JP2597863Y2 - Electromagnetic flow meter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic flowmeter used for measuring a flow rate of a conductive fluid flowing in a measuring pipe, and more particularly, to an electromagnetic flowmeter having an earth ring provided at an end of the measuring pipe. About.

[0002]

2. Description of the Related Art An electromagnetic flowmeter measures the flow rate of a conductive fluid flowing in a measuring tube by converting the flow rate into an electric signal using an electromagnetic induction phenomenon. Known from.

That is, reference numeral 1 in the figure denotes a flange 1 at both ends.
a, 1b, which is a measuring tube made of a pipe member having
Is disposed in the middle of a pipe 3 through which a fluid to be measured (conductive fluid) 2 flows by being flanged. A pair of saddle-type exciting coils 4A and 4B that form a magnetic field in a direction perpendicular to the flow direction of the fluid 2 to be measured are provided on the outer circumference of the measuring tube 1 so as to face each other.

A pair of electrodes 5A and 5B (5B not shown) are disposed on the outer periphery of the central portion of the measuring tube 1 so as to face each other so as to be orthogonal to the magnetic field. And is in contact with the fluid 2 to be measured. On the other hand, electrode 5
The outer ends of A and 5B are connected by signal leads 9 to a converter 8 provided on the outer circumference of the measuring tube 1 via a cover 7.

Further, the inner peripheral surface of the tube member constituting the measuring tube 1 and the outer surfaces (end surfaces) of both flanges 1a and 1b.
The lining material 10 made of fluororesin, neoprene or the like is lined to provide electrical insulation and corrosion resistance, and is insulated from the fluid 2 to be measured. The measurement pipe 1 and the pipe 3 have their flange surfaces joined to each other via an earth ring 11 and a gasket 12, and the earth ring 11 and the measurement pipe 1 are connected by a cord 13. Reference numeral 15 denotes a set screw for the earth ring 11.

The earth ring 11 grounds the measurement tube 1 and the fluid 2 to be measured to have the same potential, thereby eliminating noise generated due to the instability of the potential of the fluid 2 to be measured, and lining. It has a function of protecting the material 10. Such an earth ring 11 is usually made of stainless steel 316 or the like, but if corrosion resistance and wear resistance are required, it is made of a noble metal such as platinum, titanium, monel, and hastelloy.

[0007]

However, according to such a conventional electromagnetic flowmeter, the fluid 2 to be measured flowing in the pipe 6 leaks between the measuring pipe 1 and the earth ring 11. 4 , the leaked fluid 2 flows from the outer peripheral edge portion of the lining 10a on the outer surface of the flange toward the pipe member made of stainless steel or the like, which becomes the main body of the measuring pipe 1, and flows. There was a problem.

When the fluid 2 flows as described above, the portion of the pipe member which is in contact with the fluid 2 is liable to corrode. This is remarkable when the fluid 2 to be measured is a corrosive fluid. It is desired to take some measures that can solve the problem caused by the leaking fluid 2 coming into contact with the liquid.

In particular, such a problem is caused when the measuring pipe 1 and the pipe 3 are flange-connected, the lining 10a of the flange outer surface exposed at both ends of the measuring pipe 1 is deformed by the tightening of the flanges. , Its outer edge
As shown in FIG. 4, the outer end side (earth ring 11
Side) to the inner end side (flange 1a side), the shape becomes smoothly curved and inclined so that the diameter dimension gradually decreases.

That is, in the lining material 10 lined with the pipe member constituting the measuring pipe 1, the flanges 1a,
1b, a flange-like lining 10 formed on the outer surface
The peripheral portion at a is formed with a simple peripheral surface shape. When the pipe 3 is pressed against the lining 10a portion of the measuring pipe 1 via the earth ring 11 and flange-connected, the lining 10a is tightened from both sides, deformed by receiving a compressive load, and deformed as described above. It is inevitable that the side has an outer peripheral shape having a large diameter.

With such an outer peripheral shape, FIG.
As is clear from the middle arrow, the fluid leaking from the gap between the lining 10a and the earth ring 11 flows down the outer periphery of the lining 10a toward the flange 1a,
The main body (tube member) of the measuring tube 1 comes into contact with the liquid and causes the above-mentioned corrosion problem and the like. It is difficult to reliably maintain the sealing property between the lining 10a and the earth ring 11 described above, and it is desired to take some measures to minimize the influence of fluid leakage at this portion. ing.

The present invention has been made in view of such circumstances, and the fluid to be measured leaks from between the lining formed on the flange end surface of the measuring tube and the earth ring to the measuring tube main body side. It is an object of the present invention to provide an electromagnetic flowmeter capable of preventing the occurrence of such a phenomenon and preventing the fluid from causing an influence such as corrosion in a measurement tube.

[0013]

In order to meet such a demand, an electromagnetic flowmeter according to the present invention is provided with an outer peripheral edge of a lining formed on both end faces of a pipe member having flanges at both ends constituting a measuring pipe. , Earthlin than the side in contact with the pipe member
Is formed so that the side on which the contact is arranged is small in diameter.
Things.

[0014]

According to the present invention, the pipe member is formed on both end faces.
Pressure is applied to the lining by connecting piping to both ends of the measuring pipe.
Even if compressive force is applied, the outer rim of the lining
The edge portion on the sling side is closer than the side in contact with the pipe member.
The small diameter state can be maintained. Therefore, according to the present invention, at the pipe connection portions at both ends of the measurement pipe,
Even if the internal fluid leaks out of the gap between the end surface of the lining and the earth ring, the leaked fluid flows through the groove formed by the small-diameter portion formed at the outer peripheral edge of the lining and at the end portion on the earth ring side, and then leaks to the outside. And flowing toward the main body of the tube member constituting the measuring tube can be prevented.

[0015]

1 and 2 (a), (b) and (c) show an embodiment of an electromagnetic flow meter according to the present invention.
In these figures, the same or corresponding parts as those in FIG. 3 described above are denoted by the same reference numerals, and description thereof is omitted.

According to the present invention, in the electromagnetic flow meter, the outer peripheral edge of the lining 10a formed on both end faces of the pipe member having the flanges 1a and 1b at both ends constituting the measuring pipe 1 is shown in FIG. , (C), the tube member
The earth ring 11 is disposed in contact with the
Is formed so that the end portion on the other side has a small diameter. this
The small-diameter portion 20 is formed on both end surfaces of the pipe member.
Linings 10a, 10a to be measured
Even if a compressive force is applied due to the piping connection to the end, the lining
And the earth ring 11,
The edge portion on the 11th side has a smaller diameter than the side in contact with the pipe member
It is something that can maintain the state.

The small-diameter portion 20 at the edge portion of the outer peripheral edge of the lining 10a is, for example, chamfered at the edge portion to form a corner as shown in FIG. 2C. It is good to form by doing.

According to such a configuration, the fluid to be measured 2 leaks from the gap between the end face of the lining 10a and the earth ring 11 at the connection portion between the pipe 3 at both ends of the measurement pipe 1. Even if this occurs, the leaked fluid 2 flows through the groove formed by the small diameter portion 20 formed on the outer peripheral edge of the lining 10a made of Teflon or the like on the edge portion on the earth ring 11 side and the earth ring 11, and
And will be discharged to the outside.

Accordingly, it is possible to prevent the metal member, which is corrosive, from flowing toward the pipe member (main body) constituting the measuring pipe 1 and prevent the pipe member from corroding. You can do it. In particular, in such a configuration, even if the corrosive fluid leaks, it does not affect the pipe main body (main body) of the measuring pipe 1, so that an inexpensive material can be selected for the pipe main body.

The present invention is not limited to the structure of the embodiment described above, and it goes without saying that the structure, shape and the like of each part can be changed and modified as appropriate. In short, at the outer peripheral edge portion of the lining formed on both end surfaces of the measuring tube 1, the edge portion may be formed to have a small diameter.

[0021]

As described above, according to the electromagnetic flowmeter according to the present invention, the outer peripheral edge of the lining formed on both end surfaces of the pipe member having the flanges at both ends constituting the measuring pipe is provided.
The earth ring is placed in contact with the
Since the side to be formed is formed to have a small diameter , the following excellent effects can be obtained despite the simple configuration. According to the present invention, the leaked fluid from between the lining end face and the earth ring at the pipe connection portion at both ends of the measurement pipe passes through the groove formed by the small-diameter portion formed at the edge of the earth ring at the outer peripheral edge of the lining. It can be drained and transmitted to the outside through the earth ring . Therefore, it is prevented from flowing toward the tube member body side constituting the measuring tube,
Thus, the problem of corrosion in the pipe member can be prevented, and the pipe member can be formed with a cheap material.

[Brief description of the drawings]

FIG. 1 is an overall schematic cross-sectional view showing one embodiment of an electromagnetic flow meter according to the present invention.

2A is a schematic view showing the appearance of an electromagnetic flowmeter according to the present invention, FIG. 2B is an enlarged view of a main part thereof, and FIG. 2C is a detailed view of a small-diameter portion of a lining characterizing the present invention. .

FIG. 3 is a schematic sectional view illustrating a conventional electromagnetic flow meter.

FIG. 4 is an enlarged view of a main part for explaining a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measuring pipe (tube member) 1a Flange 1b Flange 2 Fluid to be measured 3 Piping 10 Lining material 10a Lining 11 Earth ring 12 Gasket 20 Small diameter portion 21 Lining outer peripheral portion

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01F 1/58

Claims (1)

(57) [Scope of request for utility model registration] 1. A measuring pipe having a lining formed on the inner peripheral surface and both end faces of a pipe member having flanges at both ends, and an earth ring disposed at least at one end of the measuring pipe in contact with the lining. An electromagnetic flowmeter comprising: a lining outer peripheral edge at both end faces of the pipe member;
The side in contact with the earth ring has a smaller diameter than the side in contact with
An electromagnetic flowmeter characterized by being formed as follows .