DD276160A1

DD276160A1 - DEVICE FOR DETECTING GASES IN STREAMING LIQUID METAL

Info

Publication number: DD276160A1
Application number: DD32051188A
Authority: DD
Inventors: Olgert Lielausis; Horst Langenbrunner
Original assignee: Akad Wissenschaften Ddr
Priority date: 1988-10-06
Filing date: 1988-10-06
Publication date: 1990-02-14

Abstract

Die Anwendung der Erfindung ist zur Untersuchung von Fluessigmetall-Zweiphasenstroemungen und zur Gaseinschluss- und Leckdetektion an natriumbeheizten Dampferzeugern gegeben. Die Loesung beinhaltet, dass die Sonde mehrere scheibenfoermige Dauermagnete enthaelt, die flaechenhaft polarisiert sind, so dass gleichpolige Flaechen nebeneinander liegen. Zwischen diesen sind Weicheisen-Metallscheiben angeordnet. Die Anbringung der Sonde erfolgt quer zur Stroemungskanal-Laengsachse. Es werden Elektroden eingesetzt, die jeweils in Hoehe der neutralen Zone der Dauermagneten innen am Sondenrohr angebracht sind. Die Anzahl der Elektroden ist waehlbar. Fig. 1The application of the invention is for the investigation of liquid-metal two-phase flows and gas entrapment and leak detection on sodium-heated steam generators. The solution includes that the probe contains several disk-shaped permanent magnets, which are polarized surface, so that gleichpolige surfaces are adjacent. Between these soft iron metal discs are arranged. The attachment of the probe is transverse to the flow channel Laengsachse. Electrodes are used which are each mounted at the level of the neutral zone of the permanent magnets on the inside of the probe tube. The number of electrodes can be selected. Fig. 1

Description

Hierzu 1 Seite ZeichnungenFor this 1 page drawings

Application blot of the invention

Die Erfindung betrifft eine Vorrichtung zur Detektion von Gaseinschlüssen in strömendem Flüssigmetall nach dem Prinzip des induktiven Durchflußmessers.The invention relates to a device for detecting gas inclusions in flowing liquid metal according to the principle of inductive flow meter.

Die Anwendung der Erfindung ist zur Untersuchung von Flüssigmetall-Zweiphasenströmungen und zur Gaseinschluß· und Leckdetektor) an natriumbeheizten Dampferzeugern gegeben.The application of the invention is for the investigation of liquid metal two-phase flows and gas entrapment and leak detectors on sodium-heated steam generators.

Characteristic of the known state of the art There is already known a device for the detection of gas inclusions in liquid sodium, consisting of a with a Air gap at the pipeline of the liquid sodium «ordered electromagnet and a system of electrodes for Decrease of the tension exists (H.Langenbrunner, detection of inhomogeneities in liquids by means of inductive Flow measurement, ZfK 387). There is also known a device for the detection of gas inclusions in liquid metals, in which at the pipeline two Magnet systems are arranged (DD-PS 138824). Furthermore, an inductive flow probe for measuring the flow velocity and the gas volume fraction of a Liquid metal stream known in which in a probe tube two disc-shaped permanent magnets in an axial distance

angeordnet sind (DE-AS 2632042).are arranged (DE-AS 2632042).

All known technical solutions have in common that they have only a low sensitivity. Thereby are

geringe Voidanteile sehr kleiner Blasen nicht detektierbar.low void content of very small bubbles not detectable.

ZIoI the invention

Es ist das Ziel der Erfindung, die Empfindlichkeit der Vorrichtung zur Detektion von Gaseinschlüssen in strömendem Flüssigmetall zu erhöhen.It is the object of the invention to increase the sensitivity of the apparatus for detecting gas inclusions in flowing liquid metal.

Explanation of the essence of the invention

Der Erfindung liegt die Aufgabe zugrunde, aussagekräftigere Signale bei der Detektion von Gaseinschlüssen bereitzustellen. Erfindungsgemäß wird die Aufgabe dadurch gelöst, daß die Sonde mehrere scheibenförmige Dauermagnete enthält, die flächenhaft polarisiert sind, so daß gleichpolige Flächen nebeneinander liegen. Zwischen diesen sind Weicheisen-Metallscheiben angeordnet. Die Anbringung der Sonde erfolgt quer zur Strömungskanal-Längsachse. Es werden Elekiroden eingesetzt, die jeweils in Nähe der neutralen Zone der Dauermagneten innen am Sondenrohr angebracht sind. Die Anzahl der Elektroden ist wählbar. Es sollten je Dauermagnet mindestens eine Elektrode gewählt werden, bei der Absicht höherer Auflösung werden vier Elektroden, gleichmäßig am Umfang je Dauermagnat verteilt, empfohlen. Als vorteilhaft hat sich die Verwendung von sechs Dauermagneten erwiesen.The invention has for its object to provide more meaningful signals in the detection of gas inclusions. According to the invention the object is achieved in that the probe contains a plurality of disc-shaped permanent magnets which are polarized areally, so that gleichpolige surfaces are adjacent. Between these soft iron metal discs are arranged. The attachment of the probe is transverse to the flow channel longitudinal axis. Elecodes are used, each mounted near the neutral zone of the permanent magnet inside the probe tube. The number of electrodes is selectable. At least one electrode should be chosen per permanent magnet, with the intention of higher resolution, four electrodes, evenly distributed per circumference per permanent typhoon, are recommended. The use of six permanent magnets has proved to be advantageous.

Austührungsbelspiel

Die Erfindung wird nachfolgend an einem Ausführungsbeispiel näher erläutert. In der zugehörigen Zeichnung zeigenThe invention will be explained in more detail using an exemplary embodiment. In the accompanying drawing show

Fig. 1: einen Schnitt durch den Strömungskanal mit der eingebauten induktiven Sonde, Fig. 2: den Schnitt A-A durch den Strömungskanal nach Fig. 1.1 shows a section through the flow channel with the built-in inductive probe, Fig. 2: the section A-A through the flow channel of Fig. 1st

In the flow channel 1 for the liquid metal is a hollow cylindrical probe 2, which is fixed transversely to the flow direction

ist und den Strömungskanal 1 einseitig durchdringt.is and the flow channel 1 penetrates on one side.

In the probe 2, six disc-shaped permanent magnets 3 are arranged such that the polarity over the longitudinal axis of Probe 2 changes and always the same polarized surfaces of adjacent permanent magnets 3 arranged between them Soft iron metal discs 4 abut. For signal recovery are at the inner periphery of the probe 2 at the height of the neutral zones of the permanent magnets 3 electrodes fifth

angebracht, die über Leitungen mit einer an sich bekannten Signalverarbeitungseinheit verbunden sind.attached, which are connected via lines with a signal processing unit known per se.

The number of electrodes 5 can be determined depending on the concern of the measurement. To monitor the entire Cross-section of the flow channel 1 should at least one electrode 5 used in the region of each permanent magnet 3

werden. Bei der Vorwendung mehrerer Elektroden 6 in Höhe eines Dauermagneten 3 sollen sich die Elektroden 5 auf gleicherbecome. In the Vorwendung of several electrodes 6 in the amount of a permanent magnet 3, the electrodes 5 are on the same

Height in the probe 2 are located. The electrodes 5 are formed between the permanent magnets 3 and the inner wall of the probe 2

deren einseitiger Öffnung herausgeführt.whose one-sided opening led out.

Claims

1. Device for detecting gas inclusions in flowing liquid metal, consisting essentially of a probe containing two permanent magnets and electrodes, which is connected by lines to a signal processing unit and output elements, characterized in that in the probe (2) a plurality of disc-shaped permanent magnets (3) in planar polarization are arranged and that the probe (2) is mounted transversely to the flowing liquid metal in a flow channel (1).

2. Apparatus according to claim!, Characterized in that between the permanent magnets (3) soft iron metal discs (4) are arranged.

3. Apparatus according to claim 1 and 2, characterized in that in the probe (2) six permanent magnets (3) are arranged.

4. Apparatus according to claim 1 to 3, characterized in that per permanent magnet (3) at least one electrode (5) is provided, which is attached to the inside of the probe (2).