Separation membrane element

Abstract

An object of the present invention is to provide a separation membrane element having high fluid permeability and separation performance. The separation membrane element of the present invention includes a central tube with holes, a plurality of separation membrane pairs formed so that the permeation-side surfaces of the separation membranes having a supply-side surface and a permeation-side surface face each other, and a pair of separation membranes provided on the supply side of the separation membrane pair. The supply-side channel member between the surfaces, and the permeation-side channel member disposed between the permeation-side surfaces of the separation membrane pair, the separation membrane pair is wound around the perforated central tube, the supply-measuring channel member, On the surface of the separation membrane on the supply side, one end face and the other end face in the longitudinal direction of the perforated central tube and the inner periphery in the direction perpendicular to the longitudinal direction of the perforated central tube Two or more of the end faces or ends of the end and the outer peripheral end are respectively open by more than 5%, and the plurality of separation membrane pairs are composed of at least one first separation membrane pair and at least one second separation membrane pair, and the first separation membrane The combination of end surfaces or end portions of the openings in the pair and the second separation membrane pair are different.

Description

technical field [0001] The present invention relates to a separation membrane element for separating components contained in fluids such as liquids and gases. Background technique [0002] In recent years, as a technique for removing ionic substances contained in seawater, salt water, etc., as a process for energy saving and resource saving, a separation method by a separation membrane element is widely used. Separation membranes used in separation methods using separation membrane elements can be classified into fine filtration membranes, ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, and forward osmosis membranes based on their pore size and separation function. These membranes are used in the production of potable water from, for example, seawater, brine, and water containing hazardous substances, in the production of ultrapure water for industrial use, and in wastewater treatment and recovery of valuable substances, etc., depending on the...

AI Technical Summary

Problems solved by technology

[0010] Although the separation membrane elements described in Patent Document 1 and Patent Document 2 can improve the turbulent flow effect on the membrane surface and suppress concentration polarization, they have the following problems: especially when performing high recovery rate operation (recovery rate: permeate fluid volume vs. In the case of the ratio of the amount of feed fluid supplied to the element), the flow rate of the feed fluid decreases as it approaches the outlet of the feed fluid, so the separated components in the feed fluid are concentrated, and the effect of turbulence on the membrane surface decreases, resulting in a concentration of Increased, fluid permeability, separation performance decreased, easy to produce scale (scaling)

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