Distillation column problems
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I would like to ask: after a distillation column has been in operation for some time, the temperature at the top of the column rises while the temperature at the bottom drops. What causes this?
Possible reasons include: an increase in the feed rate to the distillation tower, but no corresponding increase in the steam supply to the reboiler or other heat sources； At this time, the amount of reflux at the top of the distillation column happened to decrease, which caused the top temperature to rise while the bottom temperature remained unchanged.
If you have just started operating the plant, it might be because the light components at the bottom of the tower absorb heat and move up to the top of the tower, resulting in that situation. If the distillation column was stable at first and then became that way, it might be due to flooding
This question is too vague; there should be many control points in a distillation column – feed temperature, sensitivity plate temperature, top temperature, bottom temperature, as well as pressure, reflux, steam, and so on. It’s difficult to determine the cause based solely on your description!
The feed rate may be low, the temperature at the bottom of the tower has changed, and there is a delay at the top of the tower
First of all, I think the question posed by the original poster isn’t very clear; for example, whether the product is qualified or not? Has there been a significant change in the load of the distillation tower? How much do the temperatures at the top and bottom of the tower change? Has the reflux ratio been adjusted? These are all very important analysis parameters; a comprehensive analysis should not be difficult.
Hehe! ! I think what was said on the sixth floor is correct. At first, the product is not up to standard and may contain light components; once it meets the standards, the operating temperature naturally increases. After that, the pressure drop required for separation in the tower can be reduced. With a constant heating amount, the amount of evaporation naturally decreases! I wonder what method you use to control your tower? If the original pressure drop is maintained, you will need to increase the heat source, and energy consumption will rise! !
This post was last edited by shmily327 on 2010-5-11 at 15:47. It is likely that the feed rate was too high, exceeding the tower’s capacity; as a result, the material inside the tower could not undergo adequate heat exchange. This caused the low-boiling components to move downward, while the heavier components rose to the top of the tower. In the end, the temperature difference within the tower became minimal. The solution is to reduce the feed rate in order to restore balance!
This analysis at the second floor occurs under normal operating conditions of the distillation tower, and it also happens in the early stage of flooding under abnormal operating conditions.
Temporarily stop feeding, use full reflux to observe for any abnormalities before resuming feeding