interior chamber 22 a a method of using the subject spray dryer absorption system 18 for flue gas fg impurity reduction comprises providing a vessel 22 defining an interior chamber 22 a of approximately 12 to approximately 22 meters or larger in diameter and arranging one or more dispersers 24 26 28 30 in a roof 32 of the interior chamber 22 a an atomizer 34 for atomization and dispersal of absorption liquid or reagent slurry droplets therefrom across interior chamber 22 a is centered within the disperser 24 26 28 30 surrounding the atomizer 34 is a flow directing device 36 38 40 42 comprising three annular channels 60 62 64 formed concentrically around the atomizer 34 for a flow of flue gas fg therethrough of the three annular channels 60 62 64 an inner channel 60 without or optionally with a vane pack 60 a comprising a plurality of approximately 8 to approximately 12 rotational vanes 60 b of a like angle of approximately 25 to approximately 35 degrees or approximately 30 degrees from vertical reduces scale formation on the disperser shroud 34 a a middle channel 62 comprises a plurality of rotational vanes 70 a angled approximately 35 degrees to approximately 55 degrees or approximately 40 degrees to approximately 50 degrees or approximately 45 degrees from vertical.