The differential pressure level gauge is inaccurate
Thread Content
The liquid level displays normally when stirring and the system is at rest, but it shows abnormally high values when the stirrer is rotating at high speed; the DCS keeps reporting high levels. The instrument maintenance staff cleared the insert tube inside the level gauge as well as the pressure guide tube, yet the issue of abnormally high readings persists. What could be causing this problem? Thank you to all experts for sharing their insights
It seems that during high-speed mixing, the material is flung toward the side walls, causing the material level at those walls to rise. The liquid level at rest before mixing should be lowered.
Our company uses butyllithium in its products, and a certain amount of mineral oil is added to dissolve lithium metal. At present, even before lithium metal is added for melting, high readings are obtained due to rapid stirring. The person who posted the question suggested reducing the liquid level during standing time, but this might affect dispersion. We have two production lines, and such problems do not occur on one of them
First, is the tank not large enough? Second, is the level controller set too low? Third, is the flange below the level gauge positioned directly opposite the impeller blades?
Well, the container isn’t very large; we haven’t encountered this issue before. Once it’s cleared, everything will be fine, and the other line is working normally
The differential pressure transmitter has its high-pressure end inserted below via an insertion tube, as the tank is used for storing dispersed metallic lithium
It’s inevitable when using a stirrer; there is a certain centrifugal force during stirring, which will definitely affect the measurements
Yes, stirring does indeed affect the liquid level; I have observed this, and we also use differential pressure transmitters to measure the liquid level
Well, DCS has set high-reporting limits based on production data; this didn’t happen before, and the other line doesn’t have such an issue either
I can understand this; it hasn’t happened much over all these years of production, and it should just be fixed by clearing things out. But clearing them out doesn’t work anymore