Porous, lubricated nozzle for abrasive fluid suspension jet

An abrasive fluid jet cutting system comprising:

• a source of pressurized slurry consisting of a carrier fluid and abrasive particles,
• a source of pressurized lubricating fluid,
• a nozzle having an entry port for connecting to said slurry source and receiving said slurry, an inner wall for directing the flow of said slurry, and an outlet port through which said slurry exits said nozzle,
• wherein at least a portion of said nozzle wall being porous,
• a lubricating fluid chamber that surrounds said porous portion of the outer wall of said nozzle, said chamber having a port for connecting to an input pipe that connects to said lubricating fluid source, said input pipe also connecting to a filter for filtering contaminants from said lubricating fluid that might clog the pores of said porous portion of said nozzle, and
• wherein said lubricating fluid passes from said lubricating reservoir and through said porous wall to lubricate at least a portion of the surface of said nozzle wall.

A method for reducing erosion on the inner wall of a nozzle for an abrasive fluid jet cutting system said erosion due to an abrasive slurry flowing from said nozzle's inlet port, along said nozzle's wall and exiting through said nozzle's outlet port, said method comprises the steps of:

• forming said nozzle so that at least a portion of it is porous,
• surrounding said porous portion of the outer wall of said nozzle with a lubricating fluid chamber,
• forcing lubricating fluid to pass from said lubricating chamber and through said porous wall to form a lubricating film between said nozzle inner wall and said flow of abrasive slurry,
• wherein said lubrication fluid having been filtered to eliminate contaminants from said lubricating fluid that might clog the pores of said porous portion of said nozzle.