Patent ID: 7032849

Claim:
A method of pulverizing and classifying a powder in an apparatus having a vessel with a pulverizing nozzle in a pulverizing section, a classifying section with a classifying rotor disposed over the pulverizing section, a fluidized bed, and an air supplier configured to supply a secondary air, the method comprising: spraying compressed air from the pulverizing nozzle to pulverize the powder in the vessel while supplying secondary air from the secondary air supply there into; and classifying the pulverized powder with the classifying rotor in the vessel, wherein a flow rate Q 2 of the secondary air and a flow rate Q 1 of the compressed air of the pulverizing nozzle satisfy the following relationship: Q 1 20 ≤ Q 2 ≤ 3 ⁢ Q 1 20 .