APPARATUS FOR PRODUCING METAL OXIDE NANOPOWDER

PROBLEM TO BE SOLVED: To provide an apparatus for producing metal oxide particles, which is substantially free from coarse wastes generated because of an oxidizing agent and a metal reactant in a flow reactor. SOLUTION: The apparatus of the present invention is a concentric cylindrical flow reactor containing a substantially-funnel-shaped contact region for a reactant, the region of which is arranged adjacently to a reaction zone. The contact region for the reactant enables to cause a hot oxidizing agent to flow to the flow of the metal reactant, so as to be able to form a reaction flow. Hence, the flow of the hot oxidizing agent, that is the reaction flow, can enclose the flow of the metal reactant sufficiently for preventing the metal reactant from coming into contact with the wall of the above reactant contact region and from resultant formation of scale on the wall. A cooling fluid conduit capable of directing the flow of a cooling fluid into the reaction zone to flow coaxially with the reaction flow and thus forming a fluid curtain between the reaction flow and a baffle prevents scale formation on the baffle during the metal reactant and the hot oxidizing agent react within the reaction flow to form a metal oxide nanopowder. COPYRIGHT: (C)2006,JPO&NCIPI