US3622508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sludge disposal
Assignee: Komline Sanderson Engineering Corp
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Filing: 1970-08-19
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Granted: 1971-11-23
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Expires: 1990-08-19
Abstract
Abstract Sewage is subjected in sequence to primary and secondary treatment to derive separately therefrom a primary sludge formed of heavier solids and a secondary sludge formed of relatively lighter solids. The primary sludge is concentrated by filtering to form a comparatively dry filter cake, and the secondary sludge is delivered into a flotation tank, together with a pressurized solution of air and water, so that air bubbles released incident to the reduction of pressure attach to the agglomerated sludge particles and float them to the surface of the body of liquid within the tank. The floating blanket of sludge is removed from the tank and blended with the filter cake to form a substantially homogeneous liquid slurry which is then spray-dried and incinerated.
Inventors
- 👤 Thomas R Komline
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:12
CPC Classifications
C; C02; C02F; C02F9/00; C02F11/00; C02F11/12; C02F11/13; Y; Y10; Y10S; Y10S159/00; Y10S159/905
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
44 words
The method of sludge disposal defined in claim 1, in which said secondary sludge has a sufficiently high moisture content, and is provided in sufficient proportion, to form a liquid slurry without the addition of further moisture when blended with said solid filter cake.
Claim 2
Independent Claim
160 words
The method of sludge disposal wherein sewage is subjected in succession to primary and secondary treatment to settle the heavier and lighter solids therefrom in the form of sludge in separate primary and secondary settling tank, respectively; transferring the settled sludge from said secondary settling tank to a flotation tank; dissolving air at superatmospheric pressure in a body of water within a pressure tank; releasing said air-water solution from the pressure tank into said flotation tank, whereby air bubbles released from the water will attach to the sludge particles and float them to the surface of said body of water; removing said sludge particles from the surface of said body of water; dewatering the sludge from said primary settling tank to form a substantially solid filter cake of relatively low moisture content; then blending said floated sludge particles with the sludge removed from said primary settling tank and dewatered to form a liquid slurry; and spraydrying and incinerating said slurry.
Claim 3
Dependent Claim
58 words
The method of sludge disposal defined in claim 3, in which said filter cake is dewatered to a moisture content in the order of 65 percent by weight and said floated sludge particles have a moisture content of the order of 92 percent by weight, the excess moisture of the floated particles serving to liquify the blended sludges.
Claim 4
Dependent Claim
36 words
The method of sludge disposal defined in claim 3, including the steps of introducing a first flocculating agent into said primary sludge before dewatering it; and of introducing a second flocculating agent into said secondary sludge.
Claim 5
Independent Claim
180 words
The method of sludge disposal which comprises the steps of: a. Subjecting sewage to a primary clarification which includes the separation of the heavier solids by settling as sludge in a primary settling tank; b. Then subjecting said sewage to a secondary clarification which includes separation of the lighter solids therefrom by settling as sludge in a secondary settling tank; c. Removing and filtering the settled sludge from said primary settling tank to form a solid filter cake, wherein the improvement comprises: d. Transferring the settled sludge from said secondary settling tank into a flotation tank e. Releasing small air bubbles in the bottom portion of said flotation tank to attach to the sludge particles and float them to the surface of the liquid within the flotation tank; f. Removing the floating sludge particles from the surface of the liquid; g. Comminuting and blending said solid filter cake with the last mentioned sludge particles to form a liquid slurry; and: h. Centrifugally atomizing said slurry in a current of hot gases to convert said sludge into substantially dry comminuted solids.
Claim 6
Dependent Claim
17 words
The method of sludge disposal defined in claim 5, including the step of incinerating said comminuted solids.
Claim 7
Dependent Claim
21 words
The method of sludge disposal defined in claim 6, including the step of introducing a flocculating agent into said flotation tank.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |