US4452698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rigid filter plate and process for manufacture of the same
Assignee: U S Environmental Products Inc
•
Filing: 1983-05-02
•
Granted: 1984-06-05
•
Expires: 2003-05-02
Abstract
Abstract An improved rigid filter plate for sludge dewatering is comprised of a filter element of two or more sizes within the range of 0.2 to 0.002 inch of irregular hard particles of aluminum oxide or similar materials, and of a supporting element of larger particles all bonded with an adhesive bonding agent. A process for manufacturing the improved rigid filter plate is also set forth.
Inventors
- 👤 Robert L. Roberts
- 👤 Felix G. Janssen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:21
CPC Classifications
B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2072; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
130 words
An improved rigid sludge dewatering filter plate comprising at least two layers; the first layer comprising a thin, flat filtering element having an exposed, dense upper surface and a lower surface; said filtering element consisting essentially of irregular particles of one or more substances selected from the group consisting of aluminum oxide, corundum, emery, garnet, silicon carbide, boron carbide and manufactured crystalline alumina products, bonded together with an adhesive bonding agent, wherein the particles are of at least two sizes within the range consisting essentially of about 0.2 inch to about 0.002 inch; and the second layer being a supporting element comprised of particles larger than the largest particles used in the filtering element, bonded together and to the lower surface of the filtering element with an adhesive bonding agent.
Claim 2
Dependent Claim
130 words
An improved rigid sludge dewatering filter plate comprising at least two layers; the first layer comprising a thin, flat filtering element having an exposed, dense upper surface and a lower surface; said filtering element consisting essentially of irregular particles of one or more substances selected from the group consisting of aluminum oxide, corundum, emery, garnet, silicon carbide, boron carbide and manufactured crystalline alumina products, bonded together with an adhesive bonding agent, wherein the particles are of at least two sizes within the range consisting essentially of about 0.2 inch to about 0.002 inch; and the second layer being a supporting element comprised of particles larger than the largest particles used in the filtering element, bonded together and to the lower surface of the filtering element with an adhesive bonding agent.
Claim 3
Dependent Claim
23 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are of aluminum oxide.
Claim 4
Dependent Claim
36 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are of three sizes within the range consisting essentially of about 0.2 inch to about 0.002 inch.
Claim 5
Dependent Claim
36 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are of four sizes within the range consisting essentially of about 0.2 inch to about 0.002 inch.
Claim 6
Dependent Claim
26 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the thickness of the filtering element is between about 1/8 inch and 2 inches.
Claim 7
Dependent Claim
26 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the thickness of the supporting element is between about 1/4 and about 33/4 inches.
Claim 8
Dependent Claim
29 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the supporting element is composed of particles ranging in diameter from 1/8 to 11/2 inches in diameter.
Claim 9
Dependent Claim
20 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the supporting element is reinforced with reinforcing means.
Claim 10
Dependent Claim
23 words
An improved rigid sludge dewatering filter plate as in claim 8 wherein the reinforcing means is steel bars located within the supporting element.
Claim 11
Dependent Claim
23 words
An improved rigid sludge dewatering filter plate as in claim 8 wherein the reinforcing means is wire mesh located within the supporting element.
Claim 12
Dependent Claim
47 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are arranged in a distribution of sizes such that about 90% of the particles are about 0.043 inch and about 10% of the particles are about 0.012 inch.
Claim 13
Dependent Claim
56 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are arranged in a distribution of sizes such that about 70% of the particles are about 0.043 inch, about 20% of the particles are about 0.012 inch, and about 10% of the particles are about 0.0048 inch.
Claim 14
Dependent Claim
56 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are arranged in a distribution of sizes such that about 45% of the particles are about 0.043 inch, about 45% of the particles are about 0.012 inch, and about 10% of the particles are about 0.0048 inch.
Claim 15
Dependent Claim
56 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are arranged in a distribution of sizes such that about 20% of the particles are about 0.043 inch, about 70% of the particles are about 0.012 inch, and about 10% of the particles are about 0.0048 inch.
Claim 16
Dependent Claim
56 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are arranged in a distribution of size such that about 10% of the particles are about 0.043 inch, about 60% of the particles are about 0.012 inch, and about 30% of the particles are about 0.0048 inch.
Claim 17
Dependent Claim
65 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are arranged in a distribution of sizes such that about 10% of the particles are about 0.063 inch, about 40% of the particles are about 0.043 inch, about 40% of the particles are about 0.012 inch, and about 10% of the particles are about 0.0048 inch.
Claim 18
Dependent Claim
53 words
An improved rigid sludge dewatering filter plate as in claim 16 wherein the weight ratio of adhesive bonding agent to particles in the filtering element is between about 1:8 and about 1:20 and the weight ratio of adhesive bonding agent to particles in the supporting element is between about 1:6 and about 1:5.
Claim 19
Dependent Claim
65 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles of the filtering element are arranged in a distribution of sizes such that about 40% of the particles are about 0.063 inch, about 40% of the particles are about 0.043 inch, about 10% of the particles are about 0.012 inch, and about 10% of the particles are about 0.0048 inch.
Claim 20
Dependent Claim
52 words
An improved rigid sludge dewatering filter plate as in claim 1 wherein the irregular particles are arranged in a distribution of sizes such that about 80% of the particles are about 0.063 inch, about 10% of the particles are about 0.012 inch, and about 10% of the particles are about 0.0048 inch.
Claim 21
Dependent Claim
28 words
An improved rigid sludge dewatring filter plate as in claim 1 wherein the adhesive bonding agent is a mixture of a low viscosity epoxy resin and a hardener.
References Cited (Backward Citations)
US2732078A
Cited
US1987721A
Cited
US624893A
Cited
US421238A
Cited
US730518A
Cited
US1081573A
Cited
US1117601A
Cited
US1277832A
Cited
US1543939A
Cited
US1671325A
Cited
US1918893A
Cited
US1910758A
Cited
US1844528A
Cited
US1988478A
Cited
US2018192A
Cited
US2155016A
Cited
US2345827A
Cited
US2293099A
Cited
US2335749A
Cited
US2303629A
Cited
US2464517A
Cited
US2597217A
Cited
AT176849B
Cited
US3056704A
Cited
US3011643A
Cited
US3195105A
Cited
US3166615A
Cited
US3171804A
Cited
US3178026A
Cited
US3279606A
Cited
US3545622A
Cited
US3630384A
Cited
US3587861A
Cited
US3716459A
Cited
US3615019A
Cited
US3779910A
Cited
US3771655A
Cited
US3959126A
Cited
US3847808A
Cited
US3969248A
Cited
US4081371A
Cited
US4088576A
Cited
US4186100A
Cited
US4190534A
Cited
US4382863A
Cited
US4340478A
Cited
US4381998A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |