Abstract: A filter system 10 includes a pre-filter in a pre-filter zone 18 and a final filter in a final filter zone 22. The pre-filter is in the form of at least one inertial filter, e.g. an array 28 of axial flow cyclones 30. The final filter is in the form of a media filter 36 formed of a lofted bat of fibrous material which is of non-homogeneous structure through its depth. An upstream side is lofty, and a downstream side is of set structure. A contaminated fluid flow stream enters via an inlet 12. Contaminants are filtered out by the axial flow cyclones to be removed via a dust cover 32. Pre-filtered fluid flows via a chamber 20 through the media filter 36. After final filtration in the media filter it exits via a chamber 24 and an outlet 14.

Abstract: A filter system 10 includes a pre-filter in a pre-filter zone 18 and a final filter in a final filter zone 22. The pre-filter is in the form of at least one inertial filter, e.g. an array 28 of axial flow cyclones 30. The final filter is in the form of a media filter 36 formed of a lofted bat of fibrous material which is of non-homogeneous structure through its depth. An upstream side is lofty, and a downstream side is of set structure. A contaminated fluid flow stream enters via an inlet 12. Contaminants are filtered out by the axial flow cyclones to be removed via a dust cover 32. Pre-filtered fluid flows via a chamber 20 through the media filter 36. After final filtration in the media filter it exits via a chamber 24 and an outlet 14.