|Publication number||USRE40035 E1|
|Application number||US 09/784,131|
|Publication date||Jan 29, 2008|
|Filing date||Feb 16, 2001|
|Priority date||Aug 24, 1995|
|Also published as||CA2182069A1, CA2182069C, DE69630263D1, DE69630263T2, DE69636203D1, DE69636203T2, EP0761284A1, EP0761284B1, EP1374975A1, EP1374975B1, US5871624|
|Publication number||09784131, 784131, US RE40035 E1, US RE40035E1, US-E1-RE40035, USRE40035 E1, USRE40035E1|
|Inventors||Victor P. Crome|
|Original Assignee||Carleton Life Support Systems, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (14), Referenced by (2), Classifications (52), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation of application Ser. No. 08/518,646 filed Aug. 24, 1995 now abandoned.
This invention relates to devices for separating oxygen from a more complex gas containing oxygen to deliver the separated oxygen for use. More particularly, the invention relates to solid state electrochemical devices for separating oxygen from a more complex gas.
It has been demonstrated that oxygen can be removed from more complex gasses, such as air, by an electrochemical process of ionizing the oxygen molecules transporting the oxygen ions through a solid electrolyte and reforming the oxygen molecules on the opposite electrolyte surface of the electric potential is applied to a suitable catalyzing electrode coating applied to the surface of the electrolyte which is porous to oxygen molecules and which acts to dissociate oxygen molecules into oxygen ions at its interface with the electrolyte. The oxygen ions are transported through the electrolyte to the opposite surface, which is also coated with a catalyzing electrode and electrically charged with the opposite electric potential which removes the excess electrons from the oxygen ions, and the oxygen molecules are reformed.
The material forming the ion conductor, as is known, is a ceramic, and a wide variety of ceramics have been found useful for this purpose. For example, as discussed in U.S. Pat. No. 5,385,874 doped metal oxide ceramics have been found to provide high oxygen ion conductivity. The metal oxide may comprise from about 75% to about 90% of the overall composition, and typical oxides used to form the basis of the compositions may include zirconia, ceria, bismuth oxide, thoria, hafnia and similar materials known in the ceramics art. These are but examples, and the specific selection of material is not a part of the invention described herein.
As discussed, the generation of oxygen from electroded ceramic electrolytes or ion conductors is well knows These principles have been used in a wide variety of structural forms, i.e, the shape of the ceramic electrolyte and the arrangement of electrodes on or within the electrolyte have taken a variety forms. Each of these forms, how ever, has been found to have significant disadvantages in terms of the amount of surface area available for oxygen generation per unit volume and weight, the electrical connections have been difficult to manage, the collection devices for the oxygen output are difficult to manufacture and integrate with the electrolyte and the sources of gas from which oxygen is to be separated often are restricted.
For example, in some of the devices of this type, the ceramic electrolyte is constructed as a large flat plate, and this has significant disadvantages. It is limited in its ability to withstand high output delivery pressures Consequently, the plate must be either thicker, have stiffening ribs or have short spans between the sealed edges all of which add significantly to cost and manufacturing complexity.
U.S. Pat. No. 5,302,258 describes a device where a plurality of tubes each having electrodes on the interior and exterior surfaces thereof, are used The tube design is an improvement in terms of its ability to withstand higher pressures. However, considerable labor cost are are involved for sealing each tube to a manifold and to make the necessary electrical connections to each of the tubes.
U.S. Pat. No. 5,205,990 describes a honeycomb configuration which provides a less expensive way to produce the necessary surface area for the process and is structurally adequate to withstand the higher delivery pressures desirable. The ceramic electrolyte in this configuration has a series of channels, a portion of which are electroded with a first polarity, and the others of which are electroded with a second polarity, these channels are said to form the honeycomb appearance This arrangement has significant disadvantages in the labor required to seal the ends of numerous oxygen collecting channels and the wiring needed to connect those same channels. The alternating rows of oxygen and air channels provide only the effective surface area as might be available from the amount of ceramic electrolyte used, and the electrical connections throughout this honeycomb structure are intricate and expensive to manufacture.
It is therefore an object of this invention to provide a ceramic oxygen generator having an electrolyte configuration which provides for an increased active surface area per unit volume and weight of ceramic material.
Another object of this invention is to provide a ceramic oxygen generator wherein the electrical connections to the individual anode and cathode surfaces are simplified and less costly to make.
A further object of this invention is to provide a ceramic oxygen generator wherein the manifold structure for receiving the separated oxygen is an integral part of the manufactured generator structure and is less costly to make.
Still another object or this invention is to provide a ceramic oxygen generator which is of a modular configuration and thereby provides a simple “building block” approach to meet differing requirements for amounts of oxygen to be generated.
An additional object of the invention is to provide a ceramic oxygen generator meeting the foregoing objectives which is capable of operating with oxygen containing entrance gasses of a wide variety of pressures.
The foregoing and other objects are achieved in a modular ceramic oxygen generating system constructed according to the invention wherein an ionically conductive ceramic electrolyte is molded to have a plurality of tubes extending from a support member forming a module. The tubes are closed at the ends thereof outermost from the foregoing surface while open ends of the tube form openings in the support member for the tubes. All surfaces of the electrolyte including the inner and outer surfaces of the tubes and the top and bottom of the sup port support member are coated with a porous ionizing electrode material in a continuous fashion. A second coating of a different material may be applied to the same surfaces, if desired, to act as a low resistance current carrier and distributor. The tube-like members are formed into rows and columns on the tube support member. The aforementioned coatings of material are formed into electrical circuits which are created such that the columns of said tubes are connected in parallel while the rows thereof are connected in series. The tube support member includes a lower surface which is adapted to be joined with a like surface of another element to form an oxygen generator module assembly. A number of module assemblies can hie have their output ports connected together to form a system of greater capacity.
The principles of the intention will be more readily understood by reference to the description of a preferred embodiment given below along with the drawings which are briefly described as follow.
In each of the figures of the drawings like elements are referred to with like reference numerals.
The ceramic oxygen generating assembly according to the invention is generally comprised of pairs of molded “building block” or modular elements such as the one depicted in FIG. 1. The modular element 10 can be, for example, injection molded of an ionically conductive ceramic electrolyte and in the configuration shown provides a large surface area per unit volume, and it includes an integral manifold structure (to be described) for collecting oxygen. As is shown in
Referring again to
As stated, the elements 10 and 10′ forming the
In order to form these coatings into electrical circuits capable of creating oxygen generation devices of the above described type it is necessary to selectively burn away a portion of the electrode material to produce the desired electrical connections. To this end, a series of cuts in the electrode material 24 on the lower surface 18 of tube support member 14 are made as shown at 30a-c. These cuts may be made with a suitable laser. These cuts extend longitudinally of the columns the full dimension of tube support member 14 between each of the columns of tubes 12. Likewise, cuts 32 a-d are made in the electrode surface 21 formed on the upper surface 16 of tube support member 14. Again, these cuts 32 extend longitudinally the full dimension of tube support member 14 along each column of tubes 12. It will be noted, for example, that cut 32a is made on the side of via 20a nearer tube 12a while cut 30a is made on the side of via 20a nearer tuber 12b. Thus, a series connection is made between electrode surface 21 of tube 12b and that portion of electrode surface 24 on tube 12a. The same relationships will then occur between the first and second electrode surfaces of the next succeeding tubes in the row, and this same relationship will follow in each of the rows. By allowing the electrode material to remain in the vias 20 the best possible low resistance connection between the tubes is formed.
The cuts 30 and 32 made longitudinally of columns of tubes, such as the cuts 30a and 32a between columns formed by tubes 12a, 12b, and the like cuts between the other columns of tubes, in effect, form the tubes in a column into a parallel electrical circuit.
The result of this arrangement, using the
In operation, the air or other gas from which oxygen is to be extracted flows across the tubes 12 and by reason of the principles of ionic conductivity discussed hereinabove, a gas having a higher pressure of oxygen is formed in the interiors of tubes 12 and is collected in manifold 24. This supply of oxygen is communicated via port 26 to the component having the oxygen requirement.
It is to be understood that while circular or cylindrical tubes having exterior and interior surfaces are shown in the described embodiment other configurations for the “tubes” could be us used and the term “tube” is used herein only for purposes of convenience of reference.
An alternative arrangement to each column of hollow tubes is a hollow “cantilever shelf” configuration which would provide approximately the same effective surface area. These flat hollow sections with one end molded closed would be manifolded together as the tubes are to provide a common output port. Internal stiffening ribs could be added between the opposing flat walls to increase the ability to withstand internal pressure as required.
The principles of this invention are described hereinabove by describing a preferred embodiment constructed according to those principles. It will be understood that the described embodiment can be modified or changed in a number of ways without departing from the spirit and scope of the invention as defined by the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4640875||Feb 7, 1985||Feb 3, 1987||Westinghouse Electric Corp.||Fuel cell generator containing a gas sealing means|
|US4649003||Mar 18, 1985||Mar 10, 1987||Sumitomo Chemical Company, Limited||Method for producing an inorganic sintered body|
|US4686158||Oct 23, 1985||Aug 11, 1987||Mitsubishi Jukogyo Kabushiki Kaisha||Solid electrolyte fuel cell and method for preparing it|
|US4851303||Nov 26, 1986||Jul 25, 1989||Sri-International||Solid compositions for fuel cells, sensors and catalysts|
|US4943494||Apr 22, 1988||Jul 24, 1990||The United States Of America As Represented By The United States Department Of Energy||Solid oxide fuel cell matrix and modules|
|US5155158||Nov 7, 1989||Oct 13, 1992||Hoechst Celanese Corp.||Moldable ceramic compositions|
|US5205990||Aug 2, 1990||Apr 27, 1993||Lawless William N||Oxygen generator having honeycomb structure|
|US5302258||Feb 28, 1992||Apr 12, 1994||Triox Technologies, Inc.||Method and apparatus for separating oxygen from a gaseous mixture|
|US5306574||Oct 7, 1992||Apr 26, 1994||Westinghouse Electric Corp.||Method of low temperature operation of an electrochemical cell array|
|US5332483||Jan 15, 1992||Jul 26, 1994||Igr Enterprises, Inc.||Gas separation system|
|US5385874||Aug 26, 1993||Jan 31, 1995||Triox Technologies, Inc.||Ceramic compositions|
|US5582710||Sep 13, 1992||Dec 10, 1996||L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude||Electrochemical cell and its use for the separation and the electrochemical extraction of oxygen|
|US5723101||Oct 15, 1996||Mar 3, 1998||Rhone-Poulenc Inc.||Method for producing cerium and zirconium oxides, mixed oxides and solid solutions having improved thermal stability|
|US5852925||Sep 18, 1997||Dec 29, 1998||Praxair Technology, Inc.||Method for producing oxygen and generating power using a solid electrolyte membrane integrated with a gas turbine|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US8092506 *||Sep 7, 2007||Jan 10, 2012||Steven Haase||Ionic foot bath array with ionic circulation|
|US20090065353 *||Sep 7, 2007||Mar 12, 2009||Steven Haase||Ionic foot bath array with ionic circulation|
|U.S. Classification||205/634, 204/289, 204/263, 204/280, 204/288, 204/290.01, 204/266, 422/122, 204/421, 422/120, 204/278, 204/279, 204/265, 204/297.06, 204/277, 205/633, 204/297.01, 204/281, 429/505, 429/486, 429/410|
|International Classification||H01M8/24, B01D53/32, C01B13/02, H01M8/12, C25B11/00|
|Cooperative Classification||Y02P70/56, Y02E60/525, Y02E60/50, B01D53/326, H01M4/9033, H01M8/243, H01M8/0252, H01M8/1246, C01B13/0251, H01M8/0256, H01M8/126, H01M2300/0074, H01M2008/1293, H01M8/1253, H01M8/1266, B01D53/32, C01B2210/0046, B01D2257/104, C01B13/0233|
|European Classification||H01M8/02C6V, H01M8/02C6C, B01D53/32, H01M8/24B2H2, C01B13/02D2, B01D53/32E, C01B13/02D4B|
|Apr 4, 2005||AS||Assignment|
Owner name: CARLETON LIFE SUPPORT SYSTEMS, INC., IOWA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LITTON SYSTEMS, INC.;REEL/FRAME:016427/0532
Effective date: 20030818
|Jul 22, 2005||AS||Assignment|
Owner name: LITTON SYSTEMS, INCORPORATED, CALIFORNIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CROME, MR. VICTOR P.;REEL/FRAME:016299/0273
Effective date: 19950815
|Jul 25, 2005||AS||Assignment|
Owner name: CARLETON LIFE SUPPORT SYSTEMS, INC., NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LITTON SYSTEMS, INC.;REEL/FRAME:016304/0194
Effective date: 20030813
|Jul 30, 2010||FPAY||Fee payment|
Year of fee payment: 12