| 摘要 |
1397632 Recovery of sulphur values from waste gases GONZAGA UNIVERSITY CORP OF 27 June 1972 [29 June 1971] 29980/72 Heading C1A Sulphur dioxide is recovered from effluent gases (a) cooling to 40-60‹ F. at ambient pressure; (b) spray scrubbing the cooled gases initially using water at the same temperature and pressure, from which sulphur dioxide has previously been removed; (c) recycling the scrubbing liquid until the SO 2 content approaches the maximum; (d) isolating the scrubbing liquid, precipitating and separating at least a major proportion of the SO 2 therein as a water-insoluble sulphite, e.g. CaSO 3 . The scrubbed gases may be further cooled to 35‹ F. to remove water from the scrubbed gases, the water being recycled to the scrubber. The liquid may be recycled from a first recycling tank to scrub the sulphur dioxide present in the exhaust gases, while removing the sulphur dioxide present in the liquid contained in a second recycling tank by recycling the liquid to a solid sulphite separation stage and periodically interchanging the liquid recycling modes of the recycling tanks. The pH of the liquid used to scrub the exhaust gases may be monitored and the recycling paths of the liquids interchanged in response to the measured pH. Molecular sieve may be used to adsorb water insoluble pollutents in the cooled exhaust gases. |
