How to calculate the number of boards for PRO II
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Given the flow rates and compositions of the feed, the top distillate, and the bottom extract, as well as the recovery rate of the key component, how can we determine the number of theoretical plates? For example: Flow rate in mol/hr, ethanol percentage, water percentage. Feed: 101578, 0.2722, 0.7278; Top distillate: 29802.99, 0.8814, 0.1186; Bottom extract: 71775.01, 0.0192, 0.9808. The required ethanol recovery rate is 95%. Could someone please provide a detailed explanation???
The theoretical number of theoretical plates can first be estimated using a simplified method, and then calculated precisely using a more rigorous approach.
You can estimate the number of trays first; it doesn’t matter if there are a few extra. Once the product meets the standards, reduce the number until the optimal value is reached.
What was said on the second floor is correct. One can first use a simplified method to estimate the number of theoretical plates, add a controller, and then use a more rigorous method for accurate calculation.
The rigorous calculation method for the ProII distillation column is only applicable to operational calculations.
The Shortcut module in Pro2 can be used to roughly calculate the number of theoretical plates and the reflux ratio first, followed by a precise calculation using Redfrac. However, by first performing a rough calculation and then a more precise one, I found that there is a significant difference between the ideal and non-ideal conditions for the separation of ethanol from water; in fact, precise calculations do not require as many theoretical plates. I think the original poster can look up relevant literature to find out what value others usually use, and then adjust it until the desired result is achieved.
Thank you.......................
The theoretical number of theoretical plates can first be estimated using a simplified method, after which a controller can be added; then the precise method can be used for calculation. 2 B3 ]' H! Y: T4 k0 _$ l+ }
The last edit to this post was made by Albertlu on 2009-5-1 at 21:28. The value given by PRII is the theoretical number of plates; to determine the actual number of plates, it is usually necessary to know the actual overall efficiency of the tower, which requires looking up the actual overall efficiency for towers of that type. In cases where the requirements are not strict, the overall efficiency can also be estimated using the manual.
Take a look at what type of tower the poster wants to use. In the case of a packed tower, it is possible to first estimate the number of theoretical plates and then carry out precise calculations to determine the tower diameter and the evaporation rate in the reactor bottom
It would be better to first do a simple calculation using Aspen, and then carry out the calculation in ProII