JPH05264307A - Electromagnetic flowmeter - Google Patents

Abstract

PURPOSE:To accurately measure the flow rate of a fluid to be measured even when a measuring pipe is not filled up with the fluid by arranging a cylindrical body made of a material having electric conductivity which is nearly equal to that of the fluid and provided with a plurality of through holes in the axial direction of the measuring pipe in the measuring pipe so that the cylindrical body can be brought into contact with electrodes. CONSTITUTION:In the title flowmeter 11, such a condition that a a measuring pipe 12 is filled up with a fluid to be measured can be created when a cylindrical body 15 made of a material having electric conductivity which is nearly equal to that of the fluid and provided with a plurality of through holes 14 in the axial direction of the pipe 12 is arranged in the pipe 12 so that the body 15 can be brought into contact with electrodes 13. Therefore, while the number of through holes 14 which are passed through by the fluid changes depending upon the level of the fluid, the flow rate of the fluid passing through each hole 14 accurately generates an interelectrode electromotive force due to the weight-function magnetic flux distribution of the flowmeter 11. As a result, an accurate flow rate indication can be obtained even when the pipe 12 is not filled up with the fluid to be measured.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、電磁流量計の非満管流
の測定に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to measurement of an unfilled flow of an electromagnetic flow meter.

【０００２】[0002]

【従来の技術】従来の電磁流量計では、図２（ａ）、
（ｂ）に示すように、測定流体が流れる測定管２２にお
いて流体が満水状態であるときのみ本来の測定性能を発
揮する。もし、流体が満水でない状態の場合、例えば、
満水水位Ａから電極２３が流体に接液する限界水位Ｂの
間では、電極２３が流体に接液する限界水位Ｂに下がる
に従って、電磁流量計２１の指示が実際の流量に比べて
大きく出ることが一般に知られている。2. Description of the Related Art In a conventional electromagnetic flowmeter, as shown in FIG.
As shown in (b), the original measuring performance is exhibited only when the fluid is full in the measuring pipe 22 through which the measuring fluid flows. If the fluid is not full, for example,
Between the full water level A and the limit water level B at which the electrode 23 comes into contact with the fluid, as the electrode 23 goes down to the limit water level B at which the electrode 23 comes into contact with the fluid, the indication of the electromagnetic flow meter 21 should be larger than the actual flow rate. Is generally known.

【０００３】また、限界水位Ｂよりも更に下がり、電極
２３が流体に接液しなくなると、もはや流量を測定する
ことは困難となる。When the electrode 23 does not come into contact with the fluid when the water level B drops below the limit water level B, it becomes difficult to measure the flow rate.

【０００４】実際に電磁流量計を設置する場所の配管状
態から満水状態にすることができない場合や、また、満
水状態にはできるがそれを実現するための配管に多大の
費用を要するといった場合には、電磁流量計本来の性能
の特徴である高精度な測定を行えなかったり、水位によ
っては測定不能になることがあった。[0004] In the case where the pipe condition at the place where the electromagnetic flow meter is actually installed cannot be filled with water, or when the pipe can be filled with water but a large amount of money is required for the pipe for realizing it. In some cases, the electromagnetic flowmeter could not perform high-precision measurement, which is a characteristic of the original performance of the electromagnetic flowmeter, or could not be measured depending on the water level.

【０００５】[0005]

【発明が解決しようとする課題】上記のように従来の技
術では、電磁流量計２１の測定管２２内の流体が満管状
態でない場合には、正確な流量測定が不可能であった。
そこで本発明は、たとえ測定管２２内の流体が満水状態
でなくても問題なく流量を正確に測定できる電磁流量計
を実現することを目的とする。As described above, according to the conventional technique, accurate measurement of the flow rate is impossible when the fluid in the measuring tube 22 of the electromagnetic flow meter 21 is not in a full state.
Therefore, an object of the present invention is to realize an electromagnetic flow meter that can accurately measure the flow rate without any problem even if the fluid in the measuring tube 22 is not in a full state.

【０００６】[0006]

【課題を解決するための手段】本発明の電磁流量計は、
測定管内に、測定する流体とほぼ同等の電気伝導度の材
料から成り測定管の軸線方向に複数の貫通穴が穿設され
た円柱体を電極と接触するように配置したことを特徴と
する。The electromagnetic flowmeter of the present invention comprises:
It is characterized in that a cylindrical body made of a material having substantially the same electric conductivity as that of the fluid to be measured and having a plurality of through holes formed in the axial direction of the measuring tube is arranged in contact with the electrode.

【０００７】[0007]

【作用】本発明の電磁流量計においては、測定管内に、
流体とほぼ同等の電気伝導度の材料から成り測定管の軸
線方向に複数の貫通穴が明いた円柱体を電極と接触する
ように配置したため、あたかも満水状態であるような条
件を作り出すことができる。したがって、水位によって
流体が通過する貫通穴は変るが、各穴を通過する流量
は、電磁流量計の重み関数磁束分布により正確に電極間
起電力として発生し、その結果、測定管内が満水状態で
なくても正確な流量指示が得られる。In the electromagnetic flowmeter of the present invention, the
Since a cylindrical body made of a material with almost the same electrical conductivity as the fluid and having multiple through holes in the axial direction of the measuring tube was placed in contact with the electrode, it is possible to create a condition as if it were full of water. . Therefore, the through hole through which the fluid passes changes depending on the water level, but the flow rate through each hole is accurately generated as an electromotive force between the electrodes due to the weight function magnetic flux distribution of the electromagnetic flow meter, and as a result, the inside of the measuring tube is full. An accurate flow rate indication can be obtained without it.

【０００８】[0008]

【実施例】以下、図面に示した実施例に基づいて本発明
を詳細に説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings.

【０００９】図１（ａ）、（ｂ）に本発明一実施例の電
磁流量計を示す。図示のように、従来と同様な電磁流量
計１１の測定管１２内に、測定する流体とほぼ同等の電
気伝導度の材料、例えば、導電性プラスチックス、導電
性セラミックス、または流体が浸み込むような多孔性材
料等から成り測定管１２の軸線方向に複数の貫通穴１４
が穿設された円柱体１５が、一対の電極１３と接触する
ように、測定管１２の全長にわたって配置されている。1 (a) and 1 (b) show an electromagnetic flowmeter according to an embodiment of the present invention. As shown in the figure, a material having substantially the same electric conductivity as the fluid to be measured, such as conductive plastics, conductive ceramics, or fluid, is immersed in the measuring tube 12 of the electromagnetic flowmeter 11 similar to the conventional one. A plurality of through holes 14 formed in the axial direction of the measuring tube 12 made of such a porous material.
A cylindrical body 15 having a hole is arranged over the entire length of the measuring tube 12 so as to come into contact with the pair of electrodes 13.

【００１０】上記のように構成された本発明一実施例の
電磁流量計の作用を以下に説明する。従来の電磁流量計
の磁束分布は、満水状態において測定管断面の各位置で
の流体の微小要素について電極間に発生する起電力に対
する寄与がその微小要素の断面積にほぼ比例するような
分布、すなわち、測定管中央部が強く、電極近辺が弱い
磁束分布を実現していて、いわゆる重み関数磁束分布と
なっている。すなわち、従来の電磁流量計は、測定管内
の流体が満水状態ならば、一部の断面要素の流体のみが
流れ、他の流体が停止していても、その断面要素の流量
を正確に測定することができる。The operation of the electromagnetic flowmeter according to the embodiment of the present invention constructed as described above will be described below. The magnetic flux distribution of the conventional electromagnetic flowmeter is such that the contribution to the electromotive force generated between the electrodes for the microelements of the fluid at each position of the cross section of the measuring tube in a full state is almost proportional to the cross-sectional area of the microelements. That is, the magnetic flux distribution is strong in the central portion of the measuring tube and weak in the vicinity of the electrodes, which is a so-called weighting function magnetic flux distribution. That is, the conventional electromagnetic flowmeter accurately measures the flow rate of the cross-sectional element when the fluid in the measuring tube is full and only the fluid of some cross-sectional elements flows and other fluids are stopped. be able to.

【００１１】本発明一実施例の電磁流量計１１において
は、測定管１２内に、流体とほぼ同等の電気伝導度の材
料から成り測定管１２の軸線方向に複数の貫通穴１４が
明いた円柱体１５を電極１３と接触するように配置した
ため、あたかも満水状態であるような条件を作り出すこ
とができる。したがって、水位によって流体が通過する
貫通穴１４は変るが、各貫通穴１４を通過する流量は、
電磁流量計１１の重み関数磁束分布により正確に電極間
起電力として発生し、その結果、測定管１２内が満水状
態でなくても正確な流量指示を得ることができる。In the electromagnetic flowmeter 11 according to one embodiment of the present invention, a cylinder made of a material having substantially the same electrical conductivity as a fluid and having a plurality of through holes 14 in the axial direction of the measurement tube 12 is formed in the measurement tube 12. Since the body 15 is arranged so as to be in contact with the electrode 13, it is possible to create a condition as if the body 15 is full of water. Therefore, although the through hole 14 through which the fluid passes changes depending on the water level, the flow rate through each through hole 14 is
Accurately generated as an inter-electrode electromotive force due to the weight function magnetic flux distribution of the electromagnetic flow meter 11, and as a result, an accurate flow rate instruction can be obtained even when the inside of the measurement tube 12 is not full of water.

【００１２】[0012]

【発明の効果】以上詳述したように本発明によれば、測
定管内に、測定する流体とほぼ同等の電気伝導度の材料
から成り測定管の軸線方向に複数の貫通穴が穿設された
円柱体を電極と接触するように配置したことを特徴とす
る電磁流量計を実現したことにより、測定管内があたか
も満水状態であるような条件を作り出すことができるた
め、水位によって流体が通過する貫通穴は変るが、各貫
通穴を通過する流量は、電磁流量計の重み関数磁束分布
により正確に電極間起電力として発生し、その結果、測
定管内が満水状態でない場合も正確に流量を測定でき
る。また、従来の電磁流量計に本発明にかかる円柱体を
測定管内に配置することで簡単に実現することができ、
既設の電磁流量計の活用が可能であるため、簡単且つ安
価に実現できる。As described in detail above, according to the present invention, a plurality of through holes are formed in the measuring tube in the axial direction of the measuring tube, which is made of a material having an electric conductivity substantially equal to that of the fluid to be measured. By realizing an electromagnetic flow meter characterized by arranging a cylindrical body so as to contact the electrode, it is possible to create a condition that the inside of the measuring tube is full of water. Although the hole changes, the flow rate passing through each through-hole is accurately generated as an electromotive force between the electrodes due to the magnetic flux distribution of the electromagnetic flow meter, and as a result, the flow rate can be accurately measured even when the inside of the measuring tube is not full of water. . Further, it can be easily realized by arranging the cylindrical body according to the present invention in the measuring pipe in the conventional electromagnetic flowmeter,
Since the existing electromagnetic flowmeter can be used, it can be realized easily and inexpensively.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明一実施例の電磁流量計を示し、図１
（ａ）は測定管軸を含む断面図であり、図１（ｂ）は電
極を含み測定管軸に直角な断面図である。1 shows an electromagnetic flow meter according to an embodiment of the present invention, and FIG.
1A is a cross-sectional view including the measurement tube axis, and FIG. 1B is a cross-sectional view including electrodes and perpendicular to the measurement tube axis.

【図２】従来の電磁流量計を示し、図２（ａ）は測定管
軸を含む断面図であり、図２（ｂ）は電極を含み測定管
軸に直角な断面図である。FIG. 2 shows a conventional electromagnetic flow meter, FIG. 2 (a) is a cross-sectional view including a measuring tube axis, and FIG. 2 (b) is a cross-sectional view including electrodes and being perpendicular to the measuring tube axis.

【符号の説明】[Explanation of symbols]

１１…電磁流量計 １２…測定管 １３…電極 １４…貫通穴 １５…円柱体 11 ... Electromagnetic flowmeter 12 ... Measuring tube 13 ... Electrode 14 ... Through hole 15 ... Cylindrical body

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 測定管内に、測定する流体とほぼ同等の
電気伝導度の材料から成り測定管の軸線方向に複数の貫
通穴が穿設された円柱体を電極と接触するように配置し
たことを特徴とする電磁流量計。1. A cylindrical body, which is made of a material having substantially the same electric conductivity as that of a fluid to be measured and has a plurality of through holes in the axial direction of the measuring tube, is arranged in contact with the electrode. An electromagnetic flow meter characterized by. 【請求項２】 円柱体が導電性プラスチックスから成る
ことを特徴とする請求項１記載の電磁流量計。2. The electromagnetic flowmeter according to claim 1, wherein the cylindrical body is made of conductive plastics. 【請求項３】 円柱体が導電性セラミックスから成るこ
とを特徴とする請求項１記載の電磁流量計。3. The electromagnetic flowmeter according to claim 1, wherein the cylindrical body is made of conductive ceramics. 【請求項４】 円柱体が多孔性材料から成ることを特徴
とする請求項１記載の電磁流量計。4. The electromagnetic flowmeter according to claim 1, wherein the cylindrical body is made of a porous material.