US5520818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for effecting gas-liquid contact
Assignee: University of Toronto Innovations Foundation
•
Filing: 1993-04-05
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Granted: 1996-05-28
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Expires: 2013-04-05
Abstract
Abstract PCT No. PCT/CA93/00148 Sec. 371 Date Nov. 29, 1994 Sec. 102(e) Date Nov. 29, 1994 PCT Filed Apr. 5, 1993 PCT Pub. No. WO93/19836 PCT Pub. Date Oct. 14, 1993.Components, usually but not exclusively gaseous components, are removed in a liquid medium from gas streams and chemically converted into an insoluble phase or physically removed. Specifically, hydrogen sulfide may be removed from gas streams by oxidation in aqueous chelated transition metal solution in a modified agitated flotation cell. The same principal may be employed in other procedures in which a gaseous phase is dispersed in a liquid phase to effect an interaction between components present in such phases. A gas-liquid contact apparatus, generally a combined chemical reactor and solid product separation device, comprising such modified agitated flotation cell is also described. In order to effect mass transfer and rapid reaction gas bubbles containing hydrogen sulfide and oxygen are formed by rotating an impeller at a blade tip velocity of at least about 350 in/sec. to achieve the required shear. To assist in the reaction, a surrounding shroud has a plurality of openings, generally of aspect ratio of approximately 1, of equal diameter and arranged in uniform pattern, such as to provide a gas flow therethrough less than about 0.02 lb/min/opening in the shroud. In general, the gas velocity index of gas through the openings in the shroud is at least about 18 per second per opening. Each of the openings has an area corresponding to an equivalent diameter of less than about one inch.
Inventors
- 👤 James W. Smith
- 👤 David T. R. Ellenor
- 👤 John N. Harbinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:45
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/20; C02F3/205; B; B01; B01D; B01D21/00; B01D21/0039; B01D21/0042; B01D21/24; B01D21/2427; B01D21/2433; B01D21/2438; B01D21/2494; B01D21/26; B01D53/00; B01D53/14; B01D53/18; B01D53/34; B01D53/46; B01D53/48; B01D53/52; B01D53/74; B01D53/77; B01D53/78; B01F; B01F23/00; B01F23/20; B01F23/23; B01F23/233; B01F23/2331; B01F23/2334; B01F23/23341; B01F23/23342; B01F23/2366; B01F23/2368; B03; B03D; B03D1/00; B03D1/02; B03D1/04; B03D1/14; B03D1/1493; B03D1/16; C01; C01B; C01B17/00; C01B17/02; C01B17/0232; C01B17/04; C01B17/05; C01F; C01F11/00; C01F11/18; C01F11/181; C02F1/00; C02F1/20; C02F1/72; C02F1/76; B01D2221/00; B01D2221/04; B01D2251/00; B01D2251/90; B01D2251/902; B01F27/00; B01F27/05; B01F27/11; B01F27/112; B01F27/1125; B03D1/1443; B03D1/1462; C02F1/725; C02F1/78; Y; Y02; Y02W; Y02W10/00; Y02W10/10
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
284 words
A method for the distribution of a gaseous phase in a liquid phase, which comprises: providing a rotary impeller comprising a plurality of blades at a submerged location in said liquid phase surrounded by a shroud through which are formed a plurality of openings, feeding said gaseous phase to said submerged location, rotating said impeller about a substantially vertical axis at a speed corresponding to a blade tip velocity of at least about 350 in/sec. so as to draw liquid phase into the interior of the shroud and to generate sufficient shear forces between said impeller and said plurality of openings in said shroud to distribute said gaseous phase as bubbles in said liquid phase to the interior of said shroud and to effect intimate contact of said gaseous phase and said liquid phase at said submerged location so as to form a gas-liquid mixture of bubbles of said gaseous phase in said liquid phase contained within said shroud while effecting shearing of said gas-liquid mixture within said shroud, flowing said gas-liquid mixture from within interior of said shroud through and in contact with said openings to external of said shroud at a gas velocity index (GVI) of at least about 18 per second per opening in said shroud so as to effect further shearing of the gas-liquid mixture and further intimate contact of said gaseous phase and said liquid phase, said gas velocity index (GVI) is determined by the expression: ##EQU11## where Q is the volumetric flow rate of gas (m 3 /s), n is the number of openings in the shroud, A is the area of each opening (m 2 ) and P is the length of the perimeter each opening (m).
Claim 2
Independent Claim
284 words
A method for the distribution of a gaseous phase in a liquid phase, which comprises: providing a rotary impeller comprising a plurality of blades at a submerged location in said liquid phase surrounded by a shroud through which are formed a plurality of openings, feeding said gaseous phase to said submerged location, rotating said impeller about a substantially vertical axis at a speed corresponding to a blade tip velocity of at least about 350 in/sec. so as to draw liquid phase into the interior of the shroud and to generate sufficient shear forces between said impeller and said plurality of openings in said shroud to distribute said gaseous phase as bubbles in said liquid phase to the interior of said shroud and to effect intimate contact of said gaseous phase and said liquid phase at said submerged location so as to form a gas-liquid mixture of bubbles of said gaseous phase in said liquid phase contained within said shroud while effecting shearing of said gas-liquid mixture within said shroud, flowing said gas-liquid mixture from within interior of said shroud through and in contact with said openings to external of said shroud at a gas velocity index (GVI) of at least about 18 per second per opening in said shroud so as to effect further shearing of the gas-liquid mixture and further intimate contact of said gaseous phase and said liquid phase, said gas velocity index (GVI) is determined by the expression: ##EQU11## where Q is the volumetric flow rate of gas (m 3 /s), n is the number of openings in the shroud, A is the area of each opening (m 2 ) and P is the length of the perimeter each opening (m).
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said blade tip velocity is at least about 500 in/sec. (at least about 12.5 m/s).
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said gas velocity index is at least about 24 per second per opening.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein said gas velocity index is from about 30 to about 500 per second per opening.
Claim 6
Dependent Claim
33 words
The method of claim 1 wherein said blade tip velocity is at least about 500 in/sec. (about 12.5 m/s) and said gas velocity index is at least about 30 per second per opening.
Claim 7
Dependent Claim
71 words
The method of claim 1 which is carried at an Effective Shear Index (ESI) value of about 1 to about 2500, in which the Effective Shear Index is determined by the relationship: ##EQU12## in which GVI is the Gas Velocity Index (/s), V i is the blade tip velocity (m/s), D s is the inside diameter (m) of the shroud and D i is the outside diameter (m) of the impeller.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein said ESI value is determined at a V i value of at least about 500 in/sec. (at least about 12.5 m/s).
Claim 9
Dependent Claim
87 words
The method of claim 7 wherein said ESI value is about 10 to about 250 and is carried out at a Shear Effectiveness Index (SEI) value of about 4 to about 5, in which the Shear Effectiveness Index is determined by the relationship: ##EQU13## in which Q is the gas flow rate to the impeller (m 3 /s) h is the height (m) of the impeller blades, D i is the outside diameter (m) of the impeller, and V i is the impeller blade tip velocity (m/s).
Claim 10
Dependent Claim
77 words
The method of claim 1 which is carried out at a Shear Effectiveness Index (SEI) value of about 1 to about 10, in which the Shear Effectiveness Index is determined by the relationship: ##EQU14## in which Q is the gas flow rate to the impeller (m 3 /s) h is the height (m) of the impeller blades, D i is the outside diameter (m) of the impeller, and V i is the impeller blade tip velocity (m/s).
Claim 11
Dependent Claim
27 words
The method of claim 9 wherein said SEI value is determined at a V i value of at least about 500 in/sec. (at least about 12.5 m/s).
Claim 12
Dependent Claim
43 words
The method of claim 1 wherein said gas-liquid mixture is flowed from the interior of the shroud through the openings to an annular flow path out of fluid flow communication with a body of said liquid phase except at the lower extremity thereof.
Claim 13
Dependent Claim
31 words
The method of claim 1 wherein said gas-liquid mixture is flowed from the interior of the shroud through the openings directly into a body of said liquid phase surrounding said shroud.
Claim 14
Dependent Claim
28 words
The method of claim 1 wherein said liquid phase contains an undesired dissolved component and said gaseous phase effects removal of said dissolved component from said liquid phase.
Claim 15
Dependent Claim
12 words
The method of claim 13 wherein said dissolved component is hydrogen sulfide.
Claim 16
Dependent Claim
15 words
The method of claim 14 wherein said hydrogen sulfide is dissolved in an aqueous phase.
Claim 17
Dependent Claim
14 words
The method of claim 14 wherein said hydrogen sulfide is dissolved in liquid sulfur.
Claim 18
Dependent Claim
22 words
The method of claim 13 wherein said liquid phase comprises waste water and said undesired dissolved component comprises BOD and/or COD material.
Claim 19
Dependent Claim
35 words
The method of claim 1 wherein said liquid phase comprises white, green or black liquor and said gaseous phase comprises an oxidizing gas, so as to effect stripping and/or oxidation of components of said liquor.
Claim 20
Dependent Claim
41 words
The method of claim 1 wherein said liquid phase contains volatile organic compounds (VOCs) normally resistant to oxidation, said gaseous phase strips said VOCs from said liquid phase, and said stripped VOCs are further processed to recover or destroy the same.
Claim 21
Dependent Claim
23 words
The method of claim 19 wherein said liquid phase is subjected to sequential treatments by gaseous phase in a plurality of contacting stages.
Claim 22
Dependent Claim
42 words
The method of claim 1 wherein said liquid phase is confined within an enclosed reaction zone which is maintained under a superatmospheric pressure, and wherein said rotary impeller is driven by a hydraulic or pneumatic motor located within said enclosed reaction zone.
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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) | 1999-05-28 | 1999-11-27 | 2000-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-28 | 2003-11-27 | 2004-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-28 | 2007-11-27 | 2008-05-28 | $7700.00 | Window Closed / Lapsed |