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. 13, 1999
Filed:
Oct. 06, 1997
John C Gunther, Bensalem, PA (US);
Haiwen Chen, Holland, PA (US);
John A Muccitelli, Oreland, PA (US);
BetzDearborn, Inc., Trevose, PA (US);
Abstract
Two control methods and systems for automatically achieving and maintaining a desired sodium/phosphate ratio and phosphate concentration of the boiler waters in a plurality of parallel industrial boilers linked by a common feedwater line for minimizing corrosion. The first control system uses an adaptive controller that models the boilers which enables the system to predict boiler pH and phosphate concentrations at any future time given the feed rates, feed concentrations of high and low sodium/phosphate stocks, blowdown rate, mass of the boiler water, initial boiler phosphate concentration and initial pH. Once these future concentrations are determined, the controller then determines a common normalized control (target) region among all the boilers and feed rates that will drive at least one of the boilers into that region in the least amount of time. Subsequent iterations of feed rates are made based on updated boiler water concentrations to drive all of the boiler waters into that target region. The second control system monitors a maximum cycle boiler ratio to keep the boiler waters within the phosphate control range of the system. This arrangement allows for the control of sodium by switching between the high and low ratio sodium/phosphate stocks based on the average sodium-to-phosphate ratio among all the boilers with respect to a desired average predetermined sodium-to-phosphate ratio.