US4172786A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ozonation of cooling tower waters
Assignee: National Aeronautics and Space Administration
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Filing: 1978-09-29
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Granted: 1979-10-30
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Expires: 1998-09-29
Abstract
Abstract Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.
Inventors
- 👤 with respect to an invention of Frosch Robert A. Administrator of the National Aeronautics and Space Administration
- 👤 Marshall F. Humphrey
- 👤 Kenneth R. French
- 👤 Ronald D. Howe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:12
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/18; C02; C02F; C02F1/00; C02F1/72; C02F1/78; C02F5/00; C02F5/08; C02F5/083; C02F2103/00; C02F2103/02; C02F2103/023
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
104 words
A method of inhibiting formation of scale, corrosion and algae growth on the surfaces in contact with corrosive and scaling ion containing water circulating through a circuit including a heat exchanger and a cooling tower in which air containing algae forming micro-organisms is blown through water downwardly falling into a basin comprising the steps of: injecting ozone into the water in the basin at a level of at least 2 milligrams per liter in the absence of any other corrosion or scale inhibitor; and maintaining the ozone level in the water in the circuit at a level between 2 to 20 milligrams per liter.
Claim 2
Independent Claim
104 words
A method of inhibiting formation of scale, corrosion and algae growth on the surfaces in contact with corrosive and scaling ion containing water circulating through a circuit including a heat exchanger and a cooling tower in which air containing algae forming micro-organisms is blown through water downwardly falling into a basin comprising the steps of: injecting ozone into the water in the basin at a level of at least 2 milligrams per liter in the absence of any other corrosion or scale inhibitor; and maintaining the ozone level in the water in the circuit at a level between 2 to 20 milligrams per liter.
Claim 3
Dependent Claim
22 words
A method according to claim 1 in which the ozone is generated by subjecting an oxygen containing gas to a corona discharge.
Claim 4
Dependent Claim
12 words
A method according to claim 2 in which the gas is air.
Claim 5
Dependent Claim
15 words
A method according to claim 3 in which the air is dried before being ozonated.
Claim 6
Dependent Claim
25 words
A method according to claim 3 in which the scale comprises calcium carbonate and further including the step of flaking the scale from the surfaces.
Claim 7
Dependent Claim
13 words
A method according to claim 1 in which the scale comprises calcium carbonate.
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) | 1982-10-29 | 1983-04-30 | 1983-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-29 | 1987-04-30 | 1987-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-29 | 1991-04-30 | 1991-10-30 | $7700.00 | Window Closed / Lapsed |