Off-gas scrubber system

摘要

An off-gas quencher and solid recovery scrubber unit includes a wet flue gas scrubber which has the dual responsibilities of lowering the temperature of the inlet hot gas entering through the scrubber and trapping contaminants from the gas stream into the liquid stream. The hot exhaust gases are first cooled by evaporating the liquid scrubber solution. The contaminants of the exhaust gas are neutralized by a suitable reagent such as sodium hydroxide and the product is collected in the scrubbing solution. Since the solution is continuously recycled, the concentration of the scrubbing agent will be diminished as the scrubbing proceeds, while the concentration of the scrubbing product in the solution will rise to the solubility limit of the product. The scrubbing products start to precipitate and are collected at the bottom of the scrubber and are withdrawn. The scrubbing reagents are continuously replenished to the scrubber. The secondary scrubber is another wet scrubber which uses reagents/water from spray nozzles to scrub off any contaminants that might have escaped the solid recovery scrubber. In addition, the exhaust gas entering the secondary scrubber is cooled below its dew point which results in condensation of water in the scrubber.