Patent ID: 8021455

Claim:
A filter element comprising a layered composite of non-woven air laid and wet laid media, comprising at least three layers of a nonwoven filter media, the filter element comprising: (a) An upstream media comprising at least two media layers of a first filter medium that is an air laid medium, the medium comprising 1 to 100 wt % of a first fiber comprising a bicomponent fiber comprising a diameter of 5 to 50 microns, and 5 to 50 wt % of a second fiber, wherein the first filter medium has a pore size of 50 to 100 micrometers, a permeability of 50 to 800 ft-min −1 , a solidity of about 2 to 25% at 860 Pa, a basis weight of 150 to 350 g-m −2 , and a compressibility of greater than 0.7 between 860 Pa and 3860 Pa; and (b) at least two media layers of a filter medium that is a wet laid medium comprising a pore size of 4 to 200 micrometers, a permeability of 50 to 800 ft-min −1 , a solidity of about 2 to 25% at 860 Pa, a basis weight of 20 to 120 g-m −2 , and a compressibility of about 0.5 to 1.0 between 860 Pa and 3860 Pa, (c) at least two media layers of a filter medium that is a wet laid medium comprising a pore size of 4 to 200 micrometers, a permeability of 1 to 1000 ft-min −1 , a solidity of about 2 to 25% at 860 Pa, a basis weight of 20 to 120 g-m 2 , and a compressibility of about 0.5 to 1 between 860 Pa and 3860 Pa, wherein the filter element is capable of filtering both solid and liquid particulates from a heavily loaded fluid stream.