Composite filter medium and fluid filters containing same

摘要

A composite filter medium for removing at least 99.95 percent of particulates of a size in the 3 to 4 micron range and dissolved chemical contaminants from a fluid and filters of various configurations employing the composite filter medium are disclosed. The composite filter medium comprises an adsorbent layer containing an adsorbent agent and a hydrophilic particulate intercepting layer disposed adjacent to the adsorbent layer. The composite medium has a mean flow pore diameter of about 1 to 10 microns, a bubble point of about 3 to 15 microns and an air permeability of about 0.5 to 7 liters per minute/cm2 with a pressure drop of about 0.1 bar.