Co-current contacting separation tray design and methods for using same

Abstract

Tray designs for use in a separation column for distilling or fractionating a feed stream are provided that incorporate co-current contact of the liquid and vapor streams and their subsequent separation on each tray. In one embodiment, located on the trays are a plurality of co-current vapor and liquid contacting sections including a volume of the tray in which vapors and liquid can be in co-current contact. Also located on the trays are a plurality of de-entrainment devices for separating entrained liquids from a vapor stream, the de-entrainment devices having an inner and an outer side, the inner side being adjacent to the co-current contacting sections. The tray design further incorporates a plurality of liquid downcomers, having an upper portion and a lower portion, where the upper portion of the liquid downcomer is capable of accepting liquid from the outer or bottom side of the de-entrainment device of a first tray, and the lower portion of the liquid downcomer is located within the co-current contacting section of a second tray that is vertically lower in the column from the first tray. The trays further contain vapor openings located through the bottom of the trays at a point beneath the co-current contacting sections through which vapors can pass into the co-current contacting section of a tray. In another embodiment, the liquid from some of the de-entrainment devices is directed through conduits to co-current contacting sections that are located horizontally adjacent on the same tray, thereby providing multiple contacts of the liquid with the vapor on a given tray before the liquid is passed down via a downcomer to a lower tray in the column.