US4159684A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for incinerating waste sludges
Assignee: Esmil Envirotech Ltd
•
Filing: 1976-11-23
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Granted: 1979-07-03
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Expires: 1996-11-23
Abstract
Abstract Dewatered sewage sludge (i.e. sewage sludge containing e.g. 75% water when dewatered) is incinerated when mixed with coal fines recovered from a wet benification process for coal, the coal fines being in the form of either coal filter cake or ex-lagoon sludge. If the coal fines are added to the sewage sludge before or during dewatering of the latter by filtration, the coal acts as a filter aid. Autothermic combustion of the mixture can be obtained.
Inventors
- 👤 William M. Kirkup
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:20
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/06; C02F11/12; C02F11/121; C02F11/127; F; F23; F23G; F23G7/00; F23G7/001; C02F11/14; C02F11/143; Y; Y02; Y02W; Y02W10/00; Y02W10/40
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
47 words
A method of incinerating a sewage sludge comprising incinerating a sludge, in dewatered but wet condition, when mixed with wet coal fines as a supplementary fuel recovered from a wet benification process for coal, in the form of one of a coal filter cake and ex-lagoon sludge.
Claim 2
Independent Claim
47 words
A method of incinerating a sewage sludge comprising incinerating a sludge, in dewatered but wet condition, when mixed with wet coal fines as a supplementary fuel recovered from a wet benification process for coal, in the form of one of a coal filter cake and ex-lagoon sludge.
Claim 3
Dependent Claim
16 words
The method according to claim 1 wherein the sewage sludge is dewatered in a continuous process.
Claim 4
Dependent Claim
27 words
The method according to claim 1 wherein the coal fines are admixed to the sewage sludge prior to at least the completion of dewatering of the sludge.
Claim 5
Dependent Claim
27 words
The method according to claim 1 wherein the mixture of sewage sludge and coal fines is dewatered by one of centrifugation and filtration and is continuously incinerated.
Claim 6
Dependent Claim
32 words
The method according to claim 4 wherein the sewage sludge is dewatered by filtration, and the coal fines are added before or during filtration so as to act as a filter aid.
Claim 7
Dependent Claim
41 words
The method according to claim 1 wherein the quantity of coal fines added is at least 80% by weight (calculated on the basis of the weights of the sludge in dewatered condition and of the dry matter of the coal fines).
Claim 8
Dependent Claim
16 words
The method according to claim 1 wherein the mixture of sludge and coal fines is autothermic.
Claim 9
Dependent Claim
21 words
The method according to claim 6 wherein the moisture content of the coal fines is from 20 to 35% by weight.
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) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |