Patent ID: 7448794

Claim:
A method for the mixing of fluid streams in a duct ( 1 ), the method comprising the steps of: positioning at least one mixing device ( 3 ) having front side and back side ( 3 ′) within said duct ( 1 ) through which a first major stream ( 2 ) travels, the at least one mixing device ( 3 ) determining a total cross-sectional area which is lower than that of the duct ( 1 ) so as to allow for the passage of said first major stream ( 2 ), in which the at least one mixing device ( 3 ) is positioned within the duct ( 1 ) so that the first major stream ( 2 ) forms with the front side of the at least one mixing device ( 3 ) an incidence angle (α) of between 10° and 80°, whereby the at least one mixing device ( 3 ) is in the form of a solid plate comprising a main solid plate body ( 10 ) having a substantially circular or elliptical configuration defining an arcuate peripheral edge and having one or more protrusions ( 9 , 11 ) extending outward from said peripheral edge, the one or more protrusions ( 9 , 11 ) having a triangular configuration and being located in the same plane defined by the cross section of the main solid plate body ( 10 ); and injecting at least one second stream ( 4 ) into said duct ( 1 ), wherein said first major stream ( 2 ) travels, so as to provide for the impact of the at least one second stream ( 4 ) onto at least a partial region of the back side ( 3 ′) of the at least one mixing device ( 3 ), and wherein said first major stream ( 2 ) is a flue gas containing nitrogen oxides and said second stream ( 4 ) is a fluid containing nitrogen oxide reducing agents.