Method for inhibiting corrosion in aqueous systems

Patent · Tue Jan 01 04:00:00 EST 1980

OSTI ID:863736

DeMonbrun, James R ^[1]; Schmitt, Charles R ^[2]; Schreyer, James M ^[2]

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1. Knoxville, TN
2. Oak Ridge, TN

This invention is a method for inhibiting corrosion in aqueous systems containing components composed of aluminum, copper, iron, or alloys thereof. The method comprises (a) incorporating in the aqueous medium 2-10 ppm by weight of tolyltriazole; an effective amount of a biodegradable organic biocide; 500-1000 ppm by weight of sodium metasilicate; 500-2000 ppm by weight of sodium nitrite; and 500-2000 ppm by weight of sodium tetraborate, all of these concentrations being based on the weight of water in the system; and (b) maintaining the pH of the resulting system in the range of 7.5 to 8.0. The method permits longterm operation with very low corrosion rates and bacteria counts. All of the additives to the system are biodegradable, permitting the treated aqueous medium to be discharged to the environment without violating current regulations. The method has special application to solar systems in which an aqueous medium is circulated through aluminum-alloy heat exchangers.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
• DOE Contract Number: W-7405-ENG-26
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4237090
• OSTI ID: 863736
• Country of Publication: United States
• Language: English

Related Subjects

/422/210/252/
2-10
500-1000
500-2000
additives
alloy heat
alloys
aluminum
aluminum-alloy
amount
application
aqueous
aqueous medium
aqueous systems
bacteria
based
biocide
biodegradable
circulated
components
components composed
composed
comprises
concentrations
containing
containing components
copper
corrosion
corrosion rate
counts
current
discharged
effective
effective amount
environment
exchangers
heat
heat exchange
heat exchanger
heat exchangers
incorporating
inhibiting
inhibiting corrosion
iron
longterm
maintaining
medium
metasilicate
method
method comprise
method comprises
method permits
nitrite
operation
organic
permits
permitting
ph
ppm
range
rates
regulations
resulting
sodium
sodium nitrite
solar
special
special application
systems
systems contain
tetraborate
tolyltriazole
treated
violating
water
weight