A device comprising a centrifugal separator for cleaning of a gas, especially a gas containing impurities in the form of solid and/or liquid particles, wherein the centrifugal separator comprises - a stationary casing, which encloses a separation space and permits the gas to flow therethrough, - an inlet channel, which extends to the separation space and forms an inlet to the separation space for a gas flow of the gas to be cleaned, - a rotating member, which is provided in the separation space downstream the inlet with regard to the gas flow and arranged to rotate in a direction (r) of rotation about an axis (x) of rotation, wherein the rotating member comprises a plurality of separation discs, which are arranged in a stack so that a gap is formed between adjacent discs, and is adapted to bring the gas to rotate in the direction (r) of rotation for separating by means of centrifugal forces at least a main part of the impurities from the gas, and wherein the separation discs form surfaces on which the particles to be separated from the gas to be cleaned may be caught and transported outwardly towards the inner wall surface, - a gas outlet channel, which with regard to the gas flow is provided downstream the rotating member for discharging the cleaned gas, and - at least a first outlet, which is provided for discharging a separated phase of the gas from the separation space, wherein the device also comprises a supply member which is configured to permit supply of a liquid to form of an aerosol to be supplied to the gas to be cleaned and which comprises a supply conduit with an outlet end, characterised in that the supply member comprises an ejector nozzle connectable to a pressurised gas conduit and comprising a nozzle outlet, and that the nozzle outlet is provided at the outlet end of the supply conduit and arranged to permit ejection of the liquid in the form of said aerosol from the outlet end of the supply conduit by means of the pressurised gas supplied to the ejector nozzle and the nozzle outlet. - a stationary casing, which encloses a separation space and permits the gas to flow therethrough, - an inlet channel, which extends to the separation space and forms an inlet to the separation space for a gas flow of the gas to be cleaned, - a rotating member, which is provided in the separation space downstream the inlet with regard to the gas flow and arranged to rotate in a direction (r) of rotation about an axis (x) of rotation, wherein the rotating member comprises a plurality of separation discs, which are arranged in a stack so that a gap is formed between adjacent discs, and is adapted to bring the gas to rotate in the direction (r) of rotation for separating by means of centrifugal forces at least a main part of the impurities from the gas, and wherein the separation discs form surfaces on which the particles to be separated from the gas to be cleaned may be caught and transported outwardly towards the inner wall surface, - a gas outlet channel, which with regard to the gas flow is provided downstream the rotating member for discharging the cleaned gas, and - at least a first outlet, which is provided for discharging a separated phase of the gas from the separation space, wherein the device also comprises a supply member which is configured to permit supply of a liquid to form of an aerosol to be supplied to the gas to be cleaned and which comprises a supply conduit with an outlet end, characterised in that the supply member comprises an ejector nozzle connectable to a pressurised gas conduit and comprising a nozzle outlet, and that the nozzle outlet is provided at the outlet end of the supply conduit and arranged to permit ejection of the liquid in the form of said aerosol from the outlet end of the supply conduit by means of the pressurised gas supplied to the ejector nozzle and the nozzle outlet. wherein the device also comprises a supply member which is configured to permit supply of a liquid to form of an aerosol to be supplied to the gas to be cleaned and which comprises a supply conduit with an outlet end, characterised in that the supply member comprises an ejector nozzle connectable to a pressurised gas conduit and comprising a nozzle outlet, and that the nozzle outlet is provided at the outlet end of the supply conduit and arranged to permit ejection of the liquid in the form of said aerosol from the outlet end of the supply conduit by means of the pressurised gas supplied to the ejector nozzle and the nozzle outlet.