Cyclonic separation device

A cyclonic separator device for removing dust or debris from dirt-laden air, the device having a separating chamber, an inlet, an outlet, and a shroud that is connected to the separating chamber at one end, and provides a plurality of openings for the passage of air to the outlet. The device further includes a dirt collection chamber in communication with the separating chamber. The separating chamber includes an airflow directing formation which is connected to an inner surface of a generally cylindrical portion and which extends inwardly towards a central axis of the generally cylindrical portion. The airflow directing formation provides a surface which follows a substantially helical path that extends away from the inlet as it extends circumferentially around the inner surface of the generally cylindrical portion.