| 摘要 |
A spiral separation membrane element which can attain a reduced pressure loss in the permeation-side passage and is effective especially when the feed-side pressure is low, is disclosed. The spiral separation membrane element comprises a perforated core tube and, wound therearound, one or more separation membranes, one or more feed-side passage materials, and one or more permeation-side passage materials, wherein the permeation-side passage materials each have warps 1 extending almost parallel with the direction of flow of a permeated liquid and wefts 2 fixed to the warps 1, a ratio of a pitch (width of each warp+distance between the opposed sides of adjacent warps) to a distance between the opposed sides of adjacent warps (w2/w1) is 1.1/1 to 3/1, and a ratio of a thickness of the passage material to a distance between the opposed sides of adjacent warps (t/w1) is 0.25/1 to 1.25/1.
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