Restricting exhaust gas treatment devices from contacting a washing medium supplied by a washing system may reduce affecting the exhaust gas treatment devices. A washing system (50) may comprise a washing device (52) configured to supply a washing medium to a turbine ( T H ) during an ON mode of the washing system (50) and a fluid flow control system (38). The fluid flow control system (38) may be configured, during an OFF mode of the washing system (50), to direct exhaust gas through the at least one exhaust gas treatment device (41), and during the ON mode of the washing system (50), to restrict a mixture of exhaust gas and washing medium exiting the turbine ( T H ) from being directed through the at least one exhaust gas treatment device (41).
