US3695173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sludge dewatering
Assignee: Individual
•
Filing: 1972-01-28
•
Granted: 1972-10-03
•
Expires: 1992-01-28
Abstract
Abstract Sludge dewatering is achieved with the aid of a flow-impeding, continuous, self-cleaning, non-blinding or clogging and permanent filtering-dewatering device. The device is partly cylindrical and partly conical and comprises closely spaced rings or hoops held rigid by a frame. Inlet pressure created by a low-pressure sludge pump along with the movement of sludge through the filterdewatering unit, where squeezing and pressing takes place, forces most of the liquid or water associated with the sludge through the filtering medium or slots formed by successive closely spaced filter rings, while the solids are trapped on the inside surface before they are conveyed along the length of the filterdewatering unit and are discharged relatively dry from the solids-discharge end by a filter-cake discharger. To prevent clogging and interruption of continuous filtration or dewatering, cutter or slot-cleaning blades or brushes are secured to the outside edge of the filter-cake discharger, projecting out radially and spaced to extend into the slots or spaces between the closely spaced successive filter rings or hoops. The solids tending to clog or blind the slots or spaces pass through and out with the filtrate, or they may be forced back into the filterdewatering unit by the cutting or cleaning action of the cutterslot cleaning blades or brushes, when the leading edge of the filter cake discharger and conveyed sludge cuts and scrapes away the solids protruding within the filter-dewatering unit.
Inventors
- 👤 Clyde Harold Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:44
CPC Classifications
B; B30; B30B; B30B9/00; B30B9/02; B30B9/26; B30B9/12; B30B9/121
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
137 words
A device for dewatering sludge, including in combination: a filter-dewatering shell having an initial portion comprising a series of longitudinally and closely spaced-apart circular rings that are identical in size, presenting a smooth cylindrical inner surface interrupted only by the space between successive rings, said filter-dewatering shell having a succeeding portion comprising a series of longitudinally closely spaced-apart circular rings that gradually diminish in size to provide a smooth frustoconical inner surface, support means aligning and retaining all said rings in place, filtrate collection means outside said shell for collecting filtrate and spaced therefrom, a central shaft along the axis of said filter-dewatering shell, wiping and filter-cake discharging means secured to said shaft in both said initial and succeeding portions, and wiping both said cylindrical and said frustoconical inner surfaces, and power means for rotating said shaft.
Claim 2
Independent Claim
137 words
A device for dewatering sludge, including in combination: a filter-dewatering shell having an initial portion comprising a series of longitudinally and closely spaced-apart circular rings that are identical in size, presenting a smooth cylindrical inner surface interrupted only by the space between successive rings, said filter-dewatering shell having a succeeding portion comprising a series of longitudinally closely spaced-apart circular rings that gradually diminish in size to provide a smooth frustoconical inner surface, support means aligning and retaining all said rings in place, filtrate collection means outside said shell for collecting filtrate and spaced therefrom, a central shaft along the axis of said filter-dewatering shell, wiping and filter-cake discharging means secured to said shaft in both said initial and succeeding portions, and wiping both said cylindrical and said frustoconical inner surfaces, and power means for rotating said shaft.
Claim 3
Dependent Claim
27 words
The device of claim 1 wherein said rings are semicircular in cross section with the arc thereof facing outwardly to provide outwardly flaring spaces between adjacent rings.
Claim 4
Dependent Claim
12 words
The device of claim 1 wherein said rings are rectangular in cross-section.
Claim 5
Dependent Claim
25 words
The device of claim 1 wherein said rings have access openings enabling access into the filter-dewatering shell, and means normally closing said openings during operation.
Claim 6
Dependent Claim
24 words
The device of claim 1 wherein said rings are bolted to said support means, thereby enabling disassemblage, replacement, resurfacing, and variation in ring spacing.
Claim 7
Dependent Claim
26 words
The device of claim 1 wherein said rings and said support means comprise a pair of sections hinged together to provide access into the filter-dewatering shell.
Claim 8
Dependent Claim
23 words
The device of claim 1 having a wearable replacable edge strip attached to the wiping surface of said wiping and filter-cake discharging means.
Claim 9
Dependent Claim
44 words
The device of claim 1 wherein said wiping and filter-cake discharging means has a series of projecting cleaning blades attached thereto projecting out radially and spaced to engage the spaces between successive rings, to prevent filter clogging and interruption of continuous filtration or dewatering.
Claim 10
Dependent Claim
51 words
The device of claim 8 wherein said rings have access openings therethrough and means for normally closing said access openings, so that said cleaning blades can be inserted through said spaces and attached and locked into cutting position on said wiping and filter-cake discharging means, by means of said access openings.
Claim 11
Dependent Claim
64 words
The device of claim 8 wherein said cleaning blades are rotatably attached to said wiping and filter-cake dischaRging means so that they may be locked into their cleaning position after insertion of said wiping and filter-cake discharging means into said shell and may be rotated into a down, non-cleaning position for insertion and removal of said wiping and filter-cake discharging means into said shell.
Claim 12
Dependent Claim
64 words
The device of claim 1 wherein there is space-bridging means at each space between adjacent rings, for greater solids capture by reducing or partially closing said space while enabling passage of and operation by the cleaning blades to keep the spaces clear and unclogged, said bridging means having resilience for springing back to bridge or reduce said spaces after passage of the cleaning blades.
Claim 13
Dependent Claim
30 words
The device of claim 1 having a wire-brush wiper secured to said wiping and filter-cake discharging means to penetrate into the spaces between successive rings and keep those spaces unplugged.
Claim 14
Dependent Claim
16 words
The device of claim 1 wherein said wiping and filter-cake discharge means is a spiral-helical blade.
Claim 15
Dependent Claim
28 words
The device of claim 1 wherein said wiping and filter-cake discharge means is a paddle scraper in the cylindrical section and a spiral-helical blade in the frustoconical section.
Claim 16
Dependent Claim
33 words
The device of claim 1 wherein said filter-dewatering shell has a terminal small-diameter cylindrical portion secured to said frustoconical portion, said wiping and filter-cake discharging means having a cylindrical portion for wiping it.
Claim 17
Dependent Claim
24 words
The device of claim 15 having a removable plug for closing the end of said shell during start-up, the plug being removed after start-up.
Claim 18
Dependent Claim
19 words
The device of claim 15 having lubrication means in the last part of said frustoconical portion of said shell.
Claim 19
Independent Claim
163 words
A device for dewatering sludge, including in combination: a filter-dewatering shell having an initial portion comprising a series of longitudinally and closely spaced-apart rings that are identical in size and are semicircular in cross section, presenting a smooth cylindrical inner surface interrupted only by the space between successive rings, said space in each instance flaring outwardly due to the circular section of the outer portions of the successive rings, said filter-dewatering shell having a succeeding portion comprising a series of longitudinally closely spaced-apart rings that gradually diminish in size and are semicircular in cross section to provide a smooth frustoconical inner surface, with similar outwardly flaring spaces, an outer housing surrounding said shell and spaced therefrom and having a filtrate outlet, a central shaft along the axis of said filter-dewatering shell, a spiral-helical blade secured to said shaft in both said initial and succeeding portion, said blade wiping both said cylindrical and said frustoconical inner surfaces, and power means for rotating said shaft.
Claim 20
Independent Claim
163 words
A device for dewatering sludge, including in combination: a filter-dewatering shell having an initial portion comprising a series of longitudinally and closely spaced-apart rings that are identical in size and are semicircular in cross section, presenting a smooth cylindrical inner surface interrupted only by the space between successive rings, said space in each instance flaring outwardly due to the circular section of the outer portions of the successive rings, said filter-dewatering shell having a succeeding portion comprising a series of longitudinally closely spaced-apart rings that gradually diminish in size and are semicircular in cross section to provide a smooth frustoconical inner surface, with similar outwardly flaring spaces, an outer housing surrounding said shell and spaced therefrom and having a filtrate outlet, a central shaft along the axis of said filter-dewatering shell, a spiral-helical blade secured to said shaft in both said initial and succeeding portion, said blade wiping both said cylindrical and said frustoconical inner surfaces, and power means for rotating said shaft.
Claim 21
Dependent Claim
35 words
The device of claim 18 wherein a wire-brush wiper is secured to said spiral-helical blade, bridging successive turns thereof at the outer periphery, to penetrate into the spaces between successive rings and keep them unplugged.
Claim 22
Dependent Claim
33 words
The device of claim 18 wherein a wire-brush wiper is secured to said spiral-helical blade, following the helix of the blade, to penetrate into the spaces between successive rings and keep them unplugged.
Claim 23
Dependent Claim
43 words
The device of claim 18 wherein said spiral-helical blade has a series of projecting cleaning blades attached to it and projecting out radially and spaced to engage the spaces between successive rings to prevent filter clogging and interruption of continuous filtration and dewatering.
Claim 24
Dependent Claim
25 words
The device of claim 21 wherein the cleaning blades are rotatably attached to said spiral-helical blade, to enable insertion and removal of said spiral-helical blade.
Claim 25
Dependent Claim
58 words
The device of claim 21 wherein said rings have access openings and means for normally plugging said openings, said access openings enabling access into the filter-dewatering shell at each ring and wherein the cleaning blades are capable of attachment to the spiral-helical blades by insertion through the spaces between rings and by nuts inserted through the access openings.
Claim 26
Dependent Claim
74 words
The device of claim 21 wherein space bridging means is secured within said filter-dewatering shell at each space between adjacent rings for greater solids capture by reducing or partially closing said space, said bridging means being capable of movement by said cleaning blades, so that said cleaning blades keep the spaces clear and unclogged, said bridging means having resilience for springing back to bridge or reduce said spaces after passage of said cleaning blades.
Claim 27
Dependent Claim
34 words
The device of claim 18 having a pre-treatment portion ahead of said cylindrical portion having a cylindrical section made up of a series of closely spaced rings and having a paddle scraper wiping them.
Claim 28
Dependent Claim
12 words
The device of claim 25 having cleaning blades on the paddle scraper.
Claim 29
Dependent Claim
12 words
The device of claim 25 having cleaning brushes on the paddle scraper.
Claim 30
Dependent Claim
52 words
The device of claim 18 wherein said filter-dewatering shell has a terminal small-diameter cylindrical portion secured to said frustoconical portion, and said spiral helical blade wipes this small-diameter cylindrical portion also, and a removable plug for closing the normally open end of said shell during start-up, said plug being removed after start-up.
Claim 31
Dependent Claim
20 words
The device of claim 18 having lubrication means in the last part of the frustoconical portion of the filter-dewatering shell.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |