JPS6161008A - Differential pressure generator - Google Patents
Differential pressure generatorInfo
- Publication number
- JPS6161008A JPS6161008A JP59184206A JP18420684A JPS6161008A JP S6161008 A JPS6161008 A JP S6161008A JP 59184206 A JP59184206 A JP 59184206A JP 18420684 A JP18420684 A JP 18420684A JP S6161008 A JPS6161008 A JP S6161008A
- Authority
- JP
- Japan
- Prior art keywords
- differential pressure
- pressure generator
- scale
- flow rate
- base material
- 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.)
- Granted
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
- G01F1/34—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 measuring pressure or differential pressure
- G01F1/36—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 measuring pressure or differential pressure the pressure or differential pressure being created by the use of flow constriction
- G01F1/40—Details of construction of the flow constriction devices
- G01F1/42—Orifices or nozzles
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Volume Flow (AREA)
- Monitoring And Testing Of Nuclear Reactors (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、流量計測における差圧発生器に係り特に高温
高圧水の流量計測を必要とするボイラあるいは原子炉ま
わりの給水、スプレ水、再循環水の計測に好適な差圧発
生器に関する。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a differential pressure generator for flow measurement, and is particularly applicable to feed water, spray water, and recirculation around boilers or nuclear reactors that require flow measurement of high-temperature, high-pressure water. This invention relates to a differential pressure generator suitable for measuring water.
従来、給水系などの流量計測の為には絞り機構を有する
差圧発生器を用いている。この差圧発生器は例えば材質
は5O8304で構成していた為酸化鉄のイオン化から
生ずる電気的現象による差圧発生器へのスケール付着が
避けられず、開口面積、開口形状の変化による流量計測
への誤差が生じるといった問題があった。Conventionally, a differential pressure generator with a throttle mechanism has been used to measure the flow rate of water supply systems, etc. For example, since this differential pressure generator was made of 5O8304, scale adhesion to the differential pressure generator due to electrical phenomena caused by ionization of iron oxide was unavoidable, and flow rate measurement due to changes in opening area and opening shape was inevitable. There was a problem that an error occurred.
しかしながら、スケール付着は知られてはいても、その
原因がイオン化鉄にあることについて言及した論文等は
皆無といってよい状況であった。However, although scale adhesion is known, there are no papers that mention that the cause is ionized iron.
本発明の目的は、スケールの付着を無くシ、流量に対す
る正しい差圧を発生する差圧発生器を実現することによ
り、正確な流量計測を行なう計測器を提供することにあ
る。SUMMARY OF THE INVENTION An object of the present invention is to provide a measuring instrument that accurately measures a flow rate by realizing a differential pressure generator that generates a correct differential pressure with respect to the flow rate while eliminating scale adhesion.
スケールの付着は、流体中のイオンが差圧発生器の金属
表面電位の作用で引き付けられ、付着するということが
判った。ここに着目して、本発明では差圧発生器自体を
絶縁物にすることにより付着を防ぐことができる。本発
明は金属表面に、絶縁性のセラミックをコーティングま
たは蒸着することにより例えば実現できる。It has been found that scale adhesion is caused by ions in the fluid being attracted by the metal surface potential of the differential pressure generator. Focusing on this, in the present invention, adhesion can be prevented by making the differential pressure generator itself an insulator. The present invention can be realized, for example, by coating or vapor depositing an insulating ceramic on a metal surface.
本発明の実施例を第1図に示す。差圧発生器としては一
般罠、同図(a)のオリフィスプレート1、同図伽)の
フローノズル2、同図(C)のベンチュリ10などがあ
げられるがいずれもボイラの給水流量計などではスケー
ルの付着が認められる。このスケールの付着は、流体と
接する差圧発生器の金属表面の電位と、流体中のイオン
化されたスケール成分の電気的相互作用であるというこ
とが新たに判った。この電気的相互作用を排除するため
、本発明ではオリフィスプレートやフローノズルに対し
、絶縁物で表面を構成する。例えば、第1図の斜線部を
絶縁物とするこの絶縁物で表面を構成する手段としては
、差圧発生器自体を絶縁性のセラミックなどで構成した
り、ステンレスなどの金属材料を母材として、絶縁物で
表面を覆う方式にしたりする方法がある。実現の可能性
としては、直径600f1以上のものをセラミックで精
度よく製作するのは現状では難しいことと、配管側との
温度膨張率の差から測定誤差を生じることがあることか
ら、高精度で製作した金属の母材に、蒸着やイオンブレ
ーティングなどの手段で数ミクロンから数10ミクロン
程度のセラミック厚さで覆う方が実用的である。これに
より、熱膨張は金属の母材の性質で決まり、高精度の計
測が可能となる。An embodiment of the invention is shown in FIG. Examples of differential pressure generators include general traps, orifice plate 1 in the same figure (a), flow nozzle 2 in the same figure (Fig. Adhesion of scale is observed. It has been newly found that this scale adhesion is due to the electrical interaction between the potential of the metal surface of the differential pressure generator that comes into contact with the fluid and the ionized scale components in the fluid. In order to eliminate this electrical interaction, in the present invention, the surfaces of the orifice plate and flow nozzle are made of an insulating material. For example, the shaded area in Figure 1 is an insulator.As a means of constructing the surface with this insulator, the differential pressure generator itself may be constructed of insulating ceramic, or a metal material such as stainless steel may be used as the base material. Another method is to cover the surface with an insulating material. The possibility of realization is that it is currently difficult to accurately manufacture ceramics with a diameter of 600 f1 or more, and measurement errors may occur due to the difference in temperature expansion coefficient with the piping side. It is more practical to cover the manufactured metal base material with a ceramic thickness of several microns to several tens of microns by means such as vapor deposition or ion blating. As a result, thermal expansion is determined by the properties of the metal base material, allowing highly accurate measurement.
第2図は、第1図(a)のオリフィスプレート1を例に
あげて、配管3への布設状態(同図(a))とスケール
の付着例(同図(b))’を示す。オリフィスプレート
1は図の様に、ドーナツ状に穴のあいたプレートでこれ
がフランジその他により、配管3へ固定される。配管内
径に応じた流速で流れてきた流体は、このオリフィスプ
レート1により縮流され、これによって発生する差圧を
、差圧検出器6で検出し、信号処理して流量が検出され
る。このときよく知られているようにオリフィスプレー
ト1の開口面積比が変わると、同一流量でも発生差圧が
異なり、流量計測上誤差が生じることになる。Taking the orifice plate 1 of FIG. 1(a) as an example, FIG. 2 shows the installation state of the pipe 3 (FIG. 1(a)) and an example of scale adhesion (FIG. 1(b))'. As shown in the figure, the orifice plate 1 is a donut-shaped plate with holes and is fixed to the pipe 3 by a flange or the like. The fluid flowing at a flow rate corresponding to the inner diameter of the pipe is constricted by the orifice plate 1, and the differential pressure generated thereby is detected by the differential pressure detector 6, and the flow rate is detected by signal processing. At this time, as is well known, if the opening area ratio of the orifice plate 1 changes, the differential pressure generated will differ even with the same flow rate, resulting in an error in flow rate measurement.
従来の例でいくと、スケール4は図の様に付着するケー
スが多く、これがオリフィスプレート1の開口面積を見
かけ上小さくする結果となり、同一流量での発生差圧は
大きくなって、計測流量は大きな誤差を含むことになる
。In the conventional example, the scale 4 is often attached as shown in the figure, which results in the apparent opening area of the orifice plate 1 becoming smaller, the differential pressure generated at the same flow rate increases, and the measured flow rate decreases. This will include a large error.
第3図により、このスケール付着のメカニズムを説明す
る。一般には、差圧発生器などの金属表面にプラス電荷
があり、静止水中ではこの表面にマイナス電荷をもった
イオンが付着してバランスを保っている。流体の流速が
速くなると、このマイナスイオンが強制的に取り除かれ
、金属表面のプラス電荷の影響が遠くまで及びこれに、
マイナス電荷をもったスケール成分が金属表面に付着す
るというメカニズムで説明される。したがってこの金属
(差圧発生器の母材に当る)表面の電荷の影響を取り去
れば、スケールの付着は削減されることになる。The mechanism of scale adhesion will be explained with reference to FIG. Generally, the metal surface of a differential pressure generator or the like has a positive charge, and in still water, negatively charged ions adhere to this surface to maintain balance. When the flow rate of the fluid increases, these negative ions are forcibly removed, and the positive charge on the metal surface spreads over a long distance.
The mechanism is explained by the fact that negatively charged scale components adhere to metal surfaces. Therefore, if the influence of the charge on the surface of this metal (corresponding to the base material of the differential pressure generator) is removed, scale adhesion will be reduced.
本発明によれば、流量計測用差圧発生器へのスケール付
着が除かれ、流量計測の精度を高く保つことができる。According to the present invention, scale adhesion to the differential pressure generator for flow rate measurement is removed, and the accuracy of flow rate measurement can be maintained at a high level.
これによりボイラの性能管理などが正確にできる様にな
り、効率改善にも役に立つことになる。This makes it possible to accurately manage boiler performance and improve efficiency.
第1図は本発明に係る、絶縁材料による差圧発生器表面
のコーティング説明図、第2図はスケール付着状況説明
図、第3図はスケールの付着メカニズムの説明図。
1・・・オリフィスプレート、2・・・フローノズル、
3・・・配管、4・・・付着したスケール、5・・・表
面をコーティングした絶縁物、6・・・差圧検出器。
第1図
第1図
(C)
一〇
CC’@面 しC′
52図
第3図
距離FIG. 1 is an explanatory diagram of coating the surface of a differential pressure generator with an insulating material according to the present invention, FIG. 2 is an explanatory diagram of scale adhesion, and FIG. 3 is an explanatory diagram of the scale adhesion mechanism. 1... Orifice plate, 2... Flow nozzle,
3... Piping, 4... Adhering scale, 5... Insulating material coated on the surface, 6... Differential pressure detector. Figure 1 Figure 1 (C) 10CC'@plane ShiC' Figure 52 Figure 3 Distance
Claims (1)
圧を検出して流量計測を行なう差圧発生器において、絞
り機構の少なくとも表面を絶縁物とすることを特徴とす
る差圧発生器。1. In a differential pressure generator that measures the flow rate by inserting a throttle mechanism into the flow path and detecting the differential pressure between the upstream and downstream sides thereof, at least the surface of the throttle mechanism is made of an insulator. pressure generator.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59184206A JPS6161008A (en) | 1984-09-03 | 1984-09-03 | Differential pressure generator |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP59184206A JPS6161008A (en) | 1984-09-03 | 1984-09-03 | Differential pressure generator |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6161008A true JPS6161008A (en) | 1986-03-28 |
JPH0215806B2 JPH0215806B2 (en) | 1990-04-13 |
Family
ID=16149211
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP59184206A Granted JPS6161008A (en) | 1984-09-03 | 1984-09-03 | Differential pressure generator |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6161008A (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56143914A (en) * | 1980-04-11 | 1981-11-10 | Hitachi Ltd | Method for preventing scale sticking to orifice flowmeter |
-
1984
- 1984-09-03 JP JP59184206A patent/JPS6161008A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS56143914A (en) * | 1980-04-11 | 1981-11-10 | Hitachi Ltd | Method for preventing scale sticking to orifice flowmeter |
Also Published As
Publication number | Publication date |
---|---|
JPH0215806B2 (en) | 1990-04-13 |
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