Effect of increasing and decreasing distillation column reflux on column pressure
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As the title suggests, when analyzing the operation of a distillation column, sometimes increasing the reflux can lead to an increase in column pressure, while sometimes reducing the reflux can also cause pressure to rise. How exactly do these factors influence each other?
This post was last edited by Green Lotus on 2018-8-11 at 10:41. As an operator, it is essential to control the process parameters as required by the operating procedures. On this basis, it is best to understand the basis for setting the parameters. Then you can explain this question by yourself. Such issues of taking things out of context are too broad and not specific. There are many factors related to the relationship between the amount of reflux and distillation; the pressure in a certain section of the distillation column is related to the reflux, and the design of the entire distillation column also varies. It’s best to use pictures to convey the message; visuals are more effective.
The problem description is too vague to allow for a clear explanation. When the reflux is increased, the load pressure surely rises; when the reflux is reduced, the pressure also increases. Could it be that there has been a change in the feed composition, with more light components present? By checking the test data and the processing volume, among other factors, it should be possible to identify the cause.
This post was last edited by Green Lotus on 2018-9-11 at 14:35. Presumably, you too realized this only after experiencing hot summers: everything has its limits. When the reflux temperature is low, increasing the amount of reflux appropriately can reduce the tower pressure; however, excessive amounts will increase the load on the tower, resulting in the opposite effect. On the other hand, when the reflux temperature is high and the top condenser is overloaded, increasing reflux will only further increase the load on the tower and raise the pressure. In such cases, where the pressure at the top of the tower is too high, it is necessary to reduce the amount of reflux appropriately
It’s mainly a problem with the reflow temperature and volume; what was said upstairs makes a lot of sense
This post was last edited by Green Lotus on 2018-10-3 at 10:13. The tower pressure is generally set in advance, allowing different pressures to correspond to different reflux ratios and heating loads. Reflux generally corresponds to changes in the top temperature of the tower, and is not used to directly control changes in the tower pressure.
What was said on the 4th floor is correct – different situations require different analyses; temperature and recirculation rates also have a significant impact on tower pressure!