Distillation

Dear Norm – How can I tell for sure my debutanizer trays are flooding without running an expensive TRU-TEC radiation scan?

--Fred, Texas

Fred – A delta P survey is not always meaningful unless flooding is starting at the lower trays. Thus, with the reboiler on auto, increase the reflux. The tower bottom minus top temperature should increase. If this doesn’t happen, then the tower is losing tray efficiency due to entrainment. A loss of tray efficiency with increasing vapor-liquid traffic is due to jet flood.

---Norm