Ionizing method and apparatus

Claim 2

In a plasma gun for ionizing a stream of gas, said gun including a double-walled chamber contAining an elongate cathode and an annular anode for striking an ionizing arc upon the application of electrical power thereto; cooling means for cooling said anode and said chamber, said cooling means including a source of cooling fluid at relatively low temperature and a supply line connecting said source and said gun for flowing said fluid from said source to said gun, said cooling means further including coil means between the said walls of said chamber for conducting said fluid from the inlet connection of said line and said gun directly to the area between the walls of said double-walled chamber in closest proximity to said anode, said cooling means further including a return line for returning said fluid from said gun to said source, and heat exchange means connected between said source of cooling fluid and said gun for lowering the temperature of said cooling fluid.

Claim 3

The apparatus as set forth in claim 1 above, wherein: said coil means comprises a hollow tubular coil and said cooling means further includes passage means between said walls for flowing said cooling fluid over said hollow tubular coil and between said walls.

Claim 4

In a plasma gun for ionizing a stream of gas, said gun including an elongate cathode and an annular anode for striking an ionizing arc upon the application of electrical power thereto; mounting means for adjustably holding said cathode with one end thereof in spaced relationship with respect to said anode, said mounting means being contained within a double-walled chamber having two generally concentric and spaced-apart walls forming a portion of said gun, said mounting means including a closed chamber coaxially aligned with said cathode and said double-walled chamber, said closed chamber surrounding a substantial portion of said cathode, first cooling means for flowing a cooling agent through said closed chamber in contact with said portion of said cathode to cool the same, second cooling means for cooling said anode and said double-walled chamber, a source of cooling fluid at relatively low temperature, and a supply line connecting said source to said gun for flowing said fluid from said source to said gun, said second cooling means further including coil conduit means situated in said space between said double walls for conducting said fluid from the inlet connection of said line and said gun directly to an area between the walls of said double-walled chamber, said area being situated in close proximity to said anode.

Claim 5

In a plasma gun for ionizing a stream of gas, said gun including an elongate cathode and an annular anode for striking an ionizing arc upon the application of electrical power thereto; mounting means for adjustably holding said cathode with one end thereof in spaced relationship with respect to said anode, said mounting means being contained within a double-walled chamber having two generally concentric and spaced-apart walls forming a portion of said gun, said mounting means including a closed chamber coaxially aligned with said cathode and said double-walled chamber, said closed chamber surrounding a substantial portion of said cathode, first cooling means for flowing a cooling agent through said closed chamber in contact with said portion of said cathode to cool the same, second cooling means for cooling said anode and said double-walled chamber, a source of cooling fluid at relatively low temperature, and a supply line connecting said source to said gun for flowing said fluid from said source to said gun, said second cooling means further including coil conduit means situated in said space between said double walls for conducting said fluid from the inlet connection of said line and said gun directly to an area between the walls of said double-walled chamber, said area being situated in close proximity to said anode.

Claim 6

In an ionizing system for a plasma gun adapted to spray coat powdered material on a target surface: hopper means for storage of said material, feed means adapted to receive said material from said hopper means and feed the same to said gun at a predetermined rate, means rendering said hopper means and said feed means airtight to prevent contact of air with said material while contained in said system so that said material is preserved in the same state of purity when fed into said gun as when placed in said hopper, a source of gas, first conduit means connecting said source of gas to said hopper means second conduit means connecting said source of gas to said plasma gun through said feed means, and valve means for selectively flowing gas from said source through said second conduit means, said feed means and said gun in an amount sufficient to purge all gases and particles from within said conduit means, said feed means and said plasma gun.

Claim 7

In an ionizing system for a plasma gun adapted to spray coat powdered material on a target surface: hopper means for storage of said material, feed means adapted to receive said material from said hopper means and feed the same to said gun at a predetermined rate, means rendering said hopper means and said feed means airtight to prevent contact of air with said material while contained in said system so that said material is preserved in the same state of purity when fed into said gun as when placed in said hopper, a source of gas, first conduit means connecting said source of gas to said hopper means second conduit means connecting said source of gas to said plasma gun through said feed means, and valve means for selectively flowing gas from said source through said second conduit means, said feed means and said gun in an amount sufficient to purge all gases and particles from within said conduit means, said feed means and said plasma gun.

Claim 8

In an ionizing system: a plasma gun, feeder means for feeding powdered material to said gun, conduit means connecting to said feeder means with said gun, purge means connected to said feeder means for flowing a purging agent through said feeder means, said conduit means, and said gun in amount sufficient to purge all gases and particles from therewithin other than said agent, a source of said powdered material operatively communicatiNg with said feeder means, said purge means comprising a source of gas, first conduit means connecting said source of gas with said source of powdered material, and bypass means selectively operable to bypass said source of powdered material by connecting and disconnecting said source of gas with said feeder means for flowing said gas through said feeder means, said gun, and said conduit means connecting said feeder means with said gun.

Claim 9

In an ionizing system: a plasma gun, feeder means for feeding powdered material to said gun, conduit means connecting to said feeder means with said gun, purge means connected to said feeder means for flowing a purging agent through said feeder means, said conduit means, and said gun in amount sufficient to purge all gases and particles from therewithin other than said agent, a source of said powdered material operatively communicatiNg with said feeder means, said purge means comprising a source of gas, first conduit means connecting said source of gas with said source of powdered material, and bypass means selectively operable to bypass said source of powdered material by connecting and disconnecting said source of gas with said feeder means for flowing said gas through said feeder means, said gun, and said conduit means connecting said feeder means with said gun.

Claim 10

The structure set forth in claim 5 above, further including: valve means between said source of powdered material and said feeder means for selectively permitting and preventing said operative communication of said source of powdered material with said feeder means.

Claim 11

Apparatus for spray coating powdered materials on a target surface by mixing said materials with a stream of gas and ionizing a portion of said mixture, said apparatus comprising: a plasma gun, chamber means in said gun containing electrode means for striking a continuous ionizing arc through which said mixture flows, perforated manifold means within said chamber means including a tubular manifold at least partially encircling the area of said arc and having a plurality of radially inwardly directed holes in said manifold for conducting said materials to said area, feeder means for feeding powdered material to said manifold, conduit means connecting said feeder means with said manifold, purge means connected to said feeder means for flowing a purging agent through said feeder means, said conduit means, and said manifold in an amount sufficient to purge all gases and particles from therewithin other than said agent, a source of said powdered material operatively communicating with said feeder means, said purge means comprising a source of gas, first conduit means connecting said source of gas with said source of powdered material, bypass valve means selectively operable to bypass said source of powdered material by connecting or disconnecting said source of gas with said feeder means for flowing said gas through said feeder means, said manifold, and said conduit means connecting said feeder means with said manifold second conduit means connecting said source of gas to said gun for ionization of by said arc, and control valve means in said second conduit means for automatically controlling a flow rate of said gas through said second conduit means to maintain a constant predetermined rate of flow.

Claim 12

Apparatus for spray coating powdered materials on a target surface by mixing said materials with a stream of gas and ionizing a portion of said mixture, said apparatus comprising: a plasma gun, chamber means in said gun containing electrode means for striking a continuous ionizing arc through which said mixture flows, perforated manifold means within said chamber means including a tubular manifold at least partially encircling the area of said arc and having a plurality of radially inwardly directed holes in said manifold for conducting said materials to said area, feeder means for feeding powdered material to said manifold, conduit means connecting said feeder means with said manifold, purge means connected to said feeder means for flowing a purging agent through said feeder means, said conduit means, and said manifold in an amount sufficient to purge all gases and particles from therewithin other than said agent, a source of said powdered material operatively communicating with said feeder means, said purge means comprising a source of gas, first conduit means connecting said source of gas with said source of powdered material, bypass valve means selectively operable to bypass said source of powdered material by connecting or disconnecting said source of gas with said feeder means for flowing said gas through said feeder means, said manifold, and said conduit means connecting said feeder means with said manifold second conduit means connecting said source of gas to said gun for ionization of by said arc, and control valve means in said second conduit means for automatically controlling a flow rate of said gas through said second conduit means to maintain a constant predetermined rate of flow.

Claim 13

Apparatus adapted to spray coat powdered materials on a target surface by mixing said materials with a stream of gas and ionizing a portion of said mixture, comprising: a plasma gun having a chamber therein containing electrode means for striking a continuous ionizing arc through which said mixture flows, perforated manifold means including a tubular manifold at least partially encircling the area of said arc and having a plurality of radially inwardly directed holes in said manifold for conducting said mixture to said area, feeder means connected to said manifold means for feeding powdered materials to said gun, said feeder means including means for automatically controlling said feed of powdered materials at a constant feed rate, a source of gas connected to said feeder means and to said gun for flowing said gas through said feeder means and said gun, said chamber having double spaced-apart walls, said electrode means comprising an elongate cathode and an annular anode for striking said ionizing arc upon the application of electrical power thereto, cooling means for cooling said anode and said chamber, said cooling means including a source of cooling fluid at relatively low temperature and a supply line connecting said source and said gun for flowing said fluid from said source to said gun, said cooling means further including coil means between said double walls of said chamber for conducting said fluid from the inlet connection of said supPly line and said gun directly to the area between the walls of said double-walled chamber in closest proximity to said anode, and said cooling means further including a return line for returning said fluid from said gun to said cooling fluid source, and heat exchange means connected between said source of cooling fluid and said gun for lowering the temperature of said cooling fluid.

Claim 14

Apparatus adapted to spray coat powdered materials on a target surface by mixing said materials with a stream of gas and ionizing a portion of said mixture, comprising: a plasma gun having a chamber therein containing electrode means for striking a continuous ionizing arc through which said mixture flows, perforated manifold means including a tubular manifold at least partially encircling the area of said arc and having a plurality of radially inwardly directed holes in said manifold for conducting said mixture to said area, feeder means connected to said manifold means for feeding powdered materials to said gun, said feeder means including means for automatically controlling said feed of powdered materials at a constant feed rate, a source of gas connected to said feeder means and to said gun for flowing said gas through said feeder means and said gun, said chamber having double spaced-apart walls, said electrode means comprising an elongate cathode and an annular anode for striking said ionizing arc upon the application of electrical power thereto, cooling means for cooling said anode and said chamber, said cooling means including a source of cooling fluid at relatively low temperature and a supply line connecting said source and said gun for flowing said fluid from said source to said gun, said cooling means further including coil means between said double walls of said chamber for conducting said fluid from the inlet connection of said supPly line and said gun directly to the area between the walls of said double-walled chamber in closest proximity to said anode, and said cooling means further including a return line for returning said fluid from said gun to said cooling fluid source, and heat exchange means connected between said source of cooling fluid and said gun for lowering the temperature of said cooling fluid.

Claim 15

The structure set forth in claim 8 above, including in addition thereto: control valve means connected between said source of gas and said gun for automatically controlling a flow rate of said gas to maintain a constant predetermined rate of flow of said gas to said gun.