| 摘要 |
PURPOSE:To reduce the content of the remaining org. solvent to about several tens ppm by heating powdery particles while introducing an inert gas as a carrier in the reduced-pressure evaporation method for removing the solvent from the powdery particles contg. a small amt. of the remaining org. solvent. CONSTITUTION:The powdery particles charged in a vertical long-sized dryer 1 is agitated by an agitator 2, a heating medium is introduced, as required, into a jacket 3 to heat the particles, and then an evacuation source 4 is operated to reduce the pressure in the vertical long-sized dryer. When the temp. and reduced pressure in the dryer reach specified values, an inert gas (N2, CO2, air, etc.) is introduced from a nozzle 5 at the lower part of the dryer through a filter 6. The introduced inert gas is discharged from the evacuation source 4 along with the remaining org. solvent. The org. solvent remaining in the powdery particles in the range 0.1-several percent can be reduced to <=several tens ppm in this way.
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