US4057496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for filtration
Assignee: Fujifilm Holdings Corp
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Filing: 1976-06-15
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Granted: 1977-11-08
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Expires: 1996-06-15
Abstract
Abstract A device for filtering slurries comprises a bag-shaped filter medium accommodated in a filter chamber of a filter tank, in which a slurry is supplied, a baffle plate for separating the filter chamber into a side filter chamber and a bottom filter chamber, said side and bottom filter chambers each having an outlet port which can be freely opened and shut, the upper end of said baffle plate being located above the upper surface of a filter cake sedimented on the bottom of the bag-shaped filter medium and a method of filtration by means of the device.
Inventors
- 👤 Sadayoshi Itagaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:21
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/18; B01D24/00; B01D24/02; B01D24/10; B01D24/12; B01D24/48; B01D24/4807; B01D24/4815
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
167 words
A method of filtering slurries to obtain a filtrate and a sedimented filter cake, comprising, a. supplying a slurry to a bag-shaped filter medium within a filter tank, b. forcing the liquid from said slurry to enter a bottom filter chamber and a side filter chamber, separated from one another by a baffle extending slightly higher than the expected height of the sedimented filter cake on the bottom of said bag-shaped filter medium, to leave a sedimentation of filter cake on the bottom and side walls of said bag-shaped filter medium, c. said bottom and side filter chambers having exit ports for the removal of filtrate therefrom, and (d) subsequent to the forcing of the liquid, applying a pressure differential on opposite sides of said bag-shaped filter medium while simultaneously having closed all exit ports of said side filter chamber and having the exit port of said bottom filter chamber open, whereby said pressure differential draws liquid from said filter cake on the bottom of said medium.
Claim 2
Independent Claim
167 words
A method of filtering slurries to obtain a filtrate and a sedimented filter cake, comprising, a. supplying a slurry to a bag-shaped filter medium within a filter tank, b. forcing the liquid from said slurry to enter a bottom filter chamber and a side filter chamber, separated from one another by a baffle extending slightly higher than the expected height of the sedimented filter cake on the bottom of said bag-shaped filter medium, to leave a sedimentation of filter cake on the bottom and side walls of said bag-shaped filter medium, c. said bottom and side filter chambers having exit ports for the removal of filtrate therefrom, and (d) subsequent to the forcing of the liquid, applying a pressure differential on opposite sides of said bag-shaped filter medium while simultaneously having closed all exit ports of said side filter chamber and having the exit port of said bottom filter chamber open, whereby said pressure differential draws liquid from said filter cake on the bottom of said medium.
Claim 3
Dependent Claim
58 words
The method of claim 1 wherein the step of forcing comprises, a. applying a pressure differential on opposite sides of said bag-shaped filter medium during the supplying of slurry to cause filtrate to concurrently enter the side and bottom chambers and concurrently leave a sedimentation of filter cake on the bottom and sides of said bag-shaped filter medium.
Claim 4
Dependent Claim
43 words
The method of claim 2 wherein the step of applying a pressure differential subsequent to the supplying of slurry comprises supplying a gas, of a type which will not react with the slurry, under pressure to the inner part of said bag-filter medium.
Claim 5
Dependent Claim
18 words
The method of claim 3 wherein said gas is supplied at a pressure below 10 kg/cm 2 .
Claim 6
Dependent Claim
71 words
The method of claim 2 further comprising the subsequent step of supplying a filter cake cleaning solution to the inner portion of said bag-shaped filter medium and, at the same time opening the exit port of only one of said filter chambers while closing the exit port of the other of said filter chambers followed by reversing the opening and closing states of the exit ports of the respective filter chambers.
Claim 7
Dependent Claim
29 words
The method of claim 5 further comprising, after the step of supplying a cleaning solution, removing said bag-shaped filter medium with the filter cake therein from said filter tank.
Claim 8
Dependent Claim
155 words
Apparatus for filtering slurries comprising, a. a filter tank, b. filter medium holding means positioned in said tank for holding a bag-shaped filter medium in said tank above the bottom of said tank and separated from the walls of said tank, c. a slurry inlet on said tank for introducing a slurry therein at a position which will result in said slurry being supplied to the inner portion of said bag-shaped filter medium, d. a baffle, located within said tank on the filtrate side of said bag-shaped filter medium, separating the portion of said tank which will receive the filtrate through the filter medium into a side filter chamber and a bottom filter chamber, said baffle extending to a predetermined height which is slightly above the expected height of the filter cake, and e. separate exit ports for the side filter chamber and the bottom filter chamber, said exit ports being freely openable and closeable.
Claim 9
Dependent Claim
155 words
Apparatus for filtering slurries comprising, a. a filter tank, b. filter medium holding means positioned in said tank for holding a bag-shaped filter medium in said tank above the bottom of said tank and separated from the walls of said tank, c. a slurry inlet on said tank for introducing a slurry therein at a position which will result in said slurry being supplied to the inner portion of said bag-shaped filter medium, d. a baffle, located within said tank on the filtrate side of said bag-shaped filter medium, separating the portion of said tank which will receive the filtrate through the filter medium into a side filter chamber and a bottom filter chamber, said baffle extending to a predetermined height which is slightly above the expected height of the filter cake, and e. separate exit ports for the side filter chamber and the bottom filter chamber, said exit ports being freely openable and closeable.
Claim 10
Dependent Claim
18 words
Apparatus as claimed in claim 7 further comprising said bag-shaped filter medium being positioned on said holding means.
Claim 11
Dependent Claim
15 words
Apparatus as claimed in claim 8 wherein said bag-shaped filter medium is a fibrous material.
Claim 12
Dependent Claim
31 words
Apparatus as claimed in claim 7 wherein said filter tank further comprises a heat control jacket around at least a portion of the outside of said filter tank wall and bottom.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |