Two Phase Flow Pipe Sizing - A Major subject for a Process Engineer

Hi

Proper pipe sizing is crucial for a process engineer to optimize the fluid flow. This shall ensure efficient operation of different equipment plant.

But did you know that two-phase flow - the simultaneous flow of both liquid and gas - is one of the most critical and complex aspects of pipe sizing?

The most important aspect of two-phase flow is the prediction of flow regimes.

Within a pipe, the liquid-vapor mixture can be shaped in different flow regimes, from wave and stratified flow to the dreaded slug flow, which is the one we should avoid or at least minimize its effect.

Prediction of the flow regime is very complex. It depends on several factors ike vapor fraction, flow rate, physical properties. However, the pipe orientation is may be the most common factor.

In order to predict the flow regime, we have different charts, and whether the pipe orientation being vertical or horizontal, this shall lead to different charts. For example, this is an example of a flow calculation for the same fluid. One is based on a horizontal pipe. The flow regime was bubble:

However, when carrying out the calculation for a vertical pipe, which is based on another correlation, it yielded slug flow:

That's why a process engineer should understand well the issues with two-phase flow and how to solve these issues.

For example, if the pipe can be sized to eliminate slug flow, then this would be the optimal solution. If not, then pipes experiencing slug flow should be well supported, and this requirement should be clearly conveyed to the piping engineer.

If a high slug volume is expected, then the receiving vessel should consider accommodating it. Pockets in the pipe should be minimized and eliminated, and so on.

Here we see that pipe sizing is a major activity that is carried out by a process engineer. In my article, "Pipe Sizing Criteria and Calculation Procedure for Process Engineers," I dive deep into the factors that influence two-phase flow and the various calculation methods used to determine the optimal pipe size for these challenging scenarios. You can check out the article through the below button:

Check Article!

I hope you shall like the article. If you have any questions or want to share your experience. I'm more than welcoming your feedback in the article comments.

Invest in your expertise today and take your process engineering skills to the next level.

Regards,

Mohamad

P.S. I have also created a new video explaining how to create pipe sizing function in Excel using VBA. You can check it out by clicking here.