Mixer duct and process of operation

A mixer duct for mixing of a turbulent flow, the mixer duct comprising:

• an inlet;
• an outlet in fluid communication with the inlet;
• and
• a static mixer element located between the inlet and the outlet, the static mixer element including two at least substantially coplanar plate-like segments meaning that the plate-like segments are inclined with each other with regard to a longitudinal plane of an outer duct wall by not more than 10°, with the static mixer element comprising exactly two at least substantially coplanar plate-like segments and no further segment in addition thereto, and with the two at least substantially coplanar plate-like segments being spaced apart by a substantially longitudinal gap, each segment attached to a duct wall and comprising at least two free edges, with one free edge being a leading edge and the other free edge adjacent to the longitudinal gap;
• the two segments inclined relative to a duct axis so that their leading edge is oriented up-stream in the mixer duct and substantially perpendicular to a direction of a main fluid flow,
• wherein the static mixer element is linearly spaced from any other static mixer element in the direction of the duct axis, if the mixer duct contains one or more further static mixer element.