The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 14, 1976
Filed:
Jan. 28, 1974
Donn Lewis Dixson, Granby, CT (US);
Carl Richard Bozzuto, Enfield, CT (US);
Combustion Engineering, Inc., Windsor, CT (US);
Abstract
Gases containing SO.sub.2 from a furnace are contacted in the scrubbing zone of a scrubber with an aqueous scrubbing medium containing solid alkaline earth metal carbonate, seed crystals of alkaline earth metal sulfate and dissolved alkaline earth metal carbonate and sulfate and having a pH of from 6.0 to 6.5. The SO.sub.2 reacts to form sulfites and bisulfites. The scrubbing medium is then withdrawn from the scrubbing zone and discharged to a reaction tank. Air is blown through the scrubbing medium in the reaction tank and then up into and through the scrubber and scrubbing zone. The oxygen reacts with sulfite to form sulfate in both the reaction tank and the scrubbing zone. The amount of oxygen is controlled so that the pH in the scrubber will not drop below about 4.5 and so as to oxidize not more than about 30 to 50% of the sulfite. Fresh additives in the form of alkaline earth metal carbonate or alkaline earth metal oxide which has been formed by calcining alkaline earth metal carbonate in the furnace is also introduced into the reaction tank and the pH returned to 6.0 to 6.5. A portion of the medium from the reaction tank is returned to the scrubbing zone and the remainder is further treated with oxygen to convert the remaining sulfite to sulfate which is precipitated and separated from the liquid. The liquid is then returned to the scrubbing cycle.