JPH0712927U - Electromagnetic flow meter - Google Patents

Abstract

(57) [Summary] [Purpose] Prevents fluid leaking from between the lining of the end surface of the measuring pipe and the earth ring from flowing into the main body of the measuring pipe.
Prevents corrosion problems due to this fluid. [Structure] A small diameter portion 20 is formed at an end portion of an outer peripheral edge of a lining 10a formed on both end surfaces of a pipe member serving as a measuring pipe 1 on a side where an earth ring 11 abuts. This small-diameter portion is kept smaller than the other lining outer peripheral edge portion 21 even if the lining is compressed by the pipe connection to both ends of the measuring pipe. The leakage fluid can be discharged through the groove formed by the small diameter portion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electromagnetic flowmeter used for measuring the flow rate of a conductive fluid flowing in a measuring pipe, and more particularly to an electromagnetic flowmeter having an earth ring arranged at the end of the measuring pipe.

[0002]

[Prior art]

 An electromagnetic flow meter converts the flow rate of a conductive fluid flowing in a measuring pipe into an electric signal by using an electromagnetic induction phenomenon and measures the flow rate. For example, one having a configuration shown in FIG. 3 has been conventionally known. .

That is, reference numeral 1 in the drawing is a measuring pipe using a pipe member having flanges 1a and 1b at both ends, and this measuring pipe 1 is flange-connected in the middle of a pipe 3 through which a fluid to be measured (conductive fluid) 2 flows. It is arranged by interposing. A pair of saddle-type excitation coils 4A and 4B that form a magnetic field in a direction orthogonal to the flow direction of the fluid to be measured 2 are provided on the outer circumference of the measurement tube 1 so as to face each other.

A pair of electrodes 5A and 5B (5B is not shown) are arranged so as to penetrate through the outer periphery of the central portion of the measuring tube 1 so as to be orthogonal to the magnetic field, and the inner end of the pair of electrodes 5A and 5B is arranged in the conduit 6 It is exposed to the inside and is in contact with the fluid to be measured 2. On the other hand, the outer ends of the electrodes 5A and 5B are connected by signal lead wires 9 to converters 8 provided on the outer circumference of the measuring tube 1 via a cover 7, respectively.

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

The grounding ring 11 grounds the measuring tube 1 and the fluid to be measured 2 to the same potential, thereby eliminating noise generated due to unstable potential of the fluid to be measured 2, and a lining. It has a function of protecting the material 10. The earth ring 11 is usually made of stainless steel 316 or the like. However, when corrosion resistance and wear resistance are required, it is made of noble metal such as platinum, titanium, monel, and Hastelloy.

[0007]

[Problems to be solved by the device]

 However, according to such a conventional electromagnetic flowmeter, when the fluid to be measured 2 flowing in the pipe 6 leaks between the measuring pipe 1 and the earth ring 11, the leaked fluid is leaked. As is apparent from FIG. 2, there was a problem that 2 flows around from the outer peripheral edge portion of the lining 10a on the outer surface of the flange to the side of the pipe member made of stainless steel or the like which is the main body of the measuring pipe 1 and flows.

When the fluid 2 flows in this way, the portion of the pipe member that is in contact with the fluid 2 is likely to corrode, which 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 leaked fluid 2 coming into contact with the liquid.

Particularly, such a problem is that when the measurement pipe 1 and the pipe 3 are flange-connected, the lining 10a on the outer side surface of the flange exposed at both end portions of the measurement pipe 1 is deformed by tightening the flanges together. Then, as shown in FIG. 4, the outer peripheral edge portion is smoothly curved so that the diameter dimension gradually decreases from the outer end side (earth ring 11 side) to the inner end side (flange 1a side). This is because the shape becomes inclined.

That is, in the lining material 10 lined in the pipe member constituting the measurement pipe 1, the peripheral edge portion of the flange-shaped lining 10a formed on the outer surface of the flanges 1a and 1b has a simple peripheral surface shape. Has been formed. When the pipe 3 is pressed against the lining 10a portion of the measuring pipe 1 via the earth ring 11 and flanged, the lining 10a is clamped from both sides and deformed by receiving a compressive load. It was unavoidable that the ring 11 side had an outer peripheral edge shape with a large diameter.

With such an outer peripheral edge shape, as is clear from the arrow in FIG. 4, the fluid leaking from the gap between the lining 10 a and the earth ring 11 causes the outer peripheral edge portion of the lining 10 a to be flanged. It flows down to the 1a side, and the main body (tube material) of the measuring tube 1 comes into contact with the liquid, causing the above-mentioned corrosion problem and the like. It is difficult to reliably maintain the sealability between the lining 10a and the earth ring 11 described above, and it is desirable to take some measures so as to minimize the influence of fluid leakage at this portion. It is rare.

The present invention has been made in view of such circumstances, and the fluid to be measured leaked from between the lining formed on the flange end surface of the measuring pipe and the earth ring flows to the measuring pipe main body side. The purpose is to obtain an electromagnetic flowmeter that can prevent the occurrence of the above and prevent the influence of this fluid such as corrosion in the measuring pipe.

[0013]

[Means for Solving the Problems]

 In order to meet such a demand, the electromagnetic flowmeter according to the present invention is arranged such that the earth ring is in contact with 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. The end of the lining is formed as a small diameter part, and this small diameter part can be kept smaller than the other peripheral edge parts of the lining even if the lining is compressed by connecting pipes to both ends of the measuring pipe. It is configured in.

[0014]

[Action]

 According to the present invention, even if the internal fluid leaks from the gap between the end surface of the lining and the earth ring at the pipe connecting portions at both ends of the measuring pipe, the leaking fluid is grounded at the outer peripheral edge of the lining. It is possible to prevent the small-diameter portion formed at the edge portion on the ring side from flowing through the groove portion to be discharged to the outside and flowing toward the main body side of the pipe member forming the measuring pipe.

[0015]

【Example】

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

According to the present invention, in the electromagnetic flow meter, the earth ring 11 is formed on the outer peripheral edge of the lining 10a formed on both end surfaces of the pipe member having the flanges 1a and 1b forming the measuring pipe 1. As shown in FIGS. 2 (b) and 2 (c), the edge portion on the side where the contact is provided is formed as a small diameter portion 20, and this small diameter portion 20 extends to both ends of the measuring tube 1. Even if the lining 10a is compressed by connecting the pipe 3, the diameter of the lining 10a is kept smaller than that of the other outer peripheral edge portion 21 of the lining.

As the small-diameter portion 20 at the edge portion of the outer peripheral edge of the lining 10a described above, for example, as shown in (c) of FIG. It may be formed by

Further, according to such a configuration, at the connection portions of the measurement pipe 1 with the pipe 3 at both ends, the measured fluid 2 is passed through the gap between the end surface of the lining 10 a and the earth ring 11. Even if the gas leaks, the leaking fluid 2 flows in the groove formed by the small diameter portion 20 and the ground ring 11 formed at the end edge portion on the side of the earth ring 11 at the outer peripheral edge of the lining 10a made of Teflon or the like, It will be discharged to the outside through the earth ring 11.

Therefore, it is possible to prevent the metal member portion that flows toward the side of the pipe member (main body) forming the measuring pipe 1 and has a corrosive problem, from coming into contact with the pipe member, and to prevent the pipe member from corroding. It is possible. 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.

It is needless to say that the present invention is not limited to the structure of the above-described embodiment, and the structure, shape, etc. of each part can be appropriately changed and modified. In short, in the outer peripheral edge portions of the lining formed on both end surfaces of the measuring tube 1, the edge portions may be formed to have a small diameter.

[0021]

[Effect of device]

 As described above, according to the electromagnetic flowmeter of the present invention, the earth ring is disposed in contact with 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. The edge part on the side is formed as a small diameter part, and this small diameter part can be kept smaller than other lining outer peripheral edge parts even if the lining is compressed by connecting pipes to both ends of the measuring pipe. Therefore, despite the simple structure, the fluid leaking from between the lining end face and the earth ring at the pipe connection at both ends of the measuring pipe is formed at the edge part on the earth ring side at the outer peripheral edge of the lining. It can be discharged through the earth ring through the groove of the small diameter part, which prevents it from flowing toward the tube member body side that constitutes the measuring tube. Prevent corrosion problems in member exhibits a practically various excellent effects such as can be formed by inexpensive as the material.

[Brief description of drawings]

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

2 (a) is a schematic view showing the external appearance of an electromagnetic flowmeter according to the present invention, FIG. 2 (b) is an enlarged view of a main part thereof, and FIG. 2 (c) is a detailed view of a small diameter portion of a lining that characterizes the present invention. .

FIG. 3 is a schematic cross-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]

 1 Measuring Pipe (Pipe 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 Part 21 Lining Outer Edge

Claims (1)

[Scope of utility model registration request] 1. A measuring pipe in which a lining is formed on an inner peripheral surface and both end faces of a pipe member having flanges at both ends, and an earth ring arranged to abut the lining on at least one end side of the measuring pipe. In an electromagnetic flowmeter equipped with, the lining outside of the lining outside edge of the pipe member, even if a compressive force acts on the lining by the pipe connection to both ends of the measuring pipe, at the edge portions on the side of the earth ring. An electromagnetic flowmeter characterized in that a small diameter portion is formed so as to maintain a smaller diameter state than the remaining portion of the peripheral edge.