Method and device for mass transport and separation through selective barriers

A method for carrying out mass transport and subsequent physical, substantially quantitative separation of one or more components from one phase to another phase, the phases comprising a solid and a liquid phase and including in each instance an upper liquid phase, in the same device, which comprises:

• a vertical mixing reservoir, having an inner diameter, an outer diameter, an inner wall an an upper end;
• a mixer-separator snugly fitted into said reservoir for sliding movement therein and including means defining at least one channel passing axially through said mixer-separator, said mixer-separator including at its lower end at least one barrier which is selectively permeable to the upper liquid phase in said mixing reservoir and at its upper end a container which has a top and into which opens said at least one channel for accumulating separated liquid from said upper liquid phase from the mixing-reservoir forced through said barrier and said at least one channel in response to sliding movement of said mixer-separator is pushed down into said mixing reservoir;
• a sealing element surrounding said mixer-separator at a preselected distance above the lower end of said mixer-separator, said sealing element being positioned above said barrier;
• and
• means defining a space positioned in the axial direction between said barrier and said element, for providing a gas cushion for decreasing the pressure exerted on said barrier in response to sliding movement of said mixer-separator into said mixing reservoir, the configuration of said space and the gas cushion being selected so as to force back into said mixing reservoir any of the liquid phase which has crept up along the inner wall of the mixing reservoir above the lower end of the mixer-separator, whereby substantially quantitative separation of the upper liquid phase can be accomplished, said method comprising the steps of:
• introducing the phases to be contacted including a liquid phase into said vertical mixing reservoir, mixing the components, pushing into said mixing reservoir with a sliding movement said mixer-separator possessing at least one barrier and said sealing element located above said at least one barrier so as to force a clear liquid phase through said at least one barrier and convey it through said at least one channel in the mixer-separator into a container at the upper end of the mixer-separator, and accumulating a gas cushion between said sealing element and the surface of the liquid phase in said mixing reservoir sufficient to decrease the pressure exerted on said at least one barrier in response to the sliding movement of said mixer-separator into said mixing reservoir and to force back into said mixing reservoir any of the liquid phase which has crept up along the inner wall of the mixing reservoir above the lower end of the mixer-separator, said gas cushion being maintained during the entire sliding movement of the mixer-separator into the mixing reservoir until all of the liquid phase is forced through said at least one barrier, whereby substantially quantitative separation of the liquid phase can be accomplished.