Abstract: Fluid separating apparatus in which a stack of membrane support plates are clamped between two end plates, each membrane support plate including two elementary plates of generally rectangular configuration and substantially constant wall thickness, said elementary plates being assembled in back-to-back relationship. The elementary plates are joined in fluidtight manner to one another, at least one orifice extending through each elementary plate in the vicinity of at least one end thereof for the passage of fluid to be treated, a first recess being provided on the front face of at least one of the two elementary plates, said recess forming a cell. A chamber is located between the back faces of the elementary plates and perforations through at least one elementary plate provide communication between each cell and the associated chamber and duct forming means provide communication between the chamber and the edge of the support plate.

Abstract: Separation apparatus useful particularly for ultrafiltration in which a series of membranes are mounted in superposed relationship with membrane supports, and, where appropriate, distribution plates therebetween, the membranes being mounted in subassemblies so that the flow of fluid through the individual chambers between the membranes of a particular sub-assembly is substantially in parallel. .Iadd.