US4144807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for dewatering sludge
Assignee: Alb Klein KG
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Filing: 1977-03-16
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Granted: 1979-03-20
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Expires: 1997-03-16
Abstract
Abstract There is disclosed a device for dewatering sludge such as residuals in sewage discharge processing installations. The device provides that cakes are formed of the sludge. These cakes have initially a high water content and are of non-homogenous, loose consistency. They are guided between filter bands through a preliminary filtering zone in which some of the water contained in the cakes is extracted by straining and pressure action applied thereto. The filter bands with the cakes therebetween are then successively guided over a first dewatering drum and a subsequent second dewatering drum. Pressure is applied to the filter band while being guided about the drums, thereby extracting further water from the cakes. Additionally, the cakes while traveling from the feed-in point toward and through pressure zones are deformed and also turned over thereby compacting the cakes as water is extracted therefrom. Finally, the cakes after being sufficiently dewatered and compressed are discharged.
Inventors
- 👤 Wendel Bastgen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:03
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/12; C02F11/121; C02F11/123; B; B01; B01D; B01D33/00; B01D33/04; B01D33/042; B01D33/80; B01D33/82; B30; B30B; B30B9/00; B30B9/02; B30B9/24; B30B9/243; B30B9/246
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
224 words
A device for dewatering sludge in the form of cakes, said device comprising in combination: a first rotary dewatering drum; a second rotary dewatering drum disposed side-by-side with said first drum, said drums being rotatable in opposite directions; two parallel spaced apart filter bands for supporting and conveying sludge cakes placed therebetween, said filter bands being guided around part of the circumferential wall of the first drum for conveying the bands in the rotational direction of the first drum and also being guided around part of the circumferential wall of the second drum for conveying the bands in the rotational direction of the second drum and thus in opposition to the moving direction of the bands while being conveyed around the first drum; said filter bands being guided around and by said drums to define an apporximately S-shape in an upright plane; said circumferential walls of the drums being water permeable; pressure rolls disposed at the walls of the drums for pressing the filter bands against the circumferential wall of at least one of said drums; said filter bands being guided to constitute a straining and preliminary pressure zone for causing partial dewatering of sludge cakes upstream of said first rotary drum, and guide rolls at the inlet end of said straining and preliminary pressure zone for guiding the filter bands into said zone.
Claim 2
Independent Claim
224 words
A device for dewatering sludge in the form of cakes, said device comprising in combination: a first rotary dewatering drum; a second rotary dewatering drum disposed side-by-side with said first drum, said drums being rotatable in opposite directions; two parallel spaced apart filter bands for supporting and conveying sludge cakes placed therebetween, said filter bands being guided around part of the circumferential wall of the first drum for conveying the bands in the rotational direction of the first drum and also being guided around part of the circumferential wall of the second drum for conveying the bands in the rotational direction of the second drum and thus in opposition to the moving direction of the bands while being conveyed around the first drum; said filter bands being guided around and by said drums to define an apporximately S-shape in an upright plane; said circumferential walls of the drums being water permeable; pressure rolls disposed at the walls of the drums for pressing the filter bands against the circumferential wall of at least one of said drums; said filter bands being guided to constitute a straining and preliminary pressure zone for causing partial dewatering of sludge cakes upstream of said first rotary drum, and guide rolls at the inlet end of said straining and preliminary pressure zone for guiding the filter bands into said zone.
Claim 3
Dependent Claim
32 words
The device according to claim 1 wherein the angle of envelopment through which said filter bands are guided by and around said drums is more than 180° for at least one drum.
Claim 4
Dependent Claim
28 words
The device according to claim 1 and comprising further guide rolls guiding said filter bands along a substantially linear path while constituting said straining and preliminary pressure zone.
Claim 5
Dependent Claim
96 words
The device according to claim 1 wherein one of said filter bands is extended past the other filter band, said extended filter band portion constituting a feed station for feeding sludge cakes to the device, and comprising preliminary dewatering means for removing water from cakes, said extended filter band portion being guided past said preliminary dewatering means for coaction therewith, deflector means for deflecting said extended filter band portion into said parallel relationship with the other filter band, said filter bands being guided through said preliminary pressure zone prior to being guided to said rotary drums.
Claim 6
Dependent Claim
17 words
The device according to claim 4 wherein said preliminary pressure zone includes substantially linearly disposed pressure means.
Claim 7
Dependent Claim
35 words
The device according to claim 4 wherein the filter band having said extended portion is guided over part of the circumferential wall of the first rotary drum prior to feeding sludge cakes upon said extension.
Claim 8
Dependent Claim
73 words
The device according to claim 1 wherein one of said filter bands is guided parallel to the other filter band while passing through said preliminary pressure zone and also while being guided over part of the circumferential walls of said drums, said one filter band being deflected away from the other filter band after being guided over said wall part of the second drum to define a discharge opening for dewatered sludge cakes.
Claim 9
Dependent Claim
27 words
The device according to claim 7 wherein deflection means for deflecting said one filter band away from the other filter band are provided between said two drums.
Claim 10
Dependent Claim
27 words
The device according to claim 7 wherein said filter bands are guided around the circumferential wall of the second drum through an angle of at least 270°.
Claim 11
Dependent Claim
25 words
The device according to claim 1 wherein said pressure rolls in conjunction with the circumferential wall of the respective rotary drum constitutes a pressure zone.
Claim 12
Dependent Claim
27 words
The device according to claim 1 comprising setting means for individually varying the pressure of each of said pressure rolls toward the wall of the respective drum.
Claim 13
Dependent Claim
45 words
The device according to claim 1 and comprising means ganging a plurality of said pressure rolls for joint action, and setting means coacting with said ganging means for varying the pressure of each plurality of ganged pressure rolls toward the wall of the respective drum.
Claim 14
Dependent Claim
48 words
The device according to claim 1 and comprising adjustment means for varying the positions of the pressure rolls relative to the wall of the respective drum thereby correspondingly varying the pressure applied by said rolls upon the filter bands and thus upon sludge cakes between the filter bands.
Claim 15
Dependent Claim
34 words
The device according to claim 13 wherein said adjustment means comprise lever arms each mounting at one end a pressure roll, the other end of each lever arm being hinged to a suspension means.
Claim 16
Dependent Claim
51 words
The device according to claim 14 wherein said suspension means comprise a common carrier for a plurality of said lever arms, and comprising yieldable tension means biasing said lever arms toward the wall of the respective drum, and setting means coacting with said tensioning means for varying the bias force thereof.
Claim 17
Dependent Claim
36 words
The device according to claim 1 and comprising connection means interconnecting said pressure rolls in positions substantially parallel to the circumferential wall of the respective drum, and also connecting the interconnected rolls to a stationary point.
Claim 18
Dependent Claim
29 words
The device according to claim 16 wherein said connection means comprise strips extending between each two adjacent pressure rolls and being attached to the axles of the respective rolls.
Claim 19
Dependent Claim
27 words
The device according to claim 16 wherein said stationary point is located at the first pressure roll as seen in the rotational direction of the respective drum.
Claim 20
Dependent Claim
46 words
The device according to claim 16 wherein said pressure rolls are interconnected in the circumferential direction of the drum and also with a common stationary suspension point, and said bias means are coupled to the pressure rolls to apply a radially directed force on the rolls.
Claim 21
Dependent Claim
41 words
The device according to claim 1 and comprising preliminary pressure means in said straining and preliminary pressure zone including further pressure rolls disposed on opposite sides of said filter bands staggered in the direction in which said filter bands are driven.
Claim 22
Dependent Claim
20 words
The device according to claim 20 wherein pulling bands connect said pressure rolls on one side of said filter bands.
Claim 23
Dependent Claim
18 words
The device according to claim 1 and comprising drive means driving said dewatering drums at different circumferential speeds.
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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) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |