Patent US5740745A successfully refreshed from Google Patents.
US5740745A
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Process for increasing the effectiveness of slag control chemicals for black liquor recovery and other combustion units
Assignee: Fuel Tech Inc
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Filing: 1996-09-20
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Granted: 1998-04-21
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Expires: 2016-09-20
Abstract
Abstract Reduction of slagging is improved by targeting slag-reducing chemicals in a furnace with the aid of computational fluid dynamic modeling. Chemical utilization and boiler maintenance are improved.
Inventors
- 👤 Christopher R. Smyrniotis
- 👤 William F. Michels
- 👤 M. Damian Marshall
- 👤 William H. Sun
- 👤 Daniel V. Diep
- 👤 Cari M. Chenanda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:45
CPC Classifications
F; F23; F23J; F23J7/00; C; C10; C10L; C10L10/00; C10L10/04; C10L10/06; D; D21; D21C; D21C11/00; D21C11/10; D21C11/106; D21C11/12; F23G; F23G5/00; F23G5/44; F23G5/48; F23G7/00; F23G7/04; F23G2209/00; F23G2209/10; F23G2209/101
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A process for reducing the buildup of slag in a black liquor recovery boiler, comprising: determining slagging locations within a furnace where slagging will occur in the absence of treatment; determining the temperature and gas flow conditions within the boiler; locating introduction points on the furnace wall where introduction of chemicals could be accomplished; based on the temperature and gas flow conditions existing between the introduction points and the slagging locations, determining the droplet size, amount of treatment chemical, amount of water as a carrier, and droplet momentum necessary to direct the chemical in active form to the slagging locations; and, based on the determinations of the previous step, introducing chemical to reduce slagging.
Claim 2
Dependent Claim
114 words
A process for reducing the buildup of slag in a black liquor recovery boiler, comprising: determining slagging locations within a furnace where slagging will occur in the absence of treatment; determining the temperature and gas flow conditions within the boiler; locating introduction points on the furnace wall where introduction of chemicals could be accomplished; based on the temperature and gas flow conditions existing between the introduction points and the slagging locations, determining the droplet size, amount of treatment chemical, amount of water as a carrier, and droplet momentum necessary to direct the chemical in active form to the slagging locations; and, based on the determinations of the previous step, introducing chemical to reduce slagging.
Claim 3
Dependent Claim
19 words
A process according to claim 1 wherein the treatment chemical is a slurry of magnesium oxide or magnesium hydroxide.
Claim 4
Dependent Claim
26 words
A process according to claim 1 wherein the concentration of the chemical in the slurry is within the range of from about 1 to about 80%.
Claim 5
Dependent Claim
35 words
A process according to claim 1 wherein the chemical is introduced into the furnace at a dosage rate of from about 0.5 to about 5 pounds per ton black liquor solids burned in the furnace.
Claim 6
Dependent Claim
15 words
A process according to claim 4 wherein chemicals are introduced at more than one elevation.
Claim 7
Dependent Claim
107 words
A process for cleaning a combuster of of slag buildup, comprising: determining slagging locations within a furnace where slagging will occur in the absence of treatment; determining the temperature and gas flow conditions within the combuster; locating introduction points on the furnace wall where introduction of chemicals could be accomplished; based on the temperature and gas flow conditions existing between the introduction points and the slagging locations, determining the droplet size, amount of treatment chemical, amount of carrier for the chemical, and droplet momentum necessary to direct the chemical in active form to the slagging locations; and, based on the determinations of the previous steps, introducing chemical.
Claim 8
Dependent Claim
107 words
A process for cleaning a combuster of of slag buildup, comprising: determining slagging locations within a furnace where slagging will occur in the absence of treatment; determining the temperature and gas flow conditions within the combuster; locating introduction points on the furnace wall where introduction of chemicals could be accomplished; based on the temperature and gas flow conditions existing between the introduction points and the slagging locations, determining the droplet size, amount of treatment chemical, amount of carrier for the chemical, and droplet momentum necessary to direct the chemical in active form to the slagging locations; and, based on the determinations of the previous steps, introducing chemical.
Claim 9
Dependent Claim
18 words
A process according to claim 6 wherein the treatment chemical is a slurry of metal oxide or hydroxide.
Claim 10
Dependent Claim
26 words
A process according to claim 7 wherein the concentration of the chemical in the slurry is within the range of from about 1 to about 80%.
Claim 11
Dependent Claim
35 words
A process according to claim 8 wherein the chemical is introduced into the furnace at a dosage rate of from about 0.1 to about 10 pounds per ton black liquor solids burned in the furnace.
Claim 12
Dependent Claim
15 words
A process according to claim 6 wherein chemicals are introduced at more than one elevation.
References Cited (Backward Citations)
US3800466A
Cited
US4159683A
Cited
US4513256A
Cited
US4514256A
Cited
US4616574A
Cited
US4903642A
Cited
US5288857A
Cited
US5113802A
Cited
US5551354A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-04-20 | 2001-10-20 | 2002-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-20 | 2005-10-20 | 2006-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-20 | 2009-10-20 | 2010-04-21 | $7700.00 | Window Closed / Lapsed |