Patent ID: 6962661

Claim:
A liquid-liquid extraction method for contacting a relatively heavy liquid phase with a relatively light liquid phase, comprising: introducing a feed stream of the heavy phase for downward flow at a volumetric flow rate at an upper inlet of a liquid-liquid extraction vessel comprising a plurality of successive, vertically-arrayed trays including at least one perforated deck per tray and at least one riser per tray, wherein the risers include respective top and bottom sections, wherein the bottom riser sections have larger transverse cross-sectional areas than respective top riser sections; introducing a feed stream of the light phase into a lower inlet of the extraction vessel for upward flow as a continuous phase at a volumetric flow rate greater than the heavy phase flow rate; passing the heavy phase through perforations in the decks of successive trays to disperse droplets of the heavy phase into respective cross-flow zones below the decks; collecting the heavy phase on respective upper surfaces of the successive decks; passing the light phase through respective cross-flow zones into adjacent disengagement zones and through the respective risers to discharge into succeeding cross-flow zones.