US4398476A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for incinerating sewage sludge
Assignee: Shinryo Air Conditioning Co Ltd
•
Filing: 1981-09-21
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Granted: 1983-08-16
•
Expires: 2001-09-21
Abstract
Abstract A method and an apparatus of incinerating dewatered sludge without using an auxiliary fuel comprising pelletizing the partially dewatered sludge having a water content of 70 to 75%, drying the pellets with a heat source obtained by burning gases formed by dry-distillation and gasification, using part of the resulting dry-distilled gas in said drying step, dry-distilling the pellets by the sensible heat of a gas formed by gasification, gasifying the dry-distillation residues with air, water vapor and the remainder of said dry-distilled gas.
Inventors
- 👤 Akira Suzuki
- 👤 Yasumi Shioya
- 👤 Keiichi Kimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:27
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/10; C02F11/12; C02F11/13; F; F23; F23G; F23G7/00; F23G7/001; Y; Y02; Y02W; Y02W10/00; Y02W10/40
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
161 words
A method of incinerating sewage sludge which comprises the steps of: (a) pelletizing dewatered sludge having a water content of 70 to 75% which is obtained by dewatering excess sludge from sewage treatment, (b) drying the pellets with a heat source obtained by burning gases described hereunder which are formed by dry-distillation and gasification, (c) dry-distilling the pellets by the sensible heat of the gas described hereunder which is formed by gasification, (d) using part of the resulting dry-distilled gas in said drying step, (e) burning the remainder of the resulting dry-distilled gas in the presence of air and water vapor, (f) gasifying the residue from the dry-distillation step with the gas resulting from said burning step, (g) using the gas resulting from said gasification step in said drying step and said dry-distillation step, and (h) discharging the residue in the form of ash resulting from said gasification step, to thereby achieve incineration of the dewatered sludge without an auxiliary fuel.
Claim 2
Independent Claim
161 words
A method of incinerating sewage sludge which comprises the steps of: (a) pelletizing dewatered sludge having a water content of 70 to 75% which is obtained by dewatering excess sludge from sewage treatment, (b) drying the pellets with a heat source obtained by burning gases described hereunder which are formed by dry-distillation and gasification, (c) dry-distilling the pellets by the sensible heat of the gas described hereunder which is formed by gasification, (d) using part of the resulting dry-distilled gas in said drying step, (e) burning the remainder of the resulting dry-distilled gas in the presence of air and water vapor, (f) gasifying the residue from the dry-distillation step with the gas resulting from said burning step, (g) using the gas resulting from said gasification step in said drying step and said dry-distillation step, and (h) discharging the residue in the form of ash resulting from said gasification step, to thereby achieve incineration of the dewatered sludge without an auxiliary fuel.
Claim 3
Dependent Claim
19 words
The process of claim 1 in which said pellets are about 1 mm to about 10 mm in size.
Claim 4
Dependent Claim
30 words
The process of claim 1 in which said pellets are cylindrical forms about 5 mm to about 10 mm in diameter and about 10 mm to about 20 mm long.
Claim 5
Dependent Claim
24 words
The process of claim 1 in which said dry-distillation is carried out at a temperature of from about 400° C. to about 600° C.
Claim 6
Dependent Claim
20 words
The process of claim 1 in which said dry-distillation is carried out at about 450° C. for about 20 minutes.
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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) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |