US4248164A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sludge drying system with sand recycle
Assignee: Lurgi Corp
•
Filing: 1979-03-09
•
Granted: 1981-02-03
•
Expires: 1999-03-09
Abstract
Abstract A process and system to dry wet sewage sludge with hot sand and to burn the dried sludge. The sand is heated in a heating device by burning dried sludge, and the hot sand is mixed with wet sludge in a drying device. Thereby moisture is driven from the wet sludge to dry it. The dried sludge and sand are separated, and the sand returned to the heating device while the dried sludge is burned to heat the sand.
Inventors
- 👤 Maynard C. Isheim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:15
CPC Classifications
F; F23; F23G; F23G5/00; F23G5/24; F23G5/28; B; B01; B01J; B01J8/00; B01J8/18; B01J8/24; B01J8/26; B01J8/28; C; C02; C02F; C02F11/00; C02F11/12; C02F11/13; F23G5/30; F26; F26B; F26B3/00; F26B3/18; F26B3/20; F26B3/205; F23G2203/00; F23G2203/50; F23G2203/503
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
159 words
A system to dry wet sludge with hot granular material and to burn the dry sludge comprising: a. heating means to heat the granular material; b. burning means coupled in gas flow communication with said heating means to burn dry sludge and to produce hot gases which are transferred to said heating means; c. drying means coupled in communication with said heating means to receive hot granular material from said heating means and to receive wet sludge and to mix the hot granular material with the wet sludge to dry the wet sludge; d. classifier means coupled to receive granular material and dry sludge from said drying means and to substantially separate the granular material from the dry sludge; e. transfer means coupled to said classifier means to convey the dry sludge to said burning means; and, f. second transfer means coupled to said classifier means to convey the granular material from said classifier means to said heating means.
Claim 2
Independent Claim
159 words
A system to dry wet sludge with hot granular material and to burn the dry sludge comprising: a. heating means to heat the granular material; b. burning means coupled in gas flow communication with said heating means to burn dry sludge and to produce hot gases which are transferred to said heating means; c. drying means coupled in communication with said heating means to receive hot granular material from said heating means and to receive wet sludge and to mix the hot granular material with the wet sludge to dry the wet sludge; d. classifier means coupled to receive granular material and dry sludge from said drying means and to substantially separate the granular material from the dry sludge; e. transfer means coupled to said classifier means to convey the dry sludge to said burning means; and, f. second transfer means coupled to said classifier means to convey the granular material from said classifier means to said heating means.
Claim 3
Dependent Claim
42 words
A system according to claim 1 further including: a. purge air introduction means coupled to said drying means to introduce ambient air into said drying means; and, b. gas transfer means to convey gas from said drying means to said burning means.
Claim 4
Dependent Claim
14 words
A system according to claim 2 wherein said gas transfer means includes a condenser.
Claim 5
Dependent Claim
26 words
A system according to claim 1 wherein said heating means includes a first fluidized bed reactor, and said burning means includes a second fluidized bed reactor.
Claim 6
Dependent Claim
47 words
A system according to claim 4 further including first means to transfer the hot granular material from said first fluidized bed reactor to said second fluidized bed reactor and second means to transfer the hot granular material from said second fluidized bed reactor to said drying means.
Claim 7
Independent Claim
142 words
A system to dry wet sludge with granular material and to burn dry sludge comprising: a. multiple hearth furnace means including, i. an upper zone to heat the granular material; ii. a middle zone to burn dry sludge to heat the granular material; iii. a lower zone to receive hot granular material and the wet sludge and to mix the hot granular material with the wet sludge to dry the wet sludge; b. classifier means coupled to receive granular material and dry sludge from said multiple hearth furnace means and to substantially separate the granular material from the dry sludge; c. transfer means coupled to said classifier means to convey the dry sludge to said middle zone means; and, d. second transfer means coupled to said classifier means to convey the granular material from said classifier means to said upper zone means.
Claim 8
Independent Claim
142 words
A system to dry wet sludge with granular material and to burn dry sludge comprising: a. multiple hearth furnace means including, i. an upper zone to heat the granular material; ii. a middle zone to burn dry sludge to heat the granular material; iii. a lower zone to receive hot granular material and the wet sludge and to mix the hot granular material with the wet sludge to dry the wet sludge; b. classifier means coupled to receive granular material and dry sludge from said multiple hearth furnace means and to substantially separate the granular material from the dry sludge; c. transfer means coupled to said classifier means to convey the dry sludge to said middle zone means; and, d. second transfer means coupled to said classifier means to convey the granular material from said classifier means to said upper zone means.
Claim 9
Dependent Claim
30 words
A system according to claim 6 further including means to convey the hot granular material directly from said upper zone to said lower zone without passing through said middle zone.
Claim 10
Dependent Claim
139 words
A process for drying wet sludge with granular material and burning dry sludge comprising: a. introducing the granular material into a heating means; b. burning dry sludge in a burning means to produce hot gases; c. transferring the hot gases from the burning means to the heating means to heat the granular material; d. transferring the hot granular material and wet sludge to a drying means and mixing the hot granular material and wet sludge to substantially dry the wet sludge; e. transferring the mixture of granular material and substantially dry sludge to a classifier; f. in the classifier substantially separating the dry sludge from the granular material; g. transferring the dry sludge from the classifier to the burning means to be burned; and, h. transferring the granular material from the classifier to the heating means to be heated.
Claim 11
Dependent Claim
139 words
A process for drying wet sludge with granular material and burning dry sludge comprising: a. introducing the granular material into a heating means; b. burning dry sludge in a burning means to produce hot gases; c. transferring the hot gases from the burning means to the heating means to heat the granular material; d. transferring the hot granular material and wet sludge to a drying means and mixing the hot granular material and wet sludge to substantially dry the wet sludge; e. transferring the mixture of granular material and substantially dry sludge to a classifier; f. in the classifier substantially separating the dry sludge from the granular material; g. transferring the dry sludge from the classifier to the burning means to be burned; and, h. transferring the granular material from the classifier to the heating means to be heated.
Claim 12
Dependent Claim
11 words
The process of claim 8 wherein the granular material is sand.
References Cited (Backward Citations)
US2754105A
Cited
US2147151A
Cited
US3411465A
Cited
US3625165A
Cited
US3968756A
Cited
US3954069A
Cited
US3958920A
Cited
US4154643A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |