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:
Jul. 18, 2000
Filed:
Feb. 20, 1998
Applicant:
Inventors:
Assignee:
Ahlstrom Machinery Oy, Espoo, FI;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ; B01D / ; D21C / ; C02F / ;
U.S. Cl.
CPC ...
159 473 ; 159 163 ; 159 29 ; 159D / ; 159D / ; 159901 ; 162 29 ; 162 48 ; 203-6 ; 203-7 ; 210698 ;
Abstract
A method of inhibiting calcium carbonate scaling in a multi-stage evaporation plant of black liquor by heat-treating calcium-containing liquor includes a first stage wherein the calcium-containing liquor is heated to about 110-145.degree. C. with direct contact with the heating medium; a second stage wherein the liquor is maintained at this temperature in a retention tank for 1-20 minutes to reduce the amount of calcium in the liquor by precipitating calcium carbonate; and a third stage wherein the heat-treated liquor is evaporated for combustion.