US3601039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sludge-dewatering apparatus
Assignee: General American Transportation Corp
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Filing: 1968-11-04
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Granted: 1971-08-24
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Expires: 1988-11-04
Abstract
Abstract A process and an apparatus, for continuous operation of the process, dewaters sludges and mixtures of sludges. An illustrative sludge is secondary or activated sludge that is obtained after biological flocculation and settling of aqueous liquid that remains after separation of primary sludge in the treatment of domestic sewage solely or admixed with industrial sewage. In the process sludge is fed to the top surface of a suitable, compressible, resilient sheet of porous cellular material, preferably hydrophilic. A downward pressure, preferably through an overlaying sheet of such material, forces liquid at least through the bottom sheet, from which it is separated. When using the second sheet, sludge is trapped between the sheets prior to and during the pressure application. After that separation of liquid, pressure is released. Dewatered sludge cake is removed from the bottom sheet. In the apparatus an endless belt of such cellular material is moved past a sludge feeder and then under a compression device using a moving endless belt o apply the pressure. Advantageously the latter belt is of such material, but it may be a liquid-impervious belt relatively nonadherent with respect to sludge cake. Preferably the first belt is also compressed just prior to sludge addition.
Inventors
- 👤 Donald S Schover
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:33
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/12; C02F11/121; C02F11/123; B; B01; B01D; B01D33/00; B01D33/04; B01D33/042; B01D33/44; B01D33/46; B01D33/463; B01D33/466; B01D33/58; B01D33/62; B01D33/64; B01D33/646; B01D39/00; B01D39/14; B01D39/16; B30; B30B; B30B9/00; B30B9/02; B30B9/24; F; F23; F23G; F23G5/00; F23G5/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
66 words
The apparatus of claim 1 and further including: means to add wash water to the first belt downstream of said means to remove said dewatered product from the first belt; means to compress the first belt downstream of the means to add wash water for the removal of liquid from the belt; and means to collect water removed from the belt by said last-mentioned compression means.
Claim 2
Dependent Claim
18 words
The apparatus of claim 2 wherein said second belt is compressible and resilient and comprises porous cellular material.
Claim 3
Dependent Claim
17 words
The apparatus of claim 3 wherein at least the first of said belts comprises fine-pore cellulose sponge.
Claim 4
Dependent Claim
126 words
The apparatus of claim 4 wherein: said second belt has a thickness that is sufficiently small to transfer aqueous liquid through it to its other other surface during the transfer of such aqueous liquid through the first belt; the apparatus is constructed to allow removal of aqueous liquid as it passes out the other surface of the second belt after it is transferred through the second belt during the use of the apparatus; and wherein the upstream pOrtion of the bottom run of the second belt is slightly inclined downwardly in the direction of travel for the second belt to gradually abut the first belt so as to trap flowable aqueous material between the two belts before substantial downward pressure is applied by the second belt.
Claim 5
Dependent Claim
31 words
The apparatus of claim 5 and further including means to contact the outer surface of the second belt downstream of the compression zone for removal of dewatered product from that surface.
Claim 6
Dependent Claim
49 words
The apparatus of claim 6 wherein the top run of the first belt in the partial dewatering zone is substantially elongated from the place of application of the flowable aqueous material to provide a substantial absorption of water from said material into first belt before entering the compression zone.
Claim 7
Dependent Claim
40 words
The apparatus of claim 6 and further including means to compress the first belt upstream a short distance from the beginning of the partial dewatering zone to permit the addition of said flowable material during the expansion of the belt.
Claim 8
Dependent Claim
50 words
The apparatus of claim 6 wherein the means to apply flowable aqueous material comprises a hopper having an outlet in its bottom portion and a spout communicating with said outlet, said spout extending downwardly and having and opening at its lower end adjacent the top run of the first belt.
Claim 9
Dependent Claim
62 words
The apparatus of claim 9 wherein: said spout extends downwardly opposite to the direction of travel of the top run of the first belt; and said apparatus further includes means to compress the first belt upstream sufficiently close to the bottom opening of said spout for expansion of the first belt to occur below the bottom opening and downstream out that location.
Claim 10
Dependent Claim
274 words
The apparatus of claim 1 wherein: both endless belts comprise fine-pore cellulose sponge; said means to support said first belt includes a pair of rolls mounted to have their top surfaces at a horizontal plane and a number of intermediate rolls supported to have their top surfaces at that plane and to provide a support for the first belt at the top run between said pair of rolls, said first belt being trained about the pair of rolls; said means to move the first belt includes means to rotates one of said pair of rolls; said means to support the second belt includes another pair of rolls about which that belt is trained and a number of other rolls between and below said another pair of rolls to abut the second belt, to define its travel in its lowermost run, and to press both belts against some of said intermediate rolls; said means to move the second belt includes means to rotate one of said another pairs of rolls so that the belt is driven with its lowermost run moves the same direction moves the same direction as the opposed top run of the first belt; said dewatered product removal means for the first belt being a doctor blade abutting the outer surface of that belt as it moves around the roll rotated by the moving means, said blade being almost tangentially positioned relative to the arc of the belt about the roll; said applying means including a hopper having an outlet in its bottom portion and a spout communicating with that outlet and extending downward to the top run of the first belt.
Claim 11
Dependent Claim
132 words
The apparatus of claim 11 wherein: the bottom surfaces of some of said number of other rolls are in horizontal planes above the bottom surfaces of rest of said number of other rolls so as to move the second belt gradually onto the first belt to trap flowable aqueous material between the belts before substantial pressure application by the rest of said other rolls and some said intermediate rolls; the spout extends away downwardly and in a direction upstream of the top run of the first belt; and wherein the apparatus further includes a pair of rolls between which the first belt passes for compression, said pair being upstream of the bottom of said spout but sufficiently close for the belt to expand below the downstream of that opening oF the spout.
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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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |