Hollow fiber membrane module

A hollow fiber membrane module for use in filtration, diafiltration, or dialysis, which comprises:

• (a) a wall that surrounds an inner space;
• (b) at least one segmentation element extending from the wall into a packing space that surrounds the wall on the side opposite the inner space, the segmentation element being permeable so that liquid can pass through it;
• (c) an outer structure that surrounds the packing space;
• and
• (d) at least two hollow fiber membrane bundles arranged parallel to one another in the packing space and retained within the packing space by the wall and the outer structure, wherein each hollow fiber membrane bundle is separated from other hollow fiber membrane bundles by a segmentation element;
• each hollow fiber membrane bundle including a plurality of tubular hollow fiber membranes, wherein a volumetric ratio of the hollow fiber membranes to the packing space is less than 10%.