Seek advice on the criteria for selecting the number of trays in a packed tower calculation
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In PROII calculations, how should the number of tray levels be determined for packed columns? Those with experience, please provide some guidance. This post was last edited by HaiChuanZhiFeng on 2007-12-20 at 23:10.]
Yeah, talk about it; I’m also confused
Start: Use 1 theoretical plate per 2 feet of packing. Then: Determine using model calibration
Generally, the tower height is entered casually by a few units, and then adjustments are made based on the degree of consistency between the calculated results and the actual data.
First, some empirical data on the distillation column is needed to roughly determine the number of theoretical plates required. If you don’t have experience in this area. The theoretical number of plates can first be estimated using a simplified valve method, and then adjusted in a more rigorous algorithm based on your distillation requirements and the calculation results. The relationship between the number of theoretical plates and the packing height is complex; it depends on the type of packing, its physical properties, and the operating conditions. It is generally determined based on experience, although it can also be calculated, though not with great accuracy, especially for some special systems
The filler HETP inferred from the existing device
Generally, simulation is first carried out based on the number of theoretical plates, and then the height of the packing is selected based on experience
There is a detailed explanation in \"Principles of Chemical Engineering\"; you can take a look
I can’t quite understand it; the answers from the experts are rather scattered. Could someone experienced provide a systematic summary?
The currently popular approach is to use the DSTWU model for quick calculations based on the separation requirements of the key components, determine the relationship between the number of theoretical plates and the reflux ratio, and then select an appropriate number of theoretical plates and reflux ratio based on this relationship curve. Based on this data, a modeling process with rigorous calculations is carried out.
First, use a simplified algorithm, such as the shortcut in ProII, to estimate the approximate number of theoretical plates. Then, in a more rigorous algorithm, make some adjustments based on this estimated value in order to determine the actual number of plates. In process simulation, there is no difference in the calculation of theoretical stages for packed columns and tray columns; as for the half-height, it depends on the properties of the fluid being processed and the substances that need to be separated
First, some empirical data on the distillation column is needed to roughly determine the number of theoretical plates required. Then select an appropriate plate height to calculate the other parameters of the packed tower. I’m not sure whether Aspen and HYSYS can perform hydraulic calculations.
Chemical process simulation isn’t very precise; it involves a lot of empirical elements, and many parameters need to be determined through trial and error – in other words, they are estimated
Now I need to carry out the simulation for this packed tower as well; after doing it, I’ll look at this post again and it will seem different