US4994332A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Metal hydroxide crystallizer and filter
Assignee: Eltech Systems Corp
•
Filing: 1989-07-11
•
Granted: 1991-02-19
•
Expires: 2009-07-11
Abstract
Abstract The present invention comprises a closed-loop filter system for continuously removing a metal hydroxide precipitate from an alkali metal hydroxide solution. The filter system comprises a filter having a filter surface and a plurality of small diameter openings in said surface. The alkali metal hydroxide solution is impacted onto said filter surface, metal hydroxide precipitate agglomerating on said surface. The filter surface openings have an average diameter effective for said agglomerating. Means are provided to remove the agglomerated precipitate from said filter surface, and to separate the agglomerated precipitate from the alkali metal hydroxide solution, the agglomerated precipitate having a particle weight to surface area ratio effective for said separation.
Inventors
- 👤 Richard J. Coin
- 👤 Carl W. Brown, Jr.
- 👤 Jay M. Noscal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:22
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/06; H01M8/0693; B; B01; B01D; B01D29/00; B01D29/11; B01D29/31; B01D29/33; B01D29/62; B01D29/64; B01D29/6469; B01D29/6476; B01D36/00; C; C23; C23F; C23F1/00; C23F1/46; H01M6/00; H01M6/50; H01M6/5077; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
190 words
A closed-loop filter system for continuously removing a metal hydroxide precipitate from an alkali-metal hydroxide solution comprising: a filter tank including an inlet and an outlet; a filter at said outlet having a filter surface and a plurality of small diameter openings in said surface, said filter surface being disposed within said filter tank, means for introducing said alkali metal hydroxide solution into said tank at said tank inlet and for impacting said alkali metal hydroxide solution containing metal hydroxide precipitate onto said filter surface, metal hydroxide precipitate agglomerating on said surface, said filter surface openings having an average diameter effective for said agglomerating; means for continuously said agglomerated precipitate from said filter surface, and; means for separating said agglomerated precipitate from said alkali metal hydroxide solution, the agglomerated precipitate having a particle weight to surface area ratio effective for said separation, wherein said separation is by settling of said precipitate in said tank and wherein said filter system is constructed and arranged to allow particles of said agglomerated precipitate to settle in said solution at a rate in the range of about 2,000 to about 200,000 millimeters per hour.
Claim 2
Dependent Claim
190 words
A closed-loop filter system for continuously removing a metal hydroxide precipitate from an alkali-metal hydroxide solution comprising: a filter tank including an inlet and an outlet; a filter at said outlet having a filter surface and a plurality of small diameter openings in said surface, said filter surface being disposed within said filter tank, means for introducing said alkali metal hydroxide solution into said tank at said tank inlet and for impacting said alkali metal hydroxide solution containing metal hydroxide precipitate onto said filter surface, metal hydroxide precipitate agglomerating on said surface, said filter surface openings having an average diameter effective for said agglomerating; means for continuously said agglomerated precipitate from said filter surface, and; means for separating said agglomerated precipitate from said alkali metal hydroxide solution, the agglomerated precipitate having a particle weight to surface area ratio effective for said separation, wherein said separation is by settling of said precipitate in said tank and wherein said filter system is constructed and arranged to allow particles of said agglomerated precipitate to settle in said solution at a rate in the range of about 2,000 to about 200,000 millimeters per hour.
Claim 3
Dependent Claim
14 words
The system of claim 1 wherein said filter is a sintered powder metal cartridge.
Claim 4
Dependent Claim
36 words
The system of claim 2 wherein said metal hydroxide is aluminum hydroxide and said alkali metal hydroxide solution is a potassium hydroxide solution, and said filter has an average size opening less than about three microns.
Claim 5
Dependent Claim
18 words
The system of claim 3 wherein said means to remove said agglomerated precipitate from said filter is mechanical.
Claim 6
Dependent Claim
22 words
The system of claim 3 wherein said means to remove said agglomerated precipitate from said filter surface is back-wash through the filter.
Claim 7
Dependent Claim
18 words
The system of either claim 4 or claim 5 wherein said filter cartridge has a two micron rating.
Claim 8
Dependent Claim
23 words
The system of claim 4 including temperature control means for maintaining said electrolyte at a temperature in the range of about 50°-80° F.
Claim 9
Dependent Claim
147 words
A battery assembly comprising: (1) an aluminum air cell; (2) a closed-recirculation loop for continuously recirculating potassium hydroxide electrolyte through said cell; (3) a filter system in said loop for continuously removing aluminum hydroxide precipitate from said electrolyte, said precipitate comprising particles having an average particle size of about 0.5-20 microns, said filter system comprising; (i) a closed tank; (ii) means for introducing electrolyte from said aluminum-air cell into said tank, said tank having a residence time effective for crystallization of aluminum hydroxide precipitate to take place in said tank; (iii) means for recirculating electrolyte from said tank back to said cell; (iv) filter means in said tank for agglomerating the particles of aluminum hydroxide precipitate from electrolyte recirculated to said cell; (v) means for removing said agglomerated precipitate from the surface of said filter means and for allowing said agglomerated particles to settle in said tank.
Claim 10
Dependent Claim
147 words
A battery assembly comprising: (1) an aluminum air cell; (2) a closed-recirculation loop for continuously recirculating potassium hydroxide electrolyte through said cell; (3) a filter system in said loop for continuously removing aluminum hydroxide precipitate from said electrolyte, said precipitate comprising particles having an average particle size of about 0.5-20 microns, said filter system comprising; (i) a closed tank; (ii) means for introducing electrolyte from said aluminum-air cell into said tank, said tank having a residence time effective for crystallization of aluminum hydroxide precipitate to take place in said tank; (iii) means for recirculating electrolyte from said tank back to said cell; (iv) filter means in said tank for agglomerating the particles of aluminum hydroxide precipitate from electrolyte recirculated to said cell; (v) means for removing said agglomerated precipitate from the surface of said filter means and for allowing said agglomerated particles to settle in said tank.
Claim 11
Dependent Claim
14 words
The assembly of claim 8 including means for adding seed crystals to said tank.
Claim 12
Dependent Claim
17 words
The assembly of claim 8 wherein said tank is affixed to a side of said aluminum-air cell.
Claim 13
Dependent Claim
19 words
The assembly of claim 8 wherein said means for removing said agglomerated precipitate from said filter means is mechanical.
Claim 14
Dependent Claim
24 words
The assembly of claim 8 wherein said means for removing said agglomerated precipitate from said filter means is by back-wash through said filter means.
Claim 15
Dependent Claim
23 words
The assembly of claim 8 wherein said filter means is a filter cartridge having an average size opening less than about three microns.
Claim 16
Dependent Claim
152 words
A battery assembly comprising: (a) a metal-air cell; (b) a closed recirculation loop for continuously recirculating an alkali metal hydroxide electrolyte through said cell; (c) a filter system in said loop for continuously removing a metal hydroxide precipitate from said alkali metal hydroxide electrolyte, said filter system comprising; (i) a filter tank; (ii) a flow line for introducing said alkali metal electrolyte and metal hydroxide precipitate into said tank; (iii) means in said tank for separating said precipitate from said electrolyte; and (iv) temperature control means for maintaining a relatively constant temperature of said solution in said tank; said temperature control means comprising: (a) a heat exchanger; (b) a diverter valve having multiple ports in said flow line; and (c) means connecting said heat exchanger to one port of said diverter valve and to said tank whereby a portion of the flow in said flow line is divertible to said heat exchanger.
Claim 17
Dependent Claim
152 words
A battery assembly comprising: (a) a metal-air cell; (b) a closed recirculation loop for continuously recirculating an alkali metal hydroxide electrolyte through said cell; (c) a filter system in said loop for continuously removing a metal hydroxide precipitate from said alkali metal hydroxide electrolyte, said filter system comprising; (i) a filter tank; (ii) a flow line for introducing said alkali metal electrolyte and metal hydroxide precipitate into said tank; (iii) means in said tank for separating said precipitate from said electrolyte; and (iv) temperature control means for maintaining a relatively constant temperature of said solution in said tank; said temperature control means comprising: (a) a heat exchanger; (b) a diverter valve having multiple ports in said flow line; and (c) means connecting said heat exchanger to one port of said diverter valve and to said tank whereby a portion of the flow in said flow line is divertible to said heat exchanger.
Claim 18
Dependent Claim
12 words
The assembly of claim 14 wherein said heat exchanger is a cooler.
Claim 19
Dependent Claim
13 words
The assembly of claim 15 wherein said metal-air cell is an aluminum-air cell.
Claim 20
Dependent Claim
21 words
The assembly of claim 15 further comprising a thermostat positioned in said tank, said diverter valve being responsive to said thermostat.
Claim 21
Dependent Claim
16 words
The assembly of claim 14 wherein said diverter valve is a temperature-actuated proportioning flow diversion valve.
Claim 22
Dependent Claim
43 words
The assembly of claim 14 including cooler means and means for circulating at least a portion of said alkali metal hydroxide solution through said cooler means to maintain said solution in said tank at a temperature in the range of about 50°-80° F.
Claim 23
Independent Claim
185 words
A method for filtering a metal hydroxide precipitate from an alkali metal hydroxide solution comprising the steps of: (a) providing a filter tank including an inlet and an outlet; (b) providing a filter at said outlet having a filter surface and a plurality of small diameter openings in said filter surface, said filter surface being disposed within said filter tank; (c) introducing said alkali metal hydroxide solution into said tank at said tank inlet and impacting said alkali metal hydroxide solution containing metal hydroxide precipitate onto said filter surface, metal hydroxide precipitate agglomerating on said surface, said filter surface openings having an average diameter effective for said agglomerating; (d) continuously removing said agglomerated precipitate from said filter surface, and; (e) separating said agglomerated precipitate from said alkali metal hydroxide solution, the agglomerated precipitate having a particle weight to surface area ratio effective for said separation, said separation being by settling of said precipitate in said tank, wherein said agglomerated precipitate has a weight to surface are ratio providing particle settling in said solution with the range of about 2,000 to about 200,000 millimeters per hour.
Claim 24
Independent Claim
185 words
A method for filtering a metal hydroxide precipitate from an alkali metal hydroxide solution comprising the steps of: (a) providing a filter tank including an inlet and an outlet; (b) providing a filter at said outlet having a filter surface and a plurality of small diameter openings in said filter surface, said filter surface being disposed within said filter tank; (c) introducing said alkali metal hydroxide solution into said tank at said tank inlet and impacting said alkali metal hydroxide solution containing metal hydroxide precipitate onto said filter surface, metal hydroxide precipitate agglomerating on said surface, said filter surface openings having an average diameter effective for said agglomerating; (d) continuously removing said agglomerated precipitate from said filter surface, and; (e) separating said agglomerated precipitate from said alkali metal hydroxide solution, the agglomerated precipitate having a particle weight to surface area ratio effective for said separation, said separation being by settling of said precipitate in said tank, wherein said agglomerated precipitate has a weight to surface are ratio providing particle settling in said solution with the range of about 2,000 to about 200,000 millimeters per hour.
Claim 25
Dependent Claim
14 words
The method of claim 20 wherein said filter is a sintered powder metal cartridge.
Claim 26
Dependent Claim
35 words
The method of claim 21 wherein said metal hydroxide is aluminum hydroxide and said alkali metal hydroxide solution is a potassium hydroxide solution, said filter having an average size opening less than about three microns.
Claim 27
Dependent Claim
15 words
The method of claim 22 wherein said potassium hydroxide solution is an aluminum-air cell electrolyte.
Claim 28
Dependent Claim
16 words
The method of claim 20 wherein said agglomerated precipitate is removed from said filter surface mechanically.
Claim 29
Dependent Claim
14 words
The method of claim 24 wherein said filter cartridge has a two micron rating.
Claim 30
Dependent Claim
21 words
The method of claim 20 wherein said agglomerated precipitate is removed from said filter surface by a backwash through said filter.
Claim 31
Dependent Claim
22 words
The method of claim 20 wherein said tank has a residence time within the range of about 0.2 to about 5 minutes.
Claim 32
Dependent Claim
36 words
The method of claim 20 including the step of adding seed crystals to said tank in an amount within the range of about 5%-10% by weight based on the weight of said alkali metal hydroxide solution.
Claim 33
Dependent Claim
28 words
The method of claim 20 including the step of cooling said alkali metal hydroxide solution in said tank to a temperature in the range of about 50°-80° F.
Claim 34
Dependent Claim
116 words
A battery assembly comprising: (1) an aluminum air cell; (2) a closed-recirculation loop for continuously recirculating potassium hydroxide electrolyte through said cell; (3) a filter system in said loop for continuously removing aluminum hydroxide precipitate from said electrolyte, said precipitate comprising particles having an average particle size of about 0.5-20 microns, said filter system comprising; (i) a closed tank; (ii) means for recirculating electrolyte from said tank back to said cell; (iii) filter means in said tank for agglomerating the particles of aluminum hydroxide precipitate from electrolyte recirculated to said cell; (iv) means for removing said agglomerated precipitate from the surface of said filter means and for allowing said agglomerated particles to settle in said tank.
Claim 35
Dependent Claim
116 words
A battery assembly comprising: (1) an aluminum air cell; (2) a closed-recirculation loop for continuously recirculating potassium hydroxide electrolyte through said cell; (3) a filter system in said loop for continuously removing aluminum hydroxide precipitate from said electrolyte, said precipitate comprising particles having an average particle size of about 0.5-20 microns, said filter system comprising; (i) a closed tank; (ii) means for recirculating electrolyte from said tank back to said cell; (iii) filter means in said tank for agglomerating the particles of aluminum hydroxide precipitate from electrolyte recirculated to said cell; (iv) means for removing said agglomerated precipitate from the surface of said filter means and for allowing said agglomerated particles to settle in said tank.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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