SEPARATION FILM ELEMENT

To provide a separation film element that is able to reduce film-surface concentration polarization when operating the separation film element and improve an amount of produced water and desalination performance.SOLUTION: A separation film element according to the present invention includes a water collection pipe, a separation film, a supply-side passage member, and a permeation-side passage member. The supply-side passage member has a net shape in which at least two types of fibers of a fibrous row X composed of a plurality of fibrous materials A arranged in one direction and a fibrous row Y composed of a plurality of fibrous materials B arranged in a direction different from that of the fibrous row X cross each other three-dimensionally to form an intersection. A distance L1 between the separation film and the fibrous material A or the fibrous material B is 30 to 80 μm, a coefficient of variation of areas of division regions formed between the separation film and the fibrous material is 0 to 0.20, the ratio D1/D of a depth D of the supply-side passage member to the depth D1 of the fibrous material in a direction of the depth D of the fibrous material A and the fibrous material B is in the range of 0.4 to 0.6, and an interval between intersection parts in a direction parallel to a raw water flow direction of the supply-side passage member is in the range of 3.5 to 5.5 mm.SELECTED DRAWING: Figure 3 【課題】分離膜エレメントを運転したときの膜面濃度分極を低減し、造水量や脱塩性能を向上できる分離膜エレメントを提供する。【解決手段】本発明の分離膜エレメントは、集水管と、分離膜と、供給側流路材と、透過側流路材とを備え、供給側流路材は一方向に並んだ複数の繊維状物Ａから構成される繊維状列Ｘおよび繊維状列Ｘとは異なる方向に並んだ複数の繊維状物Ｂから構成される繊維状列Ｙの少なくとも２種類以上の繊維が互いに立体交差して交点を形成したネット形状であり、分離膜と繊維状物Ａもしくは繊維状物Ｂとの距離Ｌ１が３０～８０μｍ、分離膜と繊維状物の間に形成される分割領域の面積の変動係数が０～０．２０、供給側流路材の厚みＤと繊維状物Ａおよび繊維状物Ｂの前記厚みＤ方向における繊維状物の厚みＤ１の比Ｄ１／Ｄが０．４～０．６の範囲、供給側流路材の原水流れ方向に対して平行方向の交点部の間隔が３．５～５．５ｍｍの範囲である。【選択図】図３