Abstract: A process and apparatus for removing SO.sub.2 from low-volume gas streams containing high concentrations of SO.sub.2 includes a tank scrubber containing an aqueous SO.sub.2 absorbent and an impeller. The tank scrubber has an unpartitioned vessel. The impeller includes a vertical rotating shaft having an upper and lower impeller. The lower impeller serves to agitate the SO.sub.2 absorbent. The upper impeller includes a shroud thereby directing the absorbent and gas outwardly toward the wall of the scrubber. The gas is injected into the absorbent at a point below the shrouded impeller. The shroud prevents gas bypass and thereby promotes gas-liquid mixing and, consequently, markedly improves SO.sub.2 removal efficiency.

Abstract: A process and apparatus for removing SO.sub.2 from low-volume gas streams containing high concentrations of SO.sub.2 includes a tank scrubber containing an aqueous SO.sub.2 absorbent and an impeller. The impeller includes a vertical rotating shaft having an upper and lower impeller. The lower impeller serves to agitate the SO.sub.2 absorbent. The upper impeller includes a shroud thereby directing the absorbent and gas outwardly toward the wall of the scrubber. The gas is injected into the absorbent at a point below the shrouded impeller. The shroud prevents gas bypass and thereby promotes gas-liquid mixing and, consequently, markedly improves SO.sub.2 removal efficiency.