JP3004458B2 - Electromagnetic flowmeter for open channel - 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 for an open channel installed on a weir provided in the open channel to measure the flow rate of a fluid flowing through the open channel.

[0002]

2. Description of the Related Art Conventionally, weir type flowmeters and electromagnetic flowmeters for open channels have been known as flow meters for open channels for measuring the flow rate of fluid flowing through open channels.

A weir type flow meter is a variable weir that closes the lower side and the side of an open channel, a water head meter for measuring the water level on the upstream side of the variable weir, a measurement result of the water head meter, and a shape of the variable weir. A computing device for calculating the flow rate of the water flowing through the open channel based on the like and the like, while changing the shape of the variable weir according to the flow rate of the water flowing through the open channel, the shape of the variable weir, The flow rate of the water flowing through the open channel is calculated based on the measurement result of the water head meter and the like.

As shown in FIG. 5, an electromagnetic flowmeter for an open channel is provided with a partition plate 102 for partitioning an upstream side and a downstream side of an open channel 101, and an opening formed in a submerged portion of the partition plate 102. A cylindrical rectifying tube 104 having one end attached to the portion 103; an electromagnetic flowmeter 105 attached to the other end of the rectifying tube 104;
L-shaped outlet bent pipe 10 attached to the outlet
The water 107 flows out of the opening 103 of the partition plate 102 while the flow of the water 107 is blocked by the partition plate 102, and the water 107 is guided to the downstream side of the partition plate 102 by the flow straightening pipe 104 to perform the rectification. The flow rate is measured by an electromagnetic flow meter 105 attached to the pipe 104.

[0005]

However, in the above-mentioned conventional weir type flow meters and electromagnetic flow meters for open channels,
There were the following problems.

That is, in the weir type flow meter, the measurement accuracy is significantly reduced below a certain overflow water depth, and in the worst case, the measurement becomes impossible.

Further, in the electromagnetic flowmeter for open channel, if the flow is full, the flow rate can be measured from a state where the flow rate is zero, so that the above-mentioned problem does not occur.

However, the water 1 flowing through the open channel 101
07 flows according to the head difference “L1” between the water surface height of the open channel 101 and the outlet surface of the outlet bent pipe 106 provided on the outlet side of the electromagnetic flowmeter, so that the open channel 101 does not overflow. , The head difference "L1" must be set to a certain value.

For this reason, the water 107 flowing through the open channel 101
Is floating on the surface of the water, such as scum, such as rust or scum.
08 grows and precipitates on the upstream side of the partition plate 102 as shown in FIG. 5 and accumulates on the bottom surface. This deposit 109 generates a gas with a bad smell, which is not preferable from the viewpoint of environmental health.

In order to solve such a problem, as shown in FIG. 6, an L-shaped inlet having one end connected to an opening 103 provided in the partition plate 102 is provided upstream of the partition plate 102. A bent tube 110 is provided, and the inlet of the inlet bent tube 110 is directed to the water surface, thereby taking in the floating substance 108 on the water surface and separating the floating material 108 from the partition plate 10.
It is also conceivable to guide it to the downstream side of 2.

However, with such a configuration,
The distance “L” between the upper end of the inlet bent pipe 110 and the center portion
Since 2 "is fixed, when the water level rises and the distance" L3 "between the upper end of the inlet bent pipe 110 and the water surface is separated, the suspended matter 108 on the water surface cannot be taken in. Problem.

Further, the water level decreases, and the inlet bent pipe 11
When the upper end of 0 goes out of the water surface,
There is a problem that the water 107 on the upstream side of 02 does not flow into the electromagnetic flowmeter 105, and the original flow measurement cannot be performed.

In view of the above circumstances, the present invention can discharge suspended matters floating on the water surface from the outlet side of the electromagnetic flowmeter without becoming unmeasurable even if the water level of the open channel changes. Accordingly, it is an object of the present invention to provide an electromagnetic flowmeter for an open channel that can prevent generation of offensive odor or the like caused by sediment.

[0014]

According to a first aspect of the present invention, there is provided an electromagnetic flowmeter for an open channel according to the first aspect of the present invention, wherein the partition plate is provided on a downstream side of the partition provided in the open channel. An electromagnetic flowmeter having an inflow port connected to an opening formed in a submerged portion, and an electromagnetic flowmeter connected to an outflow port of the electromagnetic flowmeter, for discharging a fluid discharged from the outflow port of the electromagnetic flowmeter upstream of the partition plate. An outlet bent pipe that guides and discharges to a position lower than the side water level by a predetermined height, and is connected to the opening on the upstream side of the partition plate, the inflow port is directed upward, and the upper end thereof is at a predetermined depth from the water surface. A rectifying pipe to be set, a telescopic tubular member attached to the inflow port of the rectifying pipe, and an upper end of the tubular member floating at a predetermined distance from the water surface, floating on a water surface upstream of the partition plate. Just put down the flow It is characterized in that a and.

Further, in the second invention, an electromagnetic flow meter having an inflow port connected to an opening formed in a submerged portion of the partition plate downstream of the partition plate provided in the open channel, An outlet bent pipe connected to the outlet of the meter and guiding the fluid discharged from the outlet of the electromagnetic flowmeter to a position lower than the upstream water level of the partition by a predetermined height, and discharging the bent pipe; An L-shaped inlet bent pipe connected to the opening on the upstream side, the inlet side is directed upward, and a slit is formed on the side surface and the upper end of the slit is provided so as to protrude from the water surface. It is characterized by:

[0016]

According to the first aspect of the present invention, in the first aspect, when the water level on the upstream side of the partition plate rises, the float moves upward according to the rise in the water level, extends the tubular member, and floats on the water surface. When water is taken in along with suspended matter and guided to the downstream side of the partition plate via the cylindrical member → the opening of the partition plate → the electromagnetic flow meter → the outlet bent pipe, and when the water level on the upstream side of the partition plate drops In response to the drop in water level, the float moves down and shrinks the tubular member to take in water along with suspended matter floating on the surface of the water, which is then removed from the tubular member → partition plate opening → electromagnetic flow meter → outlet It is guided to the downstream side of the partition plate through a curved pipe.

In the second invention, if the water surface on the upstream side of the partition plate is within the vertical range of the vertical slit formed in the L-shaped inlet curved pipe, the water level on the upstream side of the partition plate rises. Even when the water is dropped or lowered, the suspended matter floating on the water surface is taken into the L-shaped inlet bent pipe together with the water through the slit, and the L-shaped inlet bent pipe → the opening → the electromagnetic flow meter → It is guided to the downstream side of the partition plate through the outlet bent pipe.

[0018]

FIG. 1 is a block diagram showing an embodiment of an electromagnetic flowmeter for an open channel according to the present invention.

The electromagnetic flowmeter for an open channel shown in FIG. 1 includes a partition plate 2 provided to partition an upstream side and a downstream side of an open channel 1, and a submerged portion of the partition plate 2 at a downstream side of the partition plate 2. , A cylindrical rectifying tube 4 having one end attached to the opening 3 formed therein, an electromagnetic flowmeter 5 attached to the other end of the rectifying tube 4, and an L-shaped attached to the outlet of the electromagnetic flowmeter 5 -Shaped outlet bent pipe 6, an L-shaped inlet bent pipe 7 attached to the opening 3 on the upstream side of the partition plate 2, and a cylindrical bellows structure made of a thin plastic film or a vinyl sheet. A telescopic tube 8 attached to an upper end portion of a bent tube 7, a float 9 arranged at an upper end side of the telescopic tube 8, and a predetermined distance between a lower end side of the float 9 and an upper end portion of the telescopic tube 8 Open a gap between And the lower side of the float 9 as,
And a plurality of metal fittings 10 for connecting the upper end side of the telescopic tube 8.

While the flow of the water 11 is blocked by the partition plate 2, the water 11 at the water surface portion is taken in by the telescopic tube 8, and the water 11 is partitioned by the inlet bent pipe 7, the opening 3 of the partition plate 2, and the rectifying pipe 4. An electromagnetic flow meter 5 which is guided to the downstream side of the plate 2 and attached to the straightening pipe 4.
Measure the flow rate.

In this case, since the float 9 is floating on the water surface, the upper end of the telescopic tube 8 connected to the float 9 by the metal fitting 10 is below the water surface by a predetermined distance "L4". When the water level on the upstream side rises, as shown in FIG. 2, the float 9 moves upward in accordance with the rise in the water level, extends the telescopic tube 8, and takes in the water 11 together with the suspended matter 12 floating on the water surface. This is telescopic tube 8 →
Inlet curved pipe 7 → opening 3 → straightening pipe 4 → electromagnetic flow meter 5 →
It can be guided to the downstream side of the partition plate 2 through the outlet bent pipe 6, and when the water level on the upstream side of the partition plate 2 drops, the float 9 moves downward according to the water level drop as shown in FIG. The telescopic tube 8 is contracted and water 11 is taken in together with the floating matter 12 floating on the water surface, and the water 11 is taken in. 6 can be guided downstream of the partition plate 2.

As described above, in this embodiment, the telescopic tube 8 having a bellows structure is provided at the upper end of the L-shaped inlet curved tube 7 provided on the upstream side of the partition plate 2, The upper end of the float 9
The float 9 moves up and down according to the water level so that the upper end of the telescopic tube 8 is lowered by a certain distance from the water surface. Therefore, even if the water level of the open channel 1 changes, measurement is impossible. The floating matter 12 floating on the water surface can be discharged from the outlet side of the electromagnetic flow meter 5 without causing the occurrence of odor or the like due to the sediment.

FIG. 4 is a diagram showing another embodiment of the electromagnetic flowmeter for open channels according to the present invention. In this figure, the same parts as those in FIG. 1 are denoted by the same reference numerals.

An electromagnetic flowmeter for an open channel shown in FIG. 1 is provided with a partition plate 2 provided to partition an upstream side and a downstream side of an open channel 1, and a submerged portion of the partition plate 2 at a downstream side of the partition plate 2. , A cylindrical rectifying tube 4 having one end attached to the opening 3 formed therein, an electromagnetic flowmeter 5 attached to the other end of the rectifying tube 4, and an L-shaped attached to the outlet of the electromagnetic flowmeter 5 An outlet bent pipe 6 having a slit shape and an L-shaped inlet bent pipe 15 with a slit attached to the opening 3 so that the upper end thereof protrudes from the water surface on the upstream side of the partition plate 2.

Then, while the flow of the water 11 is blocked by the partition plate 2, the water flows out from the opening 4 of the partition plate 2, and is guided to the downstream side of the partition plate 2 by the flow straightening tube 4, and is supplied to the flow straightening tube 4. The flow rate is measured by the attached electromagnetic flow meter 5.

In this case, since the L-shaped inlet bent pipe 15 is provided with a vertical slit 16, if the water surface is within the vertical range of the slit 16, when the water level on the upstream side of the partition plate 2 rises In addition, even when it is lowered, the floating matter 12 floating on the water surface is taken into the L-shaped inlet bent pipe 15 together with the water 11 through the slit 16 and is taken into the L-shaped inlet bent pipe 15 → It can be guided to the downstream side of the partition plate 2 via the opening 3 → the rectifying pipe 4 → the electromagnetic flow meter 5 → the outlet curved pipe 6.

In this manner, similarly to the above-described embodiment, even if the water level of the open channel 1 changes, the suspended matter 12 floating on the water surface can be measured by the electromagnetic flow meter 5 without becoming unmeasurable. It can be discharged from the outlet side, thereby preventing the generation of offensive odor or the like due to the sediment.

[0028]

As described above, according to the present invention, even if the water level of the open channel changes, the suspended matter floating on the water surface is discharged from the outlet side of the electromagnetic flow meter without becoming unmeasurable. This can prevent the generation of offensive odor or the like due to the sediment.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an electromagnetic flowmeter for open channel according to the present invention.

FIG. 2 is a schematic view showing an operation example of the electromagnetic flowmeter for open channel shown in FIG.

FIG. 3 is a schematic diagram showing an operation example of the open channel electromagnetic flow meter shown in FIG. 1;

FIG. 4 is a configuration diagram showing another embodiment of the electromagnetic flowmeter for open channel according to the present invention.

FIG. 5 is a configuration diagram showing an example of a conventionally known electromagnetic flowmeter for open channels.

6 is a configuration diagram showing an example of an electromagnetic flowmeter for an open channel that can be considered to solve the problem of the electromagnetic flowmeter for an open channel shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Open channel 2 Partition plate 3 Opening 4 Rectifier pipe 5 Electromagnetic flow meter 6 Outlet bent pipe 7 Inlet bent pipe 8 Telescopic pipe (tubular member) 9 Float 10 Metal fitting 15 L-shaped inlet bent pipe 16 Slit

Claims (2)

(57) [Claims] 1. An electromagnetic flowmeter having an inflow port connected to an opening formed in a submerged portion of the partition plate at a downstream side of the partition plate provided in the open channel, and an electromagnetic flowmeter connected to an outflow port of the electromagnetic flowmeter. An outlet bent pipe that guides fluid discharged from the outlet of the electromagnetic flowmeter to a position lower than a water level on the upstream side of the partition plate by a predetermined height and discharges the outlet, and the opening on the upstream side of the partition plate. Connected to
A flow straightening pipe whose inlet is directed upward and whose upper end is set to a predetermined depth from the water surface; a stretchable tubular member attached to the flow inlet of the flow straightening pipe; and an upstream side of the partition plate. A float that floats on the water surface and positions an upper end of the cylindrical member at a predetermined distance below the water surface; and a float for an open channel. 2. An electromagnetic flowmeter having an inflow port connected to an opening formed in a submerged portion of the partition plate at a downstream side of the partition plate provided in the open channel, and connected to an outflow port of the electromagnetic flowmeter. An outlet bent pipe that guides fluid discharged from the outlet of the electromagnetic flowmeter to a position lower than a water level on the upstream side of the partition plate by a predetermined height and discharges the outlet, and the opening on the upstream side of the partition plate. Connected to
An L-shaped inlet bent pipe having an inflow side facing upward, a slit formed in a side surface thereof, and an upper end of the slit being provided so as to protrude from a water surface. Flowmeter.