JP2004170346A

JP2004170346A - Flow meter

Info

Publication number: JP2004170346A
Application number: JP2002339131A
Authority: JP
Inventors: Toshihide Kuwabara; 敏英桑原
Original assignee: Kimmon Manufacturing Co Ltd
Current assignee: Kimmon Manufacturing Co Ltd
Priority date: 2002-11-22
Filing date: 2002-11-22
Publication date: 2004-06-17
Anticipated expiration: 2022-11-22
Also published as: JP4087687B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow meter capable of reducing turbulence of a gas flow flowing through a measuring tube and stabilizing a flow rate at a flow measurement point, thus improving measurement accuracy. <P>SOLUTION: The flow meter flows a gas flowing through a gas inlet 3a from a gas supply source side into a measuring channel 5 of a flow meter body 1 and, after measuring gas flow rate with a measuring instrument disposed in the measuring channel 5, directs the gas from a gas outlet 4a to a gas consuming side. The measuring channel is provided with a measuring tube 9 opened to upstream side 7 and downstream side 8. A regulator 11 consisting of plural flow regulating plates 12 arranged radially is disposed on at least the upstream side 7. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、都市ガス、プロパンガス等のガス流量を計測する流量計に関する。
【０００２】
【従来の技術】
一般家庭用のガスメータとしての超音波ガスメータが開発されている。超音波ガスメータは、既設の膜式ガスメータが取付けられている配管に対して互換性を持たせるために図６（ａ）（ｂ）に示すように構成されている。
【０００３】
すなわち、流量計本体１の上部には左右方向に離間してガス流入口３ａを形成する流入口金３とガス流出口４ａを形成する流出口金４が設けられている。流量計本体１の内部の計測流路５は隔壁６によって上流側７と下流側８に区画されている。さらに、隔壁６には上流側７及び下流側８に開口する測定管９が貫通して設けられている。
【０００４】
この測定管９は円筒または角筒であり、ガス流入口３ａから上流側７に流入したガスが測定管９の内部を流通して下流側８に流れ、ガス流出口４ａに導かれるようになっている。測定管９の内部にはガスの流れる方向（矢印ａ方向）に対して角度θを持って対向する送信センサと受信センサからなる一対の超音波センサ１０ａ，１０ｂが設置されている。そして、超音波の伝搬速度の変化を検知してガス流量を計測し、積算流量を積算指示部（図示しない）に指示するようになっている。
【０００５】
また、図７は、流量計本体１の上流側７及び下流側８の側壁に測定管９の開口に対向して送信センサと受信センサからなる一対の超音波センサ１０ａ，１０ｂを設置したものである。
【０００６】
【発明が解決しようとする課題】
しかしながら、前述のように構成された超音波ガスメータは、ガス流入口３ａから計測流路５の上流側７に流入したガスが測定管９の開口の周囲から略直角に曲がって測定管９に流入する。従って、測定管９の内部を流通するガスの流速分布に乱れが発生し、測定管９内の圧力変動（脈動）が生じて計測精度に影響を及ぼす要因となっている。
【０００７】
この発明は、前記事情に着目してなされたもので、その目的とするところは、測定管内を流通するガスの流速分布の乱れを低減し、計測精度を向上できる流量計を提供することにある。
【０００８】
【課題を解決するための手段】
この発明は、前記目的を達成するために、請求項１は、ガス供給側からガス流入口を介して流入するガスを流量計本体の計測流路に流入し、前記計測流路に設置した計器によってガス流量を計測した後、ガス流出口からガス需要側に導く流量計において、前記計測流路に、その上流側及び下流側に開口する測定管を設けるとともに、前記測定管の少なくとも上流側に複数枚の整流板を放射状に配置した整流器を設けたことを特徴とする。
【０００９】
請求項２は、請求項１の前記整流板は、その内側端部が前記測定管の内周壁より内側に突出して設けられていることを特徴とする。
【００１０】
請求項３は、請求項１の前記整流板は、その内側端部が前記測定管の外周壁に固定されていることを特徴とする。
【００１１】
請求項４は、請求項１の前記ガス流量を計測する計器は、超音波センサ、熱線センサ、タービンのいずれかであることを特徴とする。
【００１２】
前記構成によれば、計測流路の上流側から測定管に向かうガス及び測定管から下流側に向かうガスは整流器によって整流され、測定管内を流通するガスの流れの乱れを減少させることができ、流量測定点における流量を安定させることができる。従って、計測精度を向上できる。
【００１３】
【発明の実施の形態】
以下、この発明の実施の形態を図面に基づいて説明するが、従来と同一構成部分は同一番号を付して説明を省略する。
【００１４】
図１は第１の実施形態を示し、（ａ）は縦断正面図、（ｂ）はＡ−Ａ線に沿う断面図である。図１に示すように、流量計本体１の計測流路５に隔壁６を貫通して設けられた円筒状の測定管９の上流側７及び下流側８にはガスの流れを整流する整流器１１が設けられている。なお、整流器１１は測定管９の上流側７だけに設けても同様の効果がある。
【００１５】
整流器１１は、測定管９に対して複数枚の整流板１２を放射状に等間隔に配置することにより構成されている。そして、整流板１２は測定管９の開口縁と計測流路５の上流側７及び下流側８の内側壁５ａとの間の全体に亘って設けられている。さらに、整流板１２の内側端部１２ａは測定管９の内周壁９ａより内側に突出して設けられている。
【００１６】
このように構成された流量計によれば、ガス流入口３ａからガスが計測流路５の上流側７に流入すると、ガスは整流器１１の整流板１２相互間を通過して整流されて測定管９に向かう。そして、ガスは測定管９の内部を流れて下流側８に向かい、ここで、再び整流器１１によって整流されてガス流出口３ｂから流出する。
【００１７】
従って、測定管９内を流通するガスの流れの乱れを減少させることができ、送信センサと受信センサからなる一対の超音波センサ１０ａ，１０ｂの流量測定点における流量を安定させることができ、計測精度を向上できる。
【００１８】
図２は第１の実施形態の変形例を示し、角筒状の測定管１３の上流側７及び下流側８に整流器１１を設けたものであり、第１の実施形態と同様の作用効果がある。
【００１９】
図３は第２の実施形態を示し、（ａ）は縦断正面図、（ｂ）はＢ−Ｂ線に沿う断面図である。図３に示すように、流量計本体１の計測流路５に隔壁６を貫通して設けられた円筒状の測定管９の上流側７及び下流側８にはガスの流れを整流する整流器１１が設けられている。
【００２０】
整流器１１は、測定管９に対して複数枚の整流板１２を放射状に等間隔に配置することにより構成されている。そして、整流板１２は測定管９の開口縁と計測流路５の上流側７及び下流側８の内側壁５ａとの間の全体に亘って設けられている。さらに、整流板１２の内側端部１２ａは測定管９の外周壁９ｂに対して固定されており、第１の実施形態と同様の作用効果がある。
【００２１】
図４は第２の実施形態の変形例を示し、角筒状の測定管１３の上流側７及び下流側８に整流器１１を設けたものであり、第２の実施形態と同様の作用効果がある。
【００２２】
図５は第３の実施形態を示し、計測流路５の上流側７及び下流側８の側壁に測定管９の開口に対向してセンサ固定部１４を設け、このセンサ固定部１４に送信センサと受信センサからなる一対の超音波センサ１０ａ，１０ｂを設置したものである。
【００２３】
本実施形態においても、ガスは整流器１１によって整流されるため、測定管９内を流通するガスの流れの乱れを減少させることができ、一対の超音波センサ１０ａ，１０ｂの流量測定点における流量を安定させることができ、計測精度を向上できる。
【００２４】
なお、前記各実施形態においては、計測流路に超音波センサを設け、超音波の伝搬速度の変化を検知してガス流量を計測するようにしたが、熱線センサを１個もしくは複数個設けた熱線式流量計、測定管に羽根車を配置したタービン式流量計においても適用できる。
【００２５】
【発明の効果】
以上説明したように、この発明によれば、計測流路の上流側から測定管に向かうガス及び測定管から下流側に向かうガスは整流器によって整流され、測定管内を流通するガスの流れの乱れを減少させることができる。従って、流量測定点における流量を安定させることができ、計測精度を向上できる。また、計測流路に整流用のメッシュ構造物を設ける必要がなく、異物の詰りによる流量の不安定を防止できる。
【図面の簡単な説明】
【図１】この発明の第１の実施形態を示し、（ａ）は流量計本体の縦断正面図、（ｂ）はＡ−Ａ線に沿う断面図。
【図２】同実施形態の変形例を示し、流量計本体の縦断側面図。
【図３】この発明の第２の実施形態を示し、（ａ）は流量計本体の縦断正面図、（ｂ）はＢ−Ｂ線に沿う断面図。
【図４】同実施形態の変形例を示し、流量計本体の縦断側面図。
【図５】この発明の第３の実施形態を示す流量計本体の縦断正面図。
【図６】従来の超音波メータを示し、（ａ）は流量計本体の縦断正面図、（ｂ）はＣ−Ｃ線に沿う断面図。
【図７】別の従来の超音波メータを示し、流量計本体の縦断側面図。
【符号の説明】
１…流量計本体
３ａ…ガス流入口
４ａ…ガス流出口
５…計測流路
９…測定管
１０ａ，１０ｂ…超音波センサ
１１…整流器
１２…整流板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flow meter that measures a gas flow rate of city gas, propane gas, or the like.
[0002]
[Prior art]
An ultrasonic gas meter as a general household gas meter has been developed. The ultrasonic gas meter is configured as shown in FIGS. 6A and 6B in order to provide compatibility with the pipe to which the existing membrane gas meter is attached.
[0003]
That is, an inlet metal 3 forming a gas inlet 3a and an outlet metal 4 forming a gas outlet 4a are provided at an upper portion of the flow meter main body 1 so as to be separated in the left-right direction. The measurement flow path 5 inside the flowmeter main body 1 is divided into an upstream side 7 and a downstream side 8 by a partition wall 6. Further, the partition 6 is provided with a measurement tube 9 which is opened on the upstream side 7 and the downstream side 8 so as to pass therethrough.
[0004]
The measuring tube 9 is a cylinder or a square tube, and the gas flowing from the gas inlet 3a to the upstream 7 flows through the inside of the measuring tube 9 to the downstream 8 and is guided to the gas outlet 4a. ing. Inside the measuring tube 9, a pair of ultrasonic sensors 10a and 10b composed of a transmission sensor and a reception sensor facing each other at an angle θ with respect to the direction of gas flow (direction of arrow a) are installed. Then, a change in the propagation speed of the ultrasonic wave is detected, the gas flow rate is measured, and the integrated flow rate is instructed to an integration instructing unit (not shown).
[0005]
FIG. 7 shows a configuration in which a pair of ultrasonic sensors 10a and 10b including a transmission sensor and a reception sensor are installed on the side walls of the upstream side 7 and the downstream side 8 of the flowmeter main body 1 so as to face the opening of the measurement pipe 9. is there.
[0006]
[Problems to be solved by the invention]
However, in the ultrasonic gas meter configured as described above, the gas flowing into the upstream side 7 of the measurement flow path 5 from the gas inlet 3 a bends at a substantially right angle from the periphery of the opening of the measurement pipe 9 and flows into the measurement pipe 9. I do. Therefore, the flow velocity distribution of the gas flowing through the inside of the measuring pipe 9 is disturbed, and the pressure fluctuation (pulsation) in the measuring pipe 9 is generated, which is a factor affecting the measurement accuracy.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a flow meter capable of reducing disturbance of a flow velocity distribution of a gas flowing in a measurement pipe and improving measurement accuracy. .
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a gas which flows from a gas supply side through a gas inlet into a measurement flow path of a flowmeter main body and is installed in the measurement flow path After measuring the gas flow rate by the gas flow outlet from the gas outlet to the gas demand side, in the measurement flow path, while providing a measurement pipe opening on the upstream and downstream thereof, at least upstream of the measurement pipe A rectifier in which a plurality of rectifying plates are radially arranged is provided.
[0009]
A second aspect of the present invention is characterized in that the straightening plate of the first aspect is provided such that an inner end thereof protrudes inward from an inner peripheral wall of the measuring tube.
[0010]
A third aspect of the present invention is characterized in that the straightening plate of the first aspect has an inner end portion fixed to an outer peripheral wall of the measurement tube.
[0011]
A fourth aspect of the present invention is characterized in that the instrument for measuring the gas flow rate according to the first aspect is any one of an ultrasonic sensor, a hot-wire sensor, and a turbine.
[0012]
According to the configuration, the gas flowing from the upstream side of the measurement flow path to the measurement pipe and the gas flowing from the measurement pipe to the downstream side are rectified by the rectifier, and the turbulence of the gas flowing through the measurement pipe can be reduced, The flow rate at the flow rate measurement point can be stabilized. Therefore, measurement accuracy can be improved.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0014]
1A and 1B show a first embodiment, in which FIG. 1A is a vertical sectional front view, and FIG. 1B is a cross-sectional view along the line AA. As shown in FIG. 1, a rectifier 11 for rectifying a gas flow is provided on an upstream side 7 and a downstream side 8 of a cylindrical measurement tube 9 provided in a measurement flow path 5 of a flowmeter main body 1 through a partition wall 6. Is provided. The same effect can be obtained even if the rectifier 11 is provided only on the upstream side 7 of the measuring tube 9.
[0015]
The rectifier 11 is configured by arranging a plurality of rectifying plates 12 radially at equal intervals with respect to the measuring tube 9. The current plate 12 is provided entirely between the opening edge of the measurement pipe 9 and the inner side walls 5 a on the upstream side 7 and the downstream side 8 of the measurement flow path 5. Further, the inner end 12 a of the current plate 12 is provided so as to protrude inward from the inner peripheral wall 9 a of the measuring tube 9.
[0016]
According to the flow meter thus configured, when gas flows into the upstream side 7 of the measurement flow path 5 from the gas inlet 3a, the gas passes between the rectifier plates 12 of the rectifier 11 and is rectified to be measured. Go to 9. Then, the gas flows inside the measuring pipe 9 toward the downstream side 8, where it is rectified again by the rectifier 11 and flows out from the gas outlet 3b.
[0017]
Therefore, the turbulence of the flow of the gas flowing through the measuring pipe 9 can be reduced, and the flow rate at the flow rate measurement point of the pair of ultrasonic sensors 10a and 10b composed of the transmission sensor and the reception sensor can be stabilized. Accuracy can be improved.
[0018]
FIG. 2 shows a modification of the first embodiment, in which rectifiers 11 are provided on the upstream side 7 and the downstream side 8 of a rectangular tube-shaped measuring tube 13, and the same operation and effect as in the first embodiment are obtained. is there.
[0019]
3A and 3B show a second embodiment, in which FIG. 3A is a vertical sectional front view, and FIG. 3B is a cross-sectional view along line BB. As shown in FIG. 3, a rectifier 11 for rectifying a gas flow is provided on an upstream side 7 and a downstream side 8 of a cylindrical measurement tube 9 provided in the measurement flow path 5 of the flowmeter main body 1 through the partition wall 6. Is provided.
[0020]
The rectifier 11 is configured by arranging a plurality of rectifying plates 12 radially at equal intervals with respect to the measuring tube 9. The current plate 12 is provided entirely between the opening edge of the measurement pipe 9 and the inner side walls 5 a on the upstream side 7 and the downstream side 8 of the measurement flow path 5. Further, the inner end 12a of the current plate 12 is fixed to the outer peripheral wall 9b of the measuring tube 9, and has the same operation and effect as in the first embodiment.
[0021]
FIG. 4 shows a modified example of the second embodiment, in which rectifiers 11 are provided on the upstream side 7 and the downstream side 8 of a rectangular cylindrical measuring tube 13, and the same operation and effect as in the second embodiment are obtained. is there.
[0022]
FIG. 5 shows a third embodiment, in which a sensor fixing part 14 is provided on the side walls of the upstream side 7 and the downstream side 8 of the measurement flow path 5 so as to face the opening of the measuring pipe 9. And a pair of ultrasonic sensors 10a and 10b including a receiving sensor and a receiving sensor.
[0023]
Also in the present embodiment, since the gas is rectified by the rectifier 11, the turbulence of the flow of the gas flowing in the measurement pipe 9 can be reduced, and the flow rate at the flow rate measurement point of the pair of ultrasonic sensors 10a and 10b can be reduced. It can be stabilized, and the measurement accuracy can be improved.
[0024]
In each of the above embodiments, an ultrasonic sensor is provided in the measurement channel, and a change in the propagation speed of the ultrasonic wave is detected to measure the gas flow rate. However, one or more heat ray sensors are provided. The present invention can also be applied to a hot-wire flow meter and a turbine flow meter having an impeller arranged in a measurement tube.
[0025]
【The invention's effect】
As described above, according to the present invention, the gas flowing from the upstream side of the measurement flow path to the measurement pipe and the gas flowing from the measurement pipe to the downstream side are rectified by the rectifier, and the turbulence of the flow of the gas flowing in the measurement pipe is reduced. Can be reduced. Therefore, the flow rate at the flow rate measurement point can be stabilized, and the measurement accuracy can be improved. Further, there is no need to provide a rectifying mesh structure in the measurement flow path, and it is possible to prevent flow rate instability due to clogging of foreign matter.
[Brief description of the drawings]
1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a longitudinal sectional front view of a flow meter main body, and FIG. 1B is a cross-sectional view taken along line AA.
FIG. 2 is a vertical sectional side view of a flow meter main body, showing a modification of the embodiment.
3A and 3B show a second embodiment of the present invention, in which FIG. 3A is a longitudinal sectional front view of a flow meter main body, and FIG. 3B is a sectional view taken along line BB.
FIG. 4 is a longitudinal sectional side view of a flow meter main body, showing a modification of the embodiment.
FIG. 5 is a vertical sectional front view of a flow meter main body showing a third embodiment of the present invention.
6A and 6B show a conventional ultrasonic meter, in which FIG. 6A is a vertical sectional front view of a flow meter main body, and FIG. 6B is a cross-sectional view taken along line CC.
FIG. 7 is a vertical sectional side view of a flow meter main body, showing another conventional ultrasonic meter.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Flow meter main body 3a ... Gas inlet 4a ... Gas outlet 5 ... Measurement flow path 9 ... Measurement tubes 10a and 10b ... Ultrasonic sensor 11 ... Rectifier 12 ... Rectifier plate

Claims

The gas flowing from the gas supply side via the gas inlet flows into the measurement flow path of the flow meter main body, and after measuring the gas flow rate by an instrument installed in the measurement flow path, the gas is guided from the gas outlet to the gas demand side. In the flow meter,
A flowmeter, wherein the measurement flow path is provided with a measurement pipe which is opened on the upstream side and the downstream side thereof, and a rectifier in which a plurality of rectifying plates are radially arranged at least on the upstream side of the measurement pipe. .

The flow meter according to claim 1, wherein the current plate has an inner end protruding inward from an inner peripheral wall of the measurement tube.

2. The flowmeter according to claim 1, wherein the current plate has an inner end fixed to an outer peripheral wall of the measurement tube.

The flow meter according to claim 1, wherein the instrument for measuring the gas flow rate is one of an ultrasonic sensor, a hot-wire sensor, and a turbine.