JP2022083894A - Piping connection structure of electromagnetic flowmeter, electromagnetic flowmeter, and earth ring - Google Patents

Abstract

To provide the piping connection structure of an electromagnetic flowmeter, as well as the electromagnetic flowmeter and an earth ring, with which it is possible to improve the noise-resistance performance of the electromagnetic flowmeter and improve the stability of measurement.SOLUTION: Provided is a piping connection structure 10 of an electromagnetic flowmeter 1, comprising a measurement tube 2 of the electromagnetic flowmeter, two piping flanges 7 arranged across the measurement tube 2, and a plurality of shaft members 8, each connecting the two piping flanges 7 with each other and being electroconductive. The measurement tube 2 includes a measurement tube body 4 provided with an electroconductive outer circumferential surface 4a, a non-electroconductive gasket 5, and an earth ring 6, the earth ring 6 including a ring section 11 that presses the gasket 5 against an end surface 4b of the measurement tube body 4 and an electroconductive peripheral wall part 13 intermittently extending in the circumferential direction by being provided with a plurality of notches 12a. The peripheral wall part 13 covers the entire circumference of a non-electroconductive gap G1 formed by the gasket 5 between the outer circumferential surface 4a of the measurement tube body 4 and the ring part 11 by cooperation with the plurality of shaft members 8 from the radial outside.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a pipe connection structure of an electromagnetic flow meter, an electromagnetic flow meter and an earth ring.

As an electromagnetic flow meter connected between two pipes to measure the flow rate of fluid, a through bolt or the like is used in a state where the measuring pipe of the electromagnetic flow meter is sandwiched between the flanges of the two pipes (hereinafter, also referred to as pipe flanges). A type called a wafer type, which is connected to a pipe by connecting two pipe flanges to each other with a plurality of shaft members of the above, is known (see, for example, Patent Document 1).

The measuring tube of the wafer type electromagnetic flowmeter has an earth ring in order to remove noise invading through piping and fluid and to perform stable measurement. Further, a gasket is arranged between the measuring tube main body and the ground ring in order to suppress liquid leakage.

Japanese Unexamined Patent Publication No. 10-48015

The outer peripheral surface of the measuring tube body and the ground ring are conductive, and the gasket is non-conductive. Therefore, when the wafer type electromagnetic flowmeter is connected to the pipe, the gasket may form a non-conductive gap between the outer peripheral surface of the measuring tube main body and the ground ring. If noise enters the inside of the measuring tube through the gap, the measured value of the electromagnetic flowmeter may become unstable.

An object of the present disclosure is to provide a pipe connection structure for an electromagnetic flowmeter, an electromagnetic flowmeter and an earth ring capable of improving the noise resistance performance of the electromagnetic flowmeter and improving the stability of measurement.

In the piping connection structure of the electromagnetic flow meter according to some embodiments, the measuring tube of the electromagnetic flow meter, two piping flanges arranged across the measuring tube, and each connecting the two piping flanges to each other. The measuring tube has a measuring tube main body having a conductive outer peripheral surface, a non-conductive gasket, and a ground ring, and has a plurality of shaft members that are conductive. The ring has a ring portion that presses the gasket against the end surface of the measuring tube main body, and a conductive peripheral wall portion that extends intermittently in the circumferential direction by providing a plurality of notches, and the peripheral wall portion is the peripheral wall portion. The structure is such that the non-conductive gap formed between the outer peripheral surface of the measuring tube body and the ring portion by the gasket is covered from the radial outside to the entire circumference in cooperation with the plurality of shaft members. be. According to such a configuration, the non-conductive gap is covered from the radial outside to the entire circumference by the conductive member which is a combination of the plurality of shaft members and the peripheral wall portion of the earth ring, so that noise is not generated. It is possible to prevent the inside of the measuring tube from entering the inside of the measuring tube through the conductive gap. Therefore, the noise resistance performance of the electromagnetic flowmeter can be improved and the measurement stability can be improved. Further, by using a plurality of shaft members in this way, it is possible to form the peripheral wall portion of the earth ring with a small amount of members. Therefore, low cost can be realized.

In one embodiment, each of the shaft members enters the notch corresponding to the shaft member. With such a configuration, the ground ring can be easily centered with respect to the piping flange.

In one embodiment, the inner peripheral surface of the peripheral wall portion abuts on the outer peripheral surface of the measuring tube body. According to such a configuration, the earth ring can be easily centered with respect to the measuring tube main body.

In one embodiment, each of the shaft members enters the notch corresponding to the shaft member, and the inner peripheral surface of the peripheral wall portion abuts on the outer peripheral surface of the measuring tube main body. According to such a configuration, the measuring tube main body can be easily aligned with the piping flange.

In one embodiment, a gap is formed between the peripheral wall portion and the shaft member in any of the notches. According to such a configuration, the state such as the shape, crack, and hardness of the gasket is confirmed through the gap, and the replacement time of the gasket and the connection state of the two piping flanges by a plurality of shaft members are confirmed as a guide. can do.

In one embodiment, the ring portion has a notch connected to each of the notches in the peripheral wall portion. According to such a configuration, the ring portion of the earth ring can be formed with a small amount of members, so that the cost can be reduced.

In one embodiment, the ring portion has a notch connected to each of the notches of the peripheral wall portion, and the connecting portion between the peripheral wall portion and the ring portion in the notch of any of the peripheral wall portions. A gap is formed between the shaft member and the shaft member. According to such a configuration, the shape, crack, hardness, etc. of the gasket can be easily confirmed through the gap and the notch of the ring portion, the gasket replacement time, and the two piping flanges made of a plurality of shaft members. It can be used as a guide for checking the connection status.

The electromagnetic flowmeter according to some embodiments has a measuring tube main body provided with a conductive outer peripheral surface, a non-conductive gasket, and a measuring tube including a ground ring, wherein the ground ring is used for the measurement. It has a conductive ring portion that presses the gasket against the end surface of the tube body, and a conductive peripheral wall portion that extends intermittently in the circumferential direction by providing a plurality of notches, and the peripheral wall portion is formed by the gasket. The non-conductive gap formed between the outer peripheral surface of the measuring tube main body and the ring portion is conductive while connecting two piping gaskets, each of which is arranged with the measuring tube interposed therebetween. It is an electromagnetic flowmeter that covers the entire circumference from the outside in the radial direction in cooperation with a plurality of shaft members. According to such a configuration, the noise resistance performance of the electromagnetic flow meter can be improved and the measurement stability can be improved. In addition, low cost can be realized.

The earth ring according to some embodiments is provided with a conductive ring portion for pressing a non-conductive gasket against the end face of the measuring tube main body of the measuring tube of the electromagnetic flow meter, and a plurality of notches to be intermittent in the circumferential direction. It has a conductive peripheral wall portion extending in a shape, and the peripheral wall portion provides a non-conductive gap formed by the gasket between the conductive outer peripheral surface of the measuring tube body and the ring portion. Two pipe flanges, each of which is arranged with the measuring tube sandwiched between them, are connected to each other, and in cooperation with a plurality of shaft members corresponding to each of the plurality of conductive shaft members, from the outside in the radial direction to the entire circumference. It is an earth ring that covers all over. According to such a configuration, the noise resistance performance of the electromagnetic flow meter can be improved and the measurement stability can be improved. In addition, low cost can be realized.

According to the present disclosure, it is possible to provide a pipe connection structure of an electromagnetic flow meter, an electromagnetic flow meter, and an earth ring that can improve the noise resistance performance of the electromagnetic flow meter and improve the stability of measurement.

It is a top view which shows the electromagnetic flow meter which concerns on one Embodiment. It is a top view of one of the earth rings shown in FIG. It is a perspective view of the earth ring shown in FIG. It is a top view which shows the state which the electromagnetic flow meter shown in FIG. 1 is connected to a pipe. FIG. 4 is a cross-sectional view taken along the line AA of FIG.

Hereinafter, embodiments according to the present disclosure will be illustrated in detail with reference to the drawings.

As shown in FIG. 1, the electromagnetic flow meter 1 according to the present embodiment has a measuring tube 2 functioning as a detector and a converter 3. The electromagnetic flow meter 1 is an integrated type in which a measuring tube 2 and a converter 3 are connected to each other. The electromagnetic flow meter 1 may be a separate type in which the measuring tube 2 and the converter 3 are separated. The electromagnetic flow meter 1 is a field device used in a plant or the like. The measuring tube 2 has a measuring tube main body 4, two gaskets 5, and two ground rings 6 (see FIGS. 1 to 3).

As shown in FIG. 4, the electromagnetic flow meter 1 has two pipes 9 by connecting the two pipe flanges 7 to each other with a plurality of shaft members 8 in a state where the measuring pipe 2 is sandwiched between the two pipe flanges 7. It is connected between and measures the flow rate of the fluid. That is, the electromagnetic flow meter 1 is a wafer type. The pipe 9 (pipe flange 7), the measuring pipe main body 4, and the ground ring 6 are fixed to each other in a aligned state, that is, in a state where the central axis O along the pipe axis direction (fluid flow direction) is aligned.

In the following description, the direction along the straight line orthogonal to the central axis O is referred to as the radial direction, and the direction orbiting the central axis O is referred to as the circumferential direction.

Each piping flange 7 forms an annular shape. The number of shaft members 8 is eight. Therefore, the piping flange 7 has eight mounting holes through which the shaft member 8 passes. However, the number of the shaft member 8 and the mounting holes is not limited to this, and may be two or more.

Each shaft member 8 connects two piping flanges 7 to each other and is conductive. Each shaft member 8 is composed of a fastener having a through bolt 8a and two nuts 8b. In addition, each shaft member 8 may be composed of a fastener other than a fastener having a through bolt 8a and two nuts 8b. Further, each shaft member 8 may have a component other than the fastener (for example, a round nut interposed between the peripheral wall portion 13 and the through bolt 8a described later).

The pipe connection structure 10 of the electromagnetic flow meter according to the present embodiment has a measuring pipe 2, two pipe flanges 7, and a plurality of shaft members 8.

Returning to FIG. 1, the measuring tube main body 4 has a cylindrical shape having a flow path inside. The measuring tube main body 4 has a conductive outer peripheral surface 4a and two annular end surfaces 4b located on both sides in the tube axial direction. Although not shown, the measuring tube body 4 has a magnetic field generator that generates a magnetic field inside the measuring tube body 4 in a predetermined direction perpendicular to the tube axis direction, and the tube axis direction and the predetermined direction inside the measuring tube body 4. It has an electric field measuring instrument that detects a potential difference in a direction perpendicular to both. Therefore, the measuring tube 2 can generate an electric signal according to the flow rate of the fluid in the flow path.

Each gasket 5 has an annular shape and is arranged between the end surface 4b of the measuring tube main body 4 and the ground ring 6 to suppress liquid leakage. Each gasket 5 is non-conductive. Each gasket 5 is composed of, for example, a non-metal elastic member.

Each earth ring 6 is conductive and removes noise that enters the inside of the measuring tube main body 4 through the pipe 9 and the fluid in the pipe 9, thereby enabling stable measurement of the flow rate. .. Each ground ring 6 has a wetted portion 6a that comes into contact with the fluid and a contact portion 6b that comes into contact with the outer peripheral surface 4a of the measuring tube main body 4. Each ground ring 6 is connected to the ground via, for example, the outer peripheral surface 4a of the measuring tube main body 4 or via a ground wire fixed to the ground ring 6 with a screw or the like. Each earth ring 6 is composed of, for example, a metal member.

As shown in FIGS. 1 to 4, each of the ground rings 6 has a conductive ring portion 11 that presses the gasket 5 against the end surface 4b of the measuring tube main body 4, and a plurality of notches 12a (hereinafter, peripheral wall notches 12a). Also referred to as), it has a conductive peripheral wall portion 13 extending intermittently in the circumferential direction.

Each ring portion 11 has an annular flat plate shape. The inner peripheral edge of each ring portion 11 constitutes a wetted portion 6a. In the connected state in which the electromagnetic flow meter 1 is connected to the piping flange 7, a non-conductive gap G1 (see FIG. 4) is provided between each ring portion 11 and the outer peripheral surface 4a of the measuring tube main body 4 by a gasket 5. Is formed.

Each peripheral wall portion 13 has an intermittent cylindrical shape extending in the circumferential direction by providing the same number (that is, eight) of peripheral wall portion cutouts 12a as the shaft member 8. Each peripheral wall portion 13 extends from the outer peripheral edge of the ring portion 11 to one side in the pipe axis direction. Each peripheral wall portion notch 12a in each peripheral wall portion 13 forms a band shape extending along the pipe axis direction.

As shown in FIGS. 4 to 5, each peripheral wall portion 13 covers the non-conductive gap G1 from the radial outside to the entire circumference in cooperation with a plurality of shaft members 8. That is, each peripheral wall portion notch 12a in each peripheral wall portion 13 is at a position where the entire peripheral wall portion notch 12a overlaps the corresponding shaft member 8 when viewed from the radial direction (that is, 2 in FIG. 5). It is provided between the two alternate long and short dash lines).

As shown in FIG. 5, each shaft member 8 enters the peripheral wall portion notch 12a corresponding to the shaft member 8 in each peripheral wall portion 13. Further, in each peripheral wall portion notch 12a in each peripheral wall portion 13, a gap G2 (hereinafter, also referred to as a predetermined gap G2) is formed between the peripheral wall portion 13 and the shaft member 8 (see FIG. 5). The predetermined gap G2 extends from one end of the peripheral wall portion 13 in the pipe axial direction (the connecting portion between the peripheral wall portion 13 and the ring portion 11) to the other end in the pipe axial direction.

As shown in FIGS. 2 to 3, each ring portion 11 has a notch 12b (hereinafter, also referred to as a ring portion notch 12b) connected to each peripheral wall portion notch 12a of the peripheral wall portion 13. Hereinafter, the entire notch including the notch 12a of the peripheral wall portion and the notch 12b of the ring portion connected to the notch 12a is also referred to as the notch 12 of the outer peripheral portion. The shape of each outer peripheral portion notch 12 in each earth ring 6 has an arc shape when viewed from the pipe axis direction. The shape of each outer peripheral portion notch 12 in each earth ring 6 is not limited to the arc shape.

As shown in FIGS. 1 and 4, the inner peripheral surface of each peripheral wall portion 13 abuts on the outer peripheral surface 4a of the measuring tube main body 4. Therefore, the inner peripheral surface of each peripheral wall portion 13 constitutes the contact portion 6b of the earth ring 6. Each peripheral wall portion 13 is screwed to the outer peripheral surface 4a of the measuring tube main body 4 at two locations facing each other in the radial direction. Note that FIG. 1 shows one end of the measuring tube 2 (the left end in FIG. 1) before assembling the gasket 5 and the ground ring 6, while after assembling the other end of the measuring tube 2. It is shown in the state of. Each peripheral wall portion 13 may be screwed to the outer peripheral surface 4a of the measuring tube main body 4 at only one place or at three or more places, or may not be screwed to the outer peripheral surface 4a of the measuring tube main body 4. It may be a configuration.

According to the present embodiment, each non-conductive gap G1 is covered from the radial outer side to the entire circumference by a conductive member in which a plurality of shaft members 8 and a peripheral wall portion 13 of the earth ring 6 are combined. Therefore, it is possible to suppress noise from entering the inside of the measuring tube 2 through each non-conductive gap G1. Further, by using the plurality of shaft members 8 in this way, it is possible to form the peripheral wall portion 13 of each earth ring 6 with a small amount of members. Therefore, the noise resistance performance of the electromagnetic flow meter 1 can be improved and the measurement stability can be improved at low cost.

Further, according to the present embodiment, since each shaft member 8 enters the peripheral wall portion notch 12a corresponding to the shaft member 8 in each peripheral wall portion 13, each earth ring 6 can be easily connected to the pipe 9. Can be aligned. Further, according to the present embodiment, since the inner peripheral surface of each peripheral wall portion 13 comes into contact with the outer peripheral surface 4a of the measuring tube main body 4, each earth ring 6 is easily aligned with the measuring tube main body 4. be able to. Therefore, the measuring tube main body 4 can be easily aligned with the pipe 9.

Further, according to the present embodiment, a predetermined gap G2 is formed between the peripheral wall portion 13 and the shaft member 8 in the peripheral wall portion notch 12a of each peripheral wall portion 13, so that the gasket 5 is formed through the predetermined gap G2. The state such as shape, crack, and hardness can be confirmed, and it can be used as a guide for confirming the replacement time of the gasket 5 and the tightening state of the plurality of shaft members 8.

Further, according to the present embodiment, each ring portion 11 has a ring portion notch 12b, and a predetermined gap G2 extends from one end of the peripheral wall portion 13 in the pipe axial direction to the other end in the pipe axial direction. The shape, crack, hardness, and the like of the gasket 5 can be easily confirmed through the gap G2 (particularly the connecting portion between the peripheral wall portion 13 and the ring portion 11).

It goes without saying that the above-described embodiment is an example of the present disclosure and can be changed in various ways.

For example, the pipe connection structure 10, the electromagnetic flow meter 1, and the earth ring 6 of the electromagnetic flow meter according to the above-described embodiment can be variously modified as described below.

The piping connection structure 10 of the electromagnetic flow meter according to the above-described embodiment has a measuring tube 2 of the electromagnetic flow meter 1, two piping flanges 7 arranged so as to sandwich the measuring tube 2, and two piping flanges 7 each. A measuring tube main body 4 having a plurality of shaft members 8 connected to each other and having conductivity, and the measuring tube 2 having a conductive outer peripheral surface 4a, a non-conductive gasket 5, and an earth ring 6. The earth ring 6 has a ring portion 11 that presses the gasket 5 against the end surface 4b of the measuring tube main body 4, and a conductive peripheral wall portion 13 that extends intermittently in the circumferential direction by providing a plurality of notches 12a. , And the peripheral wall portion 13 has a diameter of a non-conductive gap G1 formed between the outer peripheral surface 4a of the measuring tube main body 4 and the ring portion 11 by the gasket 5 in cooperation with a plurality of shaft members 8. Various changes are possible as long as the structure covers the entire circumference from the outside of the direction.

However, it is preferable that each shaft member 8 enters the notch 12a corresponding to the shaft member 8.

Further, it is preferable that the inner peripheral surface of the peripheral wall portion 13 abuts on the outer peripheral surface 4a of the measuring tube main body 4.

Further, it is preferable that each shaft member 8 enters the notch 12a corresponding to the shaft member 8 and the inner peripheral surface of the peripheral wall portion 13 abuts on the outer peripheral surface 4a of the measuring tube main body 4.

Further, it is preferable that a gap G2 is formed between the peripheral wall portion 13 and the shaft member 8 in any of the notches 12a.

Further, it is preferable that the ring portion 11 has a notch 12b connected to each notch 12a of the peripheral wall portion 13.

Further, the ring portion 11 has a notch 12b connected to each notch 12a of the peripheral wall portion 13, and in the notch 12a of any of the peripheral wall portions 13, the connecting portion and the shaft between the peripheral wall portion 13 and the ring portion 11 It is preferable that a gap G2 is formed between the member 8 and the member 8.

The electromagnetic flow meter 1 according to the above-described embodiment has a measuring tube main body 4 having a conductive outer peripheral surface 4a, a non-conductive gasket 5, and a measuring tube 2 including a ground ring 6. 6 has a conductive ring portion 11 that presses the gasket 5 against the end surface 4b of the measuring tube main body 4, and a conductive peripheral wall portion 13 that extends intermittently in the circumferential direction by providing a plurality of notches 12a. Two pipes in which the peripheral wall portion 13 is arranged with the non-conductive gap G1 formed between the outer peripheral surface 4a of the measuring tube main body 4 and the ring portion 11 by the gasket 5, each sandwiching the measuring tube 2. Various changes can be made as long as the electromagnetic flowmeter 1 covers the flanges 7 from the outside in the radial direction to the entire circumference by cooperating with the shaft member 8 which is conductive and connects the flanges 7 to each other.

The earth ring 6 according to the above-described embodiment has a conductive ring portion 11 for pressing the non-conductive gasket 5 against the end surface 4b of the measuring tube main body 4 of the measuring tube 2 of the electromagnetic flow meter 1, and a plurality of notches 12a. It has a conductive peripheral wall portion 13 that extends intermittently in the circumferential direction, and the peripheral wall portion 13 is formed between the conductive outer peripheral surface 4a of the measuring tube main body 4 and the ring portion 11 by the gasket 5. The non-conductive gap G1 is connected to each other by connecting two piping flanges 7 each having a measuring tube 2 sandwiched between them, and by cooperating with a plurality of conductive shaft members 8 from the outside in the radial direction. As long as the earth ring 6 covers the entire circumference, various changes can be made.

1 Electromagnetic flow meter 2 Measuring tube 3 Converter 4 Measuring tube body 4a Outer peripheral surface 4b End surface 5 Gasket 6 Earth ring 6a Wet contact part 6b Contact part 7 Piping flange 8 Shaft member 8a Through bolt 8b Nut 9 Piping 10 Piping connection structure 11 Ring Part 12 Notch (Outer circumference notch)
12a Notch (notch on the peripheral wall)
12b Notch (Ring notch)
13 Peripheral wall part G1 Non-conductive gap G2 Predetermined gap O Center axis

Claims (6)

It is a piping connection structure of an electromagnetic flow meter,
The measuring tube of the electromagnetic flow meter and
Two piping flanges arranged across the measuring tube and
Each has a plurality of shaft members, which connect the two piping flanges to each other and are conductive.
The measuring tube has a measuring tube body having a conductive outer peripheral surface, a non-conductive gasket, and a ground ring.
The ground ring has a conductive ring portion that presses the gasket against the end surface of the measuring tube main body, and a conductive peripheral wall portion that extends intermittently in the circumferential direction by providing a plurality of notches.
The peripheral wall portion forms a non-conductive gap formed by the gasket between the outer peripheral surface of the measuring tube body and the ring portion from the radial outer side to the entire circumference in cooperation with the plurality of shaft members. Cover over,
structure. The structure according to claim 1, wherein each of the shaft members enters the notch corresponding to the shaft member. The structure according to claim 1 or 2, wherein the inner peripheral surface of the peripheral wall portion abuts on the outer peripheral surface of the measuring tube main body. The structure according to any one of claims 1 to 3, wherein a gap is formed between the peripheral wall portion and the shaft member in any of the notches. It ’s an electromagnetic flow meter,
It has a measuring tube body with a conductive outer peripheral surface, a measuring tube with a non-conductive gasket, and a ground ring.
The ground ring has a conductive ring portion that presses the gasket against the end surface of the measuring tube main body, and a conductive peripheral wall portion that extends intermittently in the circumferential direction by providing a plurality of notches.
The peripheral wall portion has a non-conductive gap formed between the outer peripheral surface of the measuring tube main body and the ring portion by the gasket, and two piping flanges are arranged so as to sandwich the measuring tube. By cooperating with multiple shaft members that are connected to each other and are conductive, it covers from the outside in the radial direction to the entire circumference.
Electromagnetic flow meter. It ’s an earth ring.
A conductive ring part that presses a non-conductive gasket against the end face of the measuring tube body of the measuring tube of the electromagnetic flow meter,
It has a conductive peripheral wall portion that extends intermittently in the circumferential direction by providing a plurality of notches.
Two pipes in which the peripheral wall portion is arranged with a non-conductive gap formed between the conductive outer peripheral surface of the measuring tube main body and the ring portion by the gasket, each sandwiching the measuring tube. By connecting the flanges to each other and cooperating with a plurality of conductive shaft members, the flanges are covered from the outside in the radial direction to the entire circumference.
Earth ring.

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