Patent ID: 7648128

Claim:
An apparatus for gas/liquid contact in a chemical process tower, comprising a tower and a series of trays and downcomers, in which: each tray has a deck that is perforated with apertures through which gas can rise through liquid that is flowing across said deck, forming bubbles; at least one plate descends from an edge of the deck toward a tray immediately below so as to form a downcomer volume situated between the edge of the deck and walls of the tower, the plate having several substantially vertical tubular passages by which gas can pass through said plate, a top of each of said passages being at about the same height as a surface of the deck; a baffle is situated between the edge of the deck and the walls of the tower so as to divide the downcomer volume into two substantially vertical portions, a first portion being a downcomer immediately adjacent to the walls of the tower and a second portion being an active sump situated between the first portion and the edge of the deck, there being apertures toward the bottom edge of the baffle through which liquid can descend from the active sump to a lower portion of the downcomer volume, such that gas rising through the passages in the plate is bubbled through liquid flowing into the active sump.