A system for scrubbing a gas stream by a pressurized working fluid, the system comprising: - at least one working chamber having at least one inlet and at least one outlet for the gas stream and at least one first opening for the inflow of the working fluid; - at least one first feed line of the working fluid which includes at least one spray nozzle to spray the working fluid within said at least one working chamber; - means for mounting said at least one nozzle onto said at least one working chamber in correspondence of said at least one first opening; wherein said mounting means are configured to allow said at least one nozzle to spray the working fluid within said at least one working chamber, the working fluid passing through said at least one first opening, said mounting means being further configured to allow the access to said at least one nozzle from the outside with respect to said at least one working chamber, so as to allow an operator to easily performing maintenance, replacement and / or adjustment operations thereon; wherein said mounting means are at least partially arranged externally to said working chamber, said mounting means being configured so that said at least one nozzle is placed externally to said working chamber in correspondence of said at least one first opening so that the flow of the gas stream does not invest said at least one nozzle; and further characterized in that said mounting means comprise a support structure with at least one seat defining an axis for said at least one nozzle, the latter being removably inserted in the former to spray the working fluid into said working chamber, said support structure comprising at least one tubular element defining said axis that internally includes said at least one seat, said at least one tubular element further including at least one second passing through opening transverse with respect to said axis, said at least one nozzle being slidable in said at least one tubular element between a working position wherein said at least one nozzle sprays the working fluid within said at least one working chamber and a checking position wherein said at least one nozzle is in correspondence of said at least one second opening to allow the operator to check the correct operation of said at least one nozzle. - at least one working chamber having at least one inlet and at least one outlet for the gas stream and at least one first opening for the inflow of the working fluid; - at least one first feed line of the working fluid which includes at least one spray nozzle to spray the working fluid within said at least one working chamber; - means for mounting said at least one nozzle onto said at least one working chamber in correspondence of said at least one first opening; wherein said mounting means are configured to allow said at least one nozzle to spray the working fluid within said at least one working chamber, the working fluid passing through said at least one first opening, said mounting means being further configured to allow the access to said at least one nozzle from the outside with respect to said at least one working chamber, so as to allow an operator to easily performing maintenance, replacement and / or adjustment operations thereon; wherein said mounting means are at least partially arranged externally to said working chamber, said mounting means being configured so that said at least one nozzle is placed externally to said working chamber in correspondence of said at least one first opening so that the flow of the gas stream does not invest said at least one nozzle; and further characterized in that said mounting means comprise a support structure with at least one seat defining an axis for said at least one nozzle, the latter being removably inserted in the former to spray the working fluid into said working chamber, said support structure comprising at least one tubular element defining said axis that internally includes said at least one seat, said at least one tubular element further including at least one second passing through opening transverse with respect to said axis, said at least one nozzle being slidable in said at least one tubular element between a working position wherein said at least one nozzle sprays the working fluid within said at least one working chamber and a checking position wherein said at least one nozzle is in correspondence of said at least one second opening to allow the operator to check the correct operation of said at least one nozzle.