A gas cleaning separator for separating a flowable mixture of a gas and liquid; the separator comprising: a housing (4',70') defining an inner space, a rotor assembly (78',84') for imparting a rotary motion onto said mixture of gas and liquid the rotor assembly (78',84') being located in said inner space and rotatable about an axis relative to the housing (4',70'), wherein the rotor assembly comprises an inlet for receiving said mixture of gas and liquid an outlet from which said gas and liquid are ejected from the rotor assembly during use, and a flow path for providing fluid communication between the inlet and outlet, wherein the outlet is positioned more radially outward from said axis than the inlet; and a housing member defining a region for receiving gas ejected from the rotor assembly (78',84') and directing said gas to a first outlet aperture of the housing (4',70'); characterised in that the housing member is provided with means for segregating an inlet to said region from gas which, in use, re-circulates back towards said inlet to said region after having flowed past said inlet to said region, wherein said segregating means comprises a wall extending from a downstream side of said inlet to said region in a downstream direction with respect to said flow of gas flowing, in use, past said inlet to said region, wherein said wall is spaced from said housing and comprises a free end, and wherein said wall defines a closed loop, and defines a frusto-conical shape, such as a frusto-conical shape having a longitudinal axis coincident with said axis of rotation, wherein said frusto-conical shape diverges in a downstream direction with respect to said flow of gas flowing, in use, past said inlet to said region; and in that the housing member comprises a wall for supporting the housing member relative to the housing (4',70'), the supporting wall being located downstream of the segregating means with respect to said flow of gas flowing, in use, past said inlet to said region, wherein said supporting wall has a cylindrical shape, such as a wall having a longitudinal axis coincident with said axis of rotation, and wherein the supporting wall defines a closed loop, wherein at least one aperture is provided in said supporting wall at a junction between said wall and the housing (4',70') for allowing the flow of gas and liquid past said supporting wall. a housing (4',70') defining an inner space, a rotor assembly (78',84') for imparting a rotary motion onto said mixture of gas and liquid the rotor assembly (78',84') being located in said inner space and rotatable about an axis relative to the housing (4',70'), wherein the rotor assembly comprises an inlet for receiving said mixture of gas and liquid an outlet from which said gas and liquid are ejected from the rotor assembly during use, and a flow path for providing fluid communication between the inlet and outlet, wherein the outlet is positioned more radially outward from said axis than the inlet; and a housing member defining a region for receiving gas ejected from the rotor assembly (78',84') and directing said gas to a first outlet aperture of the housing (4',70'); characterised in that the housing member is provided with means for segregating an inlet to said region from gas which, in use, re-circulates back towards said inlet to said region after having flowed past said inlet to said region, wherein said segregating means comprises a wall extending from a downstream side of said inlet to said region in a downstream direction with respect to said flow of gas flowing, in use, past said inlet to said region, wherein said wall is spaced from said housing and comprises a free end, and wherein said wall defines a closed loop, and defines a frusto-conical shape, such as a frusto-conical shape having a longitudinal axis coincident with said axis of rotation, wherein said frusto-conical shape diverges in a downstream direction with respect to said flow of gas flowing, in use, past said inlet to said region; and in that the housing member comprises a wall for supporting the housing member relative to the housing (4',70'), the supporting wall being located downstream of the segregating means with respect to said flow of gas flowing, in use, past said inlet to said region, wherein said supporting wall has a cylindrical shape, such as a wall having a longitudinal axis coincident with said axis of rotation, and wherein the supporting wall defines a closed loop, wherein at least one aperture is provided in said supporting wall at a junction between said wall and the housing (4',70') for allowing the flow of gas and liquid past said supporting wall.