JP2001201391A - Calibration system of flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance calibration precision for a flowmeter. SOLUTION: This calibration system 10 is provided with a storage tank 12 stored with a liquid oil for calibration, a liquid oil supplying route 14, a feed pump 16, the flowmeter 18 for measuring the fed liquid oil, a measuring tank 20, and a circulation route 22. An inside of the storage tank 12 is partitioned into the first chamber 36 and the second chamber 38 by a mid diaphragm 34. An upper space 40 is formed in an upper side of the diaphragm 34 to communicate the first chamber 36 with the second chamber 38. Overflow to the second chamber 38 is generated when a liquid level of the liquid oil circulated to the first chamber 36 exceeds the height of the diaphragm 34. Since a water head is thereby kept constant in the first chamber 36, supply pressure of the liquid oil fed to the flowmeter 18 is prevented from being fluctuated by a liquid level of the storage tank 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flowmeter calibration system, and more particularly to a flowmeter calibration system configured to improve the calibration accuracy of a flowmeter.

[0002]

2. Description of the Related Art In order to calibrate a flow meter that has been assembled, a flow meter is installed in the piping of a flow meter calibration system,
The amount of water sent from the pump is actually measured to check the measurement accuracy inherent to the flow meter. In a conventional flow meter calibration system, when calibrating a flow meter that measures oil liquid such as light oil or kerosene, the difference between the measured flow rate and the volume of oil liquid supplied to a graduated measuring tank (reference unit) is measured. From the measurement error.

[0003]

By the way, in the conventional flow meter calibration system, after the measured fluid stored in the storage tank is fed by the pump and supplied to the flow meter, the measured fluid is stored in the storage tank. The system has a recirculated system. In other words, when the measured fluid is once stored in the reference tank, the liquid level (water head) in the storage tank gradually decreases, and when the measurement is completed, the liquid level (water head) repeatedly increases, and the liquid level (water head) fluctuates. As a result, there is a problem that the supply pressure fluctuates, and accurate calibration of the flow meter connected to the calibration system cannot be performed.

In the conventional flow meter calibration system, since the oil liquid measured by the flow meter is measured in the reference tank and then returned to the storage tank, bubbles are contained in the oil liquid returned to the storage tank. If the oil liquid mixed with the air bubbles is supplied as it is for the next calibration of the flowmeter, there is a problem that an error occurs in the measured value of the flowmeter.

Therefore, an object of the present invention is to provide a flowmeter calibration system which has solved the above-mentioned problems.

[0006]

In order to solve the above problems, the present invention has the following features.

According to the first aspect of the present invention, there is provided a storage tank in which an oil liquid for calibration is stored, an oil liquid supply path for supplying the oil liquid in the storage tank, and an oil liquid supply path via the oil liquid supply path. Pump, a flow meter for measuring the oil liquid sent by the pump, a reference device for storing the oil liquid and measuring the amount of the liquid, and returning the oil liquid of the measuring device to the storage tank. A flow path calibration system configured to compare the measurement value of the flow meter with the measurement value of the reference meter to calibrate the flow meter, wherein the storage tanks are independent of each other. The first and second chambers, the oil liquid supply path is connected near the bottom of the first chamber, and the return path is connected to the upper part of the first chamber. During the supply of the liquid, the oil liquid in the first chamber always overflows into the second chamber. It is characterized in that the form.

Therefore, according to the first aspect of the present invention, at least while the oil liquid is being supplied to the reference device, the oil liquid in the first chamber is always overflowed into the second chamber.
While the oil liquid measured by the flow meter is being supplied to the reference device, the liquid level (head) in the storage tank is constant, and the supply pressure of the oil liquid supplied to the flow meter can be prevented from fluctuating.
Calibration accuracy can be improved.

Further, the oil liquid overflowing from the first chamber is caused to flow out to the second chamber, and the return path is connected to the upper portion of the second chamber formed in the storage tank, whereby the second chamber is formed. In order to recirculate the oil liquid to the upper part of the first chamber, the air bubbles mixed in the oil liquid are separated and discharged to the second chamber, and the oil liquid is removed from near the bottom of the first chamber from which the air bubbles have been removed. Can be sent to the flow meter, so that measurement errors due to air bubbles can be prevented.

Further, the invention according to claim 2 is characterized in that the storage tank is inclined at a predetermined angle.

According to the second aspect of the present invention, since the storage tank is inclined at a predetermined angle, the oil liquid overflowing from the first chamber can be easily discharged to the second chamber, and the first tank can be easily discharged to the second chamber. Bubbles mixed in the oil liquid in the first chamber can be separated by floating in the upper space of the first chamber.

According to a third aspect of the present invention, a partition that defines two chambers is provided inside the storage tank, and the first chamber and the second chamber communicate with each other above the partition. A communication means is provided.

Therefore, according to the third aspect of the present invention, a partition that defines two chambers is provided inside the storage tank, and a communication means that connects the first chamber and the second chamber above the partition. When the liquid level of the oil liquid refluxed to the first chamber becomes higher than the partition, the oil liquid overflowing from the first chamber overflows to the second chamber and is supplied by keeping the liquid level constant. Pressure fluctuation can be prevented, and bubbles accumulated at the upper part of the first chamber are removed from the second chamber.
Air bubbles can be separated from the oil liquid discharged to the chamber and supplied to the flow meter.

The invention according to claim 4 is characterized in that a bubble removing means is provided in the storage tank.

Therefore, according to the fourth aspect of the present invention, since the bubble removing means is provided in the storage tank, bubbles contained in the oil liquid refluxed in the storage tank can be removed by the bubble removing means. .

According to a fifth aspect of the present invention, there is provided a storage tank for storing an oil liquid for calibration, an oil liquid supply path for supplying the oil liquid in the storage tank, and an oil liquid supply path via the oil liquid supply path. A pump that sends the liquid, a flow meter that measures the oil liquid sent by the pump, a reference device that stores the oil liquid and measures the amount of the liquid, and the oil liquid of the measuring device into the storage tank. A reflux path for refluxing, wherein the flowmeter calibrating system configured to calibrate the flowmeter by comparing the measured value of the flowmeter with the measured value of the reference meter, wherein the storage tank has a predetermined angle. A partition that inclines and defines the inside of the storage tank in first and second chambers, and a space that communicates the first chamber and the second chamber is provided above the partition; An oil liquid supply path is connected near the bottom of the first chamber, and the return path is It is connected to the upper part of the first chamber, and at least during the supply of the oil liquid to the reference device, the oil liquid in the first chamber always overflows to the second chamber. is there.

Therefore, according to the fifth aspect of the present invention, at least while the oil liquid is being supplied to the reference device, the oil liquid in the first chamber always overflows into the second chamber.
While the oil liquid measured by the flow meter is being supplied to the reference device, the liquid level (head) in the storage tank is constant, and the supply pressure of the oil liquid supplied to the flow meter can be prevented from fluctuating. In addition, the calibration accuracy can be improved. In addition, since the storage tank is inclined by a predetermined angle, the oil liquid overflowing from the first chamber can easily flow out to the second chamber,
Bubbles mixed into the oil liquid in the first chamber can be separated by floating in the upper space of the first chamber. Further, since the bubble removing means is provided in the storage tank, the bubbles contained in the oil liquid refluxed in the storage tank can be removed by the bubble removing means.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing one embodiment of a flow meter calibration system according to the present invention.

As shown in FIG. 1, in a flow meter calibration system 10, a storage tank 12 storing an oil solution for calibration is provided.
And an oil supply path 14 for supplying the oil in the storage tank 12.
A pump 16 for feeding the oil through the oil supply path 14, a flow meter (test meter) 18 for measuring the oil fed by the pump 16, and a reference device. And a reflux path 22 for returning the oil liquid in the measurement tank 20 to the storage tank 12.

A circulation recovery tank 24 is provided adjacent to the measuring tank 20. Above the measuring tank 20 and the circulation collecting tank 24, an oil liquid supply path 14 passing through a flow meter 18 is provided. Commutator 26 supplied with oil flowing through
Is provided. The commutator 26 is connected to the measuring tank 20.
The communication path between the tank and the collection tank 24 is switched. That is, the commutator 26 is provided in a branch path between the measuring tank 20 and the collection tank 24, and oscillates a commutation plate (not shown) provided therein to remove the oil liquid before the flow rate measurement. It operates to guide the oil liquid to the collection tank 24 and to guide the oil liquid to the measuring tank 20 during the flow rate measurement. It is sufficient that the measuring tank 20 is configured to be able to measure the volume of the flow rate measured by the flow meter 18, and therefore, for example, a volume standard device in which a measuring cylinder is enlarged may be used.

When the flow rate measurement by the flow meter 18 is completed, the commutator 2 guides the oil liquid to the recovery tank 24.
The commutation plate 6 (not shown) returns. At the bottom of the measuring tank 20, a reference balance 28 for measuring the mass of the supplied oil liquid in the measuring tank 20 is installed. still,
An on-off valve 30 is provided in the oil liquid supply path 14 that communicates between the flow meter 18 and the commutator 26, and a return path 22 that communicates between the collection tank 24 and the storage tank 12 A pump 32 is provided. This reflux pump 32
Is always started at least while the oil liquid measured by the flow meter 18 is being supplied to the measuring tank 20.

The inside of the storage tank 12 is defined by a partitioning plate 34 into a first chamber 36 and a second chamber 38.
The middle partition plate 34 is formed so as to maintain the level of the oil liquid returned to the first chamber 36 at a predetermined level. Therefore, the first chamber 36 and the second chamber 3 are located above the partition 34.
8 is an upper space (communication means) 40 for communicating with the control unit 8.

At least while the oil liquid measured by the flow meter 18 is being supplied to the measuring tank 20,
Sufficient oil liquid is supplied to the first chamber 36, and the level of the oil liquid refluxed to the first chamber 36 exceeds the height of the partition 34 and is near the liquid level of the first chamber 36. Flows into the second chamber 38 via the upper space 40. Thereby, the first room 3
The head at 6 is kept constant. Therefore,
The supply pressure of the oil liquid sent to the flow meter 18 via the oil liquid supply path 14 is prevented from fluctuating due to the liquid level in the storage tank 12.

The circulation recovery tank 24 for recirculating the oil liquid into the first chamber 36 and the second chamber 38 have a capacity (volume) sufficiently larger than the capacity (volume) of the first chamber 36. So that the liquid level in the first chamber 36 does not become lower than the height of the partition 34 during the measurement in the measuring tank 20. The second chamber 38 is the first chamber 3
6 may be provided separately, or the circulation recovery tank 24 may be used as the second chamber 38. In that case, the first chamber 36 and the second chamber 3
A conduit communicating with the line 8 is a communication means.

Further, the first chamber 3
Even if air bubbles are mixed in the oil liquid refluxed to 6, the air bubbles tend to collect near the liquid surface of the first chamber 36 due to buoyancy.
Bubbles are formed together with the oil liquid overflowing into the second chamber 38.
To separate from the oil liquid in the first chamber 36. In the storage tank 12, the oil supply path 14
Is connected to the bottom of the first chamber 36, and the return path 22 is
Is connected to the upper part of the chamber 36. For this reason, no bubbles are mixed in the oil liquid sent to the oil liquid supply path 14, and a measurement error of the flowmeter 18 due to the mixing of the bubbles can be prevented.

The bottom of the second chamber 38 is connected to one end of a circulation path 42, and the top of the second chamber 38 is connected to one end of the circulation path 42. And circulation route 4
2 is provided with a circulation pump 44. The second
In the chamber 38, bubbles contained in the oil liquid overflowing from the first chamber 36 over the intermediate partition plate 34 accumulate near the liquid surface due to buoyancy and are separated from the oil liquid.

The circulation pump 44 is activated when it is detected that the liquid level in the first chamber 36 has dropped below a predetermined level.
The oil liquid containing no air bubbles is sucked from near the bottom of the second chamber 38 and supplied to the upper part of the first chamber 36 through the circulation path 42. As described above, the circulation of the oil liquid is performed via the circulation path 42 between the first chamber 36 and the second chamber 38 formed inside the storage tank 12. The circulation pump 44 may be always started at least while the oil liquid measured by the flow meter 18 is being supplied to the measuring tank 20.

The first chamber 36, the second chamber 38, and the collection tank 24 are provided with a liquid level meter (liquid level meter) for detecting a liquid level.
45, 46 and 47 are inserted. Further, a vent pipe 50 communicating with the upper space is provided on the upper surface of the storage tank 12.

The flow rate F1 fed by the pump 16 is the flow rate F1 fed by the reflux pump 32.
2, the flow rate F3 sent by the circulation pump 44 is substantially the same as the flow rate overflowing from the first chamber 36 to the second chamber 38.

Here, the operation in the case where the oil liquid stored in the storage tank 12 configured as described above is sent and the flow meter 18 is verified will be described. When the oil liquid stored in the first chamber 36 of the storage tank 12 is sent by the activation of the pump 16, the flow meter 18 measures the flow rate of the oil liquid flowing through the oil liquid supply path 14. The oil liquid that has passed through the flow meter 18 is supplied to the commutator 26 via the oil liquid supply path 14.

In the commutator 26, before measuring the flow rate, the commutation plate (not shown) provided therein is swung before the flow rate measurement as described above to guide the oil liquid to the recovery tank 24. The plate (not shown) is operated to swing in the opposite direction to guide the oil liquid to the measuring tank 20. Thus, the oil liquid is supplied to the measuring tank 20 only while the flow rate is measured by the flow meter 18.

When the flow rate measurement by the flow meter 18 is completed, the commutator 2 guides the oil liquid to the recovery tank 24.
The commutation plate 6 (not shown) returns. As a result, the same volume of oil liquid as the flow rate measured by the flow meter 18 is supplied to the measuring tank 20.

After that, the mass of the oil liquid supplied to the measuring tank 20 is measured by the reference balance 28. This reference scale 28
The mass of the oil liquid measured by the
8 is compared with the measured flow value. Then, based on the comparison result, the calibration of the flow measurement value is performed.

The circulation pump 44 may be started at all times, but is not limited to this, and is started when the liquid level in the first chamber 3 measured by the liquid level meter 45 falls below a predetermined value. You may do it.

FIG. 2 is a front view showing a storage tank 51 according to a modification of the present invention. FIG. 3 is a left side view of the storage tank 51 of the modified example. FIG. 4 is a cross-sectional view of the storage tank 51 according to the modification.
It is sectional drawing which follows a line. FIG. 5 is a plan view of the storage tank 51. FIG. 6 is a cross-sectional view of the storage tank 51 along the longitudinal direction.

As shown in FIGS. 2 to 6, the storage tank 51 of the modified example is formed in a cylindrical shape and is inclined at a predetermined angle θ (for example, θ = about 10 to 20 degrees) with respect to a horizontal plane. Installed in state. In addition, storage tank 5
1 is an outlet 52 to which the oil liquid supply path 14 is connected at the bottom.
Is provided, and an inflow port 5 to which a reflux path 22 is connected
4 are provided. This inflow port 54 is connected to the storage tank 5
The first chamber 64 communicates with a drop pipe 56 inserted into the first chamber 64.

Further, a vent 60 communicating with the internal upper space 58 is provided above the storage tank 51. At the center of the cross section of the storage tank 51, an intermediate partition plate 66 that defines a first chamber 62 and a second chamber 64 extends in the longitudinal direction in an upright state. The drop pipe 56 is inserted at a position communicating with the upper space of the first chamber 62, and the outlet 52 is provided so as to communicate with the lower space of the first chamber 62.

The upper end edge 66a of the middle partition plate 66 is horizontally cut so as to leave an upper space 58 communicating between the first chamber 62 and the second chamber 64. Therefore, when the liquid level of the oil recirculated to the first chamber 62 exceeds the upper edge 66 a, it flows over the upper edge 66 a of the partition 66 and overflows into the second chamber 64.

Therefore, the head in the first chamber 62 is kept constant by the height position of the upper end edge 66 a of the middle partition plate 66, and the liquid is sent to the flow meter 18 via the oil supply path 14. Oil supply pressure is prevented from fluctuating due to the liquid level in the storage tank 51.

Further, the first chamber 6 is returned to the first chamber 6 via the reflux path 22.
Even if air bubbles are mixed in the oil liquid refluxed to 2, the air bubbles tend to collect near the liquid surface of the first chamber 62 due to buoyancy.
Bubbles are formed together with the oil liquid overflowing into the second chamber 64.
And separated from the oil liquid in the first chamber 62. In the storage tank 51, the oil supply path 14
Is connected to the bottom of the first chamber 62, and the reflux path 22 is connected to the first
Is connected to a drop pipe 56 inserted from above the chamber 62. For this reason, no bubbles are mixed in the oil liquid sent to the oil liquid supply path 14, and a measurement error of the flowmeter 18 due to the mixing of the bubbles can be prevented.

The first chamber 62 is provided with three wire nets (bubble removing means) 68 for removing bubbles. The wire mesh 68 is for preventing bubbles mixed in the oil liquid from moving to the bottom side of the first chamber 62, and is included in the oil liquid refluxed through the reflux path 22. It is possible to prevent the flowing bubbles from flowing out to the oil liquid supply path 14. It should be noted that a configuration may be adopted in which a punching plate having a large number of holes, a lattice-shaped baffle plate, or the like is provided instead of the wire mesh 68.

Further, a pair of liquid level detecting pipes 70 and 71 extending upward from the lower part of the storage tank 51 are erected,
First and second liquid level gauges 72, 73 are inserted into the liquid level detection pipes 70, 71, respectively. And the liquid level detection line 7
The communication pipes 7 connected to the upper space 58 are provided at 0 and 71.
4, 75 are connected. Therefore, the liquid level detection line 7
The liquid level inside 0 and 71 has the same liquid level as the liquid level of the oil liquid supplied to the first chamber 62. Therefore,
The first liquid level meter 72 can detect the liquid level (water head) of the first chamber 62, and the second liquid level meter 73 can detect the liquid level (water head) of the second chamber 64. .

In the above embodiment, the inside of the storage tank is separated into the first chamber and the second chamber by the partition plate. However, the present invention is not limited to this. For example, the space between the separately formed chambers may be separated. It may be configured to communicate with a passage or the like.

[0045]

As described above, according to the first aspect of the present invention, at least while the oil liquid is being supplied to the reference device, the oil liquid in the first chamber constantly overflows into the second chamber. As the oil liquid measured by the flow meter is supplied to the reference device, the liquid level (water head) in the storage tank becomes constant, and the supply pressure of the oil liquid supplied to the flow meter fluctuates. Can be prevented, and the calibration accuracy can be improved.

Further, the oil liquid overflowing from the first chamber is caused to flow out to the second chamber, and the return path is connected to the upper part of the second chamber formed in the storage tank, whereby the second chamber is formed. In order to recirculate the oil liquid to the upper part of the first chamber, the air bubbles mixed in the oil liquid are separated and discharged to the second chamber, and the oil liquid is removed from near the bottom of the first chamber from which the air bubbles have been removed. Can be sent to the flow meter, so that measurement errors due to air bubbles can be prevented.

According to the second aspect of the present invention, since the storage tank is inclined at a predetermined angle, the oil liquid overflowing from the first chamber can easily flow out to the second chamber, and the first tank can be easily discharged to the second chamber. Bubbles mixed in the oil liquid in the first chamber can be separated by floating in the upper space of the first chamber.

According to the third aspect of the present invention, a partition is provided inside the storage tank to define two chambers, and a communication means for communicating the first chamber and the second chamber above the partition. When the liquid level of the oil liquid refluxed to the first chamber becomes higher than the partition, the oil liquid overflowing from the first chamber overflows to the second chamber and is supplied by keeping the liquid level constant. Fluctuations in pressure can be prevented, and bubbles accumulated in the upper portion of the first chamber can be discharged to the second chamber to separate bubbles from the oil liquid supplied to the flow meter. According to the fourth aspect of the present invention, since the bubble removing means is provided in the storage tank, bubbles contained in the oil liquid refluxed in the storage tank can be removed by the bubble removing means.

According to the fifth aspect of the present invention, at least while the oil liquid is being supplied to the reference device, the oil liquid in the first chamber is always allowed to overflow into the second chamber. While the oil liquid measured by the meter is being supplied to the reference device, the liquid level (head) in the storage tank becomes constant, and the supply pressure of the oil liquid supplied to the flow meter can be prevented from fluctuating. Calibration accuracy can be improved. In addition, since the storage tank is inclined by a predetermined angle, the oil liquid overflowing from the first chamber can easily flow out to the second chamber,
Bubbles mixed into the oil liquid in the first chamber can be separated by floating in the upper space of the first chamber. Further, since the bubble removing means is provided in the storage tank, the bubbles contained in the oil liquid refluxed in the storage tank can be removed by the bubble removing means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a flow meter calibration system according to the present invention.

FIG. 2 is a front view showing a storage tank 51 according to a modified example of the present invention.

FIG. 3 is a left side view of a storage tank 51 of a modified example.

FIG. 4 is a cross-sectional view of a storage tank 51 of a modified example taken along line CC.

FIG. 5 is a plan view of the storage tank 51.

FIG. 6 is a sectional view taken along a longitudinal direction of the storage tank 51.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flow meter calibration system 12, 51 Storage tank 14 Oil liquid supply path 16 Pump for feeding liquid 18 Flow meter 20 Metering tank 22 Reflux path 24 Recovery tank for circulation 26 Commutator 28 Reference scale 32 Reflux pump 34, 66 Middle partition Plates 36, 62 First chamber 38, 64 Second chamber 40 Upper space 42 Circulation path 44 Circulation pump 45, 46, 47, 72, 74 Level gauge 52 Outlet 54 Inlet 56 Drop pipe 70, 71 Liquid Position detection pipeline 74, 75 Communication pipeline

Claims (5)

[Claims] A storage tank storing an oil solution for calibration, an oil solution supply path for supplying the oil solution in the storage tank, a pump for sending the oil solution through the oil solution supply path, A flow meter that measures the oil liquid sent by the pump, a reference device that stores the oil liquid and measures the amount of the liquid, and a reflux path that returns the oil liquid of the measuring device to the storage tank. In a flowmeter calibration system configured to calibrate the flowmeter by comparing the measurement value of the flowmeter and the measurement value of the reference meter, the storage tanks are independent of each other, Connecting the oil liquid supply path near the bottom of the first chamber, connecting the return path to the top of the first chamber, and supplying the oil liquid to at least a reference device. The oil liquid in the first chamber is always overflowed into the second chamber. Flowmeter calibration system. 2. The flow meter calibration system according to claim 1, wherein the storage tank is inclined at a predetermined angle. 3. The storage tank is provided with a partition defining two chambers inside, and a communication means for communicating the first chamber and the second chamber is provided above the partition. The flowmeter calibration system according to claim 2, wherein 4. The flowmeter calibration system according to claim 2, wherein air bubble removing means is provided in said storage tank. 5. A storage tank in which an oil liquid for calibration is stored, an oil liquid supply path for supplying the oil liquid in the storage tank, a pump for sending the oil liquid through the oil liquid supply path, A flow meter that measures the oil liquid sent by the pump, a reference device that stores the oil liquid and measures the amount of the liquid, and a reflux path that returns the oil liquid of the measuring device to the storage tank. In a flow meter calibration system configured to calibrate the flow meter by comparing the measurement value of the flow meter with the measurement value of the reference meter, the storage tank is inclined at a predetermined angle, and the storage tank is A partition that defines the interior into first and second chambers is provided, and a space that communicates the first chamber and the second chamber is provided above the partition, and the oil liquid supply path is connected to the first chamber. Connecting the vicinity of the bottom of the first chamber, connecting the reflux path to the top of the first chamber, At least while the oil liquid is being supplied to the reference device, the oil liquid in the first chamber always overflows into the second chamber.