DD240358A1

DD240358A1 - METHOD FOR THE EARLY DETERMINATION OF LEAKAGE OF DOUBLE COATING BELESTS

Info

Publication number: DD240358A1
Application number: DD27995285A
Authority: DD
Inventors: Manfred Koch; Volker Denk
Original assignee: Zentralinstitut Schweiss
Priority date: 1985-08-26
Filing date: 1985-08-26
Publication date: 1986-10-29

Abstract

Die Erfindung bezieht sich auf ein Verfahren zur fruehzeitigen Ermittlung von Leckagen an Doppelmantelboeden, vorzugsweise am oberirdisch stehenden, mit einem aggressiven Medium gefuellten Tankbauwerken. Ziel ist, derartige Leckagen mit einem geringen Zeit- und Arbeitsaufwand zu ermitteln. Nach der Aufgabe sollen bereits geringste Leckagen in Groesse und Menge im Hohlraum eins Doppelmantelbodens eines mit einem aggressiven Medium gefuellten Behaelters feststellbar sein, um letzteren aus Sicherheitsgruenden zum Zwecke der Reparatur entleeren zu koennen. Erfindungsgemaess wird in den Hohlraum des Doppelmantelbodens ueber eine Zuleitung ein trockenes Inertgas eingefuehrt mit einem Druck von 30 bis 60 mm WS, einer Menge von 3 bis 50 m3 und einer Geschwindigkeit von 1,5 bis 2,5 l/min. Anschliessend wird das den Hohlraum kontinuierlich durchstroemende und sich bei einer Undichtheit des Doppelmantelbodens mit dem Medium anreichernde Gas mittels einer Austrittsleitung aus dem Behaelter abgeleitet und mit Hilfe bekannter Einrichtungen laufend analysiert, wonach in ueblicher Weise der Behaelter entleert und die ermittelten Leckagen lokalisiert werden. Als Inertgas wird vorzugsweise Argon verwendet. FigurThe invention relates to a method for the early detection of leaks on Doppelmantelboeden, preferably at the above-ground standing, filled with an aggressive medium tanks. The aim is to detect such leaks with little time and effort. After the task even smallest leaks in size and quantity in the cavity of a double jacket bottom of a container filled with an aggressive medium tank should be detectable to be able to empty the latter for safety reasons for the purpose of repair. According to the invention, a dry inert gas is introduced into the cavity of the double-jacket bottom via a feed line at a pressure of 30 to 60 mmWS, in an amount of 3 to 50 m 3 and at a speed of 1.5 to 2.5 l / min. Subsequently, the cavity which continuously flows through the cavity and accumulates with the medium in the event of a leakage of the jacket is discharged from the container by means of an outlet conduit and continuously analyzed with the aid of known devices, whereupon the container is emptied in the usual way and the detected leakages are localized. Argon is preferably used as the inert gas. figure

Description

Gegenstand der Erfindung ist somit ein Verfahren, das einmal der Ermittlung schon geringster Leckagen in Hohlräumen der Doppelmantelböden von Behältern, die insbesondere mit aggressiven Medien gefüllt sind und zum anderen einer Durchspülung und gewissen Konservierung dieser Hohlräume dient, um das Eindringen von feuchter Luft oder anderer Schadstoffe, die den Doppelmantelboden im Inneren korrosiv angreifen können, zu vermeiden. Dazu ist es erforderlich, daß das Gas bestimmte Parameter und Eigenschaften hat. Ein trockenes Gas wird verlangt, damit im Doppelmantelboden keine Feuchtigkeit entstehen kann. Um unerwünschte Reaktionen zwischen dem Gas und dem eventuell durch Leckstellen eindringenden Medium zu vermeiden, ist ein inertes Gas zu verwenden. Damit vorhandene Leckagen erfaßt und eine optimale Spülung des Hohlraumes erfolgt, sollte der Gasdruck im Bereich zwischen ρ = 30... 60mm WS bei Strömungsgeschwindigkeiten von ν = 1,5... 2,5 l/min liegen. Die Gasmenge muß so groß sein, daß der Doppelmantelboden vollständig und ausreichend durchströmt und gespült wird. .The invention thus relates to a method that once even the determination of even the smallest leaks in cavities of the double jacket bottoms of containers that are filled in particular with aggressive media and on the other a flushing and certain preservation of these cavities, the ingress of moist air or other pollutants , which can corrosively attack the double jacket floor inside to avoid. This requires that the gas has certain parameters and properties. A dry gas is required so that no moisture can form in the double jacket floor. In order to avoid undesired reactions between the gas and the medium which may leak through leaks, an inert gas should be used. So that existing leaks are detected and an optimal flushing of the cavity takes place, the gas pressure should be in the range between ρ = 30 ... 60mm WS at flow velocities of ν = 1.5 ... 2.5 l / min. The amount of gas must be so large that the double jacket floor is completely and sufficiently flowed through and rinsed. ,

embodiment

Die Erfindung soll nachstehend an einem Ausführungsbeispiel näher erläutert werden. In der Zeichnung ist das Prinzip des Verfahrens zur Ermittlung von Leckagen an einem Doppelmantelboden dargestellt.The invention will be explained in more detail below using an exemplary embodiment. The drawing shows the principle of the method for detecting leaks on a double jacket floor.

In den Hohlraum 1 eines Doppelmanteibodens 2 eines oberirdisch stehenden Tanks 3, der mit einem aggressiven Medium 7, in diesem Fall mit einer Säure, gefüllt ist, wird über eine die Behälterwand 4 durchdringende Zuleitung 5 als inertes Gas Argon eingeführt mit einem Druck von 50 mm WS, einer Menge von 50 m³ und einer Geschwindigkeit von 2 l/min. Das Gas durchströmt den mit Asbeststeinen ausgelegten Hohlraum 1, spült ihn dabei und führt zwangsläufig gleichzeitig eine Konservierung gegenüber äußeren schädlichen Einflüssen durch.Into the cavity 1 of a Doppelmanteibodens 2 an above-ground tank 3, which is filled with an aggressive medium 7, in this case with an acid, is introduced via a container wall 4 penetrating supply line 5 as an inert gas argon at a pressure of 50 mm WS, a quantity of 50 m ³ and a speed of 2 l / min. The gas flows through the cavity 1 designed with asbestos stones, rinsing it and, at the same time, inevitably preserves it against external harmful influences.

Sind an der mit dem im Tank 3 befindlichen Medium in Berührung stehenden Seite des Doppelmanteibodens 2 selbst kleinste Leckstellen, beispielsweise in den Schweißnähten, vorhanden, dringt aufgrund des hohen Außendruckes von etwa 15000 mm WS das Medium 7 in den Hohlraum 1 ein. Dabei reichert sich das den Hohlraum 1 durchströmende Gas mit dem Medium 7, alsoIf even the smallest leaks, for example in the weld seams, are present at the side of the double ribbed bottom 2 which is in contact with the medium in the tank 3, the medium 7 penetrates into the hollow space 1 due to the high external pressure of approximately 15,000 mm. In this case, the gas flowing through the cavity 1 accumulates with the medium 7, that is

mit der Säure, an. ·with the acid, on. ·

Über die Leitung 6 tritt das mit dem Medium 7 angereicherte Gas aus dem Hohlraum 1 aus und wird unmittelbar auf seinen Schadstoffgehalt analysiert. Damit wird gewährleistet. Undichtheiten sofort nach ihrem Entstehen zu ermitteln. Durch Außerbetriebnahme und Leeren des Tanks 3 können die Leckagen in üblicher Weise lokalisiert werden. Dadurch werden folgenschwere Havarien und Umweltschäden vermieden.Via line 6, the gas enriched with the medium 7 exits from the cavity 1 and is analyzed directly for its pollutant content. This is guaranteed. Identify leaks immediately after their emergence. By decommissioning and emptying the tank 3, the leaks can be localized in the usual way. This avoids serious accidents and environmental damage.

Claims

Invention claim:

1. A method for the early detection of leaks on double-walled floors, preferably of above ground, filled with an aggressive medium tank structures, leaks in the double casing floor are already detectable in smaller sizes and quantities, characterized in that in the cavity (1) of a double-jacket bottom (2 ) via a feed line (5) a dry, preferably inert, gas is introduced at a pressure of 30 to 60 mm of WS, an amount of 3 to 50 m ³ and a speed of 1.5 to 2.5 l / min, that subsequently that the cavity (1) continuously flowing and in leakage of the double jacket bottom (2) enriched with the medium gas by means of an outlet line (6) is derived from the container, that then using known means, the gas is analyzed continuously, which in the usual way the container is emptied and the detected leaks are localized.

2. A method for the early detection of leaks on double jacket floors after item !, characterized in that argon is preferably used as the inert gas. .

For this 1 page drawing

Field of application of the invention

The invention relates to a method for the early detection of leaks on double-walled floors, preferably on above-ground, filled with an aggressive medium tanks, leaks in double-walled floors are already recognizable in small sizes and quantities during operation of the container.

Characteristic of the known technical solutions

For reasons of safety, tanks with double floors, the so-called double-walled floors, are produced for the storage of particularly aggressive and dangerous media. It is known that these soils are checked before startup by means of a vacuum chamber and by injecting suitable gases into the cavity of the double jacket floor and lathering the welds for leaks. Another possibility is spraying the welds from the inside or outside with a test gas, which are then examined on the opposite side with a leak tester for any existing leak. Leaks can continue to be determined by the fact that the entire container z. B. filled with water and is introduced into the double jacket floor compressed air. Blistering or rising bubble chains allow for a determination of leakage at the double-mantle bottom.

However, these known test methods all have the disadvantage that they allow hureine statement about the tightness of double jacket floors before the actual commissioning of the container or individual test methods due to the container size are not applicable at all.

But it is significantly more important to detect any existing leaks on the double skirt during operation of a container. Therefore, the double jacket floor by the container wall leading drain pipes, u-pipe Manpmeter u. Ä. Attached, via which the discharge of medium from the container is to be signaled in the Qoppelmantelboden. However, this method has the significant disadvantage that only leaks of certain size and quantity can be determined. Underlying leaks, but which are already crucial for the safety of the container to be operated, are not detectable with this procedure. Another disadvantage is that moist air can penetrate through the existing, necessary outflows or breakthroughs into the double jacket floor, which can cause corrosion damage or accelerate its growth with a corresponding concentration of ions and, together with the possibly invaded aggressive container medium. -

Object of the invention

By means of the invention, leaks on double-jacket bottoms of containers filled with an aggressive medium can be determined with little time and effort.

The essence of the invention

The invention has for its object to develop a method with which even the smallest leaks in size and quantity in the cavity of a Doppelmäntelbodens a filled with an aggressive medium container can be determined to be able to empty the latter for safety reasons for the purpose of repair. -

The object of the invention was achieved in that, according to the invention, a dry, preferably inert, gas is introduced into the cavity of a double-jacket bottom via a feed line at a pressure of 30 to 60 mm of WS, an amount of 3 to 50 m ³ and a speed of 1, 5 to 2.5l / min, then that the cavity continuously flowing through and accumulating in case of leakage of the double jacket bottom with the medium gas is discharged by means of an outlet line from the container and analyzed by known means continuously, after which emptied and in the usual way the container the detected leaks are localized. Argon is preferably used as the inert gas.