Countercurrent

Name:
Countercurrent
Detailed information:
Descriptive of a process in which a liquid and a vapor stream, or two streams of immiscible liquids, or a liquid and a solid are caused to flow in opposite directions and past or through one another with more or less intimate contact so that the individual substances present are more or less completely transferred to that stream in which they are more soluble or stable under the conditions existing. The streams leaving such a process are usually of higher purity that can be attained otherwise at equal cost. Distillation with a fractionating column is also a typical countercurrent process, in which rising vapor is purified by contact with descending liquid (reflux). Leaching, washing, and chemical reaction are frequently carried out in a countercurrent manner.See Liquid-liquid Extraction.