Nozzle and torch for plasma jet

Claim 2

A plasma jet nozzle for directing a flame in the form of a thin film comprising an elongated narrow passage having a pair of smooth generally longitudinally straight opposed side walls equidistantly spaced from each other over their entire surfaces and a pair of smooth generally longitudinally straight opposed end walls, said side and end walls defining a slotted transverse inlet opening at one end of the passage and a slotted transverse outlet opening at the other end of the passage, one end of the nozzle being provided with a transversely disposed concave inlet surface generally complementary to the end surface of an electrode rod to be positioned in axially spaced relationship to said inlet surface, said pairs of side and end walls all intersecting said concave inlet surface at one end of the passage and terminating at said intersection to provide an unobstructed space completely surrounding the tip of an electrode rod and lying between said tip and the concave surface for gases entering the inlet opening of said passage, the outer diameter of said concave surface being at least equal to the transverse length of the passage at the intersection of the passage and concave surface, whereby gases move through the passage from inlet opening to outlet opening in longitudinally straight directions.

Claim 3

A plasma jet nozzle as defined in claim 1, wherein the end walls of the passage diverge in the direction toward the outlet opening of the passage.

Claim 4

A plasma jet nozzle as defined in claim 1, wherein the side walls of the passage are arcuate in transverse cross-section to define a narrow curved outlet opening.

Claim 5

A plasma jet nozzle as defined in claim 1, wherein the exterior of said nozzle includes at least one heat-conducting cooling fin.

Claim 6

A plasma jet nozzle as defined in claim 1, wherein the ratio of the length of the wall surrounding said passage to the cross-sectional area of the pasasage is greater than 1.00.

Claim 7

A plasma jet nozzle as defined in claim 1, wherein the ratio of the length of the wall surrounding said passage to the cross-sectional area of the passage is greater than 1.20.

Claim 8

A plasma jet nozzle as defined in claim 1, wherein the transverse width of said passage is less than 2.5 mm.

Claim 9

A plasma jet torch comprising an elongated housing having a nozzle at one end and inlet means at the other end for gases and cooling fluid, the interior of the housing being provided with a first cylindrical conduit in communication with the nozzle at one end and with the inlet means at the other end for conducting gases to said nozzle, a second cylindrical conduit surrounding said first conduit in concentric relationship thereto and in communication with said inlet means, said second conduit forming with said first conduit a passage for circulating cooling fluid in heat-exchanging relationship with said first conduit, said nozzle being provided with an interior longitudinally extending passage having a narrow slotted inlet opening at one end and a narrow slotteD outlet opening at the other end generally similar to and in axial alignment with said inlet opening, an elongated electrode rod concentrically positioned in said first conduit having an exposed tip spaced from and in axial alignment with the slotted inlet opening of the nozzle, the interior walls of said first conduit and said passage in the nozzle being smooth and defined by longitudinally extending straight lines whereby gases moving from said inlet means of the torch to the outlet opening of the nozzle do not acquire any spiral motion.

Claim 10

A plasma jet torch comprising an elongated housing having a nozzle at one end and inlet means at the other end for gases and cooling fluid, the interior of the housing being provided with a first cylindrical conduit in communication with the nozzle at one end and with the inlet means at the other end for conducting gases to said nozzle, a second cylindrical conduit surrounding said first conduit in concentric relationship thereto and in communication with said inlet means, said second conduit forming with said first conduit a passage for circulating cooling fluid in heat-exchanging relationship with said first conduit, said nozzle being provided with an interior longitudinally extending passage having a narrow slotted inlet opening at one end and a narrow slotteD outlet opening at the other end generally similar to and in axial alignment with said inlet opening, an elongated electrode rod concentrically positioned in said first conduit having an exposed tip spaced from and in axial alignment with the slotted inlet opening of the nozzle, the interior walls of said first conduit and said passage in the nozzle being smooth and defined by longitudinally extending straight lines whereby gases moving from said inlet means of the torch to the outlet opening of the nozzle do not acquire any spiral motion.

Claim 11

A plasma jet torch as defined in claim 8, wherein the outlet opening of the nozzle has a deflected configuration.

Claim 12

A plasma jet torch as defined in claim 8, wherein said nozzle is provided with at least two slotted outlet openings in communication with the internal passage.

Claim 13

A plasma jet torch as defined in claim 8, wherein at least a portion of the outlet opening of the nozzle has an L-shaped configuration in transverse cross-section.

Claim 14

A plasma jet torch as defined in claim 8, wherein the outlet opening of the nozzle has an arcuate configuration in transverse cross-section.

Claim 15

A plasma jet torch as defined in claim 8, wherein the outlet opening of the nozzle has an X-shaped configuration in transverse cross-section.

Claim 16

A plasma jet torch as defined in claim 8, wherein said nozzle is also provided with at least one discharge orifice for a fluid under pressure adjacent said outlet opening.