Devices for gas cooling plasma arc torches and related systems and methods

A nozzle-shield cooling system comprising:

• a nozzle having a body with a first end and a second end that define a longitudinal axis;
• a plenum region substantially formed within the body, the plenum region extending from the first end of the body and configured to receive a plasma gas flow;
• an exit orifice located at the second end of the body and oriented substantially coaxially with the longitudinal axis, the exit orifice fluidly connected to the plenum region;
• and a feature on an outer surface of the body configured to increase cooling by receiving a cooling gas flow flowing at high velocity generally in a direction of the longitudinal axis along a length of the body, an impingement surface of the feature configured to receive the cooling gas flow at a substantially perpendicular direction relative to the impingement surface and to redirect the cooling gas flow to promote cooling and uniform shield flow;
• and
• a shield for the plasma arc torch comprising a generally conical body and an end face having a shield exit orifice, an interior surface of the shield comprising a mixing chamber at a location corresponding to the impingement feature of the nozzle when assembled together, the mixing chamber comprising an inlet edge positioned to direct the cooling gas from the impingement feature into the mixing chamber.