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:
May. 18, 1976
Filed:
Aug. 23, 1974
Allan E Hokanson, Cincinnati, OH (US);
Raphael Katzen, Cincinnati, OH (US);
Edward F Button, Greenwich, CT (US);
International Telephone and Telegraph Corporation, New York, NY (US);
Abstract
A process for removing sulfur dioxide and other contaminants from a hot waste gas stream in which the waste gas stream is cooled to a temperature below 100.degree.F and then passed in sequence through two separate absorption zones utilizing as the absorbent a recirculated aqueous solution of ammonium sulfite-bisulfite salts. Heat is continuously withdrawn from the recirculated salt solution in each zone. The absorbent solution in the first zone has an initial pH of from 6 to 7.2 and a salt concentration of from 1 to 20% by weight. The absorbent solution in the second zone has an initial pH of from 5.2 to 6.5 and a salt concentration, lower than said first zone of, from 0.1 to 5% by weight. The process provides for the efficient absorption and substantial removal of SO.sub.2, SO.sub.3 and particulate contaminants and for the economic recovery and use of heat from stack gases of a variety of industrial and commercial operations.