Ammo-oxidation or oxidation has been carried out industrially for a long time, and a large number of fluidized-bed reactors used therefor have been proposed. The structure of a sparger for supplying and dispersing a raw material therefor, however, has been only disclosed in British Patent No. 1,265,770, JP-A-2-258, JP-A-6-211768, etc. (The term "JP-A" used herein means an unexamined published Japanese patent application.)
The former two, British Patent No. 1,265,770 and JP-A-2-258, are designed so that oxygen gas outlet orifices and propylene/ammonia outlet orifices are made to be opposite to each other, i.e., one oxygen gas outlet orifice directly faces one propylene/ammonia outlet orifice with both orifices aligning on the same axis, but there is no recognition concerning the hole size of the orifices. The latter, JP-A-6-211768, relates to a method of keeping the temperature of ammonia in conduit pipes to be not higher than the dissociation point thereof in order to prevent the nitrization of the supply conduit pipes. Specifically, the latter proposes to provide a protective layer of a heat insulating material in each of the conduit pipes, but there is no recognition concerning the hole size of orifices as similar to the former two.