Patent ID: 8387804

Claim:
An end cap for at least one of a diffusion device and a filtration device, the end cap having an inner surface which is axially symmetrical with regard to a longitudinal axis of the end cap and an inner surface having the form of a funnel and comprising, in the direction of increasing diameter, a first section (I) taking the form of at least one of a cylinder and a truncated cone, a middle section (II) taking the form of a torus segment, the radius R of the middle section (II) being in the range of from 4 mm to 10 mm, and a third section (III) taking the form of a truncated cone, wherein the diameter D of the base of the third section (III) and the angle α between the base of the third section and the lateral surface of the third section (III) and the volume V calculated according to the formula V =(π D 2 /4)×( h+D tan α/6) (I), wherein h is the minimum distance between the inner surface of the third section (III) of the end cap and the plane defined by the ends of the hollow fiber membranes, when the end cap is mounted on the at least one of a diffusion device and a filtration device, meet the condition: 1,000 ×D/V>a 1 ×(tan α) 2 +6 (II), with a 1 =100.