(124b) Is the Hydraulic Gradient on Sieve and Valve Trays Negligible?

Hydraulic gradient estimates are important for troubleshooting channeling and multipass maldistribution problem on trays, yet there is no satisfactory method in the open literature to evaluate it. A common assumption in sieve and valve tray calculations is that the hydraulic gradient is negligible. This is supported by the literature leading method for hydraulic gradient calculations. In contrast, a rule of thumb we published in the 8th edition of Perry’s Handbook, based on quantitative gamma scan data analysis, suggests that the hydraulic gradient on these trays may be significant when the liquid load is high and the flow path is long.

This paper looks further into the prediction of hydraulic gradients by comparing to published FRI data.