US5174877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for photocatalytic treatment of liquids
Assignee: Photo Catalytics Inc
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Filing: 1989-12-15
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Granted: 1992-12-29
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Expires: 2009-12-15
Abstract
Abstract Apparatus for decontaminating a contaminated fluid by using photocatalytic particles. The apparatus includes a reactor tank for holding a slurry of the contaminated fluid and the photocatalytic particles ultraviolet light irradiates the surface of the slurry, thereby activating the photocatalytic properties of the particles. Stirring blades for continuously agitate the irradiated fluid surface maintaining the particles in a suspended state within the fluid. A cross flow filter is used for separating the fluid from the semiconductor powder after the decomposition reaction is ended. The cross flow filter is occasionally back flushed to remove any caked semiconductor powder. The semiconductor powder may be recirculated back to the tank for reuse, or may be stored for future use. A series of reactor tanks may be used to gradually decompose a chemical in the fluid. The fluid may be pretreated to remove certain metal ions which interfere with the photocatalytic process. Such pretreatment may be accomplished by dispersing semiconductor particles within the fluid, which particles adsorb ions or photodeposit the metal as the free metal or its insoluble oxide or hydroxide, and then removing the semiconductor particles together with the adsorbed metal ions/oxides/hydroxide/free metal from the fluid.
Inventors
- 👤 Gerald Cooper
- 👤 Matthew A. Ratcliff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:38
CPC Classifications
A; A62; A62D; A62D3/00; A62D3/10; A62D3/15; A62D3/17; A62D3/176; B; B01; B01J; B01J19/00; B01J19/08; B01J19/12; B01J19/122; B01J19/123; B01J35/00; B01J35/50; B01J35/58; B01J8/00; B01J8/02; C; C02; C02F; C02F1/00; C02F1/72; C02F1/725; A62D2101/00; A62D2101/20; A62D2101/24; A62D2101/40; A62D2101/43; A62D2203/00; A62D2203/10; B01J2208/00; B01J2208/00008; B01J2208/00017; B01J2208/00433; C02F1/30; C02F1/32; C02F2305/00; C02F2305/10
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
103 words
Apparatus for decontaminating a contaminated fluid by using photocatalytic powder particles comprising: a tank holding the contaminated fluid and the photocatalytic powder particles suspended in the contaminated fluid; means for maintaining the photocatalytic particles in a suspended state substantially uniformly throughout the fluid; a filter through which the fluid passes and through which the photocatalytic powder particles suspended therein are substantially prevented from passing such that the fluid substantially alone passes through said filter; means for directing the fluid and the photocatalytic particles suspended therein from said tank to said filter; and means for removing the photocatalytic powder particles away from said filter.
Claim 2
Dependent Claim
103 words
Apparatus for decontaminating a contaminated fluid by using photocatalytic powder particles comprising: a tank holding the contaminated fluid and the photocatalytic powder particles suspended in the contaminated fluid; means for maintaining the photocatalytic particles in a suspended state substantially uniformly throughout the fluid; a filter through which the fluid passes and through which the photocatalytic powder particles suspended therein are substantially prevented from passing such that the fluid substantially alone passes through said filter; means for directing the fluid and the photocatalytic particles suspended therein from said tank to said filter; and means for removing the photocatalytic powder particles away from said filter.
Claim 3
Dependent Claim
26 words
Apparatus as defined in claim 1 wherein said removing means includes means for changing the direction of fluid flow in the region adjacent to the filter.
Claim 4
Dependent Claim
41 words
Apparatus as defined in claim 2 wherein said fluid direction changing means includes means for selectively causing fluid that has passed through said filter to flow back through said filter whereby the photocatalytic powder particles are removed away from said filter.
Claim 5
Dependent Claim
126 words
Apparatus as defined in claim 2 wherein said fluid direction changing means includes: a conduit through which said fluid directing means causes the fluid and the photocatalytic powder particle suspended therein to pass, said conduit having an inlet and an outlet, said filter being in communication with the interior of said conduit; means defining an exit port in communication with the interior of said conduit, the fluid in said conduit passing into said exit port substantially only by passing through said filter; a closed cylinder the interior or which is in communication with the interior of said conduit; a piston slideably disposed within said cylinder; and means for selectively sliding said piston within said cylinder whereby a pressurized pulse of fluid is created within said conduit.
Claim 6
Dependent Claim
72 words
Apparatus as defined in claim 4 wherein said fluid direction changing means further includes: means for creating a back pressure of fluid within said conduit whereby the fluid pressure within said conduit is higher than the fluid pressure within said exit port; and means for selectively prohibiting the low of fluid within said exit port whenever said piston slides within said cylinder to create a pressurized pulse of fluid within said conduit.
Claim 7
Dependent Claim
40 words
Apparatus as defined in claim 1 wherein said filter comprises a cross flow filter having a first surface and wherein said fluid directing means directs the fluid and the photocatalytic powder particles suspended therein substantially parallel to a filter surface.
Claim 8
Dependent Claim
99 words
A reactor for decontaminating a contaminated fluid by using photocatalytic particles, comprising: a shallow tank containing a slurry of contaminated fluid and photocatalytic particles, said slurry having a fluid surface; means for illuminating said fluid surface to activate said photocatalytic particles; and agitator means at least partially submerged in said slurry for maintaining said photocatalytic particles in a suspended state substantially throughout the slurry, for creating turbulence and aerating the slurry in a photoactive zone extending from the fluid surface to a predetermined depth where the ultraviolet light is effective to activate said photocatalytic particles and decontaminate the fluid.
Claim 9
Dependent Claim
99 words
A reactor for decontaminating a contaminated fluid by using photocatalytic particles, comprising: a shallow tank containing a slurry of contaminated fluid and photocatalytic particles, said slurry having a fluid surface; means for illuminating said fluid surface to activate said photocatalytic particles; and agitator means at least partially submerged in said slurry for maintaining said photocatalytic particles in a suspended state substantially throughout the slurry, for creating turbulence and aerating the slurry in a photoactive zone extending from the fluid surface to a predetermined depth where the ultraviolet light is effective to activate said photocatalytic particles and decontaminate the fluid.
Claim 10
Dependent Claim
13 words
The reactor as defined in claim 7 wherein the illumination means comprises sunlight.
Claim 11
Dependent Claim
14 words
The reactor as defined in claim 7 wherein the illumination means comprises artificial light.
Claim 12
Dependent Claim
21 words
The reactor as defined in claim 7 wherein the agitator means comprises at least one moveable blade positioned within said zone.
Claim 13
Dependent Claim
21 words
Reactor as defined in claim 10 wherein said blade includes means for injecting a gas into the fluid within said tank.
Claim 14
Dependent Claim
23 words
Reactor as defined in claim 11 wherein said injecting means injects gas into the fluid substantially along the entire length of said blade.
Claim 15
Dependent Claim
31 words
Reactor as defined in claim 11 wherein said injecting means injects gas into the fluid so as to create a force tending to cause said blade to rotate in the fluid.
Claim 16
Dependent Claim
54 words
Reactor as defined in claim 10 wherein said blade has a hollow interior and defines a series of ports in fluid communication with said hollow interior and wherein said system further includes means for supplying a gas under pressure to said blade hollow interior whereby the pressurized gas exits said blade through said ports.
Claim 17
Dependent Claim
14 words
The reactor as defined in claim 10 wherein the blade comprises a polymeric material.
Claim 18
Dependent Claim
38 words
The reactor as defined in claim 10 wherein the blade is a rod possessing a thickness extending in a dimension transverse to the length of the rod, said thickness being between substantially one-fifth and one-half of an inch.
Claim 19
Dependent Claim
85 words
The reactor as defined in claim 10 wherein the blade is elongated and pivotably connected for movement within the tank about a pivot point, the blade further having a thickness extending in a dimension transverse to the length of the blade, the thickness of the blade decreasing along its length from the pivot point substantially in proportion to 1/L x where L equals the distance away from the pivot point and where x is a number substantially in the range of from 0 to 2.
Claim 20
Dependent Claim
14 words
The reactor as defined in claim 10 wherein said blade is substantially conically shaped.
Claim 21
Dependent Claim
16 words
The reactor as defined in claim 10 wherein said blade is diametrically stepped along its length.
Claim 22
Dependent Claim
64 words
The reactor as defined in claim 10 wherein the blade is elongated and pivotably connected for movement within the tank about a pivot pint, the blade further being twisted and having a cross section extending in a dimension transverse to the length of the blade, said cross section being substantially rectangular and decreasing along the length of the blade away from the pivot point.
Claim 23
Dependent Claim
44 words
The reactor as defined in claim 10 wherein the blade is elongated and pivotably connected for movement within the tank about a pivot point, the blade having a plurality of apertures extending through said blade in a direction substantially parallel to the fluid surface.
Claim 24
Dependent Claim
27 words
The reactor as defined in claim 21 wherein the diameter of each aperture is larger than the diameters of apertures located farther away from the pivot point.
Claim 25
Dependent Claim
13 words
The reactor as defined in claim 10 wherein said blade is substantially rigid.
Claim 26
Dependent Claim
12 words
The reactor as defined in claim 10 wherein said blade is flexible.
Claim 27
Dependent Claim
23 words
The reactor as defined in claim 10 wherein the blade is disposed between substantially one millimeter to five millimeters below the fluid surface.
Claim 28
Dependent Claim
18 words
The reactor as defined in claim 10 wherein the blade possesses a blade edge which is substantially serrated.
Claim 29
Dependent Claim
29 words
The reactor as defined in claim 10 wherein a plurality of discs are spaced radially along said blade, said discs extending substantially orthogonally to the length of said blade.
Claim 30
Dependent Claim
17 words
The reactor as defined in claim 10 wherein a series of comb-like fingers depend from said blade.
Claim 31
Dependent Claim
34 words
The reactor as defined in claim 28 wherein said agitator means further comprises means for selectively adjusting the orientation of said blade to selectively vary the direction said comb-like fingers depend from said blade.
Claim 32
Dependent Claim
19 words
The reactor as defined in claim 10 wherein said blade includes means for injecting a gas into the slurry.
Claim 33
Dependent Claim
38 words
The reactor as defined in claim 30 wherein said blade is rotatable about a pivot point and the gas is injected into the slurry creating a force tending to cause said blade to rotate about said pivot point.
Claim 34
Dependent Claim
55 words
The reactor as defined in claim 30 wherein said blade has a hollow interior and defines a series of ports in fluid communication with said hollow interior and wherein said system further includes means for supplying a gas under pressure to said blade hollow interior whereby the pressurized gas exits said blade through said ports.
Claim 35
Dependent Claim
38 words
The reactor as defined in claim 7 wherein said agitating means includes at least two moveable blades, a first moveable blade disposed substantially near the fluid surface and a second moveable blade disposed below the first moveable blade.
Claim 36
Dependent Claim
23 words
The reactor as defined in claim 33 wherein said first moveable blade is at least fifty percent longer than said second moveable blade.
Claim 37
Dependent Claim
41 words
The reactor as defined in claim 33 wherein said first and second moveable blades are rotated and second moveable blade is rotated at a speed at least fifty percent faster than the speed at which said first moveable blade is rotated.
Claim 38
Dependent Claim
34 words
The reactor as defined in claim 33 wherein said first and second moveable blades are rotated, said first moveable blade rotated in one direction and said second moveable blade rotated in the opposite direction.
Claim 39
Dependent Claim
27 words
The reactor as defined in claim 7 wherein said tank is open on one side and wherein the fluid surface is exposed to the open tank side.
Claim 40
Dependent Claim
35 words
The reactor as defined in claim 7 wherein the ratio of the area of the fluid surface to the volume of the slurry is in the range of between substantially 1:12 inches to 1:1 inches.
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) | 1995-12-29 | 1996-06-29 | 1996-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-29 | 2000-06-29 | 2000-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-29 | 2004-06-29 | 2004-12-29 | $7700.00 | Window Closed / Lapsed |