PURPOSE: To provide a spray dryer so designed that an exhaust duct arranged in series at the bottom of a pressure spray dryer is connected to cyclones and a fine powder returning line from the cyclones is connected to an in-house type fluidized bed to quickly stabilize the fluidized bed in its startup.
CONSTITUTION: An exhaust duct 4 at a pressure spray drying column 1 equipped with an in-house type fluidized bed 3 at the bottom is connected to cyclones 5, 5a, 5b, 5c. Fine powder recovered by the cyclones is brought, through a fine powder returning line via a changeover valve, to the top of the column 1 and the inlet and then outlet 25 of an outer fluidized bed 33. Pipes 31, 32 are connected to the fine powder returning line to blow returned powder into the fluidized bed 3, thus securing the height of the fluidized bed at its initial level in its startup.
UCHIYAMA MASASHI
KUDO TAKEO
MACHIDA RYOJI
KOJIMA EIICHI
TAKENOBU YOSHIYUKI
