To supply clean cooling air to interior components of a ram air fan.

A particle separator includes a first housing 44 and a second housing 46. The first housing extends along an axis from an open proximal end 52 to an open distal end 54. The second housing has a closed proximal end 56 disposed adjacent to the open proximal end of the outer housing. The second housing extends from the closed proximal end into the first housing along substantially the same axis as the axis of the first housing. The second housing has one or more passages 48 disposed at a distance from the closed proximal end of the second housing. Additionally, the one or more passages are disposed within the first housing at a distance from the open proximal end thereof.