SPRAY DRYER AND SPRAY DRYING METHOD USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a spray dryer that prevents back flow of drying gas caused inside the dryer and formation of coarse particles by the back flow of the drying gas to obtain fine dried particles stably in spray-drying a solution or dispersion of solid material, particularly a vinyl chloride-based polymer latex. SOLUTION: The spray dryer is constructed as a parallel-flow type that has a cylindrical part, conical parts on the top and bottom of the cylindrical part under the conditions that the opening angle (α) of the upper conical part and the ratio (DIN/D) of the inlet diameter (DIN) of the upper conical part to the diameter of the cylindrical part of the dryer (D) satisfy the relationships: 10 deg.<=α<=60 deg.; 0.3<= DIN/D<=0.7.