Atomizer wheel with wear-resistant, sintered bushings

Abstract

An atomizer wheel for the atomization of dispersions of very highly wearing materials for example a caoline dispersion, said wheel comprising an annular bowl-shaped space defined by a hub, a cylindrical wall concentrically surrounding the hub, and a bottom part connecting said hub and said wall. The wall is provided with a number of holes lined with bushings of a highly wearproof sintered material embedded in cylindrical bushings of a material able to resist tensile stresses such as steel or plastic, said cylindrical bushings fitting loosely in the holes and abutting at their outer end an inwardly projecting edge of the holes and with their inner ends projecting a distance into the annular space.

What we claim is: 
     
       1. In an atomizer wheel for atomization of slurries of highly abrasive materials having a bowl-shaped wheel with a cylindrical outer wall and a plurality of ejection openings disposed in said outer wall distributed around the circumference thereof, each said opening having its axis in a radial direction, and a lining, said lining having a first bushing constituting the sole defining path for exhausting slurry and made of a sintered wear-resistant material with a conical outer surface, wherein the improvement comprises a second bushing fitted over said first bushing, said second bushing having an outside diameter small enough to define a clearance fit with said opening so that it will remain circular even if the opening is deformed when running, .Iadd.said first and second bushings both extending into the bowl of said wheel;   a sealing ring between said second bushing and its respective opening at a location adjacent the outer wall of said bowl; .Iaddend.   said second bushing being provided with shoulder means .Iadd.on the outer surface thereof in its region radially outwardly of said sealing ring .Iaddend.so as to be rotatable to positions throughout 360° to compensate for wear, said shoulder means engaging an inwardly extending edge of said opening and constituting the sole means preventing outward movement of said bushing from said opening but permitting free inward movement for easy removal or adjustment thereof.[...]..Iadd., said first bushings extend a distance outside said second bushings at the inwardly turned ends of same. .Iaddend.   
     
     
       2. An atomizer wheel as claimed in claim 1, wherein said second bushings are of steel. 
     
     
       3. An atomizer wheel as claimed in claim 1, wherein said second bushings are of a plastic polymer material. 
     
     
       4. An atomizer wheel as claimed in claim 1, wherein said first bushings are conical and in that said second bushings possess a corresponding internal conicity. .[.5. An atomizer wheel as claimed in claim 1, wherein said first bushings extend a distance outside said second bushings at the inwardly turned ends of same..]. .[.6. An atomizer wheel as claimed in claim 1, wherein said first bushings are shaped as bodies of revolution which over at least part of their length are of convex generatrices, and are molded into said second bushings..]. .[.7. An atomizer wheel as claimed in claim 6, wherein said first bushings are molded into said 
     
     
        second bushings with prestressing..]. 8. An atomizer wheel as claimed in claim 1, wherein said second bushings extend a distance into said 
     
     
        .[.annular space.]. .Iadd.bowl.Iaddend.. .Iadd.9.  In an atomizer wheel for atomization of slurries of highly abrasive materials having: a bowl-shaped wheel with a central hub and a cylindrical outer wall coaxially disposed about said hub and a bottom part connecting said outer wall with said hub to define an annular chamber; an annular cover member on said outer wall, said cover member having a central opening defining together with said hub an unobstructed space in communication with said annular chamber; a plurality of ejection openings disposed in said outer wall distributed around the circumference thereof, each said opening having its axis in a radial direction, and a lining, said lining having a first bushing with its inner end projecting into said annular chamber; said first bushing constituting the sole defining path for exhausting slurry and made of a sintered wear resistant material with a conical outer surface, wherein the improvement comprises a second bushing fitted over said first bushing, said second bushing having an outside diameter small enough to define a clearance fit with said opening so that it will remain circular even if the opening is deformed when running, and a sealing ring around the outer circumference of the second bushing at a location adjacent the outer wall of said annular chamber to prevent escape of slurry into the clearance fit space between the second bushing and the opening into which it is inserted;   said second bushing being provided with shoulder means on the outer surface thereof in its region radially outwardly of said sealing ring so as to be rotatable to positions throughout 360° to compensate for wear, said shoulder means engaging an inwardly extending edge of said opening and constituting the sole means preventing outward movement of said bushing from said opening but permitting free inward movement for easy removal or   
     
     
        adjustment thereof. .Iaddend. .Iadd.10.  An atomizer wheel for abrasive slurry comprising a hub, a cylindrical outer wall coaxially disposed about said hub and a bottom wall connecting said outer wall and said hub to define between them an annular chamber; a ring shaped cover on said outer wall having a central opening, said opening defining together with said hub an unobstructed space in communication with said annular chamber; a plurality of cylindrical ejection apertures extending through said outer wall and uniformly distributed around the circumference thereof, each said aperture having its length running in the radial direction of the wheel and an inwardly turned abutment edge along that length but spaced between the ends thereof; a bushing in said aperture having a corresponding outwardly turned abutment edge abutting said inwardly turned edge, the bushing having a smaller diameter than the corresponding diameter of the aperture in which it is fitted so as to define a clearance fit therein and to be freely rotatable therein throughout 360°, with the abutting edges constituting the sole means preventing outward movement of the bushing from the aperture but permitting inward movement for easy removal; a sealing ring between the bushing and the aperture positioned adjacent the outer wall of the annular chamber and radially inwardly of said abutment edge, said sealing ring preventing the escape of slurry to the clearance fit space between the bushing and the aperture; said bushing having an inner opening with a conical shape, a lining of sintered wear resistant material within said inner opening, said lining having a conical outer surface corresponding to the conical inner surface of the bushing, the outside end of the lining being approximately flush with the outer surface of the outer wall and the inside end of the lining of sintered material projecting into said annular chamber by a distance sufficient to cause accummulation on the outer wall of a layer of solid material from the slurry between adjacent linings so as to avoid harmful wear of the outer wall by the abrasive slurry rotating within the chamber. .Iaddend.