EP0010395A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Settling tank
Assignee: Dorr Oliver Inc
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Filing: 1979-10-09
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Granted: —
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Expires: 1999-10-09
Abstract
Abstract A sedimentation tank (10) has a central feedwell (21) comprising upper and lower cylindrical channels (25-26) or raceways for receiving the influent feed (27) in split counter-rotative streams, and an intermediate raceway (30) is provided between the upper and lower channels (25-26) for receiving a flocculant for mixing with the influent feed in the shear zone (B) where the split streams remerge.
Inventors
- 👤 Elliot Bryant Fitch
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 19:02
CPC Classifications
B; B01; B01D; B01D21/00; B01D21/0018; B01D21/02; B01D21/04; B01D21/06; B01D21/08; B01D21/24; B01D21/2405; B01D21/2411; B01D21/2427
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
114 words
A device for feeding a suspension of solids in a liquid to a sedimentation tank for separating solids from the liquid suspension,including influent feed means (27), and a cylindrical feedwell (21) for receiving the influent feed from said influent feed means (27), said feedwell (21) including upper and lower channel members (25-26) adapted to tangentially and simultaneously receive the influent feed in split counter-rotative streams and to discharge said streams within a common zone of shear (b) within said feedwell, characterised by flocculant dispersing means (32-35) located within said feedwell adjacent said upper and lower channels for introducing and mixing a preselected flocculant dosage with said remerging streams within said zone of shear (b).
Claim 2
Independent Claim
114 words
A device for feeding a suspension of solids in a liquid to a sedimentation tank for separating solids from the liquid suspension,including influent feed means (27), and a cylindrical feedwell (21) for receiving the influent feed from said influent feed means (27), said feedwell (21) including upper and lower channel members (25-26) adapted to tangentially and simultaneously receive the influent feed in split counter-rotative streams and to discharge said streams within a common zone of shear (b) within said feedwell, characterised by flocculant dispersing means (32-35) located within said feedwell adjacent said upper and lower channels for introducing and mixing a preselected flocculant dosage with said remerging streams within said zone of shear (b).
Claim 3
Dependent Claim
39 words
The device of claim 1 wherein said upper and lower channels (25-26) comprise inwardly curved members open to the longitudinal axis of said feedwell (21) and wherein said flocculant dispersing means (35) is arranged between said channel members (25-26).
Claim 4
Dependent Claim
26 words
The device of claim 2 wherein said flocculant dispersing means (35) is located in a third channel member (30) interposed between said upper and lower channels.
Claim 5
Dependent Claim
51 words
The device of claim 3 wherein said feedwell (21) further includes an elongated vertical cylindrical column having a lower discharge opening in lower region of said tank (10) to discharge settling solids into a bed (A) and wherein said channel members (25-26-30) are arranged near the upper portion of said column.
Claim 6
Dependent Claim
17 words
The device of claim 4 wherein said discharge opening extends into the bed (A) of settled solids.
Claim 7
Dependent Claim
172 words
The device of claim 1 wherein said cylindrical settling tank (10) has peripheral overflow means (13) for clarified liquid separated from the influent feed and rotating raking apparatus (20) for directing settled solids to a central discharge sump in said tank, said feedwell (21) for receiving said influent feed comprising a cylindrical hollow column arranged at the centre cf the tank and open to the bottom thereof, a feed inlet (24) located in said column and including upper and lower cylindrical channel members (25-26) open to the longitudinal axis of said column, means for splitting the influent feed into separate streams directed respectively to said upper and lower channels (25-26) for rotation in respective counter and counterclockwise paths for discharge and remerging in a zone of shear (B) within an area in said feedwell (24) defined by said channel members (25-26), and wherein said flocculant dispersing means (32-35) is located in said feedwell (21) adjacent said channel members (25-26) for dispersing a preselected dosage of flocculants into said zone of shear (B).
Claim 8
Dependent Claim
54 words
The settling tank of claim 6 wherein solids are settled from said influent feed within said feedwell column (21) to discharge from the open lower end of said column (21) into a settled solids bed (A) and wherein said column is of predetermined length adapted to extend either into or above said bed (a).
Claim 9
Dependent Claim
35 words
The settling tank of claim 7 wherein said feed inlet includes an influent feed pipe (27) having branch feed pipes (28-29) for tangentially directing the split streams into said upper and lower channel members (25-26).
Claim 10
Dependent Claim
28 words
9 . The settling tank of claim 6 wherein said flocculant dispersing means comprising a third channel member (30) interposed between said upper and lower channel member (25-26).
Claim 11
Dependent Claim
39 words
The settling tank of claim 9 wherein said channel member comprises flanged tray members secured to the inner walls of said cylindrical column (21) and wherein said influennt feed and flocculant feed thereto are directed tangentially into said channels.
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