Apparatus for manufacturing photographic emulsions

A process for manufacturing radiation-sensitive emulsions comprised of:

• (a) delivering a silver salt solution to a reaction zone that is annular in shape through a first annular flow path;
• (b) delivering a halide salt solution to a reaction zone through a second annular flow path, the first annular flow path being concentric to the second annular flow path, the first and second reactants intermixing in the reaction zone, the silver salt solution and the halide salt solution intermixing in the reaction zone, the reaction zone residing in a main reaction vessel containing a reaction mixture including at least a dispersion medium and water;
• (c) flowing the silver salt solution and the halide salt solution exiting the first and second annular flow against a substantially planar surface positioned to define one boundary of the reaction zone;
• and
• (d) rotating the substantially planar surface, the flow of the silver salt solution and the halide salt solution through the reaction zone being generally radial and having a residence time in the reaction zone of not more than about 100 msec, the intermixed silver salt solution and halide salt solutions forming a reaction solution, the reaction solution exiting the reaction zone directly into the reaction mixture while avoiding backflow of the reaction mixture into the reaction zone.