JP3015580B2 - 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 the measurement of non-full flow of an electromagnetic flowmeter.

[0002]

2. Description of the Related Art In a conventional electromagnetic flow meter, FIG.
As shown in (b), the original measurement performance is exhibited only when the fluid is full in the measurement tube 22 through which the measurement fluid flows. If the fluid is not full, for example,
Between the full water level A and the limit water level B at which the electrode 23 comes into contact with the fluid, the indication of the electromagnetic flowmeter 21 becomes larger than the actual flow rate as the electrode 23 comes down to the limit water level B at which it comes into contact with the fluid. Is generally known.

[0003] Further, when the water level falls further below the limit water level B and the electrode 23 does not come into contact with the fluid, it is no longer possible to measure the flow rate.

[0004] When it is not possible to make a pipe full at the place where the electromagnetic flowmeter is actually installed, or when it is possible to make the pipe full but the pipe for realizing it is very expensive. May not be able to perform high-precision measurement, which is a characteristic feature of the performance of the electromagnetic flowmeter, or may be impossible to measure depending on the water level.

[0005]

As described above, in the prior art, accurate measurement of the flow rate was impossible if the fluid in the measuring pipe 22 of the electromagnetic flow meter 21 was not full.
Therefore, an object of the present invention is to realize an electromagnetic flowmeter that can accurately measure a flow rate without any problem even if the fluid in the measurement tube 22 is not full.

[0006]

The electromagnetic flow meter according to the present invention comprises:
A cylindrical body made of a material having substantially the same electrical conductivity as the fluid to be measured and having a plurality of through holes formed in the axial direction of the measuring tube is arranged in the measuring tube so as to be in contact with the electrode.

[0007]

In the electromagnetic flow meter according to the present invention, the inside of the measuring tube is
A cylindrical body made of a material with almost the same electrical conductivity as the fluid and having multiple through holes in the axial direction of the measurement tube is arranged so as to be in contact with the electrodes, so that conditions can be created as if the water were full. . Therefore, the through hole through which the fluid passes varies depending on the water level, but the flow rate passing through each hole is accurately generated as an interelectrode electromotive force due to the weight function magnetic flux distribution of the electromagnetic flowmeter, and as a result, the measurement pipe is filled with water. Accurate flow indication can be obtained without it.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIGS. 1A and 1B show an electromagnetic flow meter according to an embodiment of the present invention. As shown in the drawing, a material having substantially the same electrical conductivity as the fluid to be measured, for example, conductive plastics, conductive ceramics, or fluid permeates into the measuring tube 12 of the electromagnetic flow meter 11 similar to the conventional one. A plurality of through-holes 14 are formed in the axial direction of the measuring tube 12 made of such a porous material.
Is arranged over the entire length of the measuring tube 12 so as to contact the pair of electrodes 13.

The operation of the electromagnetic flow meter according to the embodiment of the present invention configured as described above will be described below. The magnetic flux distribution of the conventional electromagnetic flowmeter is such that the contribution to the electromotive force generated between the electrodes with respect to the microelements of the fluid at each position of the cross section of the measurement tube in a full state is substantially proportional to the cross-sectional area of the microelements, That is, a strong magnetic flux distribution is realized in the central part of the measuring tube and weak in the vicinity of the electrode, which is a so-called weight function magnetic flux distribution. That is, when the fluid in the measuring tube is full, the conventional electromagnetic flowmeter accurately measures the flow rate of the cross-sectional element even when other fluids are stopped and only the fluid of the cross-sectional element is stopped. be able to.

In the electromagnetic flow meter 11 according to one embodiment of the present invention, a cylinder formed of a material having substantially the same electrical conductivity as a fluid and having a plurality of through holes 14 in the axial direction of the measurement tube 12 is provided in the measurement tube 12. Since the body 15 is arranged so as to be in contact with the electrode 13, it is possible to create a condition as if the body is full. Therefore, the through holes 14 through which the fluid passes vary depending on the water level, but the flow rate through each through hole 14 is
The interelectrode electromotive force is accurately generated by the weight function magnetic flux distribution of the electromagnetic flowmeter 11, and as a result, an accurate flow rate instruction can be obtained even when the inside of the measurement tube 12 is not full.

[0012]

As described above in detail, according to the present invention, a plurality of through-holes are formed in the measuring tube in the axial direction of the measuring tube made of a material having substantially the same electrical conductivity as the fluid to be measured. By realizing an electromagnetic flowmeter characterized by arranging a cylindrical body so as to be in contact with the electrodes, it is possible to create a condition where the inside of the measurement pipe is full, so that the fluid level allows the fluid to pass through. Although the hole changes, the flow rate passing through each through-hole is accurately generated as an interelectrode electromotive force due to the weight function magnetic flux distribution of the electromagnetic flowmeter, and as a result, the flow rate can be accurately measured even when the inside of the measurement pipe is not full. . Further, it can be easily realized by arranging the cylindrical body according to the present invention in a conventional electromagnetic flowmeter in a measurement tube,
Since the existing electromagnetic flowmeter can be used, it can be realized simply and inexpensively.

[Brief description of the drawings]

FIG. 1 shows an electromagnetic flow meter according to an embodiment of the present invention.
FIG. 1A is a cross-sectional view including a measurement tube axis, and FIG. 1B is a cross-sectional view including electrodes and perpendicular to the measurement tube axis.

FIG. 2 shows a conventional electromagnetic flowmeter, FIG. 2 (a) is a cross-sectional view including a measuring pipe axis, and FIG. 2 (b) is a cross-sectional view including electrodes and perpendicular to the measuring pipe axis.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Electromagnetic flowmeter 12 ... Measuring tube 13 ... Electrode 14 ... Through-hole 15 ... Cylindrical body

Claims (4)

(57) [Claims] 1. A cylindrical body made of a material having substantially the same electrical conductivity as a fluid to be measured and having a plurality of through holes formed in an axial direction of the measuring tube is disposed in the measuring tube so as to contact the electrode. An electromagnetic flowmeter characterized by the following. 2. The electromagnetic flow meter according to claim 1, wherein the cylindrical body is made of conductive plastics. 3. The electromagnetic flowmeter according to claim 1, wherein the cylinder is made of a conductive ceramic. 4. The electromagnetic flowmeter according to claim 1, wherein the column is made of a porous material.