A spray dryer disperser 24, 26, 28, 30 is described for use in a spray dryer absorption (SDA) system 18 for flue gas FG impurity reduction. As such, the spray dryer disperser 24, 26, 28, 30 disperses absorbent liquid or reagent slurry droplets into contact with a hot flue gas FG stream containing gaseous impurities to produce a flue gas FG stream of reduced impurity content and dry powder end products EP. The spray dryer disperser 24, 26, 28, 30 is useful in larger capacity SDA vessels 22 of approximately 12 to 22 meters in diameter or larger, to avoid disperser 24, 26, 28, 30 shroud 34a scale deposits, to avoid reagent slurry spray cloud suppression, to avoid vessel 22 wall 22b scale deposits and to achieve increased droplet rotational momentum for increased droplet flue gas FG penetration for efficient impurity reduction.