US Patent 7854778 Intake duct

An intake duct for a compressor comprises an inlet and an outlet means. The duct has a serpentine path. The outlet means comprises a first outlet and a second outlet. The duct further comprises at least one grille member configured to prevent the passage of objects over a predetermined size which is positioned in the duct out of the line of sight when viewed through the inlet. The duct is shaped such that in operation objects passing through the at least one grille member greater than a predetermined mass are directed towards the first outlet and the remainder of the objects are directed towards the second outlet. The first outlet leads overboard and/or to a trap and the second outlet leads to a compressor.