MEMBRANE FILTER UNIT

摘要

A membrane filter unit that ensures the durability of hollow fiber membrane module through prevention of, in activated sludge treatment, bundling of porous hollow fiber membranes of the hollow fiber membrane module by hair, fiber, paper piece, etc. contained in wastewater or entwining or getting stuck thereof between hollow fiber membranes and surrounding frame member, etc. The membrane filter unit (5) includes hollow fiber membrane module (9) composed of multiple sheetlike hollow fiber membrane elements (10) arrayed in parallel at given intervals, each of the hollow fiber membrane elements (10) obtained by parallel arrangement of a multiplicity of porous hollow fiber membranes (10a). Further, the membrane filter unit (5) includes, disposed inferiorly to the hollow fiber membrane module (9), air diffuser (15) capable of emitting minute bubbles toward the lower end of the hollow fiber membrane module and generating a gas-liquid mixed current vertically swirling between the internal space and external space of the hollow fiber membrane module. Still further, the membrane filter unit (5) includes residual foreign matter removing means capable of generating forced flow in part of the mixed current between porous hollow fiber membranes of the hollow fiber membrane module (9) and between sheetlike hollow fiber membrane elements to thereby expel any residual foreign matter mingled in the gas-liquid mixed current to outside of the hollow fiber membrane module.