JP3493223B2 - Electromagnetic flowmeter and flow measurement method - 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 flow meter for measuring the flow rate of sewage in sewers and a flow meter using the electromagnetic flow meter.
Regarding measurement methods .

[0002]

2. Description of the Related Art A so-called electromagnetic flowmeter for filling water is well known as a flowmeter for measuring the flow rate of a fluid flowing in a pipe when the pipe is full of water. Are known as flange type or wafer type. In addition, this type of electromagnetic flowmeter has a substantially cylindrical cover that surrounds the exciting coil and the electrode lead portion over the entire outer circumference of the flow tube for measurement.

Further, a weir type electromagnetic flowmeter suitable for measuring the flow rate of sewage flowing in a non-full state of the sewer is disclosed in Japanese Patent Laid-Open No. Hei 5-1993.
It is known from Japanese Patent No. 273015 (Japanese Patent Application No. 4-70846).

This weir type electromagnetic flow meter is provided with a weir, a pair of electrodes horizontally opposed to the weir, and at least one of an upper portion and a lower portion of a flow tube, and an excitation for generating a vertical magnetic field. This is a so-called non-full-flow electromagnetic flow meter that has a coil and can measure from a non-full state to a full state.

The construction of this weir type electromagnetic flow meter is described in Japanese Patent Laid-Open No.
5 and 6 with reference to FIG. 1 and FIG. 2 of Japanese Patent No. 273015.
Shown in. In these figures, 1 is a flow tube, 2 is a permaporous flume as a weir, 3 is a pair of electrodes horizontally opposed to the flume portion, 4 is an exciting coil provided in a space under the flume, and 5 is An amplifier for amplifying the voltage е generated at the electrodes, 6 is an A / D converter for converting the output of the amplifier 5 into a digital signal, 7 is an arithmetic circuit, 8 is an exciting power source for exciting the exciting coil 4, and 9 is a measurement or It is a timing circuit that generates a timing signal required for excitation.

The voltage е generated between the pair of electrodes 3 and 3 is proportional to the speed of the fluid flowing through the permaporous flume portion,
The flow rate Q is calculated from Q = F (е) as a function F of voltage е.

The function F of this equation is a function determined by the shape of the flow tube 1 and the shape of the permaporous flume 2 which is a weir, the shape of the electrode 3, and the excitation magnetic flux density distribution. These parameters are fixed and measured in advance. Sought and memorized.

[0008]

When it is attempted to measure the flow rate of the sewage flowing through the sewer, the electromagnetic flowmeter for so-called full water cannot be used because the flow rate of the fluid flowing in the non-full water state cannot be measured.

Therefore, the electromagnetic flowmeter for so-called non-full water is used. An electromagnetic flowmeter having a structure as shown in FIG. 7 can be configured as a weir-type electromagnetic flowmeter for non-full water having the same principle as the electromagnetic flowmeter for non-full water described in FIGS. 5 and 6.

In the figure, 1 is a cylindrical flow tube, 2 is a bulge as a weir provided at the bottom of the flow tube 1, and 3 and 3 are horizontally opposed to each other on the bulge 2 as a weir. A pair of electrodes, 4 are saddle-shaped exciting coils provided on the upper part of the flow tube 1, L
Indicates the water surface.

The overall outer shape of the electromagnetic flowmeter for non-filled water of the configuration shown in FIG. 7 can be the flange type shown in FIG. 8 or the wafer type shown in FIG. 9 as in the conventional electromagnetic flowmeter. Then, a structure having a substantially cylindrical cover portion 10 which covers the exciting coil 4 and the like and is coaxial with the flow tube 1 and covers the entire circumference is conceivable. Reference numeral 11 indicates an electromagnetic flow meter.

However, if an electromagnetic flow meter for non-filled water having an outer shape and a mounting structure as shown in FIG. 8 or 9 is to be installed in an existing sewer, the following two or three installation methods are conceivable. Both have drawbacks.

1). As shown in Fig. 10, the existing sewer pipe 12
If you try to insert and install the electromagnetic flowmeter 11 for non-filling into the cut portion by cutting it over the length A, it is necessary to dig the sewer pipe 12 buried in the ground, which is troublesome and costly. However, there was a problem that it was bulky and practically impossible.

2). As shown in FIG. 11, when there is a step in the up-down direction between the sewer pipe 14 flowing into the manhole 13 and the sewer pipe 15 flowing out from the manhole 13,
It is conceivable to install an electromagnetic flow meter 11 for non-full water as shown in the drawing at the opening where the downstream end of the upstream sewer pipe 14 opens to the manhole 13, that is, the wall surface of the manhole 13.

However, in this case, since the connection is cantilevered, a special mounting jig or the like is required, and there is a problem that strength remains uneasy. 3). As shown in FIG. 12, in a manhole where there is no step or a small step between the upstream side sewer line 14 and the downstream side sewer line 15 of the manhole 13, the bottom 13a of the manhole 13 is placed so as not to interfere with the electromagnetic flowmeter. It is necessary to install the electromagnetic flow meter 11 for non-full water on the wall surface of the manhole 13 after shaving as shown by reference numeral 13b.

Actually, the manhole 13 has a structure shown in FIG.
14, a U-shaped groove called an invert is provided as shown by reference numeral 16, and the opening of the upstream sewer pipe 14 (that is, the inlet to the manhole 13) and the downstream sewer pipe 1 are provided.
The openings 5 (that is, the outlets from the manhole 13) are smoothly connected.

Since the invert 16 is usually made of mortar, the invert part of the mortar is shaved in order to install the conventional non-filling electromagnetic flowmeter as shown in FIGS. 8 and 9 here. Civil engineering work is necessary, and the problem remains that it is a large-scale work.

Therefore, an object of the present invention is to provide a flow rate measuring method suitable for sewerage which does not have these problems and an electromagnetic flow meter used therefor.

[0019]

In order to achieve the above object, the electromagnetic flowmeter according to claim 1 is installed horizontally or substantially horizontally.
Non-filling electricity with a cylindrical flow tube (1) to be placed
In the magnetic flowmeter, an exciting coil installed above the flow tube (1).
(4) and a heap as a weir provided at the bottom of the flow tube (1)
Ascending (2) and flow pipe provided above the weir (2)
A pair of electrodes (3) and (3) facing the inner wall surface of (1)
And an outlet for the pair of electrodes (3) (3),
Above the center of the flow tube (1) to the outside of the flow tube (1)
Extruding outlet (3A) (3A) and exciting coil
Outlet (3A) (3) for the electrode (4) and electrode (3) (3)
The flow tube (1) is provided only on the upper side of the flow tube (1) so as to cover A).
A cover (20) formed in a semi-cylindrical shape concentric with the flow tube;
From the outer periphery of the central portion in the vertical direction of (1), the flow tube (1)
Plate-shaped blade-shaped mounting members (1
7) It is characterized by having (18).

The electromagnetic flowmeter according to claim 2 is the electromagnetic flowmeter according to claim 1.
In the electromagnetic flow meter, the flow pipe (1) and the mounting member (17)
(18) and cover (20) are made of resin material
Is characterized by.

The flow rate measuring method according to claim 3 is a flow tube.
Align the outer diameter of (1) with the inner diameter of the sewer pipes (14), (15), etc.
The electromagnetic flow rate for non-full water according to claim 1 or 2, which is formed by
Invert (1A) of manhole (13)
6) Place the lower surface of the flow tube (1) along the
Place it on the boot and place it flat on the side of the invert (21).
Fix the mounting members (17) and (18) to (22),
Characterized by measuring the flow rate of sewage with a magnetic flow meter (11A)
And

[0022]

[0023]

[0024]

[Operation] The outer periphery of the lower half of the flow tube (1) is attached to the manhole (1
By placing along the Invert (16) of 3),
Since the sewage flows in the flow pipe of the electromagnetic flow meter (11A), the flow rate of the non-filled sewage can be measured.

A cover (2) provided only on the upper half of the flow tube (1)
0) is the exciting coil and the electrode outlet (3A) (3A)
Is surely waterproof and does not interfere with the mounting of the electromagnetic flow meter on the invert (16).

The mounting members (17) and (18) fix the electromagnetic flowmeter. The bulge (2) as a weir effectively acts to accurately measure the flow rate in a non-full state.

In the electromagnetic flowmeter of the fifth aspect, since the flow tube 1, the mounting members 17 and 18 and the cover 20 are made of resin,
Insulation lining is unnecessary, weight is reduced, and corrosion resistance and chemical resistance can be improved.

[0028]

First Embodiment FIGS. 1A, 1B and 1C show a first embodiment of the electromagnetic flowmeter of the present invention. In the figure, 1 is SU
It is a cylindrical flow tube made of a pipe such as S and has an insulating lining 1A on its inner surface. Reference numeral 2 is a bulge as a weir provided on the bottom of the flow tube 1, and 3 and 3 are a pair of electrodes provided above the weir 2, which are arranged to face the inner wall of the flow tube 1. The outlets 3A, 3A of the pair of electrodes 3, 3 penetrate the flow tube 1 above the center of the flow tube 1 and project to the outside of the flow tube 1.

Reference numeral 4 is a saddle-shaped exciting coil provided on the upper side of the flow tube 1, and 17 and 18 are plate-like blades extending horizontally in the radial direction of the flow tube 1 from the outer periphery of the substantially central portion of the flow tube 1 in the vertical direction. This mounting member has a proper number of holes 19 through which embedded bolts, which will be described later, pass.

Reference numeral 20 denotes a cover, which is provided only in the upper half of the flow tube 1 and the exciting coils 4 and the outlets 3A and 3A for the electrodes 3 and 3 are taken out.
Is formed in a semi-cylindrical shape concentric with the flow tube 1. The flow tube 1 is a SU with an insulating lining as described above.
It is made of S material and has a SUS welded structure such as the mounting members 17 and 18 for installation and the cover 20.

The outer diameter of the flow pipe 1 is formed according to the inner diameter of the target sewer pipe or the like. Reference numeral 11A indicates an electromagnetic flow meter. The electromagnetic flow meter 11 for non-full water of FIG.
A is placed and installed on the invert portion of the manhole as described in FIGS. 2 and 3.

In FIG. 2, 13 is a manhole (main body).
And 16 is an invert. Φ is the inner diameter of the sewer pipe (the sewer pipes 14 and 15 in FIG. 13) connected to the manhole 13. The outer diameter of the flow tube 1 of FIG. 1 is formed according to this inner diameter.

Numerals 21 and 22 are flat portions of mortar on the side of the invert, and 23 and 24 are anchor bolts planted in the flat portions, at the positions of the holes 19 formed in the mounting portions 17 and 18 of the electromagnetic flow meter 11A. Hit a predetermined number in total.

Then, as shown in FIG. 3, the electromagnetic flowmeter 11A is arranged so that the lower surface of the flow tube 1 is along the invert 16 by penetrating the anchor bolts 23 and 24 through the holes 19 of the mounting members 17 and 18. As described above, the mounting members 17 and 18 are fixed by mounting them on the invert portion and screwing the nuts 25 and 26 onto the anchor bolts 23 and 24.

In this way, the electromagnetic flowmeter 1 for non-full water
When 1A is placed and installed on the invert part in the manhole 13, the sewage flowing from the upstream sewer pipe flows in the flow pipe 1 of the electromagnetic flow meter. Further, since the electromagnetic flow meter is installed in a correct posture with the exciting coil 4 facing upward, the flow rate of sewage flowing in a non-full state can be accurately measured.

[0036]

[Second Embodiment] FIG. 4 shows a second embodiment of the electromagnetic flowmeter of the present invention. In the same figure, the above-mentioned FIG. 1 (a) (b) (c)
Parts having the same functions as those in the first embodiment are designated by the same reference numerals and the description thereof will be appropriately omitted.

In the figure, reference numeral 1 is a flow pipe made of a resin pipe such as vinyl chloride, and the mounting members 17 and 18 for installation and the cover 20 are made of the same resin material such as vinyl chloride and have a welded structure.

In the present invention, since it is basically used to measure the flow rate of sewage flowing in a non-full state, it is not a pressure-feeding fluid as in the case of full state. Is sufficient, and not only can the weight be reduced, but it is also useful for cost reduction because no insulation lining is required.

Further, in comparison with SUS in the case of the first embodiment,
Since corrosion resistance and chemical resistance can be improved, it is also suitable for sewage measurement from this aspect.

[0040]

According to the flow rate measuring method of the present invention, when the flow rate of sewage is measured, an electromagnetic flow meter for non-filled water can be easily installed, so that large-scale civil engineering work is unnecessary and the construction period can be shortened. . Also, no special fixture is required. Therefore, the installation is easy and the cost can be reduced. Then, the mounting member (1
7) By fixing the electromagnetic flowmeter in (18),
The meter should be installed in the correct posture with the exciting coil facing up.
Therefore, the flow rate of sewage flowing when it is not full can be measured accurately.
It

Since the electromagnetic flowmeter can be easily removed,
Cleaning, inspection, replacement in case of accident, etc. will be easy and maintenance will be easy. Furthermore, the electromagnetic flowmeter of the present invention is an effective means for realizing such sewage flow rate measurement.

The electrode outlet is covered with a cover together with the exciting coil to ensure waterproofness, and the cover does not interfere with the mounting of the electromagnetic flow meter on the invert.

The rise of the weir contributes to highly accurate measurement of sewage in a non-full state. Furthermore, since the flow tube, the mounting member and the cover are made of resin, there is an advantage that the insulating lining is unnecessary, the weight is reduced, the corrosion resistance and the chemical resistance are improved, and the handling is easy and the labor for installation is reduced. is there.

[Brief description of drawings]

FIG. 1 is a first embodiment of an electromagnetic flow meter according to the present invention,
(A) is a horizontal sectional view, (b) is a reduced vertical sectional view, and (c) is a perspective view.

FIG. 2 is a sectional view of a manhole in which the electromagnetic flow meter of the present invention is installed.

FIG. 3 is a cross-sectional view illustrating a state in which the electromagnetic flowmeter of the present invention is installed in a manhole.

FIG. 4 is a transverse sectional view of a second embodiment of the electromagnetic flow meter of the present invention.

5 is a system diagram of a conventional weir type electromagnetic flow meter, in which the detector is taken along the line AA in FIG.

FIG. 6 is a schematic vertical sectional view of a detector of the electromagnetic flow meter of FIG.

FIG. 7 is a cross-sectional view of a possible weir type non-filled electromagnetic flow meter.

FIG. 8 is a longitudinal sectional view of a flange type electromagnetic flowmeter for non-full water.

FIG. 9 is a vertical cross-sectional view of a wafer type electromagnetic flowmeter for non-full water.

10 is a vertical cross-sectional view for explaining a state in which the electromagnetic flowmeter for non-full water of FIG. 9 is installed in the sewer pipe line.

11 is a vertical cross-sectional view for explaining an example of a state in which the electromagnetic flowmeter for non-full water of FIG. 9 is installed in a manhole.

FIG. 12 is a vertical cross-sectional view for explaining another example of a state in which the electromagnetic flowmeter for non-full water of FIG. 9 is installed in a manhole.

FIG. 13 is a plan view of a manhole.

14 is a sectional view of the manhole, which is a sectional view taken along the line AA ′ of FIG.

[Explanation of symbols]

1 flow tube 2 Rise as a weir 3 electrodes 3A electrode outlet 4 Excitation coil 11A electromagnetic flow meter 13 manholes 14,15 sewer pipe 16 Invert 17,18 Mounting member 20 cover

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Claims (3)

(57) [Claims] 1. An electromagnetic flowmeter for non-filled water having a cylindrical flow tube (1) to be installed horizontally or substantially horizontally, wherein an exciting coil (4) provided on the upper part of the flow tube (1), Rise (2) as a weir provided at the bottom of the flow tube (1 )
A pair of electrodes (3) (3) provided above the weir (2) and facing the inner wall surface of the flow tube (1), and an outlet for the pair of electrodes (3) (3). , Flow tube
Projected outside the flow tube (1) above the center of (1)
The outlets (3A) (3A) that are installed and the outlets (3) for the excitation coil (4) and the electrodes (3) (3)
A) Flow only on the upper side of the flow tube (1) so as to cover (3A).
A cover (20) formed in a semi-cylindrical shape concentric with the tube (1 )
And a plate-shaped blade-shaped mounting member (17) (18) extending horizontally from the outer periphery of the central portion of the flow tube (1) in the vertical direction in the radial direction of the flow tube (1). Electromagnetic flow meter. 2. Flow tube (1), mounting members (17) (18)
And electromagnetic flowmeter according to claim 1, wherein the cover (20), characterized by being configured of a resin material. 3. The outer diameter of the flow pipe ( 1) is the sewer pipe (14) (1
5) electromagnetic flow meter for internal diameter <br/> full level of claim 1 or 2 wherein the formation to match the such a (11A), the manhole (1
Place the lower surface of the flow tube (1) along the invert (16) of 3) so that it is placed on the invert part and
To the flat parts (21) (22) of the mounting member (17) (1
8) is fixed, and the flow rate of sewage is measured with this electromagnetic flow meter (11A).