Devices for Gas Cooling Plasma Arc Torches and Related Systems and Methods

A method for cooling a nozzle of an air-cooled plasma arc torch, the method comprising:

• supplying a shield gas at a substantially perpendicular angle to an exterior feature of the nozzle in a shield gas flow channel defined at least in part by a shield comprising:
• a body having a proximal end configured to mate with a torch body of the plasma arc torch and a distal end;
• an exit orifice formed in the distal end of the body;
• an interior of the shield comprising an interior shield flow surface that forms a portion of the shield gas flow channel, the shield gas flow channel directing a flow of shield gas along the interior shield flow surface in a flow direction from the proximal end to the exit orifice at the distal end of the body;
• a circumferentially formed flange extending from the interior shield flow surface and away from the distal end of the body, the flange defining a first outer annular surface and an opposing second inner annular surface that is between the first outer annular surface and the exit orifice;
• and
• an annular flow impingement surface, disposed between the interior shield flow surface and the first outer annular surface of the flange, that disrupts the flow direction of shield gas flowing towards the distal end of the body and directs the flow of shield gas proximally along the first outer annular surface of the flange into a continuous annularly formed flow path defined by a circumferentially formed complementary recess of a corresponding nozzle thereby distributing the flow of shield gas substantially uniformly about the complementary recess,
• the opposing second inner annular surface of the flange being configured to receive the substantially uniform flow of shield gas being re-directed and flowing distally from the circumferentially formed recess of the corresponding nozzle and out of the exit orifice;
• redirecting the shield gas from the exterior feature of the nozzle to a mixing chamber adjacent the feature;
• and
• flowing the shield gas from the mixing chamber along the shield gas flow channel to the exit orifice of the shield through the shield gas flow channel defined in part by the annular flow impingement surface, the flange, and the recess of the nozzle.

A method for providing a uniform shield gas flow for an air-cooled plasma arc torch, the method comprising:

• supplying a shield gas to a shield gas flow channel defined by an exterior surface of a nozzle and the interior surface of a shield comprising:
• a body having a proximal end configured to mate with a torch body of the plasma arc torch and a distal end;
• an exit orifice formed in the distal end of the body;
• an interior of the shield comprising an interior shield flow surface that forms a portion of the shield gas flow channel, the shield gas flow channel directing a flow of the shield gas along the interior shield flow surface in a flow direction from the proximal end to the exit orifice at the distal end of the body;
• a circumferentially formed flange extending from the interior shield flow surface and away from the distal end of the body, the flange defining a first outer annular surface and an opposing second inner annular surface that is between the first outer annular surface and the exit orifice;
• and
• an annular flow impingement surface, disposed between the interior shield flow surface and the first outer annular surface of the flange, that disrupts the flow direction of shield gas flowing towards the distal end of the body and directs the flow of shield gas proximally along the first outer annular surface of the flange into a continuous annularly formed flow path defined by a circumferentially formed complementary recess of a corresponding nozzle thereby distributing the flow of shield gas substantially uniformly about the complementary recess,
• the opposing second inner annular surface of the flange being configured to receive the substantially uniform flow of shield gas being re-directed and flowing distally from the circumferentially formed recess of the corresponding nozzle and out of the exit orifice;
• flowing the shield gas along the shield gas flow channel;
• reversing the flow of the shield gas along the shield gas flow channel by directing the shield gas away from the exit orifice using the impingement surface and the flange into the recess of the nozzle, and re-directing the shield gas towards the exit orifice along the second inner annular surface of the flange using the recess thereby distributing the flow of shield gas substantially uniformly about the complementary recess;
• and
• flowing the shield gas from the recess and the second inner annular surface to the exit orifice of the shield, thereby producing a substantially uniform shield gas flow at the exit orifice.

A shield for an air-cooled plasma arc torch, the shield comprising:

• a body having a proximal end configured to mate with a torch body of the plasma arc torch and a distal end;
• an exit orifice formed in the distal end of the body;
• an interior of the shield comprising an interior shield flow surface that forms a portion of a shield gas flow channel, the shield gas flow channel directing a flow of shield gas along the interior shield flow surface in a flow direction from the proximal end to the exit orifice at the distal end of the body;
• a circumferentially formed protuberance extending proximally away from the interior shield flow surface, the protuberance defining a first outer annular surface and an opposing second inner annular surface that is between the first outer annular surface and the exit orifice;
• and
• a transition region between the interior shield flow surface and the protuberance defining an annular flow impingement surface that disrupts the flow direction of the shield gas proximally along the protuberance into a circumferentially formed complementary flow receiving feature of a corresponding nozzle to distribute the flow of shield gas substantially uniformly about the protuberance around the exit orifice.