Source: https://patents.justia.com/patent/7670698
Timestamp: 2020-07-03 18:08:17
Document Index: 573580656

Matched Legal Cases: ['arts 921', 'art 921', 'art 22', 'art 921', 'arts 921', 'arts 1021', 'arts 921', 'Application No. 07105846']

US Patent for Silicide fueled power generators and methods related thereto Patent (Patent # 7,670,698 issued March 2, 2010) - Justia Patents Search
Justia Patents US Patent for Silicide fueled power generators and methods related thereto Patent (Patent # 7,670,698)
Mar 22, 2007 - Honeywell International Inc
FIG. 9a, 9b and 9c illustrate three positions of a grid-like valve used in a fuel cell, according to some embodiments.
FIG. 10 illustrates a cylindrical shaped fuel cell utilizing the valve of FIGS. 9a, 9b and 9c, according to some embodiments.
J A = D AB * ( P A ⁢ ⁢ 1 - P A ⁢ ⁢ 2 ) R * T * ( Z 2 - Z 1 )
kg ⁢ ⁢ A m 2 ⁢ ⁢ sec
As seen in FIGS. 1 and 2, the power generator 10 may further include a restriction 32 united with the air inlet 20, regulating the diffusion of atmospheric oxygen and atmospheric water molecules into the power generator. This restriction also aids in raising the humidity at the fuel cell cathode 16 due to impedance presented to outward diffusion of water vapor produced at the cathode 16. This increased humidity improves the operation of the fuel cell. The restriction may include a hydrophobic membrane that is substantially permeable to atmospheric oxygen gas, but substantially impermeable to water vapor, which membrane substantially obstructs the flow of fuel cell water into the atmosphere. Suitable materials for this oxygen permeable, water vapor impermeable membrane having the desired properties include fluoropolymer containing materials such as fluorinated ethylene propylene (FEP), perfluoroalkoxy, and non-fluoropolymer containing materials such as oriented polypropylene (OPP), low density polyethylene (LDPE), high density polyethylene (HDPE) and cyclic olefin copolymers (COCs). The oxygen permeable, water vapor impermeable membrane material may be manufactured of fluorinated ethylene propylene, for example. In addition, for some embodiments, the membrane alone may not allow sufficient oxygen permeation to the cathode. Accordingly, a small opening 48 (see FIG. 2) in the restriction 32 may be provided to allow the ingress of extra atmospheric oxygen and atmospheric water molecules into the cavity to diffuse to the fuel cell cathode or cathodes. However, this opening may also cause some of the water vapor to diffuse out of the power generator 10. The required opening size is a function of the power level, the diffusion path length, and the desired partial pressure drop. The size of this opening may be very small in size and may include from about 0.001% to about 1% of the entire surface area of the membrane.
The embodiment of FIG. 2 also includes a pneumatic valve 26 which may include a mesh diaphragm 30 and a water permeable, hydrogen impermeable membrane 40 in juxtaposition with the mesh diaphragm 30 of the valve 26. The mesh diaphragm 30 may be permeable to water vapor and is formed from a polymeric material, such as polyethylene terephthalate or a metal such as stainless steel. Suitable water permeable materials for this water permeable membrane 40 include perfluorinated polymers such as perfluorosulfonate ionomers. Also suitable are epoxides and chloroprene rubber. The water permeable membrane may include a perfluorosulfonate ionomer membrane commercially available under the trademark Nafion® from EI DuPont de Nemours & Co. of Delaware. Nafion® may be utilized because it has a fluorinated backbone that makes it very stable, with sulfonic acid side chains to support high ionic conductivity. The water permeable, hydrogen impermeable membrane 40 allows the diffusion of water vapor to the fuel chamber 12 without passing the water vapor through the electrolytic membrane 42. It provides a large area path for water vapor to permeate into the fuel chamber and may allow the fuel cells 14 to operate at higher current densities than if the water is recovered solely though the fuel cells themselves. A similar material forms the electrolytic membrane 42 of the at least one fuel cell 14.
FIGS. 9a, 9b and 9c illustrate an operation of the valve in the present fuel cell design. The valve in FIG. 9a may be open. A diaphragm 913 may move the valve 912 to an open position and, on the other hand, move the valve 912 to a closed position as shown in FIG. 9c. The valve may have a partially open position as identified in FIG. 9b. Valve 912 may have two mesh-, grid- or plate-like parts 921 and 922. These parts may be of other forms or design to effect the operation described here. Part 921 may be stationary relative to the fuel cell assembly or system 810. Part 22 may be positioned on or adjacent to part 921. These parts 921 and 922 may be plates or the like with numerous openings 923 in them. The openings may be in the form of, for instance, small rectangular shapes laid out in a symmetrical pattern in both plates 921 and 922. With plate 922 overlaid on plate 921, the openings 923 may be aligned such that matter may flow through the pair of plates 921 and 922, as shown in FIG. 9a. Plate 922 may be moved left relative to plate 921 and the openings 923 will become partially closed as shown in FIG. 9b. If plate 922 is further moved left, the openings 923 may be closed in that portions of plates 921 and 922 overlap each other's openings, as shown in FIG. 9c.
Plate 922 may be moved by a diaphragm 913 which is pressure sensitive. If pressure of matter in the portion of the cell assembly in the volume 926 proximate to plate 922 increases, as shown in FIGS. 9a, 9b and 9c, then the diaphragm 913 may bulge out from the chamber volume 926 proximate to plate 922. Attached at about a center 924 of diaphragm 913 may be a linkage 925 that is attached to plate 922. When bulging out at the center 924 (to the left in the FIGS.) because of pressure, then the linkage 925 may likewise pull plate 922 to the left (in the FIGS.) to reduce the flow of matter or gas through the plates in response to the increased pressure. If the pressure increases even more, then diaphragm 913 may expand further out to its stop thereby causing plate 922 to have its non-open areas overlap plate 921 openings 923, and plate 921 to have its non-open areas overlap plate 922 openings and effectively stop the flow of matter (e.g., water vapor) through plates 921 and 922. As the pressure decreases in the chamber 926 proximate to plate 922, then diaphragm 913 may begin returning to a less bulged state and via the linkage 925 push plate 922 so that a part of the openings 923 of both plates 921 and 922 are uncovered or unclosed. Further reduction of the pressure in chamber 926 may result in diaphragm 913 returning to its initial open position thereby moving plate 922 so that the openings 923 of plates 921 and 922 are aligned such that none of the openings 923 in the plates are effectively obscured by either plate. Again, as the chamber 926 pressure increases, the valve 912 begins to close, and as the chamber 926 pressure decreases, the valve 912 begins to open. Thus, the amount of flow through the valve 912 may be determined by the chamber 926 pressure. This approach may provide a regulation of the flow or volume of the gas from chamber 926 through the valve.
The valve mechanism described in FIGS. 9a, 9b and 9c may be designed into a cylindrical fuel cell device 1030 as shown in FIG. 10. The mechanism may also be designed into a fuel cell generator assembly having some other shape. In FIG. 10, the fuel volume or supply may be in the center of the cylinder. Between the cell 1014 and the fuel supply container or chamber 1011 may be a cylindrical slide valve 1012. The valve may be two cylindrical sleeves of grid, mesh, perforated material, or the like, that are concentric and adjacent to each other. The parts 1021 and 1022 of the cylindrical valve may slide relative to each other to open and close the valve 1012 (like the parts 921 and 922 in FIGS. 9a-9c). On the outside of the circumference slide valve 1012 may be a fuel cell or cells 1014 (similar to the fuel cell 814 of FIG. 8).
at least one fuel chamber within a housing;
an air inlet, positioned in the housing;
one or more fuel cells, mounted within the housing;
a cavity, extending from the one or more fuel cells to the at lest one fuel chamber; and
a porous membrane, permeable to at least water and hydrogen and positioned between the fuel chamber and the one or more fuel cells; and
a fuel enclosed within the at least one fuel chamber, wherein the fuel comprises an alkali metal silicide.
8. A hydrogen generator, comprising: wherein when the alkali metal silicide is contacted with water through the membrane, hydrogen is generated and flows through the cavity from the fuel chamber to the one or more fuel cells.
a fuel chamber, enclosing an alkali metal silicide;
a porous membrane forming at least a portion of the chamber wall;
an air inlet, adapted to receive ambient air and positioned in the housing;
one or more fuel cells, mounted within the housing; and
a cavity, extending from the one or more fuel cells to the at lest one fuel chamber;
15. The hydrogen generator of claim 8, wherein the one or more fuel cells comprise proton exchange membrane (PEM) fuel cells.
5401371 March 28, 1995 Oshima et al.
20060002839 January 5, 2006 Lefenfeld et al.
0473483 May 1969 CH
1514839 March 2005 EP
WO-2005/051839 June 2005 WO
“European Patent Application No. 07105846.5, Communication and Search Report mailed Aug. 27, 2007”, 14 pgs.
“European Application Serial No. 07105846.5, Examination Report dated Jun. 13, 2008”, 2 pgs.
“European Application Serial No. 07105846.5, Examination Report mailed Jun. 3, 2009”, 4 pgs.
“European Application Serial No. 07105846.5, Response filed Nov. 24, 2008 to Examination Report dated Jun. 13, 2008”, 11 pgs.
Patent number: 7670698
Patent Publication Number: 20070237995
Inventors: Steven J. Eickhoff (Plymouth, MN), David W. Nielsen (Maple Grove, MN)
Application Number: 11/726,491
Current U.S. Class: 429/17; 429/19; 429/30