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US4134729A Expired / Lapsed US ⏱️ 0.0 years remaining

Aqueous solution of sodium aluminate and N-aminoethyl ethanolamine as a cold end additive

Assignee: Veolia WTS USA Inc
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Filing: 1977-09-08
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Granted: 1979-01-16
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Expires: 1997-09-08
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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 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 aqueous solution of sodium aluminate and an alkanolamine, particularly N-aminoethyl ethanolamine.

Inventors

  • 👤 Bruce L. Libutti
  • 👤 Francis J. Oschell

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 04:32
CPC Classifications
C; C23; C23F; C23F15/00

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 141 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 said zone of turbulence an effective amount for the purpose of an aqueous solution of sodium aluminate and N-aminoethyl ethanolamine such that the additive will travel along with the gases as solids, 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 141 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 said zone of turbulence an effective amount for the purpose of an aqueous solution of sodium aluminate and N-aminoethyl ethanolamine such that the additive will travel along with the gases as solids, 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 14 words
The method of claim 1, wherein the additive is sprayed into the combustion gases.
Claim 4
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 5
Dependent Claim 14 words
The method of claim 3, wherein the additive is sprayed into the combustion gases.
Claim 6
Dependent Claim 81 words
The method of claim 1, wherein the sodium aluminate is added in an amount of from about 0.2 to about 0.9 pound of sodium aluminate per pound of sulfur trioxide generated upon combustion of the fuel, and wherein the alkanolamine is added in an amount of from about 0.1 to about 0.8 pound of alkanolamine per pound of sulfur trioxide generated, with the proviso that the total treatment level does not exceed about 1.0 pound per pound of sulfur trioxide generated.
Claim 7
Dependent Claim 71 words
The method of claim 5, wherein the sodium aluminate is added in an amount of from about 0.25 to about 0.75 pound per pound of sulfur trioxide generated, and wherein the alkanolamine is added in an amount of from about 0.25 to about 0.75 pound per pound of sulfur trioxide generated, with the proviso that the total treatment level does not exceed about 1.0 pound per pound of sulfur trioxide generated.
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 17 words
The method of claim 1, wherein the additive is fed in droplet form to the combustion gases
Claim 11
Dependent Claim 14 words
The method of claim 2, wherein the additive is sprayed into the combustion gases.
Claim 12
Dependent Claim 17 words
The method of claim 2, wherein the droplets have a size of less than about 360 microns.
Claim 13
Dependent Claim 17 words
The method of claim 11, wherein the droplets have a size of less than about 260 microns.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-01-15 1982-07-17 1983-01-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-01-15 1986-07-17 1987-01-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-01-15 1990-07-17 1991-01-16 $7700.00 Window Closed / Lapsed

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