Eastman-kodak Company

Douglas E Singer

Donald Robert Irwin

Rajesh Vinodrai Mehta

Benjamin T Chen

Jess B Hendricks, Iii

Michael G Antoniades

Sucheta Tandon

Heinz E Stapelfeldt

Katrin I Parsiegla

Harold G Judd

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.

Scalable impeller apparatus for preparing silver halide grains

The invention generally relates to a process for forming tabular silver chloride grains comprising nucleating silver chloride particles, introducing alkali iodide solution into the dispersing medium containing the nucleated silver chloride particles, and introducing silver ion and chloride ion solutions into said dispersing medium, with the proviso that introduction of the alkali iodide is by multiple streams of said alkali iodide at a momentum range of up to 1.times.10.sup.+9 g cm/s.sup.2.

Process for making high chloride tabular grain emulsion using multiple

The present invention is a method for cleaning and preparing photographic manufacturing equipment surfaces. An aqueous solution of potassium iodide and ferric ethylenediamine tetraacetate is prepared. The solution is flushed over the surfaces of the photographic manufacturing equipment removing deposited silver halide and silver. A high purity water flush is then performed.

Cleaning of emulsion manufacturing apparatus

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Rochester, NY, United States of America

Douglas E Singer