Arrangement and process for treating a surface

Abstract

An apparatus and method for treating a surface with a jet utilizing a multiplicity of particles, using a mixing chamber for mixing a stream of propellant gas with the multiplicity of particles, a particle generator, which is designed to generate the multiplicity of particles and introduce them into the mixing chamber in a solid state, the particle generator having at least one screen plate, and it being possible for the multiplicity of particles to be formed in a solid state by pressing a solid starting material through the screen plate, a propellant gas line with a propellant gas nozzle for introducing the propellant gas into the mixing chamber, and an outlet from the mixing chamber for the stream of propellant gas.

1 .- 10 . (canceled) 
     
     
         11 . An apparatus for treating a surface with a jet comprising a multiplicity of particles, the apparatus comprising:
 a mixing chamber for mixing a stream of propellant gas with the multiplicity of particles,   a particle generator, configured to generate the multiplicity of particles and introduce them into the mixing chamber in a solid state, the particle generator comprising at least one screen plate, wherein the multiplicity of particles are formed in a solid state by pressing a solid starting material through the at least one screen plate,   a propellant gas line with a propellant gas nozzle configured to introduce the propellant gas into the mixing chamber, and   an outlet from the mixing chamber for the stream of propellant gas.   
     
     
         12 . The apparatus of  claim 11 , wherein the propellant gas nozzle is configured as a Laval nozzle. 
     
     
         13 . The apparatus of  claim 11 , wherein the at least the mixing chamber and the propellant gas nozzle are configured to be rotationally symmetric about an axis of the apparatus. 
     
     
         14 . The apparatus of  claim 11 , wherein the particle generator further comprises a conveying screw), configured to press the solid starting material through the at least one screen plate. 
     
     
         15 . The apparatus of  claim 11 , wherein the mixing chamber is configured at least as part of an outer Laval nozzle. 
     
     
         16 . The apparatus of  claim 11 , wherein the particles is formable at least partially with solid carbon dioxide. 
     
     
         17 . A process for treating a surface with a jet comprising a multiplicity of particles, utilizing an apparatus according to  claim 11 . 
     
     
         18 . The process according to  claim 17 , wherein the multiplicity of particles are generated by a solid starting material being pressed through the at least one screen plate. 
     
     
         19 . The process according to  claim 18 , wherein the solid starting material comprises carbon dioxide. 
     
     
         20 . The process according  claim 17 , wherein the treating of the surface comprises at least one of the following steps:
 cleaning the surface, and   removing flash or burr from the surface.