Abstract: In a process for extraction of biological material, in particular of proteins or peptides, from a first aqueous solution (1) to a second aqueous solution (2), a porous membrane (3) is arranged between the aqueous solutions (1, 2). At least one of the aqueous solutions (1) is now modified by addition of a biocompatible and surface-active agent in such a way that the wetting behaviour of the two liquid phases on the membrane and in the pores of the latter differs significantly. In this way, membrane extraction of biological material from a first aqueous solution (1) to a second aqueous solution (2) is made possible in a simple and efficient manner. The process is easy to carry out and can be used on an industrial scale.

Abstract: Internal members or baffles for material exchange columns have at least one packing bed. The packing bed has at least one first packing block and at least one correction element associated with the first packing block. The first packing block and its associated correction element produce different final distributions of liquid or systematic maldistributions. The systematic maldistribution in the liquid phase caused by the first packing block is largely corrected by the systematic maldistribution of the associated correction element. Such an arrangement makes possible enhanced separation efficiency or higher packing beds.

Abstract: A sheet-metal strip provided with mutually staggered cuts is conveyed continuously at a first speed through a first conveying apparatus (23) and at a second speed, increased as related to the first speed, through a second conveying apparatus (24). Thereby, the strip section (21) freely traveling between the first and second conveying apparatus (23, 24) is stretched with the formation of a three-dimensional expanded grid structure. The process permits a continuous, rapid production of expanded grids of high precision and uniformity, especially with regard to mesh width and grid height.

Abstract: The liquid distributor has several horizontal channels (2), the sidewalls (6, 7) of which are penetrated by vertical or inclined drain slots (10) spaced apart in the longitudinal direction of the channel. At each drain slot, a plate-shaped baffle element (12) projects from the channel sidewalls (6, 7). The baffle element (12) has a baffle surface (11) directly adjoining the drain slot (10) and projecting outwardly from the channel sidewall (6, 7), and accommodates the entire amount of liquid exiting from the drain slot (10) and conducts this liquid to a (single) drainage and/or drip-off point (16). The drainage and/or drip-off point (16) is located at the lower end of the bottom edge (14) of the baffle element (12), this edge extending obliquely downwardly away from the channel (2). The liquid distributor provides locally exactly defined drainage or drip-off points, uniform liquid distribution being achieved independently of the load.

Abstract: A packing (11) consists of laminated grids (a,b, . . . ) placed directly against each other. Each grid (a,b, . . . ) consists of approximately zigzag-shaped laminated strips (13-17) which run in the direction of the flow (22), are inclined towards the grid plane and are formed jointly in one piece with areal crossing points (b 18). The laminated strips (13-17) have recesses (20, 21) at the outer edges of the crossing points (18). In this way, it is achieved that the liquid phase flowing down on a laminated strip to a crossing point is directed, at least partially, across the crossing point to the adjacent laminated strip. The packing which can be produced in a simple and inexpensive way has a high specific surface and distributes the liquid on all sides transversely to the direction of the flow (22) whereby the turbulence required for the surface renewal develops at the crossing points of the grids.