JPS6135310A - Vortex flowmeter - Google Patents
Vortex flowmeterInfo
- Publication number
- JPS6135310A JPS6135310A JP15702684A JP15702684A JPS6135310A JP S6135310 A JPS6135310 A JP S6135310A JP 15702684 A JP15702684 A JP 15702684A JP 15702684 A JP15702684 A JP 15702684A JP S6135310 A JPS6135310 A JP S6135310A
- Authority
- JP
- Japan
- Prior art keywords
- vortex
- ultrasonic wave
- transmitting means
- reflected
- load impedance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
- G01F1/32—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
- G01F1/325—Means for detecting quantities used as proxy variables for swirl
- G01F1/3282—Means for detecting quantities used as proxy variables for swirl for detecting variations in infrasonic, sonic or ultrasonic waves, due to modulation by passing through the swirling fluid
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明はカルマン渦を利用した流量計の超音波を利用し
た渦検出手段に関す石。[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a vortex detection means using ultrasonic waves in a flowmeter using Karman vortices.
〈従来技術〉
カル１ン渦を利用した流量計の渦検出手段としては種々
のものが提案され実用化されているが、可動部を有しな
い手段の一つとして超音波を用いたものがある。第５図
は従来の超音波による渦検出手段の機会を示す流量計の
断面図であわ、１は流体Ｆが流れる測定管路、２はこの
管路内にＰの方向と直角方向に固定された断面か゛台形
の棒状の渦発生体で、その下流に渦３が生じる。この渦
の周波数ｆは流速Ｖと比例関係にオシ、
ｉ＝Ｖ・ｓ、／ｄ （１）で
表わされる。ここで８ｔは比例定数（ストローノ・ル数
）、ｄは渦発生体の幅である。この渦の周波数を検出す
る手段として渦発生体２の下流側の管路壁に超音波送波
器４．受波器５を対向配置させて連続的に超音波信号６
を発信及び受信させる。<Prior art> Various methods have been proposed and put into practical use as means for detecting vortices in flowmeters that utilize Curl 1 vortices, but one method that does not have moving parts is one that uses ultrasonic waves. . FIG. 5 is a cross-sectional view of a flowmeter showing the possibility of a conventional ultrasonic vortex detection means, in which 1 is a measurement pipe through which fluid F flows, and 2 is fixed in this pipe in a direction perpendicular to the direction of P. It is a rod-shaped vortex generator with a trapezoidal cross section, and a vortex 3 is generated downstream of it. The frequency f of this vortex is proportional to the flow velocity V, and is expressed as: i=V·s,/d (1). Here, 8t is a proportionality constant (Stronle number), and d is the width of the vortex generator. As a means for detecting the frequency of this vortex, an ultrasonic wave transmitter 4. The ultrasonic signals 6 are continuously transmitted by placing the receivers 5 facing each other.
send and receive.
渦の通過によって受信波の振幅が変調されることによっ
て渦の通過を検出することが可能である。The passage of the vortex can be detected by modulating the amplitude of the received wave due to the passage of the vortex.
このような検出手段の問題点は、
（１）渦発生体と検出手段とが分離した形となっている
ため、構造が複雑になる。Problems with such a detection means are as follows: (1) Since the vortex generator and the detection means are separated, the structure becomes complicated.
（２）管路を介しての漏洩音波による結合が大牲く、連
続波を用いる検出方式では、密度の小さいガス等では測
定が困難となる。(2) Coupling due to leakage sound waves through pipes is severely compromised, and detection methods using continuous waves have difficulty measuring gases with low density.
等があり、簡素な構成で検出感度の高いものが実現困難
士あった。etc., and it was difficult to realize something with a simple configuration and high detection sensitivity.
〈発明が解決しようとする問題点〉
本発明の目的は、渦発生体と一体に超音波による検出手
段を形成すると共に検出感度も高くとれる渦流量計を実
現することにある。<Problems to be Solved by the Invention> An object of the present invention is to realize a vortex flow meter in which an ultrasonic detection means is formed integrally with a vortex generating body and the detection sensitivity is also high.
〈問題点を解決するための手段〉
本発明の構成上の特徴は、渦発生体内に設けられた下流
側への超音波送信手段と、渦による音響インピーダンス
変化によって反射される超音波を上記送信手段の負荷イ
ンピーダンス変化に基づいて検出する手段とを具備せし
めた点にある。<Means for Solving the Problems> The structural features of the present invention include an ultrasonic wave transmitting means provided in the vortex generator to the downstream side, and a means for transmitting the ultrasonic waves reflected by the change in acoustic impedance caused by the vortex. and means for detecting based on a change in load impedance of the means.
〈作用〉
渦による反射音波により音響インピーダンスが変化し、
このインピーダンス変化により送信手段の負荷インピー
ダンスが変化するので、この変化を励振信号の振幅変化
として検出することが出来る０
〈実施例〉
以下図面により本発明の渦検出の原理及び基本構成につ
き説明する。第１図において７は渦発生体２の下流側に
一体に形成された超音波送信手段であり、下流側に発生
する渦３に対して超音波６を連続的に放射する。第２図
は渦３の流れ方向の圧力分布を示す図であり、渦の中心
Ａ点の圧力はその周囲に比較して低くなっている。Ａ点
より距離層のＢとの圧力差Ｐ。は、
Ｐｏ−−！−Ｐ１・ａ・ωｏ（２）
ψ
で表わされる。ここでρ１は渦のないところでの流体の
密度、ω０はＢ点における渦の角速度である。<Effect> Acoustic impedance changes due to sound waves reflected by the vortex,
Since the load impedance of the transmitting means changes due to this change in impedance, this change can be detected as a change in the amplitude of the excitation signal.<Embodiment> The principle and basic configuration of vortex detection of the present invention will be explained below with reference to the drawings. In FIG. 1, reference numeral 7 denotes an ultrasonic transmitting means integrally formed on the downstream side of the vortex generating body 2, and continuously emits ultrasonic waves 6 to the vortex 3 generated on the downstream side. FIG. 2 is a diagram showing the pressure distribution in the flow direction of the vortex 3, and the pressure at the center point A of the vortex is lower than that around it. Pressure difference P between point A and distance layer B. Ha, Po--! −P1・a・ωo(2) It is expressed as ψ. Here, ρ1 is the density of the fluid where there is no vortex, and ω0 is the angular velocity of the vortex at point B.
すなわち、圧縮性流体の場合は渦の部分で密度が変化□
していることになり、超音波の反射が生じる。In other words, in the case of a compressible fluid, the density changes at the vortex □
This means that ultrasonic waves are reflected.
奇禍への入射波の音圧を町１反射波の音圧をｐ。The sound pressure of the incident wave on the strange land is p. The sound pressure of the reflected wave is p.
とするとき、
々る関係が成立する。ここでｚｌ、ｚ２は夫々、Ｚ、−
ＰｌＣｌ（４）
ｚ２＝ρ２Ｃ２（５）
で表わされ、ｚｌは渦のないところでの音響インピーダ
ンス、Ｚ２は渦のあるところでの音響インピーダンスで
あり、Ｐ１＃ρ２は渦のないところ及び渦の発生してい
るところでの流体密度、Ｃは音速を表わす。When , the following relationship holds true. Here, zl and z2 are respectively Z, -
PlCl(4) z2=ρ2C2(5) where zl is the acoustic impedance where there is no vortex, Z2 is the acoustic impedance where there is a vortex, and P1#ρ2 is the acoustic impedance where there is no vortex and where the vortex is generated. C represents the speed of sound.
従って反射波Ｐｒの変化によって送信手段側から見た負
荷インピーダンスは変化する。送信手段の振動子を共振
付近で小信号で励振したときの負荷インピーダンス２の
等価回路は第３区に示すごとく、振動子の容量ｃｄに対
して並列に振動子の損失分ＲＤｏ振動子の制動及び媒質
による損失分子Ｌ１．渦によって生ずる反射の損失分Δ
Ｒの直列回路が接尾４図は負荷インピーダンス２の変化
を励振信号の振幅変化として電気的に取出すための基本
構成を示す。８は一定振幅の励振信号を送信手段７に供
給するための交流発振手段、Ｒはこの交流発振手段と送
信手段との間に接続された一定の負荷抵抗で、接続点Ｃ
の電圧ｅｃが送信手段の負荷インピーダンス２の渦によ
る変化によシ振幅変調される。９はこの信号ｅｃの処理
回路、１０け検波回路であり、ｅＣのエンベロープ信号
ｅ０を取出し、渦の局周波数を検出する。Therefore, the load impedance seen from the transmitting means side changes depending on the change in the reflected wave Pr. When the transducer of the transmitting means is excited with a small signal near resonance, the equivalent circuit of load impedance 2 is as shown in the third section. and the loss molecule L1 due to the medium. Reflection loss caused by vortices Δ
Figure 4 shows a basic configuration for electrically extracting changes in the load impedance 2 as changes in the amplitude of the excitation signal. 8 is an AC oscillating means for supplying an excitation signal of constant amplitude to the transmitting means 7, R is a constant load resistance connected between this AC oscillating means and the transmitting means, and connection point C
The voltage ec is amplitude modulated by the eddy-induced change in the load impedance 2 of the transmitting means. 9 is a processing circuit for this signal ec, a 10-digit detection circuit, which takes out the envelope signal e0 of eC and detects the local frequency of the vortex.
〈効果〉
以上説明したように、本発明によれば、超音波による渦
の検出手段を渦発生体と一体に、かつ、本質的に送信手
段のみで構成とすることがでれるので、構造が簡単で渦
流量計の設計が容易となる。<Effects> As explained above, according to the present invention, the ultrasonic vortex detection means can be integrated with the vortex generator and essentially consist only of the transmitting means, so the structure can be reduced. It is simple and the design of the vortex flow meter becomes easy.
更に管路を介しての漏洩による結合も本質的に発生しな
いので、密度の小さいガス等の測定も可能である。Furthermore, since coupling due to leakage through pipes essentially does not occur, it is also possible to measure gases with low density.
第１図は本発明の原理構成図、第２図は渦の圧力分布に
関する説明図、第３図は送信手段の等価負荷インピーダ
ンスの回路図、第４図は本発明における渦の周波数検出
手段の一例を示すブロック図、第５図は従来の超音波に
よる渦検出手段を有する流量計の構成例を示す縦断面図
である。
１・・・管路、２・・・渦発生体、３・・・渦、７・・
・送信手段、８・・・交流発振手段、９・・・信号処理
回路、１０・・・検波回路、Ｆ・・・被測定流体。Fig. 1 is a diagram showing the principle configuration of the present invention, Fig. 2 is an explanatory diagram regarding the pressure distribution of the vortex, Fig. 3 is a circuit diagram of the equivalent load impedance of the transmitting means, and Fig. 4 is a diagram of the vortex frequency detection means in the present invention. FIG. 5 is a block diagram showing an example. FIG. 5 is a longitudinal cross-sectional view showing an example of the configuration of a flowmeter having a conventional ultrasonic vortex detection means. 1... Pipeline, 2... Vortex generator, 3... Vortex, 7...
- Transmission means, 8... AC oscillation means, 9... Signal processing circuit, 10... Detection circuit, F... Fluid to be measured.
Claims (1)
渦による音響インピーダンス変化によって反射される超
音波を上記送信手段の負荷インピーダンス変化に基づい
て検出する手段とを具備した渦流量計。Ultrasonic transmission means provided in the vortex generator to the downstream side;
A vortex flowmeter comprising means for detecting ultrasonic waves reflected by a change in acoustic impedance caused by the vortex based on a change in load impedance of the transmitting means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15702684A JPS6135310A (en) | 1984-07-27 | 1984-07-27 | Vortex flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15702684A JPS6135310A (en) | 1984-07-27 | 1984-07-27 | Vortex flowmeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6135310A true JPS6135310A (en) | 1986-02-19 |
Family
ID=15640558
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15702684A Pending JPS6135310A (en) | 1984-07-27 | 1984-07-27 | Vortex flowmeter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6135310A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6153517A (en) * | 1984-08-24 | 1986-03-17 | Oval Eng Co Ltd | Flow speed or flow amount meter |
| JPH04262092A (en) * | 1991-02-18 | 1992-09-17 | Kubota Corp | Operating method for pump |
-
1984
- 1984-07-27 JP JP15702684A patent/JPS6135310A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6153517A (en) * | 1984-08-24 | 1986-03-17 | Oval Eng Co Ltd | Flow speed or flow amount meter |
| JPH0564283B2 (en) * | 1984-08-24 | 1993-09-14 | Oval Eng Co Ltd | |
| JPH04262092A (en) * | 1991-02-18 | 1992-09-17 | Kubota Corp | Operating method for pump |
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