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.

Abstract: A method is disclosed for reducing the oxygen content of water using a hydrazine-free dioxo aromatic compound or organically-substituted derivative thereof.

Abstract: The present invention utilizes low volatility amines or alkanol amines to control caustic corrosion which can take place when a boiler system, treated with a coordinated phosphate/pH program, is "out of control".N-substituted hydroxyalkyl piperazines are also capable of mitigating caustic corrosion in coordinated phosphate/pH programs. Combinations of the compounds of the present invention and phosphate have also been shown to be efficacious at mitigating caustic corrosion in coordinated phosphate/pH programs.

Abstract: The present invention utilizes low volatility amines or alkanol amines to control caustic corrosion which can take place when a boiler system, treated with a coordinated phosphate/pH program, is "out of control".N-substituted hydroxyalkyl piperazines are also capable of mitigating caustic corrosion in coordinated phosphate/pH programs. Combinations of the compounds of the present invention and phosphate have also been shown to be efficacious at mitigating caustic corrosion in coordinated phosphate/pH programs.

Abstract: A method for monitoring and controlling the blowdown rate and chemical feed rate to a high pressure boiler involving the measurement of certain parameters including operating temperature, conductivity at operating temperature, temperature and pH of cooled boiler water, and then carrying out calculations to determine the estimated treatment chemical concentration and estimated boiler water conductivity, noting the critical conductivity ratio (CCR), noting the observed maximum tolerable high temperature conductivity value and comparing the relative conductivity ratio (RCR) with the critical conductivity ratio (CCR) and the value of the electrolytic conductivity of the boiler water at operating temperature (K) with the maximum tolerable high temperature conductivity value (M), followed by making any necessary adjustments to the chemical feedrate and diagonal or blowdown rate depending upon aforesaid comparison.

Abstract: An electrode assembly and a method of electrically insulating the electrode assembly for in-situ measurement of electrolytic conductivity of boiler or other hot alkaline or neutral water, the electrode assembly comprising calcia/hafnia stabilized zirconia wherein the calcia is present from 3 to 10% by weight and the hafnia is present from 0.5 to 6% by weight.

Abstract: A method for monitoring and controlling the blowdown rate and chemical feed rate to a high pressure boiler involving the measurement of certain parameters including operating temperature, conductivity at operating temperature, temperature and pH of cooled boiler water, and then carrying out calculations to determine the estimated treatment chemical concentration and estimated boiler water conductivity, noting the critical conductivity ratio (CCR), noting the observed maximum tolerable high temperature conductivity value and comparing the relative conductivity ratio (RCR) with the critical conductivity ratio (CCR) and the value of the electrolytic conductivity of the boiler water at operating temperature (K) with the maximum tolerable high temperature conductivity value (M), followed by making any necessary adjustments to the chemical feedrate and diagonal or blowdown rate depending upon aforesaid comparison.

Abstract: A method for reducing the amount of oxygen in an oxygen-containing aqueous medium comprising adding to the medium an effective amount of a hydrazine-free aqueous solution of an aminophenol compound or acid salt thereof having the formula ##STR1## where a=1, 2, or 3;b is 0 or 1 andx=amino or alkylamino (C1-C4).

Abstract: Compositions and methods for chemically scavenging oxygen from an aqueous medium are disclosed. Salicylaldehyde catalyzed by hydroquinone can be used as an oxygen scavenger in any aqueous medium, but is especially well adapted for use in boiler water systems.

Abstract: Stable oxygen scavenger compositions adapted for storage without resulting in substantial sludge formation and oxygen scavenging methods of using the compositions are disclosed. The compositions comprise hydroquinone, a compatible amine termed a mu-amine, and a member selected from the group consisting of isoascorbic acid and ascorbic acid and water soluble salt forms thereof. Methods comprise adding from about 0.05-200 ppm hydroquinone, 0.001-400 ppm mu-amine, and about 0.00025-500 ppm of isoascorbic or ascorbic acid to the desired aqueous medium.

Abstract: Compositions and methods for chemically scavenging oxygen from an aqueous medium are disclosed. Furfural catalyzed by hydroquinone can be used as an oxygen scavenger in any aqueous medium, but is especially well adapted for use in boiler water systems.

Abstract: An improved oxygen scavenger for aqueous mediums is disclosed which comprises hydrazine-free solution of hydroquinone and mu-amine.

Abstract: An improved oxygen scavenger for aqueous mediums is disclosed which comprises hydrazine-free solution of hydroquinone and mu-amine. Representative examples of mu-amines include: aminomethylpropanol, triethylenetetramine, diisopropanolamine, secbutylamine, monoisopropanolamine, ethylenediamine, dimethylaminopropylamine, monoethanolamine, dimethyl(iso)propanolamine, methoxypropylamine, and diethylaminoethanol.

Abstract: An improved oxygen scavenger for aqueous mediums is disclosed which comprises hydrazine-free solution of hydroquinone and mu-amine.