JPS58172515A - Detector for electromagnetic flowmeter - Google Patents

Abstract

PURPOSE:To obtain a detector of an electromagnetic flowmeter which has the effect of preventing the leak of liquid and has an electrode being hardly soiled, by forming the head of the electrode to be conical and by lining the inside of a conduit so as to cover the electrode with the top of the cone exposed. CONSTITUTION:The head of an electrode 14 is formed to be conical, the electrode surface thereof is covered with lining 22 with the top of the conical head exposed, and the electrode thus formed is fixed to a conduit 10 by screws 28 through the intermediary of an electrode fixing seat 26. When the pressure F of a fluid is applied to the part of the electrode, a component F1 of the pressure acts as a force pressing the lining 22 covering the conical head of the electrode against the electrode 14, and thereby the leak of liquid can be prevented. Since the prevention of the leak of liquid between the electrode and the lining is effected by utilizing the pressure of the fluid to be measured itself, the effect of the prevention is increased with an increase in the pressure of the fluid. The conical shape of the head of the electrode increases the height of the projection thereof into the conduit for securing a necessary area wherein the electrode is in contact with the fluid. This makes the electrode hardly soiled and enables the provision thereof with a self-cleaning function.

Description

【発明の詳細な説明】 本発明は、電磁流量計検出ｆｓＫＩす、特に液洩れ防止
効果に優れた電極を有する電磁流置針検出器に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic flow meter detection fsKI, and particularly to an electromagnetic flow pointer detector having an electrode having an excellent effect of preventing liquid leakage.

電磁流置針検出器の電極は、流体を流す導管の内部から
導管に取付けらｎる内挿形と、導管の外部から取付けら
れる外挿形とく部分される。−万、導管の内ＴｊＢＫは
ライニングが施され、電極はこのライニングの表面より
若干突出するように設けられ、かつライニングに強固に
押し付けられてライニングとの間からの液洩れを防止す
るように構成されている。Electrodes of electromagnetic flow needle detectors can be of an internal type, which is attached to the conduit through which the fluid flows, or of an external type, which is attached from the outside of the conduit. - TjBK inside the conduit is lined, and the electrode is provided so as to slightly protrude from the surface of this lining, and is configured to be firmly pressed against the lining to prevent liquid leakage from between it and the lining. has been done.

しかるに、所定の防水効果を得るために、ライニングに
はライニングの弾性域を越える荷重が加えられることが
多々あり、ライニングが塑性変形を起こすことになる。However, in order to obtain a predetermined waterproof effect, a load exceeding the elastic range of the lining is often applied to the lining, resulting in plastic deformation of the lining.

この結果、電極交換を行った際には、新しい電極と塑性
変形したライニングとの緊密性が低下し、所定の防水効
果を得ることは極めて困難であった。As a result, when replacing the electrodes, the tightness between the new electrodes and the plastically deformed lining deteriorates, making it extremely difficult to obtain a desired waterproof effect.

また、電極の導管内に突出する部分は一般に円筒状にな
っており、電極への汚れが付き易いという間＠を有して
いる。Furthermore, the portion of the electrode that protrudes into the conduit is generally cylindrical and has a gap that makes it easy for the electrode to become contaminated.

本発明の目的は、上記した従来技術の欠点をなくシ、液
洩れ防止効果並びに汚れの付Ｉ！離い電極を備え九電磁
流量針検出器を提供するにある。The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to improve the effect of preventing liquid leakage and preventing staining. There are nine electromagnetic flow needle detectors equipped with separate electrodes.

上記目的を達成すべく本発明は、電極の頭部を円錐形と
し、円錐形の途中から電ＶＬｔ包み込むように導管の内
面にライニングを施すようＫした−のである。この結果
、ライニングｒｉ流体の分圧によって電極の円錐面に押
されることＫより、ライニングＫｌｉ状変形を起こさせ
ずにシール効果を向上せしめることができる。また、電
極の頭部が円錐形に形成されているため、汚れが付きに
くく、かつ付着して一流体による洗浄効果を大きくする
ことができる。In order to achieve the above object, the present invention makes the head of the electrode conical, and applies a lining to the inner surface of the conduit so as to enclose the electric current VLt from the middle of the conical shape. As a result, since the lining is pressed against the conical surface of the electrode by the partial pressure of the lining fluid, the sealing effect can be improved without causing the lining to undergo Kli-like deformation. Further, since the head of the electrode is formed into a conical shape, it is difficult for dirt to adhere to the electrode, and the cleaning effect of the fluid can be increased.

以下、本発明の一実施例を図面に基づいて説明する。Hereinafter, one embodiment of the present invention will be described based on the drawings.

第１図は、電磁流量計検出器の全体構成を示す断面図で
ある。電磁流量計検出ａＦｉ、測定流体を流す導管１０
．導管１０の外側よｐ導管１０に磁界をかける励磁コイ
ル１２、磁界と流体の流れ方向に各々画直となる位置に
取付けられた一対の電極１４、磁束の帰路となる鉄心１
６、これらを包み込み固定するパイプ１８、充填剤２０
、導管１０の内面を絶縁するためのライニング２２、測
定流体の接地をとるアースリング２４とから構成されて
いる。FIG. 1 is a sectional view showing the overall configuration of an electromagnetic flowmeter detector. Electromagnetic flowmeter detection aFi, conduit 10 through which the measured fluid flows
．． An excitation coil 12 that applies a magnetic field to the conduit 10 from the outside of the conduit 10, a pair of electrodes 14 installed at positions perpendicular to the magnetic field and the flow direction of the fluid, and an iron core 1 that serves as a return path for magnetic flux.
6. Pipe 18 and filler 20 to wrap and fix these
, a lining 22 for insulating the inner surface of the conduit 10, and a grounding ring 24 for grounding the fluid to be measured.

ここで、電磁流量計検出器の電極は、測定流体の流速に
比例した起電力を検出すると共に、測定流体の液洩れ防
止を行うという２つの機ａｔ−持つていなければならな
い。Here, the electrodes of the electromagnetic flowmeter detector must have two functions: detecting an electromotive force proportional to the flow velocity of the fluid to be measured, and preventing leakage of the fluid to be measured.

票２図は、電極取付部を示す拡大断面図である。Figure 2 is an enlarged sectional view showing the electrode attachment part.

図において、電４ｊ１４は、１１１部が円錐形に形成さ
れ、その途中からライニング２２で電極面を包み込まれ
、導管１０に電極固定座２６１：介してねじ２８にて固
定される。この結果、電極部に流体の圧力Ｆが加わると
、その分力Ｆ、が円錐形の電極ｄｔ−包み込んでいるラ
イニ／グ２２ｔ−電極１４に押し付ける力として作用す
ることＫなり、液洩れ防止を行うことができる。すなわ
ち本発明は、測定流体自身の圧力を利用して電極とライ
ニングとの間の液洩れ防止を行うものである。し九がっ
て、液洩れ防止効果は、８１１１足流体の圧力が高い程
効果がある。In the figure, the electrode 4j14 has a conical portion 111, the electrode surface is wrapped with a lining 22 from the middle, and is fixed to the conduit 10 via an electrode fixing seat 261 with a screw 28. As a result, when the fluid pressure F is applied to the electrode part, the component force F acts as a pressing force against the conical electrode dt, the liner 22t surrounding the electrode 14, and prevents liquid leakage. It can be carried out. That is, the present invention uses the pressure of the measurement fluid itself to prevent liquid leakage between the electrode and the lining. Therefore, the higher the pressure of the 8111 foot fluid, the more effective the leakage prevention effect becomes.

また、電極の頭部を円錐形とすることは、必要とされる
接液面積を確保するためには、必然的に導管内への突出
高さが大きくなる。このことは、電極に汚れが付ＩＫ＜
　＜、かつ自己洗浄機能ももたせることができる。こｎ
を、電磁流量針の概略構成図を示す第３図、その等価回
路である第４図、　　′および導管内の流速分布を示す
第５図を用いて説明する。Further, when the head of the electrode is made conical, the height of the electrode protruding into the conduit inevitably increases in order to secure the necessary liquid contact area. This means that if the electrode is contaminated, IK<
< and can also have a self-cleaning function. Kon
will be explained using FIG. 3 showing a schematic diagram of the electromagnetic flow needle, FIGS. 4 and 4' showing its equivalent circuit, and FIG. 5 showing the flow velocity distribution in the conduit.

変換器３０の入力電圧ｅｔμ、（１）式で我わさｒる。The input voltage etμ of the converter 30 is expressed by equation (1).

＆１ ここで、Ｃ０：流速に比例した起電力 ｒ、：信号源インピーダンス ”Ｉ　：ｉ換器の入力インピーダンス 流量信号（起電力）が検出器から変換器３０に誤差なし
で伝送するためには、初期状態の８にｅ。&1 Here, C0: Electromotive force r proportional to the flow velocity,: Signal source impedance "I: Input impedance of the i converter In order for the flow rate signal (electromotive force) to be transmitted from the detector to the converter 30 without error, e to the initial state of 8.

となるよう（２）式の関係が必要−セある。The relationship of equation (2) is necessary so that

−キ０　　　　　　　　　　　・・・・・・・・・（２
）２− しかし、実際には、ｚ亀は有限のインビーダンは、流量
測定中、電極表面に付着物（特に絶縁性付着物）が付い
てくると、徐々に大きくなり、（２）式の関係が崩れる
ため、計器のスパン誤差が生じてくる。ここでｒ、は、
（３）式で表わされる。-Ki0 ・・・・・・・・・(2
)2- However, in reality, the z turtle is a finite impedance that gradually increases as deposits (especially insulating deposits) adhere to the electrode surface during flow rate measurement, and the relationship in equation (2) This causes a span error in the instrument. Here, r is
It is expressed by equation (3).

・・・・・・・・・（３） σ・ｄ ここで、σ；測定流体の導電率 ｄ；電極の接液面積 即ち、流体の導電率が一定であれば、電極の接液面積が
大きいほど（２）弐に近づく。しかし、接液面積ｄが大
きすぎると信号が短絡される丸め、電極の１ｉＩ！液面
積は検出器の口径ととに決定される。・・・・・・・・・(3) σ・d Here, σ: Electrical conductivity of the measuring fluid d: The contact area of the electrode, that is, if the conductivity of the fluid is constant, the contact area of the electrode is The larger it is (2), the closer it is to Ni. However, if the contact area d is too large, the signal will be short-circuited, and the electrode's 1iI! The liquid area is determined by the aperture of the detector.

この電極表面への付着物が付＜ｌＬ＆は、＠５図に示す
如く、粘性のある流体が検出器のライ；ング内面に密接
した部分Ｏ流れは、乱流、層流に＠らず流速ＵキＯとな
り、流れが停滞して付着するものである。This deposit on the electrode surface is caused by the fact that, as shown in Figure 5, the flow is turbulent, laminar, and not turbulent or laminar. The flow becomes stagnant and adheres to the surface.

したがって、電極汚れの影響がないか、あるいは影響を
少なくするためには、電極の５ｒｎｔ−円錐形に一形成
し、接液面積を一定にしたまま導管内への突出高さｈを
大きくすることにより可能となる。Therefore, in order to eliminate or reduce the influence of electrode contamination, it is necessary to form the electrode into a conical shape and increase the protrusion height h into the conduit while keeping the liquid contact area constant. This becomes possible.

第６図は電極の他の実施例を示すものである。FIG. 6 shows another embodiment of the electrode.

すなわち、電極を本体部分１４Ａと測定流体く直接接触
する接液部分１４Ｂとから構成したものである。このよ
うに構成すると、測定流体の種類が変っても接液部分１
４Ｂだけを変えれば対厄できるとともに、摩耗等による
交替に際しても接液部分３４だけを変えれば対厄できる
。That is, the electrode is composed of a main body portion 14A and a liquid contact portion 14B that comes into direct contact with the measuring fluid. With this configuration, even if the type of fluid to be measured changes, the wetted part 1
This problem can be avoided by changing only 4B, and even when replacing due to wear etc., by changing only the liquid contact part 34.

以上本発明によれば、電極の頭部を円錐形に形成し九こ
とにより、電極とライニングとの間の防水ｔ−測定流体
自身の圧力を利用して行うことができ、ライニングに塑
状変形を起こさせることが防止できる。また、導管内へ
の電極の突出高さを大きくできるため、測定流体による
電極の洗浄が可能となり、汚れにくい電極を得ることが
できる。As described above, according to the present invention, by forming the head of the electrode into a conical shape, waterproofing between the electrode and the lining can be carried out using the pressure of the measuring fluid itself, causing plastic deformation in the lining. can be prevented from occurring. Furthermore, since the height of the electrode protrusion into the conduit can be increased, the electrode can be cleaned with the measurement fluid, and an electrode that is less likely to become dirty can be obtained.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は電磁流量計検出器の全体構成断面図、第２図は
本発明になる電極を備え九電極取付部の拡大断面図、第
３図に電磁流置針の概略構成図、１１１４図は第３図の
等価回路図、第６図は導管内の流速分布を示す図、第６
図は電極の他Ｏ実施ｆｉｌｌ示す図である。 １０・・・導管、１２・・・励磁コイル、１４・・・電
極、１６・・・鉄心、１８・・・パイプ、２０・・・充
填剤、２２−５４　＝　７グ・　　　　　　　　　　　
　　　　、・、　−ｊ−５代理人　弁理士　高磯明、＊
２二♂°。 ７、−Ｉ 子　１　図 第　２　図Fig. 1 is a sectional view of the overall configuration of an electromagnetic flow meter detector, Fig. 2 is an enlarged sectional view of a nine-electrode mounting part equipped with electrodes according to the present invention, Fig. 3 is a schematic configuration diagram of an electromagnetic flow pointer, and Fig. Figure 3 is an equivalent circuit diagram, Figure 6 is a diagram showing the flow velocity distribution in the conduit, Figure 6 is a diagram showing the flow velocity distribution in the conduit,
The figure shows the O fill in addition to the electrodes. DESCRIPTION OF SYMBOLS 10... Conduit, 12... Excitation coil, 14... Electrode, 16... Iron core, 18... Pipe, 20... Filler, 22-54 = 7g.
,・, −j-5 agent Patent attorney Akira Takaiso, *
22♂°. 7, -I Child 1 Figure 2

Claims (1)

【特許請求の範囲】[Claims] １、測定流体を流す導管、この導管に前記流体の流れ方
向と直交する磁界を発生させる磁界発生装置、前記流体
の流れと磁界とに各々直角で対向して設けられ九七の頭
部が円錐形に形成された一対の電極、この電極の頭部の
一部を包み込む如く前記導管の内面に施され九ライニン
グとより構成したことｔ−特徴とする電磁流置針検出器
。1. A conduit through which the fluid to be measured flows, a magnetic field generating device that generates a magnetic field perpendicular to the flow direction of the fluid in this conduit, and a conduit with a conical head provided at right angles to the flow of the fluid and the magnetic field. 1. An electromagnetic flow needle detector comprising: a pair of shaped electrodes; and a lining provided on the inner surface of the conduit so as to enclose a part of the head of the electrode.