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:
Nov. 22, 1994
Filed:
Nov. 30, 1992
Applicant:
Inventor:
Esko Mattelmaki, Varkaus, FI;
Assignee:
A. Ahlstrom Corporation, Noormarkku, FI;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ;
U.S. Cl.
CPC ...
423539 ; 42324309 ; 42324311 ; 423519 ; 162 29 ; 162 51 ; 159 45 ; 159 49 ; 159D / ;
Abstract
Sulphur dioxide is separated from the flue gases of a cellulose pulp mill by absorbing it into a sodium sulphite solution. Sulphur dioxide is regenerated from the sodium bisulphite solution produced by an evaporation-crystallization method utilizing thermo-compressor evaporation technique. A lamella evaporator is utilized as the evaporator-crystallizer, the evaporator being divided into separate compartments for ease of cleaning the lamella surfaces. The recovered concentrated sulphur dioxide can be used wherever desired, for example for the production of chlorine dioxide.