For a project we use a saturator which is filed with benzene and N2 is passed through to carry the benzene vapours through a packed coloumn.
How can we calculate the incoming concentration of the liquid in the vapour? and also its new flow rate.
Thanks!
The problem you've described is similar to any two-phase flow calculations. Your calculations will depend the flow configuration (slug flow, mist flow, or annular flow). For example, if the liquid (benzene) forms a layer near the wall and the gas (N2) is in the core, then the flow is annular. Since, you have a packed column and the two-phased are not miscible, then most likely you will have gas bubbles dispersed in the liquid. What makes this problem more complex is that is the temperature in the column is high such that some of the liquid benzene evaporates, then the gas phase will be a mixture of N2 gas and benzene vapor. As a first approximation, you can assume that benzene will stay in the liquid phase and the has phase bubbles will be pure N2 gas. You then need to measure the percentage of the two phase flow occupied by the gas phase and calculate the so called gas void fraction (say alpha). Then the liquid void fraction will be (1 - alpha).
Use the alpha and (1-alpha) as weighing factor to calculate the mixture properties (e.g., concentration, density, etc).
I suggest that you review any textbook on two-phase flow calculations to better understand the approach that I outlined above.
Good luck!
Professor Yehia Khalil
Yale University
USA
- Badges
- Science topic
- Similar topics
- Chemistry
- Organic Chemistry