Abstract: A method and device for using the density control water to continuously flush the oxidation air header and the sparge pipes in a flue gas wet scrubber agitation tank. The density control line is routed to the elevation where the control valve is located. A U-shaped trap is located between the control valve and air sparge header such that the density control water joins the humidified oxidation air. A liquid layer forms on the floor of the header and is moved toward the distant side of the header by the motion of the air passing on top of the liquid layer and by the continuous flow of water. The bottom section of the main header is perforated to allow the flowing water to exit the header into the tank and flush any accumulated solids that might penetrate the header through the air holes. The air holes are located in a section at a minimum of five degrees off the floor and maximum of one hundred eighty degrees off the header bottom and preferably at forty-five degrees.