface of a flow tube for measuring a flow rate of a fluid flowing in the flow tube, the method comprising: energizing a coil to obtain a magnetic interaction with the fluid in the flowtube resulting in a leakage current in the flowtube due to the magnetic interaction in the flowtube; providing a current to compensate for a resulting leakage current in the flow tube by applying a potential difference to a pair of electrodes attached to a housing of the electromagnetic flow meter and in contact with the flow tube; detecting, with a processing unit, a condition in which a resulting current flowing in the flow tube is within a threshold range; and determining, with the processing unit, a measure of the flow in the flow tube based on the values of the applied potential differences.

In an embodiment of the invention, the resulting current flowing in the pipe within the threshold range has a value of zero.

In an aspect, the present invention provides an electromagnetic flow meter mountable to a surface of a flow tube for measuring a flow rate of a fluid flowing in the flow tube, the electromagnetic flow meter comprising: a housing having a support secured to the flow tube, wherein a coil is attached to an inner surface of the support, wherein the coil is electrically energized to generate an electromagnetic field for interacting with the fluid flowing through the flow tube and causing a circulating leakage current in the flow tube; a control circuit having: a controllable voltage source for supplying an electrical potential difference to a pair of electrodes attached to the housing and in contact with the flow tube to provide a compensation current for the cyclic leakage current in the flow tube; a current sensing component for measuring a current flowing in the flow tube; and a processing unit for detecting a condition in which the measured current is within a threshold range and for measuring the flow in the flow tube proportional to the applied potential difference with the controllable voltage source.

In an embodiment, the controllable voltage source is at least one of a DC source or an AC source.

In an embodiment, the electromagnetic flow meter comprises a display for indicating the determined flow rate of the fluid in the flow tube.

In an embodiment, the current sensing component is an ammeter.

In an embodiment, the electromagnetic flow meter transmits the determined flow rate of the fluid in the flow tube to a remote control center of the electromagnetic flow meter for storage and analysis.

Drawings

The drawings illustrate exemplary embodiments as disclosed herein and are not to be considered limiting in scope. In the drawings:

FIG. 1a shows a prior art electromagnetic flow meter;

FIG. 1b shows an overview of a prior art electromagnetic flow meter;

FIG. 2a shows a cross-sectional view of a clamp on an electromagnetic flow meter;

FIG. 2b shows an overview of a clamp on an electromagnetic flow meter;

FIG. 3a shows a plot of leakage current versus compensation voltage;

FIG. 3b shows signal loss due to leakage current in a cross section of a metal pipe; and

FIG. 4 shows a flow chart of a method of operating a clamp on an electromagnetic flowmeter.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments that may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, and it is to be understood that other embodiments may be utilized. The following detailed description is, therefore, not to be taken in a limiting sense.

Fig. 1a shows an electromagnetic flow meter 100. Fig. 1a shows an electromagnetic flow meter comprising: a conduit/pipe 110 through which the fluid flows; a pair of coils (top coil 120 and bottom coil 130) for generating an electromagnetic field that interacts with fluid passing through the conduit, wherein the pair of coils are positioned opposite each other on the conduit along a first axis perpendicular to a flow of fluid through the conduit; and a pair of potential sensing electrodes (140 and 150) for measuring electromotive force by means of measuring a potential difference between the electrodes generated by interaction of electromagnetic fields in the fluid, the pair of potential sensing electrodes being placed opposite to each other on the conduit along a second axis perpendicular to the first axis and perpendicular to the flow of the fluid. The pair of coils (120 and 130) is horizontally disposed parallel to the direction of fluid flow along the conduit 110. There is also an insulating layer or lining to prevent signal loss in the metal pipe. A pair of coils 120 and 130 are provided at the top and bottom of the bushing, respectively. A pair of potential sensing electrodes (140 and 150) inserted at the liner side are placed across the diameter, providing an induced EMF due to the potential difference across the catheter diameter. Fig. 1b shows an overview of a prior art electromagnetic flowmeter. The entire system is enclosed in magnetic cover (magnetic cover) that contains the magnetic field and ensures a strong signal. As shown in fig. 1b, a flange 160 is shown, said flange 160 being used to secure the electromagnetic flow meter to both sides 170a and 170b of the main pipe. In order to install the electromagnetic flow meter in the main pipe, the main pipe is required to be cut so as to fit the electromagnetic flow meter between the two sides 170a and 170b of the main pipe, and to be fitted with the electromagnetic flow meter indicated by 160 and a flange on the main pipe.

The present invention relates to a method of operating an electromagnetic flow meter. In the present invention, an electromagnetic flow meter is disclosed that can be clamped to a main pipe or flow tube through which fluid is flowing. Typically, the electromagnetic flow meter is pre-installed in the main pipe, or is installed by cutting a section of the main pipe and installing the electromagnetic flow meter in the cut section. The clamp on the electromagnetic flowmeter includes a clamp on the mechanism that is used to clamp the electromagnetic flowmeter to the side of the main pipe and avoid any cutting of the main pipe. Similar to prior art electromagnetic flow meters, the clamp on an electromagnetic flow meter comprises a coil that is electrically excited to generate a magnetic field that interacts with the fluid passing through the main conduit and that is clamped on the side of the main conduit.

Figure 2a shows a cross-sectional view of a clamp on an electromagnetic flow meter. A clamp on an electromagnetic flowmeter can be mounted to the surface of a metal pipe through which a fluid whose flow rate is to be measured is flowing. Fig. 2a shows a cross-sectional view of a main pipe or metal pipe 200 surrounded by a liner 210 for supporting a pair of coils, indicated at 220. A pair of electrodes 230 is shown in contact with the metal pipe 200. The pair of electrodes is connected to a voltage source 240, which may be a battery or any other DC or AC voltage source. The clamp on the flowmeter as shown in fig. 2a comprises a housing with a bracket 250 fastened to the flow tube, e.g. with a flange or clamp indicated 270 as also shown in fig. 2 b. The inner surface of the housing 250 has attached to it on the top and bottom sides (either side is sufficient to operate as well) a coil assembly 220. Furthermore, the clamp on the electromagnetic flow meter is provided with a control circuit. The control circuit is critical in controlling the voltage supply 240 based on the generated leakage current in the section where the clip on the electromagnetic flowmeter is installed (pivotal).

The control circuit manages a controllable voltage source (shown as 240 in fig. 2A) for supplying a potential difference to the pair of electrodes 230 so as to provide a compensation current for counteracting (nullify) a circulating current (caused by loss leakage according to the interaction of the fluid with the electromagnetic field) generated in the flow tube due to the electrical excitation of the coil and the interaction of the electromagnetic field generated by the coil with the fluid in the conduit. The pair of electrodes 230 are attached to the housing and in contact with the flow tube. Also, a current sensing part 260 is provided in a jig on the electromagnetic flowmeter to measure a current flowing in a cross section of the flow tube due to the compensation current and the leakage current provided by the voltage source. As known to those skilled in the art, the current sensing component may be an ammeter.

A processing unit (not shown) is provided to detect a condition in which the measured current is within a threshold range for a zero condition (the compensation current equals the leakage current) and to drive the control circuit to vary the voltage from the voltage source to achieve the zero condition. Thus, the measured current is driven to achieve a near zero level or to indicate no current reading. The condition in which zero current is detected when a potential difference is applied is a condition when no leakage current flows in the metal pipe, and therefore, the voltage applied to generate a compensation current for the leakage current is a voltage required for determining the flow rate of the fluid. The processing unit thus gives a measured flow rate in the flow tube proportional to the applied potential difference.

Fig. 2b shows an overview of the clamp on an electromagnetic flow meter as disclosed by the present invention. The clamp on the electromagnetic flowmeter shown in fig. 2b has a structure in which: wherein the electromagnetic flow meter is attached or bolted onto the main or end pipe using a flange 270. The main conduit, which is typically metal, is in direct electrical contact with the liquid, as there is no insulating bushing.

Fig. 3a shows the relation between the compensation voltage and the leakage current. For a given flow rate, a signal (compensation current from a voltage source) equal and opposite to the generated signal (leakage current) is applied on the pipe wall through the electrodes. The resulting current flowing through the wall of the pipe is zero. Since the voltage signal from the voltage source to be applied externally is unknown, the control circuit is used together with the processing unit for scanning a situation in which the measured resultant current is zero. The corresponding voltage is recorded and the flow rate is determined using a pre-established calibration factor (through a calibration process using a reference flow meter). Fig. 3b shows the signal loss due to leakage current in the cross section of the metal pipe. In the clamp on an electromagnetic flow meter, energy from the interaction of the electromagnetic field with the fluid is lost in the form of current circulating through the conductive pipe as indicated by 300, due to the absence of an insulating liner inside the metal flow pipe. Fig. 4 illustrates a method for operating a clamp on an electromagnetic flowmeter. As mentioned, the clamp on an electromagnetic flow meter can be mounted on a main pipe or flow pipe through which fluid is flowing. As a first step, the pair of coils is energized to provide electromagnetic interaction with the fluid in the flow tube, resulting in leakage current in the flow tube, as shown in fig. 4. Current is externally supplied to compensate for the resulting leakage current in the flowtube, as shown in step 420. The current is provided by applying a potential difference to a pair of electrodes attached to a housing of the electromagnetic flowmeter and also in contact with the flow tube. As shown in step 430, a condition is detected with the processing unit in which the resulting current flowing in the main pipe is within a threshold range. Finally, as shown in step 450, a measure of the flow is determined with the processing unit based on the value of the applied potential difference.

In an embodiment, a clamp on the flow meter may include a display for indicating the determined flow rate of the fluid in the flow tube.

In an embodiment, a clamp on the electromagnetic flow meter transmits the determined flow rate of the fluid in the flow tube to a remote control center of the electromagnetic flow meter for storage or further analysis.

In an embodiment, the fixture on the electromagnetic flow meter is an internet of things (IOT) enabled for providing remote control, better visibility of the operation of the fixture on the electromagnetic flow meter, real-time information to software systems and other surrounding IOT enabled systems.

This written description uses examples to describe the subject matter herein, including the best mode, and also to enable any person skilled in the art to make and use the subject matter. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are exactly the same as the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.