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:
Jun. 18, 1991
Filed:
Nov. 13, 1990
Bruce D Busch, Shakopee, MN (US);
Jeffrey R Nicholls, Prior Lake, MN (US);
Fremont Industries, Inc., Shakopee, MN (US);
Abstract
An in-service formulation for the removal of scale deposits from metallic working surfaces of boilers and for the ongoing prevention of build-up of such deposits on boiler surfaces, with such deposits commonly consisting of insoluble salts of calcium together with oxides of iron. The formulation comprises a blend of selected phosphonates, sodium lignosulfonate, one or more scale-modifying polymers, along with one or more chelants. Sodium gluconate is utilized for its ability to inhibit corrosion of ferrous surfaces. The pH of the working solution is adjusted to a level of between about 10.5 to 12.5. The formulation of the present invention provides a significant capacity for the removal of scale while remaining fully compatible with the water present in the system during and after scale removal, and the materials remain effective with contaminants present in the boiler water following a substantial number of cycles of concentration.