The magnetism chaos phenomenon exist in the magnetic level gauge
Author:vacorda Source:vacorda.com Date: 2016-09-18 16:33:38
In many chemical production process, level gauge is one of the most used measurement instruments. Because of its relatively low cost, wide measuring range, clear instructions, high pressure level, good safety and many other advantages, magnetic level gauge are widely used in oil refining chemical plant. However, due to the unstable of the magnet performance, after a period of time, the magnetism will be weakened, the magnetic pot in the float and the small magnet in the indicator will lose the magnetic connection, so the indicator can not make the correct indication. And this phenomenon is call “the magnetism chaos ”
In recent years, with the strength of technology of some powerful instrument manufacturers, magnetic steel to the performance of magnetic stability is improved a lot. As a result of the above reasons, the "chaotic magnetic" phenomenon is reduced, but another reason that is not detected easily appears.
When measuring the liquid level of the liquefied hydrocarbon-based vaporizing medium using a common magnetic float level gauge, the gas phase and the liquid phase of the measured medium are brought into equilibrium with each other in a stable state. At the time, if the liquid is withdrawn from the tank, the upper space of the liquid surface increases and the gas pressure decreases, so that a part of the liquid vaporizes and a large amount of bubbles are generated. Small bubbles in the rise process into large bubbles, large bubbles into the measurement chamber of the magnetic float level gauge , it may cause a rising gas phase. When the gas phase encounters the float in the rising process, the gas phase will pass around the float, and the speed of the float is too fast to lose the magnetic connection with the indicator outside the measurement chamber, resulting in "chaotic magnetic" phenomenon.
What’s more, , in the closed pipeline with normal production , and sometimes it will also be mixed in a liquid phase in many different sizes of bubbles for various reasons , even when serious, it will generate the "gas phase." The presence of a mixed gas phase in these liquid phases will vary with production changes, if the relative position of the feed line and the level gauge is facilitates the bubble entry, When the liquid phase mixed with the gas phase into the device, the gas phase will enter the measurement room of the magnetic float level gauge. If it is some small bubbles into the scattered, because the density of the media in the magnetic float level gauge changes, and the buoyancy suffered by the float will change, the position of the float will change, the magnetic float level indicator Of the level value will produce large or small errors. That is, this condition disturbs the normal indication of the magnetic level gauge.
The above causes the level gauge does not work normal because of the gas medium mixed into the liquid phase and caused the impact of the liquid level gauge, to make the float level gauge work properly, it must be modified so that it can adapt to this impact.