Static mixer assembly suitable for use with injected gas in SCR and/or other applications

A mixer assembly, comprising:

• a duct configured to pass flue gas in a first direction;
• a plurality of rows of mixing plates in said duct, mixing plates in said rows of mixing plates each having an upstream end and a downstream end and being supported at a location between said upstream end and said downstream end, each row of mixing plates extending in a second direction in said duct, said second direction being perpendicular to said first direction, said plurality of rows of mixing plates forming a set of consecutive rows of mixing plates, each consecutive row being at a different location in a third direction, said third direction extending perpendicular to said first and second directions, a mixing plate row boundary, extending parallel to the rows of mixing plates, occurring in the third direction between each pair of adjacent rows of mixing plates in said set of consecutive rows of mixing plates, adjacent mixing plates in a first row of mixing plates alternating in angle with respect to the second direction, a first mixing plate in said first row being adjacent a first mixing plate of a second row of mixing plates in said plurality of rows of mixing plates and having a different angle with respect to the second direction than the first mixing plate of the second row;
• and
• a plurality of gas injection nozzles, positioned upstream of said rows of mixing plates, said nozzles being arranged in rows which are aligned in said third direction with mixing plate row boundaries;
• wherein said first row of mixing plates includes a first plurality of pairs of angled mixing plates including a first pair of angled mixing plates, said first pair of angled mixing plates having a first upstream opening and a first downstream opening, said first downstream opening being narrower than said first upstream opening;
• wherein said second row of mixing plates includes at least a second pair of angled mixing plates located in said second direction adjacent said first pair of angled mixing plates, said second pair of angled mixing plates having a second upstream opening and a second downstream opening, said second upstream opening being offset in said second direction from the first upstream opening;
• wherein said first and second downstream openings do not overlap in said second direction;
• wherein a first nozzle of a first row of nozzles is located at the row boundary between said first and second rows of mixing plates;
• wherein said first nozzle is located at the point in said second direction where a plate of said first pair of angled mixing plates crosses an angled mixing plate of said second row of mixing plates;
• wherein said mixing plates are mounted on movable pivots;
• and
• wherein the mixer assembly further includes a control device for varying the angle of plates as a function of flue gas flow.