A mixing system is disclosed which provides improved multiphase mixing
through the use of a novel quench injection means. The mixing system
comprises a horizontal collection tray, a mixing chamber positioned below
the collection tray, and at least one passageway extending through the
collection tray into the mixing chamber. The mixing chamber and the
collection tray define a two-phase mixing volume. The passageway conducts
fluid from above the collection tray into the mixing chamber. The mixing
chamber preferably includes at least one outlet opening for the downward
passage of fluid. In particular, mixing of quench fluid is significantly
improved when quench is introduced into a region above the collection
tray and where (i) lateral velocities of the process fluids are low, (ii)
sufficient volume is available for the quench fluid to mix with the
process fluids, and (iii) quench injection occurs opposite the prevailing
direction of process fluid flow.