Membrane support and membrane filtration device

A membrane support (1), comprising

• a support surface (2) provided on an upstream side of the membrane support and adapted to support a flat deformable filtration membrane (7) thereon, and
• a drainage structure (4) arranged below the support surface (2) to collect a fluid that has passed the deformable filtration membrane (7) supported on the support surface (2) and guide the fluid away to a downstream side, wherein the drainage structure (4) comprises a channel network connected with a drainage port (5) on the downstream side of the membrane support (1),
• wherein the support surface (2) is formed by raised lands or ridges and has a plurality of recesses (6) distributed over the support surface (2), wherein the depth and width of the recesses is smaller than that of the channels and formed to absorb expansions of the deformable filtration membrane (7), wherein the ratio of depth to width of the recesses (6) is from 5 to 40,
• wherein the deformable filtration membrane (7) has an absorbed surface area of at least 8.5 mm2 of a total nominal flat surface area of 1256.6 mm2.