Patents by Inventor Donald R. Irwin

Donald R. Irwin has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Scalable impeller apparatus for preparing silver halide grains
    Patent number: 6422736
    Abstract: A mixer for preparing silver halide grains for photographic use has upper and lower impellers housed in a draft tube. The bottom impeller has flat blades for micromixing silver and halide reactants introduced into the bottom of the draft tube. The upper impeller has pitched blades for macromixing the bulk fluid. The impellers are spaced apart at least the distance of their diameters so that the upper and lower impellers operate independently of one another so that micromixing is independent of macromixing. A flow disrupter structurally associated with the draft tube and positioned above the top impeller prevents vortexing of the fluid during mixing. Baffles may be provided in the draft tube to discourage vortexing.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: July 23, 2002
    Assignee: Eastman Kodak Company
    Inventors: Michael G. Antoniades, Harold G. Judd, Katrin I. Parsiegla, Benjamin T. Chen, Douglas E. Singer, Donald R. Irwin, Sucheta Tandon, Jess B. Hendricks, III, Heinz E. Stapelfeldt