Abstract: Limestone is dried for grinding to very fine particles e.g., about 8.mu. or less with more than 99% of the particle by weight less than 44.mu., by utilizing waste heat from the flue gas from a large combustor. The finely-divided calcium carbonate is then introduced dry into a scrubbing tower where it mixes with and renews the slurry employed therein for scrubbing SO.sub.x -laden effluent.

Abstract: Sulfur oxides (SO.sub.x) are scrubbed from combustion effluents with aqueous limestone slurries with greater efficiency due to the use of an improved entrainment separator. In the preferred embodiment of a single-loop, counter-current limestone wet scrubber operating at bulk gas flow rates of greater than 4.5 meters per second, a vertical stream of flue gas is freed of a substantial portion of slurry droplets and diverted for effective mist removal by a well-drained, horizontal-flow mist eliminator. The entrainment separator is a single-pass device with individual blades aligned for effective operation with reduced droplet impingement on the upper walls (e.g., roof) of the scrubber and to permit periodic washing.

Abstract: Limestone is dried for grinding to very fine particles e.g., about 8.mu. or less with more than 99% of the particle by weight less than 44.mu., by utilizing waste heat from the flue gas from a large combustor. The finely-divided calcium carbonate is then introduced dry into a scrubbing tower where it mixes with and renews the slurry employed therein for scrubbing SO.sub.x -laden effluent.

Abstract: Sulfur oxides (SO.sub.x) are scrubbed from combustion effluents with aqueous limestone slurries with greater efficiency due to the use of an improved entrainment separator. In the preferred embodiment of a single-loop, counter-current limestone wet scrubber operating at bulk gas flow rates of greater than 4.5 meters per second, a vertical stream of flue gas is freed of a substantial portion of slurry droplets and diverted for effective mist removal by a well-drained, horizontal-flow mist eliminator. The entrainment separator is a single-pass device with individual blades aligned for effective operation with reduced droplet impingement on the upper walls (e.g., roof) of the scrubber and to permit periodic washing.