Composite filtering medium for removing particles, has diaphragm filtration layer, which exhibits porous polymer membrane, and depth filtration medium layer exhibiting fibers and arranged on upstream side of diaphragm layer

摘要

A composite filtering medium has a diaphragm filtration layer (20), which exhibits a porous polymer membrane, where the diaphragm layer has an upstream side and a downstream side relating to a gas flow direction. A depth filtration medium layer (18) exhibits fibers that have an electric charge, and is arranged on the upstream side of the diaphragm layer. A supporting layer is arranged on the downstream side of the diaphragm layer.