JP4895949B2 - Flow measuring device - Google Patents

Description

  The present invention relates to a flow measuring device for measuring a flow (flow rate or flow velocity) in a water channel.

  As a flow measuring device for measuring a flow in a water channel, specifically, a flow rate and a flow velocity, a method of projecting ultrasonic waves from a pair of ultrasonic sensors fixed to a water channel wall surface is known. For example, Non-Patent Document 1 describes an apparatus that measures a flow by fixing a pair of ultrasonic sensors to a water channel wall surface and alternately projecting ultrasonic waves from each other's sensors.

  However, when the ultrasonic sensor is fixed to the water channel wall surface, the height position of the ultrasonic sensor cannot be changed according to the fluctuation of the water level or the like. Further, when the ultrasonic sensor is fixed to the wall surface of the water channel, it is necessary to drain water from the water channel or perform underwater work with a diver for installation, removal during maintenance, and re-installation after maintenance.

Edited and published by Japan Metrology Equipment Industry Association “Practical Navigation of Flowmeters: From Beginners to Experts” March 25, 2005, p.220

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a flow measuring device that can change the height position of an ultrasonic sensor and is easy to install and maintain.

  A first aspect of the present invention is a flow measuring device for measuring a flow in a water channel, wherein the open end of the upper end is located at a position higher than the assumed maximum water level of the water channel, while the closed end of the lower end is Holding means extending in the up-down direction located on the bottom wall side of the water channel, and a pedestal arranged on the side wall of the water channel, and inserted into the holding means via the open end and upward from the closed end side A plurality of held bodies that can be stacked and arranged and can be pulled out from the holding means via the open end; and attached to at least one of the plurality of held bodies. And a flow measuring device comprising a measuring means for measuring the flow of the flow.

  In order to install the measurement means, it is only necessary to install the held bodies stacked on the holding means from the closed end via the open end positioned higher than the assumed maximum water level of the water channel. Even after the measuring means is once installed, maintenance can be performed by extracting the object to be held from the holding means via the open end. Further, when the measuring means is reinstalled after maintenance, the object to be held may be stacked and installed on the holding means from the closed end via the open end. Therefore, it is not necessary to drain water in the water channel for installation and maintenance, and there is no need for underwater work by a diver. In this respect, installation and maintenance of the measuring means are easy.

  The objects to be held are arranged by being stacked by being inserted into the holding means extending in the vertical direction in the water channel, and are extracted from the holding means. The measuring means is attached to at least one of the held objects. In other words, it is possible to pull out the held body to which the measuring means is attached from the holding means, and newly insert the held body into the holding means below, or pull out the held body below it from the holding means. At this point, the height position of the measuring means can be changed.

  As a specific means, the gantry includes a fixing portion to the wall surface of the water channel at a position higher than the assumed maximum water level.

  The gantry can be installed on the wall surface of the water channel above the water surface of the water channel. Therefore, when installing the gantry on the wall surface of the water channel, it is not necessary to drain the water in the water channel or perform underwater work by a diver. In this respect, it is easy to install the gantry.

  It is preferable that the to-be-held body includes an engagement unit that can engage with a jig for an extraction operation from the holding unit.

  Since the held body can be extracted from the holding means using the jig, it is easy to extract the held body from the holding means.

  The held body is, for example, a plate member, and the holding means is a pair of holding grooves into which both side portions of the plate member are inserted. However, the specific structures of the held body and the holding means are not particularly limited as long as the required strength can be ensured, the held bodies can be stacked on the holding means, and can be extracted. For example, a holding tube that forms a hollow elliptical or rectangular cross section on the back surface of the object to be held may be provided, and the holding tube may be inserted into a holding means that forms an elliptical or rectangular cross section.

  It is preferable that the plate-like member has a plurality of heights. The height size is not particularly limited as long as the required strength can be ensured and a space for attaching the measuring means is secured.

  It is preferable to provide a protection means detachably attached to the open end of the holding groove. The open end of the gantry can be covered by the protection means. In this respect, it is possible to prevent entry of dust and loss of the plate.

  The measurement means is, for example, an ultrasonic sensor. An electromagnetic sensor may be used as the other sensor.

  A second aspect of the present invention is a flow measurement device that measures a flow in a water channel, and includes first and second measurement units that face each other at an angle with respect to the flow of the water channel in a plan view, In the first and second measurement units, the open end of the upper end is located at a position higher than the assumed maximum water level of the water channel, while the closed end of the lower end is located in the vertical direction located on the bottom wall side of the water channel. A holding means extended, and a pedestal arranged on a side wall of the water channel, and can be arranged by being stacked on the holding means by being inserted into the holding means via the open end and stacked upward from the closed end side; and A plurality of held bodies that can be extracted from the holding means via ends, and a measuring means that is attached to at least one of the plurality of held bodies and that measures the flow in the water channel. A flow measuring device is provided.

  Ultrasound is transmitted and received between a pair of measuring means installed on both sides of the waterway, and the flow velocity is measured using the phenomenon that the ultrasonic wave propagation velocity and ultrasonic frequency in the fluid change depending on the flow velocity. Based on this, the flow rate can be calculated.

  According to the flow measuring device of the present invention, the holding means can be stacked from the closed end to the upper side through the open end of the gantry located at a position higher than the assumed maximum water level of the water channel, and can be opened. Since the measuring means is attached to the object to be held that can be pulled out from the holding means via the end, the measuring means can be removed for installation and maintenance without draining water from the channel or performing underwater work with a diver. In addition, since re-installation after maintenance is possible, installation and maintenance of the measuring means are easy.

  Further, the measuring means is attached to at least one of the objects to be held that are arranged by being stacked by being inserted into the holding means extending in the vertical direction in the water channel. Accordingly, the height of the measuring means can be increased by extracting the held body to which the measuring means is attached from the holding means and inserting the held body into the holding means below or by removing the lower held body from the holding means. The position can be easily changed.

  In addition, the gantry has a fixed part to the channel wall at a position higher than the assumed maximum water level, so the gantry is installed on the channel wall without draining water from the channel or underwater work by divers. It is easy to install the mount.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a flow measuring device (flow measuring device) 1 according to an embodiment of the present invention. The flow rate measuring device 1 includes a gantry 4 disposed on a side wall 3 of a water channel 2 and a plurality of plates (supported bodies) 6 disposed so as to be inserted into and extracted from a holding means 5 constituting a part of the gantry 4. And a pair of first measurement unit 8a and second measurement unit 8b each including ultrasonic sensors (measurement means) 7a, 7b attached to one or a plurality of plates 6 It is composed of

  Since the gantry 4 provided in each of the first and second measurement units 8a and 8b has the same shape, only the gantry 4 will be described. Referring to FIG. 2 (a), the gantry 4 of the present embodiment includes a first fixing part 11 made of L-shaped steel, a holding means 5 extending vertically downward from the first fixing part 11, and a second steel made of flat steel. A fixing unit 13. The gantry 4 is a structure configured by joining SUS L-shaped steel or steel plate by welding.

  The holding means 5 of the gantry 4 includes a holding rail 14 that extends downward from above in the water channel 2, and a pair of L-shaped cross-sections 15 disposed so as to face each other in the holding rail 14, and the L A holding groove 17 composed of a pair of smaller L-shaped cross sections 16 disposed further inside the cross section is formed. However, the structure of the holding means 5 is not particularly limited as long as it has corrosion resistance and can hold and extract the held body 6. For example, the holding means 5 may have a rod shape extending from the open end 18 toward the closed end 19 and having an oval or square cross section.

  The holding means 5 is formed with a single steel plate that is formed with an open end 18 that opens at the upper end, extends downward from the open end 18 toward the bottom wall of the water channel 2, and is joined to the lower end of the holding means 5. A closed end 19 is formed. The open end 18 is located at a position higher than the assumed maximum water level of the water channel 2. The closed end 19 is located on the bottom wall side of the water channel 2.

  A pair of wave-breaking steels 21 extending from the open end 18 to the closed end 19 and forming a predetermined angle with respect to the side wall 3 may be disposed outside the holding means 5. The wave preventing steel 21 prevents the water flow from directly hitting the holding means 5 and prevents the holding means 5 from being corroded by the water flow and reducing its strength.

  The first fixing part 11 of the gantry 4 is joined to the upper end of the holding means 5 and installed on the upper surface 23 of the water channel 2. Specifically, four attachment holes 22a are formed on the first fixing portion 11 in a straight line. On the other hand, four mounting bolts 24a are installed on the upper surface 23 of the water channel 2 in a posture that protrudes upward in the vertical direction. By inserting these mounting bolts 24a into the mounting holes 22a and tightening nuts (not shown), The upper end of the gantry 4 can be detachably installed in the vertical direction with respect to the water channel 2.

  Similarly, the 2nd fixing | fixed part 13 of the mount frame 4 is joined to the upper part of the holding means 5 so that it may be installed in the wall surface of the water channel 2 in a position higher than the assumed highest water level. Specifically, two upper and lower mounting holes 22 b are formed on both sides of the second fixing portion 13. On the other hand, four mounting bolts 24b are installed on the wall surface so as to protrude in the horizontal direction. By inserting these mounting bolts 24b through the mounting holes 22b and tightening nuts (not shown), the gantry 4 can be detachably attached to the water channel 2 in the horizontal direction.

  As long as necessary strength and corrosion resistance of the gantry 4 are ensured, the material constituting the gantry 4, the structure of the gantry 4, and the mechanism for fixing the gantry 4 to the water channel 2 are not limited to those of the embodiment. Further, in this embodiment, although fixed to the side wall 3 perpendicular to the bottom wall of the water channel 2, a configuration of fixing to the inclined wall surface of the water channel 2 can also be adopted.

  A pair of cover (protection means) attachment holes 25 are formed at the upper end of the gantry 4. The cover attachment hole 25 and a pair of cover side attachment holes 26a formed in the standing wall of the cover 26 are fitted via screws (not shown), and the cover 26 (FIG. 2B) is attached. The cover 26 has an L shape extending along the open end 18 so as to cover the open end 18 of the gantry 4. In this respect, it is possible to prevent the dust from entering the holding groove 17 of the gantry 4 and to prevent the plate 6 from being lost.

  Next, the plate 6 will be described with reference to FIGS. 2 (a) and 3 (a). The plate 6 is made of SUS and has a rectangular shape. The plate 6 is, for example, three types of plates 6a, 6b, and 6c whose height directions are 200 mm, 300 mm, and 500 mm. However, the structure and size of the plate 6 can be inserted into the holding means 5 of the gantry 4 and stacked, and can be removed from the holding means 5 as long as the required strength is ensured. The material constituting the plate 6 is not limited to that of the embodiment. For example, in the embodiment in which the holding means 5 is rod-shaped as described above, a holding tube may be provided because the back surface of the plate 6 has a hollow oval or square shape and can be inserted into the holding means 5.

  As shown in FIGS. 3A and 3B, the ultrasonic sensor 7 has one center formed on the surface of, for example, the maximum size plate 6c among the three types of plates 6a, 6b, and 6c. The holes 27 and the three peripheral holes 28 formed on the concentric circles are attached via bolts (not shown). However, as long as the surface area for attaching the ultrasonic sensor 7 is secured, it may be attached to the plate 6 of any size.

  The ultrasonic sensors 7a and 7b according to the present embodiment include piezoelectric elements for transmitting and receiving ultrasonic waves. Referring to FIG. 1, the ultrasonic sensors 7 a and 7 b are arranged to face each other at a predetermined angle that is not perpendicular to the flowing direction A of flowing water in the water channel 2. The ultrasonic sensor 7b is located on the upstream side, and the ultrasonic sensor 7a is located on the downstream side. The ultrasonic sensors 7a and 7b are arranged at the same height from the riverbed.

  The ultrasonic sensors 7 a and 7 a are connected to a processing device 29 installed outside the water channel 2 via a cable (not shown) extending along the gantry 4. The processing device 29 applies a pulse voltage for driving the piezoelectric element to the ultrasonic sensor 7a on the transmission side, and transmits an ultrasonic pulse signal to the ultrasonic sensor 7a. The pulse signal transmitted from the ultrasonic sensor 7a propagates in the water channel 2 in the opposite direction to the flow and reaches the ultrasonic sensor 7b. Similarly, the pulse signal transmitted from the ultrasonic sensor 7b propagates in the water channel 2 in the flow direction and reaches the ultrasonic sensor 7a. From the difference between the propagation time of the pulse signal transmitted from the ultrasonic sensor 7a and reaching the ultrasonic sensor 7b and the propagation time of the pulse signal transmitted from the ultrasonic sensor 7b and reaching the ultrasonic sensor 7a, The measured value is calculated, and the flow rate of the water channel 2 is calculated from the measured value.

  The ultrasonic sensors 7a and 7b and the processing device 29 may calculate the flow rate by a method other than the propagation time difference method (for example, a cross-correlation method or a Doppler method). The water level may be measured with an ultrasonic water level meter or a microwave water level meter installed on the gantry 4. A throw-in type water level gauge may also be used. Furthermore, the ultrasonic sensors 7a and 7b and the processing device 29 are not limited to those that measure the flow rate, but may measure the flow velocity distribution. Furthermore, a sensor for performing flow measurement based on a principle other than the ultrasonic sensors 7 a and 7 b may be attached to the gantry 4. An example of this type of sensor is an electromagnetic sensor.

  Further, the number of ultrasonic sensors 7 installed on one gantry 4 is not limited to one. A method is adopted in which a plurality of pairs of ultrasonic sensors 7 are installed so that the ultrasonic sensors 7 on both sides of the water channel 2 face each other at a plurality of water depth positions, and the total flow rate in the water channel 2 is estimated from changes in ultrasonic arrival time or frequency May be.

  The ultrasonic sensor 7 may be capable of adjusting the angle by rotating in a plane parallel to the surface that engages with the plate 6, and may be configured to be installed on an inclined wall surface.

  With reference to Fig.4 (a), the jig | tool 31 for extraction operation is demonstrated. The extraction operation jig 31 includes a handle portion 32 extending in a rod shape, and an L-shaped metal fitting 33 attached to the tip thereof. The diameter of the L-shaped metal fitting 33 is smaller than the diameter of the pulling hole 34 in order to pass through the pulling hole 34 formed in the upper center portion of the plate 6. As long as the jig 31 can pull the plate 6 from above the open end 18 and can ensure the necessary strength, the material constituting the jig 31, the structure of the jig 31, and the plate 6 are moved from above. The pulling mechanism is not limited to that of the present embodiment.

  Next, the operation of the flow rate measuring device 1 will be described. As described above, the plate 6 is held on the gantry 4, and the flow rate in the water channel 2 can be measured by ultrasonic waves projected from the piezoelectric element of the ultrasonic sensor 7 attached to the plate 6.

  The installation of the gantry 4 will be described. First, the 1st fixing | fixed part 11 of the mount frame 4 is fixed to the upper surface of the water channel 2 via the attachment volt | bolt 24a. Then, the 2nd fixing | fixed part 13 is fixed to the side wall 3 higher than the highest water level assumed of the water channel 2 via the attachment volt | bolt 24b. Thus, the gantry 4 can be installed on the side wall 3 above the water surface of the water channel 2. Therefore, when installing the gantry 4, it is not necessary to drain water in the water channel 2 or to perform underwater work by a diver. In this respect, installation of the gantry 4 is easy.

  Next, with reference to FIG. 4B, the operation of inserting and extracting the plate 6 into and from the holding means 5 (holding groove 17) will be described. When the ultrasonic sensor 7 is installed, both sides of the plate 6 are inserted into the holding groove 17 via the open end 18 of the gantry 4 located at a position higher than the assumed maximum water level of the water channel 2 and lowered downward. At this time, the width of any plate 6 having a different size is, for example, 315 mm and the thickness is 4 mm, whereas the horizontal distance of the holding groove 17 is 330 mm and the thickness of the plate 6 is 4 mm. Therefore, the plate 6 fits into the holding groove 17 and descends. Similarly, the plate 6 provided with the ultrasonic sensor 7 is inserted into the holding groove 17 via the open end 18 and lowered. The ultrasonic sensor 7 is installed by sequentially stacking the plate 6 including the ultrasonic sensor 7 together with the other lowered plates 6 from the closed end 19 upward.

  Even after the ultrasonic sensor 7 is once installed, the ultrasonic sensor 7 is lifted and extracted along the holding groove 17 in order from the upper plate 6 stacked through the open end 18. Similarly, maintenance can be performed by extracting the plate 6 provided with the ultrasonic sensor 7.

  As described above, in order to install the ultrasonic sensor 7, the plate 6 is stacked on the holding means 5 from the closed end 19 through the open end 18 positioned higher than the assumed maximum water level of the water channel 2. do it. Even after the ultrasonic sensor 7 is once installed, maintenance can be performed by extracting the plate 6 from the holding means 5 through the open end 18. When the ultrasonic sensor 7 is reinstalled after maintenance, the plate 6 may be stacked on the holding means 5 from the closed end 19 through the open end 18. Therefore, it is not necessary to drain water in the water channel 2 for installation and maintenance, and there is no need for underwater work by a diver. In this respect, installation and maintenance of the ultrasonic sensor 7 are easy.

  Further, the holding part 32 of the jig 31 is held, and the tip of the L-shaped metal fitting 33 can be inserted into the pulling hole 34 of the plate 6 to remove the plate 6. Therefore, using the jig 31, the plate 6 disposed below the holding means 5 can be removed from above the water channel 2 through the open end 18, and the plate 6 can be easily extracted from the holding means 5. .

  Next, the height position adjustment of the ultrasonic sensor 7 of this embodiment will be described. For example, when the ultrasonic sensor 7 is disposed on the second plate 6 from the closed end 19 of the holding means 5 as shown in FIG. 2A, the plate 6 located above the first is held first. After extracting from the means 5, the plate 6 provided with the ultrasonic sensor 7 is similarly extracted. If the height of the plate 6 below the ultrasonic sensor 7 is lower than the target height position of the ultrasonic sensor 7, the plate 6 is replaced with a larger size or added. The plate 6 provided with the ultrasonic sensor 7 is inserted and installed thereon, whereby the installation position of the ultrasonic sensor 7 can be increased and adjusted to the target height position. For example, when the height of the upper end of the plate 6 held by the gantry 4 after removing the plate 6 including the ultrasonic sensor 7 is 450 mm lower than the height at which the ultrasonic sensor 7 is installed, A plate 6 with a 300 mm dimension is inserted, and then a plate 6 with an ultrasonic sensor 7 is inserted and installed. At this time, since the ultrasonic sensor 7 is positioned about 151 mm above the lower end of the plate 6 provided with the ultrasonic sensor 7, the ultrasonic sensor 7 can be installed near the target height position.

  On the contrary, when the height of the upper end of the plate 6 below the plate 6 provided with the ultrasonic sensor 7 is higher than the target height position of the ultrasonic sensor 7, the plate 6 below the ultrasonic sensor 7. Is replaced with a smaller plate 6, or the lower plate 6 is removed, and the plate 6 with the ultrasonic sensor 7 is installed thereon, thereby lowering the installation position of the ultrasonic sensor 7, and the target height. Can be adjusted to the position.

  As described above, the plate 6 is inserted into the holding means 5 extending in the vertical direction in the water channel 2 and stacked, and is extracted from the holding means 5. The ultrasonic sensor 7 is attached to at least one of the plates 6. Accordingly, the plate 6 to which the ultrasonic sensor 7 is attached can be extracted from the holding means 5 and the plate 6 can be newly inserted below the holding means 5, or the plate 6 below the plate 6 can be extracted from the holding means 5. In this respect, the height position of the ultrasonic sensor 7 can be easily changed.

  The present invention is not limited to the above embodiment, and various modifications can be made.

  With respect to the gantry 4, as shown in FIG. 5, the first fixing portion 35 and the second fixing portion 36 of the gantry 4 may be fixed to the water channel 2 at the upper and lower portions of the side wall 3. The first fixing portion 35 and the second fixing portion 36 are respectively provided with two upper and lower mounting holes 35a and 36b on both sides, and are installed on the side wall 3 via bolts (not shown).

  Once the gantry 4 is installed, it is possible to obtain an effect that the ultrasonic sensor 7 can be installed, removed for maintenance, and re-installed without draining water. Moreover, the effect that the height adjustment of the ultrasonic sensor 7 is easy corresponding to the change of the water level is also obtained.

The perspective view in the state where the flow measuring device concerning the embodiment of the present invention was installed in the channel. (A) is a front view of a flow measuring device concerning an embodiment of the present invention, a top view, and a side view (b) are perspective views of a cover. (A) is a front view of a plate of a plurality of sizes. (B) is a top view of the ultrasonic sensor and a front view of a plate to which the ultrasonic sensor is attached. (A) is a side view of the lifting rod (b) is a perspective view of a state where the plate is lifted from the gantry via the lifting rod. The perspective view of the state which installed the modification of the mount frame in the side surface of the waterway.

Explanation of symbols

1 Flow measurement device (flow measurement device)
2 Water channel 3 Side wall 4 Base 5 Holding means 6, 6a, 6b, 6c Plate (held object)
7, 7a, 7b Ultrasonic sensor (measuring means)
8a 1st measurement unit 8b 2nd measurement unit 11 1st fixed part 13 2nd fixed part 17 Holding groove 18 Open end 19 Closed end 26 Cover (protection means)
31 Jig

Claims (8)

A flow measuring device for measuring a flow in a water channel,
The open end of the upper end is located at a position higher than the assumed maximum water level of the water channel, while the closed end of the lower end has a holding means extending in the vertical direction located on the bottom wall side of the water channel, A stand placed on the side wall;
A plurality of objects to be held that can be inserted into the holding means through the open end and stacked upward from the closed end side, and can be extracted from the holding means through the open end;
Measuring means attached to at least one of the plurality of held bodies for measuring a flow in the water channel;
A flow measuring device comprising:   The flow measurement device according to claim 1, wherein the gantry includes a fixing portion to a wall surface of the water channel at a position higher than the assumed maximum water level.   The flow measurement apparatus according to claim 1, wherein the held body includes an engagement unit that can engage a jig for an extraction operation from the holding unit. The held body is a plate-shaped member,
The flow measuring device according to any one of claims 1 to 3, wherein the holding means is a pair of holding grooves into which both side portions of the plate-like member are inserted.   The flow measuring device according to claim 4, wherein the plate-like member has a plurality of heights.   The flow measuring device according to claim 4, further comprising a protection unit that is detachably attached to the open end of the holding groove.   The flow measurement apparatus according to claim 1, wherein the measurement unit is an ultrasonic sensor. A flow measuring device for measuring a flow in a water channel,
Comprising first and second measuring units facing at an angle to the flow of the water channel in plan view;
The first and second measurement units are:
The open end of the upper end is located at a position higher than the assumed maximum water level of the water channel, while the closed end of the lower end has a holding means extending in the vertical direction located on the bottom wall side of the water channel, A stand placed on the side wall;
A plurality of objects to be held that can be inserted into the holding means through the open end and stacked upward from the closed end side, and can be extracted from the holding means through the open end;
Measuring means attached to at least one of the plurality of held bodies for measuring a flow in the water channel;
Each comprising a flow measuring device.

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