Transfer membrane apparatus

A membrane assembly, for use in mass or heat transfer apparatus, the assembly comprising a pair of generally parallel plates (7) spaced apart with a profiled surface of one plate facing a similarly profiled surface of the other plate;

• and a pair of sheets of transfer membrane material (6) closely spaced, throughout substantially their whole area, face to face between the plates with each sheet supported by and partially nesting in the profiled surface of the adjacent plate, to provide between the membranes a first conduit (5) for a first fluid and, between each sheet and the adjacent plate a second conduit for a second fluid;
• each sheet presenting in its surface facing the other sheet a regular close packed array of permanent dimple-like depressions (14), each facing and substantially aligned with a similar depression in the other sheet, whereby, in use, when the one fluid is passed through the first conduit (5) with a pulsatile flow, vortex mixing occurs in the depressions, the profiled surface of each of said plates comprising depressions in alignment with the depressions in the respective sheet partially nesting therein, and grooves (10) interconnecting adjacent said depressions in the plate, said grooves forming spaces between the respective sheet and plate profiled surface.