Spiral membrane element

Abstract

According to the present invention, a spiral membrane element in which the durability of a bonding part between a membrane leaf and a central pipe is improved, and the central pipe is more easily separated and collected at the time of recycling. The spiral membrane element includes: a plurality of membrane leaves each having a permeation-side flow-channel between separation membranes facing each other; and a perforated central pipe around which the membrane leaves are wound with a supply-side flow-channel interposed between the membrane leaves. The spiral membrane element includes a bonding part in which each of both-side ends in an axial direction among inner peripheral-side ends of the membrane leaves is bonded to the central pipe, and the central pipe includes a tapered part having a peripheral surface whose diameter expands toward a center side in the axial direction in at least a partial area of the bonding part.

Dependencies are inferred from the claim text.