CA1236373A - Method of controlling iron induced fouling in water systems - Google Patents
Method of controlling iron induced fouling in water systemsInfo
- Publication number
- CA1236373A CA1236373A CA000494331A CA494331A CA1236373A CA 1236373 A CA1236373 A CA 1236373A CA 000494331 A CA000494331 A CA 000494331A CA 494331 A CA494331 A CA 494331A CA 1236373 A CA1236373 A CA 1236373A
- Authority
- CA
- Canada
- Prior art keywords
- water
- recited
- aqueous medium
- iron
- copolymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
- C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
- C23F11/10—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using organic inhibitors
- C23F11/173—Macromolecular compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
- C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
- C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
Abstract
Abstract of the Disclosure A method of inhibiting corrosion and controlling deposition in aqueous mediums, such as in cooling water systems, wherein iron containing well water is used as a water make-up source, is disclosed. The method comprises addition of certain water soluble acrylic acid type/allyl hydroxy propyl sulfonate ether copolymers to the desired aqueous medium.
Description
~,3~3~3 METHOD OF CONTROLLING IRON INDUCED FOULING IN WATER SYSTEMS
Field of The Invention - The present invention pertains to a method of controlllng deposltion and inhlbi~ing corroslon of metal surfaces in contact with water systems, such as cooling water systems, in those instances where Iron based depositlon may be a problem. One speclfically contemplated environment is a cooling water system wherein iron containing well water Is - used as a make-up water source for the system.
BACKGROUND OF THE INVENTION
Industrial water systems are commonly chemically treated to mlnimize corrosion and reduce deposltlon along those metal surfaces In contact with the aqueous medium. Typical treatment programs Include those dlsclosed in, inter alia, U.S. Patent 3,837,803 (Vogt et al) and U.S. Patent 4,U29,577 (Godlewski et al).
One particularly troublesome fouling species is iron based foullng that typlcally occurs In water systems belng supplied wlth water from an Iron containlng well water source. One successful approach in treating such condltions has been disclosed In U.S. Patent 4,387,027 (May et al).
~L~3 Well waters typically exist under reducing conditions.
Under such conditions, iron exists primarily as the ferrous ion (Fe+2) species. Upon exposure Jo air, the ferrous ion oxld-izes to ferric ion (Fe+3). The ferrous ion is typically pre-sent as the aquo ion, Fe(H2036~2, while the ferrlc ion exists as a hydrated oxide, Fe203 . nH20. From known solubility data, the Fe 2 ion is 1015 times more soluble at pH 7 than is the Fe 3 ion. Accordingly, iron is soluble in well water (as Fe+2). Upon exposure to air (as would be encountered when such well water is admltted to a cooling water system this freshly produced iron species (Fe~3) becomes almost completely - insoluble and is the root of a most troublesome fouling problem.
In those instances in which water soluble polymers are used l in the water system to inhibit corrosion and deposition, such freshly produced iron (Fe+3) ion readily promotes coagulation of the polymer. Although the particular mechanism for such coagulation phenomenon is not known for certain, it is thought that the freshly produced Fe+3 ion, being small and highly charged, attracts the polymer causing coagulatlon thereof. This attractive force is exacerbated when anlonic polymer electrolytes are used as the water treatment polymer.
In other words, when such freshly produced Fe+3 ions enter a water system, the resultlng particulate iron oxides have a "fresh" (hlghly surface active) surface and are thus very active towards adsorption of polymers. In contrast, when iron ions are present in surface waters, they have been deactlvated by the previous adsorption of various organic molecules, biopolymers, proteins etc. thereon. The avallable adsorp~lon , i3~3 sites on these surface water iron ions are already occupied by these organics, and further adsorption is therefore precluded.
The present invention is concerned with methods of inhibiting fouling and corrosion caused by the former "freshly produced Fe+3 ions".
I have found that the use of certain water soluble copolymers inhibits fouling and corrosion in test water systems under conditions which simulate those experienced when iron containing well water is used as a make-up water source. These water soluble copolymers, which shall be explained in greater detail hereinafter, may be referred to as (meth) acrylic acid type -- allyl hydroxy propyl sulfonate ether water soluble copolymers.
These copolymers are not new per se as whey have been reported in Japanese Patent Publication 58-9987. Indeed9 whey have been touted in such publication as being useful scale preventing agents when used in, inter alia, boilers, condensors, heat exchangers etc. and the disclosure also suggests use thereof in cooling water. However, this Japanese publication does not at all suggest that the disclosed polymers could be used in the specific environment here1n required and claimed, to wit: use to inhibit corrosion and deposition in water systems having the previously described hlghly surface actlve iron ions existing therein.
Of arguably similar, although probably lesser interest, to the present invention is Japanese Patent Publicatlon Sho 58-7415. Also mentioned as being of possible interest is Japanese Patent Publication 56-155692.
~2~37~3 Detailed Description I have found that addition of a water soluble copolymer (having the following formula) to a water system, having iron ions similar to those encountered when iron containing well water is used as a make up source, inh;bits corrosion of and deposition along those metal surfaces in contact with the system water.
Specifically, the water soluble copolymer comprises repeat unit moieties (a) and (b) wherein the repeat unit moiety (a) comprises the structure:
R
~C~2--C~
x C = O
and wherein repeat unit moiety (b) comprises the structure:
{ CH2-- -CH
OH
I
CHOH
S03 -M+
~L~3~i~3~7 3 wherein x and y are integers and the ratio of x:y may be in the range of about 30:1 to 1:20, Rl ;s H or lower alkyl (Cl -C3), R2 is OH, OM, or NH2, M is H or a water soluble cation The number average molecular weight (Mn) of the copolymer may be between about 1,000 to 1,000~000. The only essential criterion regarding molecular weight is that the copolymer be water soluble. A preferred molecular weight (Mn) is between about 2,000 - 10,000.
As stated above, the molar ratio x:y of the repeat units may be 30:1 to 1:20, with a molar ratio x:y of 10:1 to 1:5 beiny even more preferred. At present, the copolymer preferred for commercial usage is a copolymer of acrylic acid (M )/allyl
Field of The Invention - The present invention pertains to a method of controlllng deposltion and inhlbi~ing corroslon of metal surfaces in contact with water systems, such as cooling water systems, in those instances where Iron based depositlon may be a problem. One speclfically contemplated environment is a cooling water system wherein iron containing well water Is - used as a make-up water source for the system.
BACKGROUND OF THE INVENTION
Industrial water systems are commonly chemically treated to mlnimize corrosion and reduce deposltlon along those metal surfaces In contact with the aqueous medium. Typical treatment programs Include those dlsclosed in, inter alia, U.S. Patent 3,837,803 (Vogt et al) and U.S. Patent 4,U29,577 (Godlewski et al).
One particularly troublesome fouling species is iron based foullng that typlcally occurs In water systems belng supplied wlth water from an Iron containlng well water source. One successful approach in treating such condltions has been disclosed In U.S. Patent 4,387,027 (May et al).
~L~3 Well waters typically exist under reducing conditions.
Under such conditions, iron exists primarily as the ferrous ion (Fe+2) species. Upon exposure Jo air, the ferrous ion oxld-izes to ferric ion (Fe+3). The ferrous ion is typically pre-sent as the aquo ion, Fe(H2036~2, while the ferrlc ion exists as a hydrated oxide, Fe203 . nH20. From known solubility data, the Fe 2 ion is 1015 times more soluble at pH 7 than is the Fe 3 ion. Accordingly, iron is soluble in well water (as Fe+2). Upon exposure to air (as would be encountered when such well water is admltted to a cooling water system this freshly produced iron species (Fe~3) becomes almost completely - insoluble and is the root of a most troublesome fouling problem.
In those instances in which water soluble polymers are used l in the water system to inhibit corrosion and deposition, such freshly produced iron (Fe+3) ion readily promotes coagulation of the polymer. Although the particular mechanism for such coagulation phenomenon is not known for certain, it is thought that the freshly produced Fe+3 ion, being small and highly charged, attracts the polymer causing coagulatlon thereof. This attractive force is exacerbated when anlonic polymer electrolytes are used as the water treatment polymer.
In other words, when such freshly produced Fe+3 ions enter a water system, the resultlng particulate iron oxides have a "fresh" (hlghly surface active) surface and are thus very active towards adsorption of polymers. In contrast, when iron ions are present in surface waters, they have been deactlvated by the previous adsorption of various organic molecules, biopolymers, proteins etc. thereon. The avallable adsorp~lon , i3~3 sites on these surface water iron ions are already occupied by these organics, and further adsorption is therefore precluded.
The present invention is concerned with methods of inhibiting fouling and corrosion caused by the former "freshly produced Fe+3 ions".
I have found that the use of certain water soluble copolymers inhibits fouling and corrosion in test water systems under conditions which simulate those experienced when iron containing well water is used as a make-up water source. These water soluble copolymers, which shall be explained in greater detail hereinafter, may be referred to as (meth) acrylic acid type -- allyl hydroxy propyl sulfonate ether water soluble copolymers.
These copolymers are not new per se as whey have been reported in Japanese Patent Publication 58-9987. Indeed9 whey have been touted in such publication as being useful scale preventing agents when used in, inter alia, boilers, condensors, heat exchangers etc. and the disclosure also suggests use thereof in cooling water. However, this Japanese publication does not at all suggest that the disclosed polymers could be used in the specific environment here1n required and claimed, to wit: use to inhibit corrosion and deposition in water systems having the previously described hlghly surface actlve iron ions existing therein.
Of arguably similar, although probably lesser interest, to the present invention is Japanese Patent Publicatlon Sho 58-7415. Also mentioned as being of possible interest is Japanese Patent Publication 56-155692.
~2~37~3 Detailed Description I have found that addition of a water soluble copolymer (having the following formula) to a water system, having iron ions similar to those encountered when iron containing well water is used as a make up source, inh;bits corrosion of and deposition along those metal surfaces in contact with the system water.
Specifically, the water soluble copolymer comprises repeat unit moieties (a) and (b) wherein the repeat unit moiety (a) comprises the structure:
R
~C~2--C~
x C = O
and wherein repeat unit moiety (b) comprises the structure:
{ CH2-- -CH
OH
I
CHOH
S03 -M+
~L~3~i~3~7 3 wherein x and y are integers and the ratio of x:y may be in the range of about 30:1 to 1:20, Rl ;s H or lower alkyl (Cl -C3), R2 is OH, OM, or NH2, M is H or a water soluble cation The number average molecular weight (Mn) of the copolymer may be between about 1,000 to 1,000~000. The only essential criterion regarding molecular weight is that the copolymer be water soluble. A preferred molecular weight (Mn) is between about 2,000 - 10,000.
As stated above, the molar ratio x:y of the repeat units may be 30:1 to 1:20, with a molar ratio x:y of 10:1 to 1:5 beiny even more preferred. At present, the copolymer preferred for commercial usage is a copolymer of acrylic acid (M )/allyl
2-hydroxypropyl sulfonate ether (AHPSE) wherein the molar ratio AA: AHPSE us 6:1 and the molecular weight (Mn) is between about 2,000 - ~,500, As to preparation of the (meth) acrylic acid type monomer (repeat unit a in the above formula), such synthetic preparatory routes are well known and do not need repeating in detail herein. Suffice it here to say that acrylic acid is commonly produced via hydrolysis of acrylonitrile or via oxidation of acrolein. Other well known vinyl containing monomers such as methacrylic acid and acrylamide may also be utilized as repeat unit a in the first formula.
The allyl hydroxy propyl sulfonate ether monomer (AHPSE) (repeat unit b in the above formula) may conveniently be prepared via a ring opening reaction of the epoxy group of an ~36~
allyl glycidyl ether precursor. Sulfontion of the epoxy group with sodium sulfite in the presence of a phase transfer catalyst such as tetra-n-butylammonium bisulfite or with fuming sulfuric acid containing sulfur ~riox;de will produce the sulfonic acid group and hydroxy group of the AHPSE. The resulting monomer can be further neutralized with caustic or other basic material.
The reaction is illustrated by the following mechanism:
H H
_llaQ1~ CH2 = CH-CH2 - O - CH2 - CHOH - CH2 - S03 - Na+
After the desired monomers have been obtained, free radical chain addition polymerization may proceed in accordance with conventional solution polymerization techniques. Polymerization initiators such as persulfate initiators, perDxide initiators, etc. may be used. Preferably, the requisite monomers are mixed with water and alcohol (preferably isopropanol). The resulting polymer maybe isolated by well-known methods such as distillation, etc. or the resulting polymer may simply be used in its aqueous solution.
The copolymers should be added to the aqueous system having surface active Fe~3 ion fouling problems in an effective amount for the purpose. This amount will vary depending upon the particular system for which treatment is desired and will be influenced by factors such as, the area subject to corrosion, pH, temperature water quantity and the concentration in the water of the highly surface active Fe~3 species. For the most l 7~
part, the polymers will be effective when used at levels of about 0.1 - 500 parts per million parts of water, and preferably from about 1.0 to 100 parts per million of water contained in the aqueous system to be treated. The polymers may be added S directly into the desired water system in a fixed quantity and in the state of aqueous solution either continuously or intermittently. The preferred environment for use is in cooling water systems wherein surface active Fe~3 is admitted to the system from a well water source. It is thought that any water system having highly surface active Fe+3 ions therein in the range of 0.5 to 10 or greater ppm of such Fe+3 will benefit from the invention.
As the recirculator tests reported in the following examples indicate, it is postulated that the water soluble copolymers can be used in systems containing such surface active re+3 ions in conjunction with a water soluble orthophosphate compound or precursor thereof (i.e., any phosphate reverting to orthophosphate in water) in order to passivate metal surfaces (without substantial deposition thereon) in contact with the system water. In such instances, postulated dosage ranges are:
Orthophosphate (P04 ): 2 - 50 ppm, preferably 6 - 30 ppm Copclymer: 0.3 - 120 ppm, preferably
The allyl hydroxy propyl sulfonate ether monomer (AHPSE) (repeat unit b in the above formula) may conveniently be prepared via a ring opening reaction of the epoxy group of an ~36~
allyl glycidyl ether precursor. Sulfontion of the epoxy group with sodium sulfite in the presence of a phase transfer catalyst such as tetra-n-butylammonium bisulfite or with fuming sulfuric acid containing sulfur ~riox;de will produce the sulfonic acid group and hydroxy group of the AHPSE. The resulting monomer can be further neutralized with caustic or other basic material.
The reaction is illustrated by the following mechanism:
H H
_llaQ1~ CH2 = CH-CH2 - O - CH2 - CHOH - CH2 - S03 - Na+
After the desired monomers have been obtained, free radical chain addition polymerization may proceed in accordance with conventional solution polymerization techniques. Polymerization initiators such as persulfate initiators, perDxide initiators, etc. may be used. Preferably, the requisite monomers are mixed with water and alcohol (preferably isopropanol). The resulting polymer maybe isolated by well-known methods such as distillation, etc. or the resulting polymer may simply be used in its aqueous solution.
The copolymers should be added to the aqueous system having surface active Fe~3 ion fouling problems in an effective amount for the purpose. This amount will vary depending upon the particular system for which treatment is desired and will be influenced by factors such as, the area subject to corrosion, pH, temperature water quantity and the concentration in the water of the highly surface active Fe~3 species. For the most l 7~
part, the polymers will be effective when used at levels of about 0.1 - 500 parts per million parts of water, and preferably from about 1.0 to 100 parts per million of water contained in the aqueous system to be treated. The polymers may be added S directly into the desired water system in a fixed quantity and in the state of aqueous solution either continuously or intermittently. The preferred environment for use is in cooling water systems wherein surface active Fe~3 is admitted to the system from a well water source. It is thought that any water system having highly surface active Fe+3 ions therein in the range of 0.5 to 10 or greater ppm of such Fe+3 will benefit from the invention.
As the recirculator tests reported in the following examples indicate, it is postulated that the water soluble copolymers can be used in systems containing such surface active re+3 ions in conjunction with a water soluble orthophosphate compound or precursor thereof (i.e., any phosphate reverting to orthophosphate in water) in order to passivate metal surfaces (without substantial deposition thereon) in contact with the system water. In such instances, postulated dosage ranges are:
Orthophosphate (P04 ): 2 - 50 ppm, preferably 6 - 30 ppm Copclymer: 0.3 - 120 ppm, preferably
3 - 25 ppm water polyphosphate (if desired): 0.1 - 30 ppm, preferably 3 - 10 ppm Other parameters which should be met in order to obtain passivation include maintenance of a pH of 5.5 or greater in the 3~3 system preferably 6.5 - 9.5) and the maintenanc2 of a calcium ion concentration in the system water of about 15 parts per mlllion parts system water. If the calcium ion content is below this range, it maybe necessary for overall effectiveness to add S metallic ions such as zinc, nickel, chromium, etc. as described in Col. 3, lines 4 - 24 of U.S. Patent 3,837,803.
Examples The invention will now be further described with reference to the following examples, which are to be regarded solely as illustrative, and not as restricting the scope of the invention.
Polymer Preparation Polymers in accordance with the invention were prepared as per the specification of pending application S.N. 464,527 (of common assignment herewith). Specifically, in each instance of polymer preparation, the following procedure was used. A
reaction flask was equipped with a mechanical agitator, a thermometer, a reflux condensor, a nitrogen inlet and two addition inlets for the initiator and monomer solutions. The flask was charged with deionized water and isopropanol. The resulting solution was then heated to reflux under a nitrogen blanket.
The requisite molar amount of acrylic acid and required molar amount of l-propane sulfonic acid, 2-hydroxy-3-(2-propenyl oxy) mono sodium salt [AHPSE] were mixed together in a separate flask so as to serve as a mixed monomer solutlon. This mixed monomer solution was then transferred to an addition funnel.
~3~
g An initiator solution containing sodium persulfate in deionized water was separately prepared and then sparged with nitrogen. The initiator solu~on was then added to the reaction flask along with the mixed monomer solution over a period of 2 hours. After this addition, the resulting mixture was heated for about 2 more hours at 65C and subsequently the isopropanol/water solution was stripped off. The reaction mixture was then cooled and neutralized by caustic addition Structures of the resulting polymers were verified by carbon 13 NMR.
The following copolymers were prepared in accordance with - the above procedure:
Monomer Ratio _ Viscosity Polymer Acrylic Acid/AHPSE % Solids Mn Mw _(cps) A 6:1 25.0 2,2176,731 15.4 B 6:1 25.0 2,77012,200 20.5 C 6:1 25.0 6,42043,300 77.0 D 6:1 25.0 3,300 - 23.0 E 6:1 25.0 2,700 - 25.6 F 6:1 25.0 3,200 - 20.7 POLARIZATIOH STUDIES
In order to produce Fe 3 ions similar to the type encountered in real cooling systems using iron containing well water as a make-up source, iron ions were generated by a method referred to as "Potentiodynamic Polarization'9. The purpose of this method is to electrically perturb a corroding metal electrode from its steady - state potential and to observe the resulting current-potential behavior. Specifically, an electrode of the desired metal - in this case low carbon steel - is placed -in a 1 liter, 5 neck flask. The flask is filled with about 850 ~236 j37 mL of a O.lN sodium sulfate solution adjusted to pH 7 + 0.2. The electrode is wet-ground with emery paper and 600 grit silicon carbide polishing compound, ultrasonically cleaned and degreased in toluene vapor. After the electrode is cleaned, it is inserted into the deaerated solution and allowed to equilibrate. A
potentiostat is operatively connected to the electrode. This process us monitored by tracking the electrode potential versus a standard reference electrode (to which the potentiostat is also operatively connected). When the potential is stable to 2 mV
for 1 hour, the experiment is initiated. The potentiostat is set to alter the electrode potentlal at 10 mV/m;nute, starting about -600 mV to the equilibrium potential, and continuing to about +400 mV to the equilibrium potential.
In the sweep from -600 mV to 0 mV (relative) the process(es) occurring at the test electrode is (are) primarily:
2H+ + 2e H2 (at low potentials) and 2 +2H20 + 4e~ ____~ 40H (at higher potentlals) In the sweep from 0 to +400 mV (relative) the primary processes at the electrode are:
Fe -I Fe+2 + 2e (at lower potentials) and Fe+2 -I+ en + Fe~3 (at higher potentials) This results in the fresh production of Fe+3 ions similar to those encountered in cooling water systems wherein iron containing well water is used as a make-up source.
.
3~3 Polymers in accordance with the invention were present in solutions in which Fe 3 ions were generated by the process hereinabove described. In tests with other polymers (not covered by the present invention), the iron ions precipitated out as Fe(OH)3 and other iron oxide species. Additionally the other polymers were gelled by the cross linking actlon of Fe~3 ions.
In sharp contrast, when polymers in accordance with the invention were present in solutions in which Fe+3 ions werè
generated by the above polarization technique, the jest solution remained clear although the presence of Fe ions was confirmed by the yellow-brown color of the test solutions. No polymer gellation occurred either. The lack of gellat~on and the solubility of iron ions indicates a good stability of the polymer towards the type of lron species encountered when iron containing well water is used as a make-up water source in cooling water systems.
The iron analysis results gathered pursuant to the "Potentiodynamic Polarization" tests reported hereinbelow in Table I indicate that when the present polymers are used, an extraordinary high level of soluble iron exists in the test solution. Ordinarily, at pH 7 the solubility limit of ferric hydroxide , as iron, is 2.5 x 10 5 ppm. As can be seen in Table I, use of the present polymers enhances the solubllity of iron at least about one million fold.
., 3~3~7~3 TABLE I
Iron Analysis of Supporting Electrolyte After Anodic Polarization of Low Carbon Steel Electrodes:
Total Corrosion Ratea Soluble Ironb PolymerConc (ppm) (mpy) OH _ (ppm) A 100 35.8 7 24.0 B 100 18.6 7 9.3 C 100 27.6 7 18.8 a Sum of values in air and under nitrogen b All iron was soluble. Differences are due to amounts of iron produced by differential corrosion rates.
Recirculator Studies In order to approximate those conditions experienced in a cooling tower, tests were conducted under recirculatory conditions with heat transfer prcvided.
These condltions closely slmulate the environment in a field cooling system. In this test system, treated water is circulated by a centrifugal pump through a corrosion coupon bypass into which corrosion coupons are inserted, and past a mild steel (AISI-1010) heat exchanger tube contained in a Plexiglas block. The inside of the exchanger tube is filled .
~3~37~3 with sillcone oil and heated with an electric heater. The temperature of the silicone oil can be regulated. The water velocity past the corroslon coupons and heat exchanger tube can be controlled anywhere from 0 to 4.5 ft/sec. The pH and temperature of the bulk water are au~omatlcally controlled. The treated water is prepared by chemical addition to deionized water. Provisions for continuous make-up and blowdown are made by pumping fresh treated water from supply tanks to the sump, with overflow from the sump serving as blowdown.
Corrosion rates are determined by exposing precleaned and weighed metal specimens for a specified period of time, after - which they are removed, cleaned and reweighed. Corrosion rates are calculated by dividing the total coupon weight loss by the number of days exposure.
The conditions used were: Heat Flux 8000 BTU/ft?/hr; Water Velocity = 3 ft/sec; Water Temperature = 120F; Re~en~îon Time =
1.3 days; Mild Steel Heat Transfer Surface.
Water Chemistry: 500 ppm Ca as CaC039 250 ppm M9~2 as CaC03; 83 ppm NaHC03; pH = 7.3 + 0.2, Fe~3 5.0 ppm as Fe *
Treatment: 12.5 ppm active polymer; 3.0 ppm tolyltriazole; 10.5 ppm tetrapotassium pyrophosphate; 15.2 ppm monosodium phosphate;
HEDP 4.0 ppm tor 0 ppm as requlred).
* Added from deaerated solution directly to sump to avoid precipitation of Fe+3 prior to addition so as to simu7ate conditions experienced upon use of Ron containing well water as a make-up source in real cooling systems.
3~3 Results of the recirculator tests are reported in the following tables.
Table 2 Comparative Recirculator Test Using 12.5 ppm acrylic acid/2-hydroxypropyl acrylate polymer (molar ratio M:HPA = 3:1 Mw 6,000) as test polymer Corrosion Results Corrosion Exposure Rate DurationAppearance Coupon # Coupon Type_~py__(Days) (Coupon) _ G-l Low carbon 10 1 Moderate, non-uni~orm steel whitish brown deposit G-2 Low carbon 3.8 4 Same as G-l but more steel severe G-3 Low carbon 3.0 3 Very thin deposit with steel spots of localized corrosion G-4 Admiralty 1.0 1 Clean with water spotting G-5 Admiralty 0.5 4 Clean with water spotting G-6 Admlralty 0.7 3 Clean with water spotting 121 Pretreated 4.0 1 Clean low carbon steel 122 Pretreated 2.3 4 Clean low carbon steel 137 Pretreated 2.7 3 Clean low carbon steel ~3~3~
heat transfer surface appearance - pretreated = localized areas of non-uniform deposit and corrosion, otherwise clean; non pretreated =
scattered pits with large patch of thin yellowish deposit.
Recirculator Water Analysis (Time) ppm soluble orthophosphate total iron retained in day retained in recirculating water reclrculating water_ 1 9.0 4.0 2 8.2 1.5 7.9 3 8.6 1.5
Examples The invention will now be further described with reference to the following examples, which are to be regarded solely as illustrative, and not as restricting the scope of the invention.
Polymer Preparation Polymers in accordance with the invention were prepared as per the specification of pending application S.N. 464,527 (of common assignment herewith). Specifically, in each instance of polymer preparation, the following procedure was used. A
reaction flask was equipped with a mechanical agitator, a thermometer, a reflux condensor, a nitrogen inlet and two addition inlets for the initiator and monomer solutions. The flask was charged with deionized water and isopropanol. The resulting solution was then heated to reflux under a nitrogen blanket.
The requisite molar amount of acrylic acid and required molar amount of l-propane sulfonic acid, 2-hydroxy-3-(2-propenyl oxy) mono sodium salt [AHPSE] were mixed together in a separate flask so as to serve as a mixed monomer solutlon. This mixed monomer solution was then transferred to an addition funnel.
~3~
g An initiator solution containing sodium persulfate in deionized water was separately prepared and then sparged with nitrogen. The initiator solu~on was then added to the reaction flask along with the mixed monomer solution over a period of 2 hours. After this addition, the resulting mixture was heated for about 2 more hours at 65C and subsequently the isopropanol/water solution was stripped off. The reaction mixture was then cooled and neutralized by caustic addition Structures of the resulting polymers were verified by carbon 13 NMR.
The following copolymers were prepared in accordance with - the above procedure:
Monomer Ratio _ Viscosity Polymer Acrylic Acid/AHPSE % Solids Mn Mw _(cps) A 6:1 25.0 2,2176,731 15.4 B 6:1 25.0 2,77012,200 20.5 C 6:1 25.0 6,42043,300 77.0 D 6:1 25.0 3,300 - 23.0 E 6:1 25.0 2,700 - 25.6 F 6:1 25.0 3,200 - 20.7 POLARIZATIOH STUDIES
In order to produce Fe 3 ions similar to the type encountered in real cooling systems using iron containing well water as a make-up source, iron ions were generated by a method referred to as "Potentiodynamic Polarization'9. The purpose of this method is to electrically perturb a corroding metal electrode from its steady - state potential and to observe the resulting current-potential behavior. Specifically, an electrode of the desired metal - in this case low carbon steel - is placed -in a 1 liter, 5 neck flask. The flask is filled with about 850 ~236 j37 mL of a O.lN sodium sulfate solution adjusted to pH 7 + 0.2. The electrode is wet-ground with emery paper and 600 grit silicon carbide polishing compound, ultrasonically cleaned and degreased in toluene vapor. After the electrode is cleaned, it is inserted into the deaerated solution and allowed to equilibrate. A
potentiostat is operatively connected to the electrode. This process us monitored by tracking the electrode potential versus a standard reference electrode (to which the potentiostat is also operatively connected). When the potential is stable to 2 mV
for 1 hour, the experiment is initiated. The potentiostat is set to alter the electrode potentlal at 10 mV/m;nute, starting about -600 mV to the equilibrium potential, and continuing to about +400 mV to the equilibrium potential.
In the sweep from -600 mV to 0 mV (relative) the process(es) occurring at the test electrode is (are) primarily:
2H+ + 2e H2 (at low potentials) and 2 +2H20 + 4e~ ____~ 40H (at higher potentlals) In the sweep from 0 to +400 mV (relative) the primary processes at the electrode are:
Fe -I Fe+2 + 2e (at lower potentials) and Fe+2 -I+ en + Fe~3 (at higher potentials) This results in the fresh production of Fe+3 ions similar to those encountered in cooling water systems wherein iron containing well water is used as a make-up source.
.
3~3 Polymers in accordance with the invention were present in solutions in which Fe 3 ions were generated by the process hereinabove described. In tests with other polymers (not covered by the present invention), the iron ions precipitated out as Fe(OH)3 and other iron oxide species. Additionally the other polymers were gelled by the cross linking actlon of Fe~3 ions.
In sharp contrast, when polymers in accordance with the invention were present in solutions in which Fe+3 ions werè
generated by the above polarization technique, the jest solution remained clear although the presence of Fe ions was confirmed by the yellow-brown color of the test solutions. No polymer gellation occurred either. The lack of gellat~on and the solubility of iron ions indicates a good stability of the polymer towards the type of lron species encountered when iron containing well water is used as a make-up water source in cooling water systems.
The iron analysis results gathered pursuant to the "Potentiodynamic Polarization" tests reported hereinbelow in Table I indicate that when the present polymers are used, an extraordinary high level of soluble iron exists in the test solution. Ordinarily, at pH 7 the solubility limit of ferric hydroxide , as iron, is 2.5 x 10 5 ppm. As can be seen in Table I, use of the present polymers enhances the solubllity of iron at least about one million fold.
., 3~3~7~3 TABLE I
Iron Analysis of Supporting Electrolyte After Anodic Polarization of Low Carbon Steel Electrodes:
Total Corrosion Ratea Soluble Ironb PolymerConc (ppm) (mpy) OH _ (ppm) A 100 35.8 7 24.0 B 100 18.6 7 9.3 C 100 27.6 7 18.8 a Sum of values in air and under nitrogen b All iron was soluble. Differences are due to amounts of iron produced by differential corrosion rates.
Recirculator Studies In order to approximate those conditions experienced in a cooling tower, tests were conducted under recirculatory conditions with heat transfer prcvided.
These condltions closely slmulate the environment in a field cooling system. In this test system, treated water is circulated by a centrifugal pump through a corrosion coupon bypass into which corrosion coupons are inserted, and past a mild steel (AISI-1010) heat exchanger tube contained in a Plexiglas block. The inside of the exchanger tube is filled .
~3~37~3 with sillcone oil and heated with an electric heater. The temperature of the silicone oil can be regulated. The water velocity past the corroslon coupons and heat exchanger tube can be controlled anywhere from 0 to 4.5 ft/sec. The pH and temperature of the bulk water are au~omatlcally controlled. The treated water is prepared by chemical addition to deionized water. Provisions for continuous make-up and blowdown are made by pumping fresh treated water from supply tanks to the sump, with overflow from the sump serving as blowdown.
Corrosion rates are determined by exposing precleaned and weighed metal specimens for a specified period of time, after - which they are removed, cleaned and reweighed. Corrosion rates are calculated by dividing the total coupon weight loss by the number of days exposure.
The conditions used were: Heat Flux 8000 BTU/ft?/hr; Water Velocity = 3 ft/sec; Water Temperature = 120F; Re~en~îon Time =
1.3 days; Mild Steel Heat Transfer Surface.
Water Chemistry: 500 ppm Ca as CaC039 250 ppm M9~2 as CaC03; 83 ppm NaHC03; pH = 7.3 + 0.2, Fe~3 5.0 ppm as Fe *
Treatment: 12.5 ppm active polymer; 3.0 ppm tolyltriazole; 10.5 ppm tetrapotassium pyrophosphate; 15.2 ppm monosodium phosphate;
HEDP 4.0 ppm tor 0 ppm as requlred).
* Added from deaerated solution directly to sump to avoid precipitation of Fe+3 prior to addition so as to simu7ate conditions experienced upon use of Ron containing well water as a make-up source in real cooling systems.
3~3 Results of the recirculator tests are reported in the following tables.
Table 2 Comparative Recirculator Test Using 12.5 ppm acrylic acid/2-hydroxypropyl acrylate polymer (molar ratio M:HPA = 3:1 Mw 6,000) as test polymer Corrosion Results Corrosion Exposure Rate DurationAppearance Coupon # Coupon Type_~py__(Days) (Coupon) _ G-l Low carbon 10 1 Moderate, non-uni~orm steel whitish brown deposit G-2 Low carbon 3.8 4 Same as G-l but more steel severe G-3 Low carbon 3.0 3 Very thin deposit with steel spots of localized corrosion G-4 Admiralty 1.0 1 Clean with water spotting G-5 Admiralty 0.5 4 Clean with water spotting G-6 Admlralty 0.7 3 Clean with water spotting 121 Pretreated 4.0 1 Clean low carbon steel 122 Pretreated 2.3 4 Clean low carbon steel 137 Pretreated 2.7 3 Clean low carbon steel ~3~3~
heat transfer surface appearance - pretreated = localized areas of non-uniform deposit and corrosion, otherwise clean; non pretreated =
scattered pits with large patch of thin yellowish deposit.
Recirculator Water Analysis (Time) ppm soluble orthophosphate total iron retained in day retained in recirculating water reclrculating water_ 1 9.0 4.0 2 8.2 1.5 7.9 3 8.6 1.5
4 9.6 1.3 9.6 2~0 -Table 3 Recirculator test using 12.5 ppm acrylic acid/AHPSE polymer*
Corrosion Result.s Corrosion Exposure RateDuration Appearance Coupon # Coupon Type mpy (Days) coupon) C-l Low carbon 9.0 1 Tan Deposit over 90%
steel surface C-2 Low carbon 3.0 4 Tan Deposit over 80%
steel surface, non-uniform C-3 Low carbon 3.3 3 Scattered pits with steel corrosion induced fouling C-4 admiralty 2.0 1 Clean with water spotting C-5 admiralty 0.8 4 Clean with water spotting C-6 admiralty 0.7 3 Clean with water spotting ~2.~3~3~
123 pretreated 4.0 1 Clean low carbon steel 124 Pretreated 1.8 4 Clean low carbon steel 140 Pretreated 2.0 3 Clean low carbon steel heat transfer surface appearance - pretreated = isolatedi localized corrosion, clean , non-pretreated = scattered pitting and localized areas of corrosion/corrosion induced fouling.
Recirculator Water Analysis (Time) ppm soluble orthophosphate total iron retained in dayretained in recirculating waterrecircula~ing water 1 9.8 4.0 2 1306 1.5 8.5 3 8.8 ~.~
4 10.8 5,0 12.2 5.0 *equal weight mixture of polymers D, E, and F) Discussion Recirculator Test Results The recirculator test data and coupon appearance demonstrate the unique ability of the M/AHPSE copolymers (Table 3) in controlling iron fouling as compared to the acrylic acfd/2-hydroxy propyl acrylate (M/HPA~ copolymers (Table 2). Of particular note is the fact that the total Ron levels in the recirculating water closely l 3~3 parallel the iron feedrate in the M/AHPSE test (Table 3) whereas with the M/HPA copolymers (Table 2) a significant loss of nearly 75 of the simulated well water iron is experienced. This difference represents precipitated iron (i.e. that iron which would adhere to S metallurgy in contact with the cooling water system). Accordingly, it is thought that the M/AHPSE copolymers will be efficacious in controlling iron deposition in cooling water systems wherein iron has been admitted to the system from a well water source.
Also noteworthy is the fact that consistently higher levels of soluble orthophosphate are retained in the M/AHPSE treated system (Table 3) than in the M/HPA treated system (Table 2). This fact indicates that the M/AHPSE copolymers may be successfully utilized in conjunction with orthophosphate based corrosion inhibltors to form the highly desired9 but elusive passivated film on system metallurgy. Presently, high levels (preferred 6 to 30 ppm) of orthophosphate are employed in conjunction with calcium phosphate dispersants so as to result in the formation of such passivated film along the metallurgical surfaces of the cooling system. The M/AHPSE
copolymers may be successfully applied to the system, in addition to such high orthophosphate dosage, even in those instances wherein Fe+3, from a well water source, is contained within the system.
In can thus be seen that the disclosed invention carries out the objects of the invention set forth above. In accord with the patent statutes , the best mode has been set forth. However, it will be apparent to those skilled in the art that many modifications can be made without departing from he invention herein disclosed and described, the scope of the invention being limited solely by the scope of the attached claims.
Corrosion Result.s Corrosion Exposure RateDuration Appearance Coupon # Coupon Type mpy (Days) coupon) C-l Low carbon 9.0 1 Tan Deposit over 90%
steel surface C-2 Low carbon 3.0 4 Tan Deposit over 80%
steel surface, non-uniform C-3 Low carbon 3.3 3 Scattered pits with steel corrosion induced fouling C-4 admiralty 2.0 1 Clean with water spotting C-5 admiralty 0.8 4 Clean with water spotting C-6 admiralty 0.7 3 Clean with water spotting ~2.~3~3~
123 pretreated 4.0 1 Clean low carbon steel 124 Pretreated 1.8 4 Clean low carbon steel 140 Pretreated 2.0 3 Clean low carbon steel heat transfer surface appearance - pretreated = isolatedi localized corrosion, clean , non-pretreated = scattered pitting and localized areas of corrosion/corrosion induced fouling.
Recirculator Water Analysis (Time) ppm soluble orthophosphate total iron retained in dayretained in recirculating waterrecircula~ing water 1 9.8 4.0 2 1306 1.5 8.5 3 8.8 ~.~
4 10.8 5,0 12.2 5.0 *equal weight mixture of polymers D, E, and F) Discussion Recirculator Test Results The recirculator test data and coupon appearance demonstrate the unique ability of the M/AHPSE copolymers (Table 3) in controlling iron fouling as compared to the acrylic acfd/2-hydroxy propyl acrylate (M/HPA~ copolymers (Table 2). Of particular note is the fact that the total Ron levels in the recirculating water closely l 3~3 parallel the iron feedrate in the M/AHPSE test (Table 3) whereas with the M/HPA copolymers (Table 2) a significant loss of nearly 75 of the simulated well water iron is experienced. This difference represents precipitated iron (i.e. that iron which would adhere to S metallurgy in contact with the cooling water system). Accordingly, it is thought that the M/AHPSE copolymers will be efficacious in controlling iron deposition in cooling water systems wherein iron has been admitted to the system from a well water source.
Also noteworthy is the fact that consistently higher levels of soluble orthophosphate are retained in the M/AHPSE treated system (Table 3) than in the M/HPA treated system (Table 2). This fact indicates that the M/AHPSE copolymers may be successfully utilized in conjunction with orthophosphate based corrosion inhibltors to form the highly desired9 but elusive passivated film on system metallurgy. Presently, high levels (preferred 6 to 30 ppm) of orthophosphate are employed in conjunction with calcium phosphate dispersants so as to result in the formation of such passivated film along the metallurgical surfaces of the cooling system. The M/AHPSE
copolymers may be successfully applied to the system, in addition to such high orthophosphate dosage, even in those instances wherein Fe+3, from a well water source, is contained within the system.
In can thus be seen that the disclosed invention carries out the objects of the invention set forth above. In accord with the patent statutes , the best mode has been set forth. However, it will be apparent to those skilled in the art that many modifications can be made without departing from he invention herein disclosed and described, the scope of the invention being limited solely by the scope of the attached claims.
Claims (9)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of inhibiting corrosion and controlling deposition in an aqueous medium of the type comprising iron species present in said medium in a deposit forming amount and under deposit forming conditions, said method comprising adding to said medium an effective amount of a water soluble copolymer comprising repeat unit moieties (a) and (b) wherein said repeat unit moiety (a) comprises the structure:
X
and wherein said repeat unit (b) comprises the structure:
wherein x and y are integers and the ratio of x:y may be in the range of about 30:1 to 1:20, R1 is H or lower alkyl (C1 -C3), R2 is OH, OM, or NH2, M is H or a water soluble cation.
X
and wherein said repeat unit (b) comprises the structure:
wherein x and y are integers and the ratio of x:y may be in the range of about 30:1 to 1:20, R1 is H or lower alkyl (C1 -C3), R2 is OH, OM, or NH2, M is H or a water soluble cation.
2. A method as recited in claim 1 wherein said aqueous medium is contained within a cooling water system.
3, A method as recited in claim 2 wherein said iron is admitted to said cooling water system from a well water makeup source.
4. A method as recited in claim 1 wherein the number average molecular weight (Mn) of said copolymer is between about 1,000 to 1,000,000.
5. A method as recited in claim 4 wherein said number average molecular weight (Mn) of said copolymer is between about 2,000 - 10,000.
6. A method as recited in claim 1 wherein the molar ratio x:y is between about 10:1 to 1:5.
7. A method as recited in claim 1 wherein said water soluble copolymer is added to said aqueous medium in an amount of about 0.1 - 500 parts polymer based upon 1 million parts of said aqueous medium.
8, A method as recited in claim 1 wherein said repeat unit (a) comprises acrylic acid or water soluble salt form thereof.
9. A method as recited in claim 1 further comprising, adding to said aqueous medium, between about 6 to 30 parts per million, based upon one million parts of said aqueous medium, of a water soluble orthophosphate compound, said copolymer and said orthophosphate compound resulting in the formation of a passivated film along metallic surfaces in contact with said aqueous medium without resulting in substantial deposition thereon.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US681,054 | 1984-12-13 | ||
| US06/681,054 US4560481A (en) | 1984-12-13 | 1984-12-13 | Method of controlling iron induced fouling in water systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1236373A true CA1236373A (en) | 1988-05-10 |
Family
ID=24733623
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000494331A Expired CA1236373A (en) | 1984-12-13 | 1985-10-31 | Method of controlling iron induced fouling in water systems |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4560481A (en) |
| EP (1) | EP0188884A1 (en) |
| AU (1) | AU5047685A (en) |
| CA (1) | CA1236373A (en) |
Families Citing this family (42)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4895916A (en) * | 1983-10-26 | 1990-01-23 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4732698A (en) * | 1983-10-26 | 1988-03-22 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4863614A (en) * | 1983-10-26 | 1989-09-05 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4898684A (en) * | 1983-10-26 | 1990-02-06 | Betz Laboratories, Inc. | Novel amine-containing copolymers and their use |
| US4980433A (en) * | 1983-10-26 | 1990-12-25 | Betz Laboratories, Inc. | Novel amine-containing copolymers and their use |
| US4869845A (en) * | 1983-10-26 | 1989-09-26 | Betz Laboratories, Inc. | Water treatment compositions |
| US4872995A (en) * | 1983-10-26 | 1989-10-10 | Betz Laboratories, Inc. | Method for calcium oxalate scale control |
| US4849129A (en) * | 1988-05-06 | 1989-07-18 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4701262A (en) * | 1983-10-26 | 1987-10-20 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4868263A (en) * | 1983-10-26 | 1989-09-19 | Betz Laboratories, Inc. | Novel amine-containing copolymers and their use |
| US4895664A (en) * | 1983-10-26 | 1990-01-23 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4759851A (en) * | 1983-10-26 | 1988-07-26 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4944885A (en) * | 1983-10-26 | 1990-07-31 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4929695A (en) * | 1983-10-26 | 1990-05-29 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| JPS60118295A (en) * | 1983-10-26 | 1985-06-25 | ベッツ・インターナショナル・インコーポレイテッド | Polymer for treating service water and usage thereof |
| US4659481A (en) * | 1983-10-26 | 1987-04-21 | Betz Laboratories Inc. | Water treatment polymers and methods of use thereof |
| US4906383A (en) * | 1983-10-26 | 1990-03-06 | Betz Laboratories, Inc. | Novel amine-containing copolymers and their use |
| US4801387A (en) * | 1983-10-26 | 1989-01-31 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4929362A (en) * | 1983-10-26 | 1990-05-29 | Betz Laboratories, Inc. | Calcium phosphate scale control methods |
| US4717499A (en) * | 1983-10-26 | 1988-01-05 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4913822A (en) * | 1983-10-26 | 1990-04-03 | Betz Laboratories, Inc. | Method for control of scale and inhibition of corrosion in cooling water systems |
| US4671880A (en) * | 1986-01-10 | 1987-06-09 | Betz Laboratories, Inc. | Method for inhibiting aluminum-based deposition in water systems |
| US4929425A (en) * | 1986-05-09 | 1990-05-29 | Nalco Chemical Company | Cooling water corrosion inhibition method |
| US4895663A (en) * | 1986-05-16 | 1990-01-23 | Betz Laboratories, Inc. | Water treatment polymers and methods of use thereof |
| US4710303A (en) * | 1986-08-14 | 1987-12-01 | Nalco Chemical Company | Low molecular weight polyvinyl sulfonate for low pH barium sulfate scale control |
| US4952327A (en) * | 1986-12-08 | 1990-08-28 | The B. F. Goodrich Company | Scale control with terpolymers containing styrene sulfonic acid |
| US4889637A (en) * | 1986-12-08 | 1989-12-26 | Zahid Amjad | Scale control with terpolymers containing vinyl alcohol |
| US4952326A (en) * | 1986-12-08 | 1990-08-28 | The B. F. Goodrich Company | Dispersion of particulates in an aqueous medium |
| US4885097A (en) * | 1986-12-08 | 1989-12-05 | The B. F. Goodrich Company | Stabilization of metal ions with terpolymers containing styrene sulfonic acid |
| US4973428A (en) * | 1987-04-27 | 1990-11-27 | Nalco Chemical Company | Zinc stabilization with modified acrylamide based polymers and corrosion inhibition derived therefrom |
| US4898686A (en) * | 1987-04-27 | 1990-02-06 | Nalco Chemical Company | Zinc stabilization with modified acrylamide based polymers and corrosion inhibition derived therefrom |
| US5049310A (en) * | 1987-04-27 | 1991-09-17 | Nalco Chemical Company | Zinc stabilization with modified acrylamide based polymers and corrosion inhibition derived therefrom |
| DE3861556D1 (en) * | 1987-06-23 | 1991-02-21 | Ciba Geigy Ag | PREVENTION OF DEPOSITS. |
| US4900451A (en) * | 1989-02-01 | 1990-02-13 | Betz Laboratories, Inc. | Method of controlling manganese deposition in open recirculating aqueous systems |
| US4941979A (en) * | 1989-02-08 | 1990-07-17 | Betz Laboratories, Inc. | Method of stabilizing manganese in aqueous systems |
| US5102555A (en) * | 1989-02-08 | 1992-04-07 | Betz Laboratories, Inc. | Method of stabilizing mangnaese in aqueous systems |
| US5200105A (en) * | 1990-04-20 | 1993-04-06 | W. R. Grace & Co.-Conn. | Scale control in aqueous systems |
| US5282976A (en) * | 1992-07-21 | 1994-02-01 | Rhone-Poulenc Inc. | Terpolymer useful as a scale inhibitor |
| US5437712A (en) * | 1994-03-01 | 1995-08-01 | Betz Laboratories, Inc. | Methods for inhibiting deposition and fouling in scrubber systems |
| US5601754A (en) * | 1995-04-21 | 1997-02-11 | Betz Laboratories, Inc. | Water treatment polymer containing poly[oxy-[(hydroxymethyl)-1,2-ethanediyl]] macromonomers and methods of use thereof |
| JP2002273478A (en) * | 2001-03-21 | 2002-09-24 | Jsr Corp | Scale prevention method |
| US8871691B2 (en) * | 2009-06-05 | 2014-10-28 | Kroff Chemical Company | Methods of treating flowback water |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3837803A (en) * | 1972-07-11 | 1974-09-24 | Betz Laboratories | Orthophosphate corrosion inhibitors and their use |
| US4029577A (en) * | 1975-11-17 | 1977-06-14 | Betz Laboratories, Inc. | Polymers for use in water treatment |
| US4500693A (en) * | 1981-07-07 | 1985-02-19 | Nippon Shokubai Kagaku Kogyo Co., Ltd. | Water soluble copolymer method for manufacture therefore and use thereof |
| JPS587415A (en) * | 1981-07-07 | 1983-01-17 | Nippon Shokubai Kagaku Kogyo Co Ltd | Novel water-soluble copolymer and its preparation |
| JPS589987A (en) * | 1981-07-08 | 1983-01-20 | Nippon Shokubai Kagaku Kogyo Co Ltd | Scale preventing agent |
| US4387027A (en) * | 1981-10-09 | 1983-06-07 | Betz Laboratories, Inc. | Control of iron induced fouling in water systems |
| US4443340A (en) * | 1981-10-09 | 1984-04-17 | Betz Laboratories, Inc. | Control of iron induced fouling in water systems |
| CA1234033A (en) * | 1983-10-26 | 1988-03-15 | Fu Chen | Water treatment polymers and methods of use thereof |
-
1984
- 1984-12-13 US US06/681,054 patent/US4560481A/en not_active Expired - Lifetime
-
1985
- 1985-10-31 CA CA000494331A patent/CA1236373A/en not_active Expired
- 1985-11-28 AU AU50476/85A patent/AU5047685A/en not_active Abandoned
- 1985-12-12 EP EP85309023A patent/EP0188884A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| EP0188884A1 (en) | 1986-07-30 |
| US4560481A (en) | 1985-12-24 |
| AU5047685A (en) | 1986-06-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1236373A (en) | Method of controlling iron induced fouling in water systems | |
| US4446028A (en) | Isopropenyl phosphonic acid copolymers used to inhibit scale formation | |
| US4913822A (en) | Method for control of scale and inhibition of corrosion in cooling water systems | |
| US3965027A (en) | Scale inhibition and corrosion inhibition | |
| US4018702A (en) | Corrosion inhibition with amine adducts of maleic anhydride polymers | |
| US4659482A (en) | Water treatment polymers and methods of use thereof | |
| US5575920A (en) | Method of inhibiting scale and controlling corrosion in cooling water systems | |
| EP0082657B1 (en) | Polyampholytes and their use | |
| US4469615A (en) | Water treating compositions | |
| US4209487A (en) | Method for corrosion inhibition | |
| US4717499A (en) | Water treatment polymers and methods of use thereof | |
| US4701262A (en) | Water treatment polymers and methods of use thereof | |
| US5282976A (en) | Terpolymer useful as a scale inhibitor | |
| EP0033417A1 (en) | Method of and composition for inhibiting corrosion | |
| EP0077187B1 (en) | Method of inhibiting corrosion and controlling deposition in an aqueous medium | |
| US5378372A (en) | Control of scale formation in aqueous systems | |
| CA1291635C (en) | Composition of corrosion inhibitors for cooling water systems using chemically modified acrylamide or methacrylamide polymers | |
| US3963636A (en) | Treatment of water or aqueous systems | |
| US4944885A (en) | Water treatment polymers and methods of use thereof | |
| US4895663A (en) | Water treatment polymers and methods of use thereof | |
| US4869845A (en) | Water treatment compositions | |
| US4530955A (en) | Water treatment composition comprising a hydrolyzed maleic anhydride copolymer and a zinc compound | |
| US5708108A (en) | Water treatment polymer containing poly oxy- (hydroxymethyl)-1,2-ethanediyl!! macromonomers and methods of use thereof | |
| CA1329474C (en) | Cooling water corrosion control method and composition | |
| US4801387A (en) | Water treatment polymers and methods of use thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |