GB973748A - Apparatus for mass transfer between two phases - Google Patents

Abstract

In apparatus comprising an exchange chamber in which two different phases are brought into intimate contact with each other so that a substance passes, at least partially, from one phase into the other phase, a mechanical pump is used to convey at least one of the <PICT:0973748/C1/1> phases to a mixing device in which the phases are contacted with each other before they flow into the exchange chamber, and a centrifugal separator is employed to separate the phases after they leave the exchange chamber. The apparatus may be used for washing carbon dioxide out of synthesis gas with a liquid, for liquid/liquid extraction processes e.g. extracting uranyl nitrate from an aqueous solution by means of ether, and for isotope exchange reactions e.g. deuterium exchange between liquid ammonia and gaseous hydrogen. The column 20 contains a series of units (of which only two are shown), each suitable for mass transfer between a liquid phase and a gaseous phase. Each unit comprises an exchange chamber 26 provided with baffles 28, an ejector 27 which serves as the mixing device, a pump 22 driven by an electric motor, a liquid level vessel 25 having an overflow conduit 24 to the next lower unit, and a centrifugal separator 23. The starting liquid phase is introduced into the vessel 25 of the top unit, and the starting gaseous phase flows into the bottom of the column. Pump 22 draws in gas from the space between two units and discharges it through nozzle 31 into the ejector 27; and liquid is drawn into the ejector from vessel 25. The mixture of liquid and gas passes out of the ejector into the exchange chamber 26. After mass transfer has taken place, the mixture passes through tangential nozzles 29 into centrifugal separator 23. The separated liquid flows down to vessel 25, and the separated gas is drawn into the pump of the unit above. Some of the liquid in vessel 25 flows down conduit 24 into the vessel 25 of the unit below. If a unit should break down during operation, e.g. owing to a motor fault, the gas flows to the next higher unit through by-pass 21.