FIELD OF THE INVENTION

The present invention relates generally to an electromagnetic flowmeter and more particularly to an electromagnetic flowmeter that can be attached to a flow pipe for measuring flow of fluid in a flow pipe.

BACKGROUND OF THE INVENTION

Measurement of flow of fluids through a conduit or pipe can be done by numerous ways like using electromagnetic flowmeters. Electromagnetic flowmeters are popular flow measurement devices owing to their non-invasiveness and accuracy.

A typical electromagnetic flowmeter works on Faraday's law of electromagnetic induction. An electromagnetic field is imposed within a flow pipe having a flow of fluid with a certain level of conductivity. Electromotive force (EMF) induced as a result of the interaction of the electromagnetic field with fluid molecules (ions in the fluid), is measured using electrodes provided at the pipe side walls. The measured EMF is proportional to the flowrate and thus used to measure flowrate. While electromagnetic flowmeters are attractive given that they are noninvasive, accurate and simplistic in construction, it is desirable to reduce the material cost and/or weight of the flowmeters, especially for application in large diameter flow pipes.

Conventionally, for large diameter flow pipes insertion type flowmeters are widely used. Insertion type flowmeters intrude into a fluid space encompassed by the flow pipe, and a flowrate is sampled over that zone of fluid space within the flow pipe (local velocity measurement). It is observed that, insertion type flowmeters intrude into the fluid space inside the flow pipe causing pressure drop and disturbing the flow dynamics of the fluid flowing the flow pipe. In insertion type flowmeters a pressure drop is caused due to the intrusion or in other words an obstruction to flow is caused in the flow pipe. Additionally, insertion types are prone to corrosion by corrosive substances in the flow pipe.

For better accuracy, full bore flowmeters are preferable over insertion type flowmeters. Accuracy is better in full bore flowmeters mainly as flowrate is measured over a larger sampling volume. However full bore flowmeters are expensive and increases the footprint of the flowmeter.

Hence there is a need for an electromagnetic flowmeter that can be used for measuring flow rate of fluids flowing in high diameter flowmeters, without compromising on cost, simplistic construction, non-invasiveness, resistance to corrosion and accuracy of measurement.

SUMMARY

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

In one aspect, the present invention provides an attachable electromagnetic flowmeter for measuring a flow of fluid in a flow pipe, the electromagnetic flowmeter comprising a housing that is attachable on an outer surface of the flow pipe on an opening provided in the flow pipe for attaching the housing of the electromagnetic flowmeter and includes a cavity within the housing with an inner sheath around the opening provided in the flow pipe with a first surface of the inner sheath on attachment of the housing on the outer surface of the flow pipe and allows the fluid flowing through the flow pipe to flow through the cavity formed with the inner sheath of the housing attached on the outer surface of the flow pipe; a coil mounted on a second surface of the inner sheath of the housing for generating electromagnetic field on electrical excitation that interacts with the fluid flowing through the cavity; and a pair of electrodes for measuring potential difference generated by the interaction of electromagnetic field in the fluid flowing in the cavity to determine the flow of fluid in the flow pipe.

In an embodiment, the attachable electromagnetic flowmeter as mentioned herein above wherein the housing can be attached to the outer surface of the flow pipe using welded joints to the opening provided in the flow pipe.

In another embodiment of the attachable electromagnetic flowmeter the housing can be attached to the outer surface of the flow pipe using bolted joints to the opening provided in the flow pipe.

In another embodiment of the attachable flowmeter comprises a display for indicating the determined flow of fluid in the flow pipe.

In another embodiment of the attachable electromagnetic flowmeter the determined flow of fluid in the flow pipe is transmitted to a remote control center of the electromagnetic flowmeter for further analysis.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 illustrates an attachable electromagnetic flowmeter for measuring a flow of fluid in a flow pipe.

Figure 2 illustrates a front view of the attachable electromagnetic flowmeter when the attachment is on top side of the flow pipe.

Figure 3 illustrates another front view of the attachable electromagnetic flowmeter when the attachment is on the bottom side of the flow pipe. Figure 4 illustrates a side view of the attachable electromagnetic flowmeter.

Figure 5 illustrates front view of the attachable electromagnetic flowmeter with bolted joints for attachment.

DETAILED DESCRIPTION

The present invention is related to an attachable electromagnetic flowmeter for measuring flow of fluid in a flow pipe. The present invention provides an attachable electromagnetic flowmeter which is low in cost, with reduced weight yet providing accurate measurements at par with full bore flowmeters. In this invention, the electromagnetic flowmeter comprises a housing that is attached through various methods like welding or through bolted connections using flanges to an opening on the outer surface of the flow pipe where the opening on the outer surface of the flow pipe is provided for attaching a flowmeter. The housing comprises a cavity with an inner sheath around the opening on the outer surface of the flow pipe. Hence, the fluid that passes through the flow pipe now also flows through the cavity formed with the inner sheath of the housing because of the fluid pressure and/or gravity. The housing further houses a coil which generates an electromagnetic field on electrical excitation and this electromagnetic field interacts with the fluid flowing through the cavity, and a potential difference is observed when measured using a pair of electrodes placed opposite to each other on the inner sheath, and thus the flow of fluid in the flow pipe can be determined as a measure of potential difference between the pair of electrodes on excitation of the coil. With regard to providing liner, in this invention it is only the housing inner wall that needs an insulating liner. This way insulating liner cost is saved reducing the overall cost of the attachable electromagnetic flowmeter.

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, which 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. Figure 1 illustrates an attachable electromagnetic flowmeter 100. Figure 1 shows an attachable electromagnetic flowmeter, which comprises a flow pipe 110 through which fluid flows, a coil 120 for generating electromagnetic fields that interact with the fluid passing through the flow pipe particularly in the cavity (150)formed inside the "D" shaped housing, a pair of electrodes (130- referencing an electrode shown in the figure, 140 referencing an electrode not visible in the figure but present at the opposite side facing the electrode 130) placed with a gap between the electrodes for measuring potential difference generated by the interaction of electromagnetic fields in the fluid in the cavity 150. The pair of electrodes (130 and 140) which are placed across the cavity of the flow pipe provide the difference in potential across the cavity. The difference in potential is proportional to the fluid flowrate in the cavity and also representative of the flowrate in the fluid pipe The relationship between velocity of the fluid in the flow pipe and that in the cavity, calculated by a Finite Element (F.E.) code shows a perfect linear relationship between the two velocities suggesting that the measurement of flow in the cavity faithfully reflects flowrate in the main pipe.

The flowing fluid fills the cavity space in the electromagnetic flowmeter. The coil is provided above the cavity, as shown in figure 100, and once the coils are electrically excited, they generate an electromagnetic field that traverses the cavity volume. As will be known to the persons skilled in the art, the coil can be of different shapes depending on the need for magnetic field intensity. Interaction of the magnetic flux and the moving fluid, causes a potential difference (Faraday's law of electromagnetic induction) to be measured by the electrodes provided at the walls encompassing the cavity.

Figure 2 illustrates a front view of the attachable electromagnetic flowmeter 200 when the attachment is on top side of the flow pipe. Figure 2 illustrates a housing 210, welded joints 220 and 230 for attaching the housing 210 to the opening provided for attaching a flowmeter in the flow pipe 110, the housing has an inner sheath that forms a hallow space (cavity, 150), the housing 210 houses the coil 120 for generating an electromagnetic field that can be placed on the inner sheath, and the front view of one of the electrodes (130 or 140) also secured on the inner sheath. The direction of the flow of fluid in the pipe is indicated as 240.

As shown in Figure 2, the housing 210 is attachable on the outer surface of the flow pipe with welded joints 220 and 230 on an opening provided in the flow pipe. A hollow space is provided within the housing with an inner sheath 260 that forms a cavity 150 around the opening provided in the flow pipe 110. A first surface 260 of the inner sheath 250 on attachment of the housing on the outer surface of the flow pipe 110 forms a cavity and allows the fluid flowing through the flow pipe to flow through the cavity 150. The coil 120 is mounted on a second surface 270 of the inner sheath 250 of the housing 210 for generating electromagnetic field on electrical excitation that interacts with the fluid flowing through the cavity 150.

Figure 3 illustrates another front view of the attachable electromagnetic flowmeter when the attachment is on the bottom side of the flow pipe. Figure 3 illustrates the flexibility that the present invention provides in terms of ability to attach the electromagnetic flowmeter to any portion or side of the flow pipe. Figure 3 also illustrates the housing 210, welded joints 220 and 230 for a attaching the housing 210 to the opening provided in the flow pipe 110, the inner sheath of the housing forms the cavity 150, the housing 210 houses the coil 120 for generating an electromagnetic field, and the front view of one of the electrodes (130 or 140). The direction of the flow of fluid in the pipe is indicated as 340 and the flow of fluid in the cavity is also assisted by gravity.

Figure 4 illustrates a side view of the attachable electromagnetic flowmeter 400. In this view of the electromagnetic flowmeter 400, the side view of the flow pipe 410, the side view of the housing 210, the side view of the cavity 150, the coil 120 above the cavity 150, and welded joints 220 and 230 are shown.

Figure 5 illustrates front view of the attachable electromagnetic flowmeter assembled with flanges having bolted joints for attachment. Figure 5 shows that the housing can be attached to the opening of the flow pipe 110 using bolted joints 510 and 520. Figure 5 illustrates a housing 210, bolted joints 510 and 520 for attaching the housing 210 to the opening provided in the flow pipe 110, the inner sheath of the housing forms the cavity 150, the housing 210 houses the coil 120 for generating an electromagnetic field, and the front view of one of the electrodes (130 or 140). The direction of the flow of fluid in the pipe is indicated as 540.

The flowmeter for exciting the coils for producing electromagnetic fields have a suitable power source and electronics circuitries for making potential difference measurements and display/transmitting the measured values. In an embodiment, the attachable flowmeter can comprise a display for indicating the determined flow of fluid in the flow pipe.

In an embodiment, the attachable electromagnetic flowmeter wherein the determined flow of fluid in the flow pipe (measured potential difference between the electrodes) is transmitted to a remote control center of the electromagnetic flowmeter for further analysis.

In an embodiment, the attachable electromagnetic flowmeter is Internet of Things (IOT) enabled for providing remote controlling, better visibility of the working of the attachable electromagnetic flowmeter, providing 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 do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.