A particle-carrying feedstock is mixed by a rotor-stator mixing mechanism placed within a mixing chamber where mixing is conducted under a negative pressure for separating and removing entrained air from the mixed feedstock, preferably before passing the de-aerated mixed feedstock to a media mill for processing into a particle dispersion. The rotor of the rotor-stator mixing mechanism preferably includes a disk carrying vanes on opposite faces of the disk for a conducting simultaneous dual mixing operations. Openings in the stator are provided with an H-shaped cross-sectional configuration and are intermingled for facilitating the mixing operation while maintaining the integrity of the rotor-stator mixing mechanism.
An improvement in an apparatus and a method produces a particle dispersion by processing a particle-carrying feedstock passed from a supply vessel through a bed of media contained within a containment wall having an inlet end and a longitudinally opposite terminal end. An auxiliary chamber surrounds the containment wall so that the feedstock is passed from the bed of media, through the containment wall and into the auxiliary chamber while the media is contained within the bed of media. An external pumping mechanism established a pressure differential that draws the feedstock into the containment wall and through the bed of media, then through the containment wall into the auxiliary chamber, and then out of the auxiliary chamber at a location juxtaposed with the containment wall between the inlet end and the terminal end, while maintaining a negative pressure within the supply vessel and within the auxiliary chamber during processing of the feedstock.
A media basket mill utilizes a media bed having very small media to attain a mixture of finely divided solids in a liquid vehicle. A method and an improvement for deterring wear at a bearing construct in the media basket mill precludes the entry into a bearing interface between a bearing surface of the bearing construct and a component rotating within the bearing construct of the very small media employed in the media basket mill. A barrier is interposed between the media held in the basket of the mill and the bearing interface so as to isolate the bearing interface from media within the basket and thereby deter the entry of media into the bearing interface and concomitant wear at the bearing interface.
Apparatus and method are disclosed for producing nanometer-range particle dispersions utilizing an immersion mill having a rotor for processing feedstock within a bed of media contained within a containment wall. An auxiliary chamber provides a chamber wall surrounding the containment wall and feedstock is passed from the bed of media, through the containment wall and into the auxiliary chamber while the media is contained within the bed of media. The feedstock is drawn from the bed of media, through the containment wall, and out of the auxiliary chamber, with an external pumping mechanism arranged for operation independent ofrotation of the rotor, whereby the containment wall is maintained unbroken by any direct connection between the rotor and the external pumping mechanism and remains effective in containing the media within the bed of media.
A mixing apparatus and method mixes constituents of a feedstock in a vessel, utilizing a mixing blade assembly rotated within the vessel in forward and reverse directions. The feedstock engages walls of the vessel, and scraper blades are carried by the mixing blade assembly to scrape feedstock from the walls of the vessel and direct scraped feedstock to feedstock being circulated within the vessel during rotation of the mixing blade assembly in either the forward direction or the reverse direction. The scraper blades each include scraper edges and are coupled to the mixing blade assembly for pivotal movement in response to engagement with feedstock during mixing, so as to juxtapose one or the other of opposite scraper edges of each scraper blade with the vessel wall for scraping feedstock during rotation of the mixing blade assembly in both the forward and reverse directions.
An apparatus and method for mixing feedstock within a vessel wherein the feedstock is moved along a heat transfer surface within the vessel. A mixing blade assembly includes a mixing blade and at least one mixing blade support member moved within the vessel to sweep forward along a path of travel extending adjacent the heat transfer surface. Feedstock is circulated within the vessel by the mixing blade, and the mixing blade support member includes a mixing surface confronting the heat transfer surface. The mixing surface is spaced from the heat transfer surface and is configured such that feedstock material is squeezed between the mixing surface and the heat transfer surface so as to be subjected to mixing shear and heat transfer between the squeezed feedstock material and the heat transfer surface. A scraper blade is located on the mixing blade support member in position to trail behind a trailing face of the mixing blade support member and is engaged with the heat transfer surface during movement of the mixing blade support member along the path of travel so as to scrape feedstock material from the heat transfer surface and direct the squeezed feedstock material to the mixing blade to be mixed with the feedstock circulated within the vessel by the mixing blade.
The containment wall of a basket media mill is constructed of a sintered porous metal having porous openings each of a pore size less than the predetermined size of the media for confining the media within the bed in the basket as feedstock is passed through the porous openings in the containment wall. The containment wall extends over an overall area and the porous openings provide an open area through which the feedstock flows as the feedstock passes through the containment wall, and the open area is at least about twenty-one percent of the overall area of the containment wall for enabling a concomitant increased volumetric flow of feedstock through the containment wall. A substantially flat sheet of sintered porous metal having porous openings is formed into a cylindrical configuration to construct a cylindrical containment wall with porous openings each increasing in pore size from the interior of the cylindrical wall toward the exterior of the cylindrical wall.
The containment wall of a basket media mill is constructed of a porous synthetic polymeric material having porous openings each of a pore size less than the predetermined size of the media for confining the media within the bed in the basket as feedstock is passed through the porous openings in the containment wall. The containment wall extends over an overall area and the porous openings provide an open area through which the feedstock flows as the feedstock passes through the containment wall, and the open area is at least about fifteen percent of the overall area of the containment wall for enabling a concomitant increased volumetric flow of feedstock through the containment wall. A substantially flat sheet of porous synthetic polymeric material having porous openings is formed into a cylindrical configuration to establish a cylindrical containment wall with porous openings each increasing in pore size from the interior of the cylindrical wall toward the exterior of the cylindrical wall.
The containment wall of a basket media mill is constructed of a porous synthetic polymeric material having porous openings each of a pore size less than the predetermined size of the media for confining the media within the bed in the basket as feedstock is passed through the porous openings in the containment wall. The containment wall extends over an overall area and the porous openings provide an open area through which the feedstock flows as the feedstock passes through the containment wall, and the open area is at least about fifteen percent of the overall area of the containment wall for enabling a concomitant increased volumetric flow of feedstock through the containment wall. A substantially flat sheet of porous synthetic polymeric material having porous openings is formed into a cylindrical configuration to establish a cylindrical containment wall with porous openings each increasing in pore size from the interior of the cylindrical wall toward the exterior of the cylindrical wall.
A media basket mill utilizes a media bed having very small media to attain a mixture of finely divided solids in a liquid vehicle. A bearing construct which journals the rotor of the basket mill within the basket of the mill includes a bearing which is protected against excessive wear by including a recess in the rotor. The recess is juxtaposed with the bearing and communicates with the media bed such that upon rotation of the rotor to pass feedstock through the media bed for a mixing operation, media and feedstock in the vicinity of the bearing will be directed from the recess into the bed of media and feedstock outside the rotor, thereby diverting media and feedstock away from the bearing and deterring excessive wear which might otherwise result from media and feedstock interacting with the bearing during rotation of the rotor for the mixing operation.
B02C 17/02 - Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls with perforated container
patents
