US3947610A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Procedure for sealing leaks in closed cooling systems
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1974-08-07
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Granted: 1976-03-30
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Expires: 1994-08-07
Abstract
Abstract Leaks in closed cooling systems containing an aqueous medium as the coolant, are sealed by electroless deposition of a metal or metal containing compound from a water soluble, easily reducible metal compound. A complexing agent may be added to the coolant to assist in solubilizing the easily reducible metal compound. In one embodiment, the reducible metal compound is formed in situ by attacking the conduit walls of the cooling system so as to form solubilized compounds, or compounds which can be solubilized by addition of suitable complexing agents.
Inventors
- 👤 Maurice Bodmer
- 👤 Edmund Hartinger
- 👤 Albert Huber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:34
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/12
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
164 words
A method for sealing leaks in a closed cooling system which contains an aqueous medium as the coolant, which comprises: introducing into the coolant a water-soluble, reducible metal hydroxide, inorganic salt, organic salt, or a complex thereof, of a metal selected from the group consisting of Cu, Bi, Cr, Fe, Mn, Mg, Zn, Al, Sb, Ca, Ba, Sr, Hg, Ag, Au, Sn, Ni, Cd, Pb, Co, Pt, Rh, Ir, and Pd, or a water-soluble, reducible metal oxide of a metal selected from the group consisting of: Bi, Cr, Fe, Mn, Mg, Zn, Al, Sb, Ca, Ba, Sr, and Hg, wherein the concentration of said soluble metal cation ranges from 10.sup. -8 to 1 molar; and introducing a reducing agent into said coolant in a concentration between 10.sup. -6 and 1 molar, so as to cause electroless deposition of the metal or a corresponding metal compound wherein the metal is present in a lower valence state, whereby leaks in the closed cooling system are sealed.
Claim 2
Independent Claim
164 words
A method for sealing leaks in a closed cooling system which contains an aqueous medium as the coolant, which comprises: introducing into the coolant a water-soluble, reducible metal hydroxide, inorganic salt, organic salt, or a complex thereof, of a metal selected from the group consisting of Cu, Bi, Cr, Fe, Mn, Mg, Zn, Al, Sb, Ca, Ba, Sr, Hg, Ag, Au, Sn, Ni, Cd, Pb, Co, Pt, Rh, Ir, and Pd, or a water-soluble, reducible metal oxide of a metal selected from the group consisting of: Bi, Cr, Fe, Mn, Mg, Zn, Al, Sb, Ca, Ba, Sr, and Hg, wherein the concentration of said soluble metal cation ranges from 10.sup. -8 to 1 molar; and introducing a reducing agent into said coolant in a concentration between 10.sup. -6 and 1 molar, so as to cause electroless deposition of the metal or a corresponding metal compound wherein the metal is present in a lower valence state, whereby leaks in the closed cooling system are sealed.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein said reducible compound is produced in situ by corrosive action of the cooling water on the cooling pipes.
Claim 4
Dependent Claim
19 words
The method of claim 2, wherein the corrosive products are induced by the addition of air into the coolant.
Claim 5
Dependent Claim
17 words
The method of claim 1, wherein said deposition is of a metal in the zero valence state.
Claim 6
Dependent Claim
26 words
The method of claim 1, wherein said deposition is of a metal compound, wherein the metal is in a lower valence state than said reducible compound.
Claim 7
Dependent Claim
29 words
The method of claim 1, wherein said reducible metal is in the form of a complex with a complexing agent in order to enhance the solubility of said compound.
Claim 8
Dependent Claim
40 words
A method of claim 1, wherein said metal hydroxide, inorganic salt, organic salt, or metal complex is comprised of a metal selected from the group consisting of Cu, Ag, Au, Sn, Ni, Cd, Pb, Co, Pt, Rh, Ir and Pd.
Claim 9
Dependent Claim
12 words
The method of claim 7, wherein said metal compound is copper oxide.
Claim 10
Dependent Claim
29 words
The method of claim 8, wherein said copper oxide is formed in situ as a corrosion product of the copper walls of the conduits of said closed cooling system.
Claim 11
Dependent Claim
21 words
The method of claim 9, wherein said corrosion products are enhanced by the addition of an oxidizing agent into the coolant.
Claim 12
Dependent Claim
11 words
The method of claim 10, wherein said oxidizing agent is oxygen.
Claim 13
Dependent Claim
11 words
The method of claim 6, wherein said complexing agent is morpholine.
Claim 14
Dependent Claim
19 words
The method of claim 1, wherein the pH of the aqueous medium is adjusted to between 7 and 10.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |