Abstract: For fluid interchange treatment, such as for heat exchanging or chemical interaction between a descending liquid and a rising gas, a flexible structure is provided which consists of stacked horizontal partition walls formed from pairs of sheets of non-woven fabric material, such as felt, heat-joined by plastic coatings on their inner surfaces and disposed in vertically-spaced parallel arrangement and sealed at their sides by accordion-folded sheets of flexible material. The paired sheets forming the spaced parallel partition walls of the structure contain ports which are arranged offset relatively to one another in successive sheets so that any fluid passing from top to bottom or vice-versa of the thus-formed cellular structure will pursue a zigzag path.

Abstract: For fluid interchange treatment, a flexible collapsible structure is provided which consists of stacked horizontal partition walls formed from pairs of sheets of non-woven fabric material such as felt heat-joined by plastic coatings on their inner surfaces and disposed in vertically-spaced parallel arrangement and sealed at their sides by accordion-folded sheets of flexible collapsible material. The paired sheets contain ports which are offset relatively to one another in successive sheets. The paired fabric sheets and their plastic-coated inner surfaces are provided with openings to form cells with which the ports communicate, these openings being so arranged that, a multi-columned collapsible structure of parallel cellular formation results, with independent zigzag paths between top and the bottom of each cellular column.