GB789274A - Centripetal classifier - Google Patents

Abstract

789,274. Centrifugal separators; grinding mills. MICROCYCLOMAT CO. April 9, 1956, No. 10718/56. Classes 23 and 59 In a classifier having a rotor comprising a series of spaced annular plates 9 intersided by generally radiating blades 10, the finer particles are entrained in an air current which flows inwardly through the rotor periphery and which is discharged axially from the rotor. The classifier and a rotary mill occupy the upper and lower parts of a cylindrical housing 1 (Fig. 1) on which is mounted a fan housing 3. A shaft 2 carries a fan 4 for drawing the air current through the rotor, the classifier rotor, and the mill rotor 5. The mill rotor comprises vertical blades held in slotted discs between further discs, and a fan 6. The particles are fed to the mill through an inlet 7, and an air flow through the bottom of the housing is induced by the fan 6. The finer particles from the mill pass to the classifier through a gap between the housing and a rotary plate 8 supporting the classifier rotor. Finer particles pass through the classifier rotor to be discharged by the fan 4 whilst coarser particles rejected by the rotor are returned to the mill. In the modification shown in Fig. 6, the classifier rotor and a fan (not shown) are mounted on a horizontal shaft 21 in a housing 19 mounted above a housing 13 containing a milling or separating rotor comprising a series of discs connected by rods 18 and mounted on a shaft 17. An air and particle mixture is fed through an inlet 14 to the periphery of the milling or separating rotor which throws out dense impurities to collect in a grit trap 15. Finer particles pass from the milling or separating rotor to the classifying rotor to be discharged by the fan. Coarser particles rejected by the classifying rotor are directed by an adjustable plate 24 to return to the mill. Air may be admitted to the classifier through a damper 23.