Help! What is the reason for the high-high interlock at the cold high-pressure liquid level? ? ?
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This post was last edited by libingtaoff8 on 2016-9-8 at 10:53. Recently, the processing volume for the cold high-pressure fractionation unit has been set at 120 t/h; the temperature after cooling is maintained around 45 degrees, and all other parameters are normal! The two-out-of-three interlock level gauge at the high level is rising, even reaching the interlock value. At the top is the two-out-of-three interlock level gauge; in the middle is the magnetic flap level gauge; and at the bottom is another level gauge. However, the magnetic flap level gauge does not show any upward trend. It is the interlock level gauge at the very top – the float level gauge, that is, the two-out-of-three interlock level gauge – which is rising. Previously, the flow rate was normal at this high level, but after oil replacement, the level began to rise. This phenomenon disappeared after reducing the flow rate. The level gauges themselves are functioning properly, and all three of them show high readings. Foam is discharged from the level gauges, and there is a liquid separation tank before the recycled hydrogen enters the desulfurization system; yet no liquid separation occurs there either! Is it due to changes in the properties of the raw materials, or some other reason? Why hasn’t the magnetic flap level gauge in the middle changed, while the level gauge above it has increased? And why is there no liquid level in the liquid removal tank at the back end? Treatment measure: perform sequential resection of the two highest-grade areas, thereby reducing the amount of work required! I hope fellow netizens can point out the reason!
Changes in oil density also have a significant impact on the float; this allows the instruments to be calibrated, with the zero point or density value being adjusted accordingly
The magnetic flap level gauge in the middle shows no change, indicating a level of around 45%; so how can it reach the level indicated by the top float level gauge?
Magnetic flap switches are relatively more accurate; float switches require calibration and comparison with instruments to set their values
Why is there a liquid level in the top float level gauge? The magnetic flap level gauge, on the other hand, showed no changes; the instrument has been checked and there is no issue with the level gauge
Can it be confirmed that it’s the liquid level? If there is no magnetic flip plate but a float is present, it might be that the separation efficiency is not good; the gas may contain oil, or the high-efficiency demister may not be effective. What enters the float is not necessarily oil, but rather a layer of floating oil
Generally, high-performance units are equipped with swirl hydrocarbon removal devices, and this can be checked.
It is a magnetic flip-disc level gauge that is used for measuring the liquid level; during normal production, the liquid level is adjusted based on the readings of this magnetic flip-disc gauge. There is no float gauge in use. The current situation is that the magnetic flip-disc gauge shows no changes and indicates a normal liquid level, while the upper-level interlocked gauge, which is actually the float gauge, shows a different liquid level level. The issue with the instruments has been ruled out
No, what’s installed above is a wire mesh demister!
What comes out is just oil foam; this issue only appears after changing the feed oil. The separation is not good – could it be due to an excess of light hydrocarbons? Additionally, there is no liquid level visible in the liquid separation tank before the hydrogen circulation desulfurization tower. How do I explain this?
I’m not sure about your manufacturing process; you should try using different raw materials to see if that resolves the issue. First, it’s necessary to determine the cause