摘要 |
A plasma arc cutting torch cools its nozzle with a water flow between an inner metallic nozzle member and an outer ceramic nozzle member. A set of auxiliary ports formed in the ceramic element each extend from an associated radial channel that directs a portion of the water to the plasma arc where it forms an annular "jet" that constricts the arc. The auxiliary ports are located and sized to provide an enhanced flow of water through the nozzle while maintaining an optimal flow rate through the radial channel. When a gas flow through the cooling passages is used to sense the height of the torch over a workpiece, the gas flow through the auxiliary ports clears residual water from the nozzle to avoid a false height sensing due to an emission of droplets of the water.
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