Plasma spray apparatus integrating water cleaning

Abstract

An integrated apparatus and method comprises a plasma gun with a water supply, treatment fluid supply, and controls, the combination of which is adapted for directing a plume onto a surface of a three-dimensional part to treat the surface; and for controlling injection of water into the plume with the plume directed onto an adjacent surface to clean debris and undesired material from the adjacent surface; and for subsequently directing the plume (without water) onto the adjacent surface to treat the adjacent surface. The apparatus and method are particularly useful in suspension plasma spray systems, but are not believed to be limited to that.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . An integrated method of suspension plasma surface (SPS) coating process comprising:
 providing a suspension plasma spray system including a plasma torch generating a heated plasma plume of at least 10,000 Centigrade and having a nozzle that defines a plasma flow direction;   injecting water into the plasma plume through a solid stream orifice located external to the plasma torch and orientated radial to the plasma flow direction, the solid stream orifice being connected to a steel tube mounted onto a face of the nozzle and that connects to tubing that runs from the steel tube to a pneumatically-actuated, normally-closed water-control solenoid, the solenoid being in turn connected to a water supply;   closing the water-control solenoid to stop flow of water from the water supply to the injection orifice; and   opening a separate tubing-solenoid combination to deliver suspension material from a suspension treatment fluid supply for the SPS coating process to the injection orifice mounted on the plasma gun.