Is jet flooding and or foaming a composition only issue for a hydrotreater stripper column?
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10/12/2012
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Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
The short answer to your question is no. Jet flooding is function of the vapor and liquid loadings and the design of the tray, but compositional factors of the stream being fractionated also come into play. There are a number of tray design programs which will calculate the % of jet flood for a given set of operating conditions and tray design parameters. There can be compositional parameters that go into these calculations because some services are more prone to foaming than others.
Things like high levels of solids from corrosion products, surfactants or entrained water can promote foaming, resulting in premature flooding of your column.
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08/12/2012
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Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
In any distillation column, jet flooding, or any kind of flooding, can cause loss of bottoms level, an upset by definition.
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07/12/2012
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Alan Goelzer, Jacobs Consultancy, alan.goelzer@jacobs.com
I am not sure that I understand the question. Well designed product steam stripper should employ latest generation trays in both stripping zone and rectification zone [valve trays or fixed mini valve trays with sloped downcomers preferably in stripping zone]. Modern trays should be operating at reasonable percentage of flooding [not too low and not too high and certainly NOT flooding]. Modern trays can and will operate with a temporary working 'foam' in the open space between active decks. Height of temporary working 'foam' should not exceed much above 18 inches if trays are 24 inches apart. With excessive hydraulic loadings and excessive 'foam' heights, there will be dramatic drop off in tray efficiencies versus theoretical stages. Stripping performance will decline and chances increase that flash point may drift downward and actual residual H2S will drift upward. Note that Copper Strip Corrosion Test is very sensitive to actual residual H2S levels (especially if there is any significant residual of RSH mercaptans).
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