Refrigeration section tower diameter and stripping section tower diameter
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This post was last edited by brainandrain on 2009-5-6 at 16:45. I am working on the design of a packing distillation column; the diameter of the distillation section calculated to be only 0.189 meters, while the diameter of the stripping section is 0.306 meters. How can the diameter of a tower like this be made round? Does the tower diameter in the distillation section need to be the same as that in the stripping section?
There are two methods: 1. The diameters of the two sections are the same; the larger one is taken as the standard； 2. The diameters of the two sections are different, with a diameter-changing section in between. Under normal circumstances, the stripping section of a distillation column calculated to be required is larger than the rectifying section; if the difference is not significant, the same column diameter is adopted, based on the requirements of the stripping section. If the difference is significant, it can also be designed as a tapered tower, which is used in chemical production. For your case, either method can be used; however, if a tapered tower is designed, the amount of calculation work will be greater.
What kind of tower did the original poster build? It’s so thin! Based on your question, I think it’s better for the diameters of the distillation section and the stripping section to be different, as there is a significant difference between them (if you’ve done the calculations correctly); a tapered connection should be used between the distillation section and the stripping section
I would like to ask my colleagues: if it is required that the diameters of the two sections of the tower be the same, then the diameter of the distillation section needs to be increased. In that case, the speckle density and F-factor will become very small; is such a design feasible?
I think such a design is acceptable. It doesn’t matter if the spread coefficient and F factor are a bit low; for packed columns, this is beneficial for separation.
As mentioned earlier, if the differences in tower diameter are not significant, rounding is done using the larger diameter as a reference； If there is a large difference in tower diameter between the rectification section and the stripping section, a variable-diameter design is advisable. However, in the case described by the poster, although there is a significant difference between the refining and distillation sections, the maximum tower diameter is only 0.306 meters; such a small tower does not require a variable-diameter design.
It is best to have a variable diameter, as this ensures that the process design meets the technical requirements of the tower, saves materials; even with an investment, the operational energy consumption is low, resulting in good economic benefits
Although the tower diameter is not large, the calculation results show that there is a significant difference in diameter between the rectification section and the stripping section; therefore, it is reasonable to use a variable diameter design.