Abstract: A gas-liquid contactor for removing gases and particulate matter from flue gases produced by processing operations of the type carried out in utility and industrial plants. The contactor is generally an open spray absorber having a spray tower (110) whose walls (114) form a passage within the tower (110). Flue gases are introduced into the tower (110) so as to flow vertically upward or downward through the passage. Disposed within the passage are heads (116) for introducing a liquid (118) into the passage such that the liquid (118) contacts the flue gases. A portion of the liquid (118) contacts the wall (114) of the tower (110), such that the portion of the liquid (118) flows downwardly along the wall (114). The tower (110) is equipped with a deflecting device (122) disposed on the wall (114) for deflecting the portion of the liquid (118) away from the wall (114), and thereafter reintroducing the portion of the liquid (118) into the passage so as to contact the gases flowing through the passage.

Abstract: A wet flue gas desulfurization process for removing sulfur dioxide from flue gases. The process utilizes an ammonium sulfate scrubbing solution containing free dissolved ammonia as the reagent for the desulfurization process to produce ammonium sulfate as a valuable byproduct. The scrubbing solution contacts the flue gases and absorbs sulfur dioxide within an absorber of a flue gas scrubbing apparatus, and is then accumulated in a tank where the absorbed sulfur dioxide is reacted with oxygen and ammonia to produce ammonium sulfate. The scrubbing solution has a concentration of greater than 46% ammonium sulfate so as to have suspended solids of ammonium sulfate precipitate, preferably 1% to 20% suspended solids.