Betz Laboratories, Inc.

Betzdearborn, Inc.

Scott M Boyette

Fu Chen

Keith A Bair

Alan E Goliaszewski

Paul R Burgmayer

John C Gunther

Eric A Thungstrom

Norman B Worrell

Radislav A Potyrailo

Andrew M Leach

Caibin Xiao

A control system for automatically achieving and maintaining a desired sodium/phosphate ratio and phosphate concentration of the boiler water in an industrial boiler for minimizing corrosion. The system uses an adaptive controller that models the boiler 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 which feed rates will return the current boiler water state to, and then maintain the boiler water at, the desired sodium/phosphate congruency ratio in the least amount of time. Where the controller determines that it is not possible to move the current boiler water state to the desired congruency setpoint, the controller determines a feed rate program that will move the current boiler water state to the attainable steady state point closest to the desired setpoint. An alternative embodiment fixes the phosphate concentration by ratioing the phosphate feed with the blowdown rate while continuously monitoring blowdown pH. This arrangement allows for the control of sodium by switching between the high and low ratio sodium/phosphate stocks based on the measured pH with respect to the pH setpoint.

Apparatus and method for automatically achieving and maintaining

A water soluble isopropenylphosphonic acid copolymer composition and method of use thereof are disclosed. The copolymer comprises repeat units (a) of the formula: ##STR1## wherein X=OH or OM, wherein M is a cation, and repeat units (b) of the formula: ##STR2## wherein R.sub.1 and R.sub.2 are independently hydrogen, C.sub.1-10 linear or branched alkyl, phenyl or alkyl substituted phenyl. The copolymers are effective in inhibiting the precipitation of scale forming salts and also act to inhibit corrosion in boiler water systems.

Alkyl-allylphosphonate copolymer used for boiler water treatment

A treatment for controlling the deposition of scale imparting species on the structural surfaces of steam generating systems, wherein the aqueous medium is maintained at a pH which minimizes magnetite solubility, comprising the use of a combination of an organic amine and a nonionic polymer having the structure: ##STR1## wherein R.sub.1 is H or lower (C.sub.1 -C.sub.4) alkyl, R.sub.2 is (CH.sub.2 --CH.sub.2 --O).sub.n, ##STR2## or a mixture of both, n is an integer of from 1 to about 40, and R.sub.3 is H, lower (C.sub.1 -C.sub.4) alkyl or an acetate.

Nonionic polymers for the treatment of boiler water

A composition for controlling the deposition of scale imparting species on the structural surfaces of steam generating systems comprising the use of a water soluble polymer having the structure ##STR1## wherein R.sub.1 is H or lower (C.sub.1 -C.sub.4) alkyl, R.sub.2 is (CH.sub.2 --CH.sub.2 --O).sub.n, ##STR2## or a mixture of both, and n is an integer of from about 1 to about 40, R.sub.3 is H, lower (C.sub.1 -C.sub.4) alkyl or an acetate. This polymer may also be used in concert with topping agents such as phosphoric acids, phosphonic acids, amines, metal chelating agents and oxygen scavengers.

Copolymers of ethylenically unsaturated and polyethylene-glycol

A composition for controlling the deposition of scale imparting species on the structural surfaces of steam generating systems comprising the use of a water soluble polymer having the structure ##STR1## wherein R.sub.1 is H or lower (C.sub.1 14 C.sub.4) alkyl, R.sub.2 is (CH.sub.2 --CH.sub.2 --O).sub.n, ##STR2## or a mixture of both, and n is an integer of from about 1 to about 40, R.sub.3 is H, lower (C.sub.1-C.sub.4) alkyl or an acetate. This polymer may also be used in concert with topping agents such as phosphoric acids, phosphonic acids, amines, metal chelating agents and oxygen scavengers.

A method for controlling the deposition of silica on the structural surfaces of steam generating systems comprising the use of a water soluble polymer having the structure ##STR1## wherein E is the repeat unit remaining after polymerization of an alpha, beta ethylenically unsaturated compound. This polymer may also be used in concert with topping agents such as phosphoric acids, phosphonic acids, polyvalent metal salts, metal chelating agents and oxygen scavengers.

Polymers for the treatment of boiler water

A method for controlling the deposition of scale imparting species on the structural surfaces of steam generating systems comprising the use of a water soluble polymer having the structure ##STR1## wherein R.sub.1 is H or lower (C.sub.1 -C.sub.4) alkyl, R.sub.2 is (CH.sub.2 --CH.sub.2 --O).sub.n, ##STR2## or a mixture of both, and n is an integer of from about 1 to about 40, R.sub.3 is H, lower (C.sub.1 -C.sub.4) alkyl or an acetate. This polymer may also be used in concert with topping agents such as phosphoric acids, phosphonic acids, amines, metal chelating agents and oxygen scavengers.

A method for controlling the deposition of scale imparting species on the structural surfaces of steam generating systems comprising the use of a water soluble polymer having the structure ##STR1## wherein E is the repeat unit remaining after polymerization of an alpha, beta ethylenically unsaturated compound. This polymer may also be used in concert with topping agents such as phosphoric acids, phosphonic acids, polyvalent metal salts, metal chelating agents and oxygen scavengers.

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Wilmington, DE, United States of America

Scott M Boyette