JP2000241218A - Flow meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the man-hour for developing a plurality of different-volume flow meters and expand the rangeability. SOLUTION: Low flow-rate ultrasonic flow meters 7, 8, 9 having the same flow cross section are disposed in mutually parallel passages 4, 5, 6. A fluid flowing from an entrance 2 flows in the passages 4, 5, 6 to an outlet 3. Signals from the flow meters 7, 8, 9 enter an electronic arithmetic indicator 10 to compute and indicate the total flow rate. If the test fluid is different from an actually used fluid, the characteristic difference between both fluids may be checked at a small volume of the ultrasonic flow meters, without needing checking at a large volume of a flow meter 1 because of the same characteristics of the ultrasonic flow meters 7, 8, 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flow meter.

[0002]

The development of a flow meter for each capacity from a small flow rate (small capacity) to a large flow rate (large capacity) requires a large number of development steps as a whole.

Particularly, in the case of a flow meter used for measuring the flow rate of a fluid other than water, since the test fluid and the actual working fluid such as oil, chemical solution, combustion gas and the like are different, the characteristic difference between the test fluid and the actual working fluid may be different. Verification is required, which becomes more difficult as the capacity increases.

Accordingly, an object of the present invention is to provide a flow meter capable of developing a plurality of types of flow meters having different capacities with a small number of man-hours and eliminating the difficulty in verifying the characteristic difference in the large capacity.

[0005]

In order to achieve the above object, according to the present invention, a plurality of flow paths which are connected in parallel with each other and communicate between an inflow portion and an outflow portion of a measurement fluid are provided. An ultrasonic flow meter provided in each of the plurality of flow paths, and the like,
An electronic computer display unit for receiving a signal from the flow meter and displaying a flow signal.

According to a second aspect of the present invention, in the flow meter of the first aspect, an on-off valve is provided in each of the plurality of flow paths except one of the plurality of flow paths, and the on-off valve is electrically operated. It opens and closes according to the measured flow rate of the calculation display unit.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described with reference to the drawings. [Embodiment 1] In FIG. 1 to FIG. 3, three parallel-connected three parts are connected between a fluid inlet part 2 and a fluid outlet part 3 of a flow meter 1.
The two flow paths 4, 5, 6 communicate with each other, and the ultrasonic flow meters 7, 8, 9 are disposed in the respective flow paths 4, 5, 6, respectively.

[0008] The electronic operation and display unit 10 displays the ultrasonic flow meters 7,
Receiving the signals from 8 and 9, the total flow rate measured by the three ultrasonic flow meters is calculated and the flow rate signal is displayed. A same capacity each ultrasonic flow meter in the same caliber, the small lower limit flow rate Qa determined from the respective detection limit flow rate, the maximum of the flow rate Q _A of the upper limit determined by the measurement upper limit flow rate can be measured, the flow meter 1 the lower limit flow rate 3Qa, the upper limit flow rate becomes 3Q _a.

Therefore, since it is sufficient to use the ultrasonic flowmeters 7, 8, and 9 having a capacity of 1/3 of that of the flowmeter 1, the characteristic difference between the test fluid and the actual use fluid must be verified by using one of the flowmeters 1. The ultrasonic flow meters 7, 8, and 9 having a capacity of / 3 may be performed. Further, since each of the ultrasonic flow meters 7, 8, and 9 is a small ultrasonic flow meter having the same capacity, an apparatus for verification is required. It can be small and does not require the expense of installing new large-capacity inspection equipment.

[0010] In Example 1, the maximum flow rate of the flow meter 1 is 3Q _A, as a flow meter, the casing of the flow meter so disposed e.g. six ultrasonic flowmeter 7 in parallel If six ultrasonic flow meters are installed side by side in a large size,
A flow meter having twice the measurement capacity of the first embodiment can be obtained.

In this case, the test fluid and the actual fluid are used.
Verification of the difference in characteristics of only one small ultrasonic flowmeter 7
Do not need a large, large-capacity inspection device.
No. Therefore, the maximum flow rate is 3Q_AExample 1 of Example 6
Q_AAlso the measurement range Qa-Q of one ultrasonic flow meter
_AAnd use 3 (Qa ~ Q_A) Or 6 (Qa-Q _A)
Several types of flow meters with different capacities
Can be developed in a short time with a small number of man-hours.

[Embodiment 2] Embodiment 2 shown in FIGS.
Are compared with the first embodiment shown in FIGS.
The difference is that on-off valves (bidirectional shutoff valves) 11 and 12 are inserted and connected in series with the ultrasonic flow meters 8 and 9, respectively, and upstream of each ultrasonic flow meter. The on / off valves 11 and 12 are controlled to be opened and closed by the electronic operation display unit 10 according to the total flow rate calculated by the electronic operation display unit 10.

[0013] In other words, the flow rate is up to Q _A both opening and closing valve 11, 1
2 is closed and measurement is performed only by the ultrasonic flow meter 7. Flow rate is Q _A
From to 2Q _A opens the on-off valve 11, closes the on-off valve 12 measured by the ultrasonic flow meter 7 and 8. And the flow rate is 2Q
From _A to 3Q _A is measured by the three ultrasonic flowmeter 7, 8 and 9 by opening the two closing valves 11 and 12. Thus can be measured from the lower limit flow rate Qa to the upper limit flow rate 3Q _A in flowmeter 1,
Its range catcher capability is Qa～3Q _A, and the one ultrasonic flowmeter 7, 8 or 9 range catcher capability Qa～Q _A of
A wider measurement range can be obtained.

[Other Embodiments] In the second embodiment, the ultrasonic flowmeters 7, 8, and 9 are of a small size having the same diameter, but are not necessarily limited to the same diameter. May be used, and the other two ultrasonic flowmeters 8 and 9 may have larger diameters. In this case, the lower limit flow rate of the ultrasonic flow meter 8 and 9 and Qb> Qa, when the upper limit flow rate to Q _B> Q _A,
In flow Qa～Q _A close both opening and closing valves 11 and 12, the flow rate Q
_{A ~ (Q A + Q B} ) the open close valve 11 opens and closes valve 12
Closed and the flow rate (Q _A + Q _B) is measured by opening the ~ (Q _A + 2Q _B) in both the opening and closing valves 11 and 12. The range catcher capability becomes larger value as _{Qa~ (Q A + 2Q B)} .

[0015] Then, when increasing the measurement range so as to control the opening and closing valve further to a large number of n as well two ultrasonic flowmeter Qb～Q _B, range catcher capability is Qa~ (Q _A + NQ _B ). In these cases, since the ultrasonic flow meter 7 and the measurement range of the ultrasonic flow meter measurement range Qa～Q _A is only ultrasonic flowmeter 8,9 ... two of Qb～Q _B, the maximum flow rate For a flow meter with a large flow rate of Q _A + nQ _B , it is not necessary to perform the verification at the maximum flow rate.

In the above embodiment, if a mechanism for opening and closing the entire flow is added, a gas meter with security,
It can be applied to water meters and the like as advance payment meters.

[0017]

Since the flow meter of the present invention is constructed as described above, a flow meter of various capacities can be constructed by combining a plurality of relatively small ultrasonic flow meters, so that the man-hour for development is reduced. Development time can be shortened.

Further, in developing a large-capacity flow meter, there is no need to construct a large-capacity test device corresponding to the capacity of the flow meter. ) Can be made in time with a small-capacity test device. Therefore, it leads to cost reduction.

Further, according to the invention of claim 2, there is an advantage that rangeability can be expanded. Further, by combining the ultrasonic flowmeter, the flowmeter can be downsized, and the upstream and downstream straight pipes are not required.

[Brief description of the drawings]

FIG. 1A is a connection diagram of a fluid circuit, and FIG. 1B is a longitudinal sectional view of a flow meter in an embodiment of the present invention.

FIG. 2 is a front view of the flow meter of the embodiment of FIG.

FIG. 3 is a cross-sectional view of the flow meter of the embodiment of FIG.

FIG. 4 is a fluid circuit diagram of another embodiment of the present invention.

5 is a longitudinal sectional view of the flow meter of the embodiment of FIG.

FIG. 6 is a front view of the flow meter of the embodiment of FIG.

FIG. 7 is a cross-sectional view of the flow meter of the embodiment of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flowmeter 2 Inflow part 3 Outflow part 4,5,6 Flow path 7,8,9 Ultrasonic flowmeter 10 Electronic calculation display part 11,12 On-off valve (bidirectional shutoff valve)

Claims (2)

[Claims] A plurality of flow paths which are connected in parallel with each other and communicate between an inflow portion and an outflow portion of a measurement fluid; and an ultrasonic flowmeter provided in each of the plurality of flow channels; An electronic computer display unit for receiving a signal from the flow meter and displaying a flow signal. 2. An on-off valve is provided in each of the plurality of flow paths except one of the plurality of flow paths, and the on-off valve is opened and closed according to a flow rate measured by an electronic calculation display unit. The flowmeter according to claim 1, wherein