Vacuum tower operation
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A few days ago, the vacuum level in our plant fluctuated once, which disrupted the operation of the entire tower. Temperature control was set at 150°C for Unit 1 and 250°C for Unit 2. Currently, the extraction temperatures on all sides are basically normal. However, the flow rate back to Unit 2 is lower than before – it used to be 450 t/h, but now it’s around 200 t/h. If this flow rate is increased to 450 t/h again, it is likely that the extraction temperature of Unit 2 will drop. What should we do? We would appreciate advice from those with experience in this area
1. Increase the outlet temperature of the furnace. 2. Has the feed changed? 3. Check whether the reflux ratios in the middle sections have changed; reduce the heat taken from the sections below the second level and increase the heat taken from the upper sections.
Thank you for your reply. The issue has been resolved by now; the pipeline connected to the subtraction unit was a bit blocked. After switching to the exhaust port on the other side, the temperature returned to normal. Some time ago, I suspect it was underflow reduction that caused chaos in the temperature gradient throughout the tower.