US4472283A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of carbon dioxide to reduce the pH in circulating hard water
Assignee: Individual
•
Filing: 1984-01-17
•
Granted: 1984-09-18
•
Expires: 2004-01-17
Abstract
Abstract The disclosure teaches a method of retarding the loss of carbon dioxide from a circulating water system by means of quaternary ammonium compounds having at least one hydrocarbon radical containing twelve or more carbon atoms or at least two hydrocarbon radicals each containing seven or more carbon atoms. In the method an effective amount of a suitable quaternary ammonium compound is added to the water in the system, surprisingly slowing the rate of loss of carbon dioxide from the water. Carbon dioxide is added to the water as needed to maintain the desired pH. The method provides an advantageous alternative to using stronger and more hazardous acids in maintaining a lowered pH in circulating water systems, for example, in heat exchange systems that utilize cooling towers.
Inventors
- 👤 William W. Brooks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:50
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/66; C02F5/00; C02F5/08; C02F5/10; C02F5/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
135 words
In a recirculating, aqueous system containing carbon dioxide as a pH modifier and subject to aeration, the method comprising the steps of lowering and maintaining pH by adding amounts of carbon dioxide effective to achieve a pH that controls the rate of deposition of scale by increasing the solubility of dissolved salts, and lowering the consumption of said carbon dioxide by adding to the system an uncrosslinked, water soluble quaternary ammonium salt having at least one hydrocarbon radical having twelve or more carbon atoms, or at least two hydrocarbon radicals each having seven or more carbon atoms, wherein the concentration of quaternary ammonium salts in the system is at least one-half part per million, whereby a substantial part of the carbon dioxide is retained in the system in active form from one cycle to another.
Claim 2
Dependent Claim
135 words
In a recirculating, aqueous system containing carbon dioxide as a pH modifier and subject to aeration, the method comprising the steps of lowering and maintaining pH by adding amounts of carbon dioxide effective to achieve a pH that controls the rate of deposition of scale by increasing the solubility of dissolved salts, and lowering the consumption of said carbon dioxide by adding to the system an uncrosslinked, water soluble quaternary ammonium salt having at least one hydrocarbon radical having twelve or more carbon atoms, or at least two hydrocarbon radicals each having seven or more carbon atoms, wherein the concentration of quaternary ammonium salts in the system is at least one-half part per million, whereby a substantial part of the carbon dioxide is retained in the system in active form from one cycle to another.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium compound is n-alkyl-dimethylbenzylammonium chloride.
Claim 4
Dependent Claim
25 words
The method of claim 2 wherein the alkyl moiety is a mixture of alkyl radicals having from 12 to 18 carbon atoms in each radical.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein the quaternary ammonium compound is a mixture of n-alkyldimethylbenzylammonium chloride and n-alkyldimethylethylbenzylammonium chloride.
Claim 6
Dependent Claim
55 words
The method of claim 4 wherein the alkyl moiety of the quaternary ammonium compound comprises a mixture of alkyl radicals having from 12 to 18 carbon atoms in each radical and wherein the alkyl moiety of the dimethylethylbenzylammonium chloride is a mixture of alkyl radicals having from 12 to 14 carbon atoms in each radical.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein the quaternary ammonium compound is a mixture of octyldecyldimethylammonium chloride, dioctyldimethylammonium chloride and didecyldimethylammonium chloride.
Claim 8
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium compound is cetyldimethylethylammonium bromide.
Claim 9
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium compound is trimethyltetradecylammonium bromide.
Claim 10
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium compound is myristyldimethylbenzylammonium chloride.
Claim 11
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium compound is cetylpyridinium chloride.
Claim 12
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium chloride is 1-coco-imidazolinebenzyl chloride.
Claim 13
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium chloride is didecyldimethylammonium chloride.
Claim 14
Dependent Claim
13 words
The method of claim 1 wherein the quaternary ammonium chloride is dioctyldimethylammonium chloride.
Claim 15
Dependent Claim
20 words
The method of claim 1 wherein the concentration of quaternary ammonium chloride is at least about one-half part per million.
Claim 16
Dependent Claim
21 words
The method of claim 1 wherein the quaternary ammonium chloride is a mixture of octyldecyldimethylammonium chloride, dioctyldimethylammonium chloride and didecyldimethylammonium chloride.
References Cited (Backward Citations)
US2259169A
Cited
US2801151A
Cited
US2713077A
Cited
GB959422A
Cited
US3579445A
Cited
US3658463A
Cited
DE2030430A1
Cited
CA948379A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |