One Minute Process Engineering: Optimize the Size of Two-phase Vertical Separators

It is nothing new for process engineers to size a vertical two phase separator. However, the challenge is no two process engineers will give you the same design, though the same information is given. In this video, Guofu will show you how you can optimally size a two phase vertical separator with confidence in one minute.

The process data can be directly imported from the commercial simulator ProMax. As you can see, right after the process data is imported, you've already had a separator design. The program first sizes all the nozzles, then vessel diameter, then the vessel height and finally the vessel weight.

In the calculation area, there are four columns. The first column is named "Final Actual", which stands for the final dimension or actual velocity. The second column is named "Intermediate", which is an intermediate value that helps to derive the final value. The third column is named "Recommend" which is the recommendation value by the program. And the last column is called "User Input", where you can override all the recommendation by the program.

The feed nozzle diameter is calculated based on the Ro-v-square criteria. As you see, the inlet feed nozzle Ro-v-square criteria is set to 1000 and the feed nozzle diameter is calculated as 12 inch. If you have a different criteria, just type it in the user input cell, say 1500, instantly the feed nozzle diameter is adjusted to 10 inch. Vapor nozzle and liquid nozzle are sized the similar way.

Vessel diameter is based on the K factor which is calculated based on GPSA guideline. The final diameter will be round to the next larger half feet or whole feet.

Vessel height is calculated based on the retention time and the recommendation from the GPSA handbook.

Most of the software stops right here. However, Guofu Chen goes an extra mile to bring the software to the next level.

This spread sheet will also calculate the thickness of the shell and the head and the weight of the vessel.

As you probably know, the diameter calculated by GPSA is the minimum diameter to allow a good separation between gas and liquid. Most of the time, a larger diameter will allow to have a shorter height and it might save cost. Based on experience, the vessel cost is highly related to the vessel weight. Thus this tool aims at reducing the vessel weight to reduce cost, while still functional.

Currently the vessel weight is 7435 lb with a diameter of 36". Simply click the "Optimize" button, The program suggests you can reduce the vessel weight by 5.7% by changing the diameter from 36" to 48".

Now you have a separator design not only full functional, but also the lowest cost. All this is done in just one minute.

Thanks for watching this video. It is brought to you by Guofu Chen. More interesting topics can be found at showcase.guofuchen.com.

For those who can't see the embedded video in this blog, please watch this video on youtube.com at https://youtu.be/QuuBRHWbO30