Abstract: An air treatment unit for treatment of an air stream, including a pad having a multitude of narrow air-flow channels, the walls of which are formed by corrugated sheets of a stiff material, the sheets being positioned and fixed generally in parallel planes next to each other in such a way that, as seen from an inlet side of the pad to an outlet side thereof, the channels formed by the corrugations of any two sheets located next to each other extend in two different directions the vertical plane of the respective sheet. At least in a central region of the pad, all sheets are positioned obliquely sideways, whereby all channels extend obliquely sideways relative to inlet and outlet surfaces of the pad.

Abstract: A method of preparing cells for the purpose of enabling one fluid to be affected by another fluid via thin membranes of inorganic artificial fibres, which membranes are corrugated all over or in part and caused to bear upon each other along discrete lines of contact so as to form through passages or compartments for the fluids. The cell is constructed of membranes of artificial fibres which have a filament diameter of at least 3 and at most 20 micrometers and are elastic. The fibres are loosely matted so that when the spaces between the fibres in the assembled cell have been filled with a fine powder which is bound with an inorganic binder the powder forms a load-bearing layer which is cohesive throughout the surface extension of the membrane and through its cross-section and in which the fibres act as reinforcement.