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US4168291A
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Alkanolamines as cold-end additives
Assignee: Veolia WTS USA Inc
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Filing: 1978-10-30
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Granted: 1979-09-18
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Expires: 1998-10-30
Abstract
Abstract A method of reducing the amount of sulfur trioxide condensation on, and therefore the amount of sulfuric acid corrosion of, metal parts at the cold-end of a combustion system and in contact with combustion gases derived from the combustion of sulfur containing fuel, said method comprising adding to the combustion gases an effective amount for the purpose of an aliphatic, water-soluble alkanolamine additive.
Inventors
- 👤 Bruce L. Libutti
- 👤 Francis J. Oschell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:00
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/02; C23F15/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
139 words
A method of reducing the amount of sulfur trioxide condensation on, and therefore the amount of sulfuric acid corrosion of, metal parts at the cold-end of a combustion system in contact with combustion gases derived from the combustion of sulfur-containing fuel, which combustion gases flow along a path at the cold-end of the combustion system from a first zone of relative turbulence to a second zone at which the turbulence subsides, said method comprising: adding to the combustion gases at the cold-end of the combustion system and at the zone of turbulence an effective amount for the purpose of an alkanolamine additive comprising an aliphatic, water-soluble alkanolamine such that said additive will travel along with said gases, as vapor and/or liquid droplets, from said zone of turbulence to said second zone and deposit on surfaces of said metal parts.
Claim 2
Independent Claim
139 words
A method of reducing the amount of sulfur trioxide condensation on, and therefore the amount of sulfuric acid corrosion of, metal parts at the cold-end of a combustion system in contact with combustion gases derived from the combustion of sulfur-containing fuel, which combustion gases flow along a path at the cold-end of the combustion system from a first zone of relative turbulence to a second zone at which the turbulence subsides, said method comprising: adding to the combustion gases at the cold-end of the combustion system and at the zone of turbulence an effective amount for the purpose of an alkanolamine additive comprising an aliphatic, water-soluble alkanolamine such that said additive will travel along with said gases, as vapor and/or liquid droplets, from said zone of turbulence to said second zone and deposit on surfaces of said metal parts.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein an aqueous solution of the additive is added to the combustion gases.
Claim 4
Dependent Claim
32 words
The method of claim 1, wherein the alkanolamine is added in an amount of from about 0.1 to about 2.0 pound per pound of sulfur trioxide produced upon combustion of the fuel.
Claim 5
Dependent Claim
32 words
The method of claim 3, wherein the alkanolamine is added in an amount of from about 0.25 to about 1.0 pound per pound of sulfur trioxide produced upon combustion of the fuel.
Claim 6
Dependent Claim
17 words
The method of claim 1, wherein the alkanolamine is added in droplet form to the combustion gases.
Claim 7
Dependent Claim
26 words
The method of claim 5, wherein the temperature of the combustion gases at the time of addition is from about 250° F. to about 675° F.
Claim 8
Dependent Claim
26 words
The method of claim 1, wherein the temperature of the combustion gases at the time of addition is from about 250° F. to about 675° F.
Claim 9
Dependent Claim
26 words
The method of claim 7, wherein the temperature of the combustion gases at the time of addition is from about 350° F. to about 650° F.
Claim 10
Dependent Claim
21 words
The method of claim 1, wherein the combustion system is a steam generating system, and wherein the fuel is sulfur-containing oil.
Claim 11
Dependent Claim
17 words
The method of claim 9, wherein the alkanolamine is added in droplet form to the combustion gases.
Claim 12
Dependent Claim
26 words
The method of claim 10, wherein the temperature of the combustion gases at the time of addition is from about 250° F. to about 675° F.
Claim 13
Dependent Claim
18 words
The method of claim 10, wherein an aqueous solution of the additive is added to the combustion gases.
Claim 14
Dependent Claim
10 words
The method of claim 12, wherein the additive is monoethanolamine.
References Cited (Backward Citations)
US2106446A
Cited
US2155853A
Cited
US2972861A
Cited
GB872984A
Cited
US3343908A
Cited
US3547583A
Cited
US3809745A
Cited
US3856921A
Cited
GB1305750A
Cited
US3709977A
Cited
US3720754A
Cited
US3873673A
Cited
US3904735A
Cited
US3962404A
Cited
US3886261A
Cited
US3932588A
Cited
US3961018A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-09-17 | 1983-03-19 | 1983-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-17 | 1987-03-19 | 1987-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-17 | 1991-03-19 | 1991-09-18 | $7700.00 | Window Closed / Lapsed |