US5405537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for combusting dewatered sludge waste in a municipal solid waste incinerator
Assignee: Air Products and Chemicals Inc
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Filing: 1993-03-26
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Granted: 1995-04-11
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Expires: 2013-03-26
Abstract
Abstract This invention relates to an improved process for the coincineration of municipal solid waste and municipal sewage sludge by dewatering the sludge, breaking it up into sufficiently small particles and employing oxygen enrichment of the combustion process. These small particles of sludge are introduced into the combustion zone above the grate in the combustion zone but at a distance above the grate no higher than that of the point of introduction of secondary air. This is accomplished without undesired excursions of flue gas flow rate and temperature.
Inventors
- 👤 Stephen P. Goff
- 👤 Diane M. DeVincentis
- 👤 Shoou-I Wang
- 👤 Donald P. Bucci
- 👤 Frank J. Romano
- 👤 Goutam H. Shahani
- 👤 Matthew J. Foder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:41
CPC Classifications
F; F23; F23L; F23L7/00; F23L7/007; F23G; F23G5/00; F23G5/002; F23G5/008; F23G5/44; F23G5/442; F23G2201/00; F23G2201/20; F23G2203/00; F23G2203/103; F23G2205/00; F23G2205/10; F23G2205/14; F23G2205/16; F23G2209/00; F23G2209/12; F23L2900/00; F23L2900/07005; Y; Y02; Y02E; Y02E20/00; Y02E20/34
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
228 words
In a process for the co-incineration of a solid waste and sewage sludge containing solid particulate matter in an incineration system comprising a combustion zone containing a grate on which the solid waste is combusted, means for introducing the solid waste onto the grate, means for introducing a flow of combustion supporting air into the combustion zone including primary air inlet means for introducing combustion supporting air at a point beneath the grate and secondary air inlet means for introducing combustion supporting air at a point above the grate, and means for introducing sewage sludge into the combustion zone, which process comprises combusting the solid waste on the grate, introducing combustion supporting air, and combusting the sewage sludge in the combustion zone, the improvement which comprises: a) dewatering the sludge to a solids content from in the range of about 15 to about 30 percent by weight; b) finely dividing the solid particulate matter in the dewatered sludge to particles smaller than about 1000 microns; c) introducing the dewatered sludge into the combustion zone at a point above the solid waste on the grate and not above the point at which the secondary air is introduced to the combustion zone; and d) enriching at least a portion of the flow of combustion supporting air with oxygen to an oxygen concentration of at least about 21 percent by volume.
Claim 2
Dependent Claim
228 words
In a process for the co-incineration of a solid waste and sewage sludge containing solid particulate matter in an incineration system comprising a combustion zone containing a grate on which the solid waste is combusted, means for introducing the solid waste onto the grate, means for introducing a flow of combustion supporting air into the combustion zone including primary air inlet means for introducing combustion supporting air at a point beneath the grate and secondary air inlet means for introducing combustion supporting air at a point above the grate, and means for introducing sewage sludge into the combustion zone, which process comprises combusting the solid waste on the grate, introducing combustion supporting air, and combusting the sewage sludge in the combustion zone, the improvement which comprises: a) dewatering the sludge to a solids content from in the range of about 15 to about 30 percent by weight; b) finely dividing the solid particulate matter in the dewatered sludge to particles smaller than about 1000 microns; c) introducing the dewatered sludge into the combustion zone at a point above the solid waste on the grate and not above the point at which the secondary air is introduced to the combustion zone; and d) enriching at least a portion of the flow of combustion supporting air with oxygen to an oxygen concentration of at least about 21 percent by volume.
Claim 3
Dependent Claim
40 words
The process of claim 1 wherein the amount of enriching oxygen added to the combustion zone is in the range of from about 0.5 to about 8 pounds of oxygen per pounds of dry solids contained in the dewatered sludge.
Claim 4
Dependent Claim
40 words
The process of claim 2 wherein the amount of enriching oxygen added to the combination zone is in the range of from about 3.5 to about 5.5 pounds of oxygen per pound of dry solids contained in the dewatered sludge.
Claim 5
Dependent Claim
36 words
The process of claim 1 wherein the particulate matter in the sludge is finely divided by introducing the sludge into the combustion zone by means of a dual-fluid atomizer which utilizes a secondary fluid atomizing medium.
Claim 6
Dependent Claim
11 words
The process of claim 4 wherein the atomizing medium is gas.
Claim 7
Dependent Claim
11 words
The process of claim 5 wherein the atomizing medium is air.
Claim 8
Dependent Claim
13 words
The process of claim 6 wherein the atomizing medium is oxygen enriched air.
Claim 9
Dependent Claim
22 words
The process of claim 1 wherein the solid particulate matter in the sludge is divided into particles smaller than about 500 microns.
Claim 10
Dependent Claim
34 words
The process of claim 1 wherein CO in gas exiting the combustion zone is measured and the quantity of enrichment oxygen added is controlled so as to maintain the CO at a predetermined level.
Claim 11
Dependent Claim
40 words
The process of claim 1 wherein the flow rate of flue gas exiting the combustion zone is measured and the quantity of enrichment oxygen added is controlled so as to maintain the flue gas flow rate at a predetermined level.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-04-10 | 1998-10-10 | 1999-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-10 | 2002-10-10 | 2003-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-10 | 2006-10-10 | 2007-04-11 | $7700.00 | Window Closed / Lapsed |