Abnormalities occurred after replacing the reboiler and condenser in the continuous distillation column; please help analyze it
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This post was last edited by msailz2009 on 2011-9-6 at 19:36. We have a series of fractional distillation columns, and one of these columns is experiencing problems due to severe scaling and corrosion in its original reboiler and condenser. These components have now been replaced, but anomalies have arisen: despite the operating conditions remaining unchanged (temperature around 80 degrees, pressure of 4.5 kilograms, etc.), the liquid level in the bottom of this column fluctuates significantly, making it difficult to control the composition of the liquid and preventing continuous operation. Everyone, please help analyze it; I thank you in advance
It might be flooding; the opening degrees of the water and steam valves should be reduced appropriately compared to before, and too much material should not accumulate inside the tower. In the case of a thermal siphon reboiler, maintaining a minimum liquid level is a prerequisite for the stability of the column.
Now both the steam and condensed water are at lower levels than before; give it a try
Have you adjusted the steam tower? Our tower is the same; the liquid level fluctuates, and the amount of vapor produced varies from time to time. After reducing the steam supply, what used to be 120 is now between 60 and 70 – it doesn’t help at all. The tower pressure gauge is still broken, and this is the case for single-tower circulation as well. Reasons for flooding: ① Properties of the packing; ② Physical properties of the liquid; ③ Liquid-to-gas ratio. If steam is not used, there shouldn’t be any major problems, right? Is there too much contamination in the packing? What other situations can cause fluctuations in the liquid level inside the tower?
The fluctuations are smaller now; let’s try again
First, it is necessary to determine whether the instability of the liquid level at the bottom of the distillation column is caused by the operating conditions of the process. (Such as feed rate, steam volume, reflux volume, etc.) Was a leak check performed again before installing the reboiler? Is the fluctuating liquid level caused by a leak inside the reboiler? Finally, are the form, structure, size, and installation method of the reboiler the same as before the replacement? (Primarily, we need to consider whether the vapor outlet of the reboiler could cause the airflow to spray downward.) Let’s discuss these points first; we can talk further if there are any issues
All the replaced equipment is the same as before; leaks have also been tried to be addressed. Currently, we are reducing the steam volume and operating at low liquid levels, and we plan to clean the packing during maintenance
Reply to 7# msailz2009: In my opinion, it’s the blockage of the filler that causes the levels to fluctuate