Nozzle configurations for abrasive blasting

Abstract

Disclosed herein are nozzle configurations for an abrasive blasting system. The system can comprise multiple hoppers for feeding separate powders streams to a fluid jet. The separate powder streams can be mixed in a frustoconical or conical mixer prior to delivery to the substrate surface. Also disclosed are methods of texturizing the substrate surface by moving the substrate or nozzle(s) during the delivery of dopant(s). Methods for achieving a uniform distribution of dopant are also described. Also disclosed herein are coaxial nozzle configurations having an outer focusing stream to converge and/or mix with an inner particle stream.

1 . An apparatus for abrasively blasting a substrate, comprising:
 at least two hoppers for receiving at least two sets of particles including a first set of particles comprising an abrasive and a second set of particles comprising a dopant;   a mixer for receiving and mixing the at least two sets of particles from the at least two hoppers to form a particulate mixture; and   at least one fluid jet for delivering the at least two sets of particles to the mixer, or the particulate mixture to the substrate, the at least one fluid jet being positioned downstream of the at least two hoppers.   
     
     
         2 . The apparatus of  claim 1 , wherein the at least one fluid jet is positioned at the base of the at least two hoppers. 
     
     
         3 . The apparatus of  claim 1 , wherein the at least one fluid jet is positioned at the base of the mixer. 
     
     
         4 . The apparatus of  claim 1 , further comprising delivery tubes connecting each of the at least two hoppers to the mixer. 
     
     
         5 . The apparatus of  claim 1 , wherein each delivery tube is linear and has an incident angle with respect to the vertical. 
     
     
         6 . The apparatus of  claim 5 , wherein the delivery tube for the first set of particles has an incident angle normal to the vertical and the delivery tube for the second set of particles comprising the dopant is delivered at an incident angle parallel to the vertical. 
     
     
         7 . The apparatus of  claim 1 , further comprising a second fluid jet for delivering the second set of particles to the mixer. 
     
     
         8 . An apparatus for abrasively blasting a substrate, comprising:
 a first particle stream comprising an abrasive and a second particle stream comprising a dopant;   a conical or frustoconical mixer comprising at least two channels penetrating through the mixer, wherein the respective particle streams enter the channels separately and exit the mixer to impact the substrate as a particulate mixture of the first and second particle streams; and   at least one fluid jet to deliver at least one of the first and second particle streams to the mixer, or to deliver the particulate mixture to the substrate.   
     
     
         9 . The apparatus of  claim 8 , wherein the two or more channels are linear. 
     
     
         10 . The apparatus of  claim 9 , wherein the block has a longitudinal axis and each of the two or more channels has an incident angle relative to the longitudinal axis ranging from 0° to an angle formed by the outer conical surface of the block, the incident angle of each of the channels being the same or different. 
     
     
         11 . The apparatus of  claim 8 , wherein the at least one fluid jet is positioned upstream of the mixer to deliver at least one of the first and second particle streams to the mixer. 
     
     
         12 . The apparatus of  claim 8 , wherein the at least one fluid jet is positioned between the mixer and the substrate to deliver the particulate mixture to the substrate. 
     
     
         13 . The apparatus of  claim 8 , wherein the two ore more channels merge into a single channel within the block. 
     
     
         14 . An apparatus for abrasively blasting a substrate, comprising:
 a coaxial nozzle for delivering a first set of particles comprising at least one dopant and a second set of particles comprising an abrasive,   wherein an inner tubing of the nozzle delivers a particle stream comprising a first set of particles, and an outer tubing delivers a pressurized gas comprising the second set of particles that encircles and converges inwardly toward the first set of particles to mix and homogenize the first and second set of particles, and   wherein a resulting mixture of the first and second particles bombard and impregnate and/or coat the substrate with the at least one dopant.   
     
     
         15 . The apparatus of  claim 14 , wherein the nozzle is a fluid jet. 
     
     
         16 . A method of modifying a substrate, comprising:
 delivering substantially simultaneously a first set of particles comprising a dopant and a second set of particles comprising an abrasive from at least one fluid jet to a surface of the substrate to impregnate the substrate with the dopant, each nozzle having an incident angle to the vertical ranging from 0° to 85°; and   moving the substrate in a direction parallel to the substrate surface during the delivering to deposit a track of the dopant on the substrate surface.   
     
     
         17 . A method of modifying a substrate, comprising:
 delivering substantially simultaneously a first set of particles comprising a dopant and a second set of particles comprising an abrasive from at least one fluid jet to the substrate to impregnate the substrate with the dopant,   wherein the first and second set of particles overlap at an area between the at least one fluid jet and the substrate, and   wherein a cross section of the overlap area has a substantially homogeneous distribution of the first set of particles.   
     
     
         18 - 57 . (canceled)