The distillation column is not operating stably, and it is difficult to control the medium temperature – what are the possible reasons?
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As the title suggests~~:) It’s still manageable when the processing volume is low, but once the volume increases, the operation of the fractionation tower becomes abnormal, and it’s difficult to control the fluctuations in temperature. Last year, the tower was washed, and a considerable amount of catalyst was removed – could it be that the trays are blocked? Also~~a gentle question: Are all questions related to catalytic cracking posted here?
This situation arises due to a local imbalance between the vapor and liquid phases; blockages in the downcomer or stuck floating valves result in excessive leakage. If washing cannot resolve the issue, it is necessary to urgently inspect and address the tower. Only by increasing the volume of processing can there be benefits.
I guess there’s a problem with your process too! Could you provide some detailed data? I can do a simulated calculation for you – it’s solvable!
The mid-range temperature of the original poster fluctuates greatly, but remains stable at low processing volumes. It is possible that 1. the absorption of the stable portion is not smooth. When the processing volume is large, the absorption stabilization section also requires more heat source. If the temperature fluctuation at the middle section of the tower is significant, it may be caused by poor heat exchange between the oil in the middle section and the heat exchanger used for absorption stabilization. The opening changes of the stable associated control valve can be observed. We have also encountered situations where, in severe cases, the middle section would shake as well. 2. There is a problem with the sensitivity of the control valve; contact the instrumentation team to adjust the proportional-integral settings. 3. Fluctuations in the temperature and liquid level at the bottom of the tower cause fluctuations in the middle and upper sections. 4. There is a problem with the middle tray.