Abstract: Sulfur dioxides are dry scrubbed from a flue gas by introducing minute droplets containing a liquid, such as water, and an alkali or alkaline reactant, such as lime, into the spray zone in the primary spray drying chamber of a spray dryer and concurrently contacting these droplets with the hot flue gas. The droplets are partially dried to a tacky condition before reaching a foraminous collecting member extending through the primary spray drying chamber and collect on the collecting member as a moist, porous mat. As the flue gas continues to flow through the mat, the mat serves as a filter for removing fly ash and other particulate matter and remaining sulfur oxides react with unreacted particles of the reactant and reactive ingredients of the fly ash particles in the mat.

Abstract: A processing housing containing a primary stage spray chamber, a filter stage and redryer chamber, a second stage drying chamber and a cooling stage chamber all in communication one with the other. The primary stage spray chamber has an outlet at the lower end thereof and at least one hot gas inlet port thereof in the upper portion thereof with a source of drying gas connected thereto. At least one spray nozzle extends into the spray chamber and a draft producing means is provided to force the drying gas from the gas source through the spray chamber and out through the outlet thereof. An endless connecting belt is supported for horizontal movement adjacent the outlet of the spray chamber, said belt traveling from the primary stage spray chamber through the filter stage redryer chamber, then through the second stage drying chamber and then through the cooling stage chamber.