The present invention relates to a
spiral wound reverse osmosis membrane element which is formed by winding at least one set of water purification membrane module around a central
treated water pipe, and each set of the water purification membrane module is formed by laminating a mesh-like
treated water flow guiding member, a
reverse osmosis membrane and a mesh-like feed
water flow guiding member; the
reverse osmosis membrane is folded at a folded side to form a feed
water flow channel therein along its inner surface; a
treated water flow channel is formed between outer surfaces of adjacent reverse
osmosis membranes; the mesh-like feed
water flow guiding member is disposed inside the feed water flow channel; the mesh-like treated water flow guiding channel is disposed inside the treated water flow channel; the treated water flow channel is opened only at a treated water outlet which opens towards the central treated water tube, and the treated water flow channel is closed and sealed at remaining three sides; the feed water flow channel is closed and sealed at areas remote from the central treated water tube at two sides adjacent to the folded side, so that the feed water flow channel forms small sections of
raw water inlets respectively at areas closer to the central treated water tube at the two sides, and a concentrate outlet is formed at the feed water flow channel at a side opposite to the folded side. The improved reverse
osmosis membrane element of the present invention increases the water flow velocity along the
membrane surface and therefore reduces
concentration polarization and slows down the speed of
contamination of the
spiral wound type membrane element, and thereby enhancing the durability of the membrane element.