Apparatus and methods for the production of powders
First Claim
1. An apparatus (20) for the production of powder from a wire (31) comprising:
- a reaction chamber (100) in which an initial particulate is generated by an EEW process;
an extractor (32) for extracting at least a portion of such particulate from a gas flowing along a gas path having;
a first portion extending from the reaction chamber to tie extractor; and
a second portion returning from the extractor to the reaction chamber;
a multiple stage turbine (600) within the second portion of the flow path configured to drive the flow along the flow path;
a wire source (400) for delivering the wire along a wire path;
a first electrode (200) along the wire path within the reaction chamber;
a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; and
an energy source (26) of electrical energy configured to be coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate.
1 Assignment
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Accused Products
Abstract
Metallic powders are formed by the electrically exploded wire (EEW) process. An apparatus (20) for manufacturing such powders includes a closed loop recirculating gas path between a reaction chamber (100) and an extractor (32). A wire (31) is delivered from a source (400) along a wire path from ambient conditions outside the chamber to within the chamber. Within the chamber, a first electrode (200) has an aperture circumscribing the wire path and a second electrode (203) is located proximate to a terminal end of the wire path. A source (26) of electrical energy applies a discharge voltage between the electrodes to explode the length of wire therebetween to form an initial particulate. The initial particulate may be selectively extracted and processed to produce desired powders, in particular, energetic powders which are passivated for stability under ambient conditions.
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Citations
33 Claims
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1. An apparatus (20) for the production of powder from a wire (31) comprising:
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a reaction chamber (100) in which an initial particulate is generated by an EEW process; an extractor (32) for extracting at least a portion of such particulate from a gas flowing along a gas path having;
a first portion extending from the reaction chamber to tie extractor; and
a second portion returning from the extractor to the reaction chamber;a multiple stage turbine (600) within the second portion of the flow path configured to drive the flow along the flow path; a wire source (400) for delivering the wire along a wire path; a first electrode (200) along the wire path within the reaction chamber; a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; and an energy source (26) of electrical energy configured to be coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate. - View Dependent Claims (2, 3, 4, 5)
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6. An apparatus (20) for the production of powder from a wire (31) comprising:
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a recirculating gas path having;
a first portion extending between a reaction chamber (100) in which an initial particulate is generated by an EEW process and an extractor (32) for extracting at least a portion of such particulate from the recirculating gas; and
a second portion returning from the extractor to the reaction chamber;a wire source (400) for delivering the wire along a wire path; a first electrode (200) proximate the wire path within the reaction chamber; a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; an energy source (26) of electrical energy coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate; and at least one cooled surface (652, 656) along the first portion for removing heat from particles moving along the first portion. - View Dependent Claims (7)
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8. An apparatus (20) for the production of powder from a wire (31) comprising:
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a reaction chamber (100) in which an initial particulate is generated by an EEW process;
an extractor (32) for extracting at least a portion of such particulate from a recirculating gas flowing along a recirculating gas path having;
a first portion extending from the reaction chamber to the extractor; and
a second portion returning from the extractor to the reaction chamber, the extractor configured to be effective to permit no more than 1% of the initial particulate to return to the reaction chamber along the recirculating gas path;a wire source (400) located external to the reaction chamber for delivering the wire along a wire path extending into the chamber, an upstream portion of the wire path configured to be isolated from the recirculating gas in the reaction chamber; a first electrode (200) having an aperture (258) circumscribing the wire path within the reaction chamber; a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; and an energy source (26) of electrical energy configured to be coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate. - View Dependent Claims (9, 10)
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11. An apparatus (20) for the production of powder from a wire (31) comprising:
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a recirculating gas path having;
a first portion extending between a reaction chamber (100) in which an initial particulate is generated by an EEW process and an extractor (32) for extracting at least a portion of such particulate from the recirculating gas; and
a second portion returning from the extractor to the reaction chamber;a wire source (400) for delivering the wire along a wire path; a first electrode (200) having a plurality of apertures (258), the first electrode configured to be shiftable to sequentially bring each such aperture into an operational position circumscribing the wire path within the reaction chamber, a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; and an energy source (26) electrical energy configured to be coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate. - View Dependent Claims (12, 13, 14, 15, 16)
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17. An apparatus (20) for the production of powder from a wire (31) comprising:
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a reaction chamber (100) in which an initial particulate is generated by an EEW process; an extractor (32) for extracting at least a portion of such particulate from a recirculating gas flowing along a gas path, the gas path having;
a first portion extending from the reaction chamber to the extractor; and
a second portion returning from the extractor to the reaction chamber;a wire source (400) for delivering the wire along a wire path; a first electrode (200) along the wire path within the reaction chamber; a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; and an energy source (26) of electrical energy configured to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate, characterized in that; the second electrode is configured to be supported by and electrically coupled to the energy source by a conductor (203) extending through the chamber wall and within the chamber substantially surrounded by an insulator (204); and a substantially nonconductive baffle surrounds the insulator and has a slope which is directed generally downward toward an outlet effective to guide any stubs remaining after explosion out of the chamber. - View Dependent Claims (18)
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19. An apparatus (20) for the production of powder from a wire (31) comprising:
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a reaction chamber (100) in which an initial particulate is generated by an EEW process;
an extractor (32) for extracting at least a portion of such particulate from a recirculating gas flowing along a recirculating gas path having;
a first portion extending from the reaction chamber to the extractor, and a second portion returning from the extractor to the reaction chamber;a wire source (400) for delivering the wire along a wire path; a first electrode (200) along the wire path within the reaction chamber, a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; and an energy source (26) of electrical energy configured to be coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate, characterized by; a wire straightening mechanism (402) comprising; a first engagement member (468) configured to receive the wire from the wire source; and a second engagement member (470) downstream of the first engagement member during operation the first and second engagement members configured to reciprocally moveable relative to each other to place an at least partially inelastic longitudinal strain on a length of the wire between the first and second engagement members of between 1% and 10% of a yield strain. - View Dependent Claims (20)
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21. An apparatus (20) for the production of powder from a wire (31) comprising:
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a recirculating gas path having;
a first portion extending between a reaction chamber (100) in which an initial particulate is generated by an EEW process and an extractor (32) for extracting at least a portion of such particulate from the recirculating gas; and
a second portion returning from the extractor to the reaction chamber;a wire source (400) for delivering the wire along a wire path; a first electrode (200) having an aperture (258) circumscribing the wire path within the reaction chamber; a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; an energy source (26) of electrical energy configured to be coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate, and a processing subsystem (33) coupled to the extractor (32) and comprising; a processing chamber (800) for containing a processing gas; a plurality of vessels (826) within the processing chamber each having an upper port and a lower port, the vessels configured to be moveable through a plurality of vessel positions, including; a loading position in which the vessel receives, through its upper port, powder separated by the extractor; at least one processing position in which the processing gas may communicate trough the upper port for contacting the powder in the vessel; and an unloading position in which the vessel discharges, through its lower port, processed powder. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. An apparatus (20) for the production of powder from a wire (31) comprising:
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a recirculating gas path having;
a first portion extending between a reaction chamber (100) in which an initial particulate is generated by an EEW process and an extractor (32) for extracting at least a portion of such particulate from the recirculating gas; and
a second portion returning from the extractor to the reaction chamber;a wire source (400) located external to the reaction chamber and delivering the wire along a wire path extending into the chamber, an upstream portion of the wire path isolated from the recirculating gas in the reaction chamber; a first electrode (200) having an aperture (258) circumscribing the wire path within the reaction chamber; a second electrode (202) proximate a terminal end of the wire path within the reaction chamber; and an energy source (26) of electrical energy configured to be coupled to the first and second electrodes to selectively apply a discharge current between the first and second electrodes sufficient to explode a length of the wire to form said initial particulate; an isolator (502) along said wire path and providing said isolation, the isolator comprising; a first conduit (500, 505) for receiving the wire from upstream and having an inner surface of a first minimum cross sectional area; a second conduit (506, 512) for admitting the wire to the chamber interior downstream and having an inner surface of a second minimum cross sectional area; a pressure balancing chamber (504) enclosing respective downstream and upstream ends of the first and second conduits and having a gas inlet port; and a balancing gas source (514) for introducing a balancing gas through the gas inlet port and for maintaining an internal pressure of the balancing chamber slightly below an internal pressure of the reaction chamber downstream of the balancing chamber along the wire path. - View Dependent Claims (29, 30, 31, 32, 33)
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Specification