Improvements in and relating to pulverising and like mills

摘要

357,542. Ball-and-ring mills. GREEN, E. W., Blackwall Yard, Poplar, and UNTHANK, G. R., 10, Churston Gardens, New Southgate, both in London. June 19, 1930, No. 18793. [Class 59.] A pulverizing mill comprises a casing g, a rotary track f within the casing provided with a plurality of balls i maintained therein by a second track k rotating in an opposite direction to the track f1, a third track k1 combined with the track k, a plurality of balls l pressed against the track k1 by an elastically loaded non-rotary track n, means q, q1 for separately feeding material to each row of balls and means for producing annular streams of air for entraining the material delivered from the tracks by centrifugal force, the coarse particles being returned to the tracks for regrinding. A central shaft b is driven by a worm wheel d and is provided with a head m engaging lugs on a floating member j which includes the bottom track k1 for the upper row of balls and the upper track k for the lower row of balls. The bottom track f1 of the lower row of balls i is mounted on a conical member f integral with a sleeve loosely mounted on the shaft b and driven by a worm wheel h. An extension of the head m is provided with a conical crusher p1 which grinds fresh material delivered by the left-hand feeder q and the coarse material separated out in the hopper p, the ground material passing through the passage around the head m on its way to the inside of the lower row of balls. The material ground by the row of balls i is carried up by an air current drawn in through the lips f2, f3 into a passage r3 in the rotatable member j, the coarse material falling back to the balls through a passage f4 and the fines being carried off by the air current, generated by the rotation of the balls, through a passage r2 into the interior of the hopper p, where coarse material is deposited to fall into the crusher p1 and the fines discharged through an outlet s1 provided with a telescopic extension s2. The raw material in the right-hand feeder q falls through a pocket in the passage g2 to the inside of the row of balls l, the upper track of which is pressed down by springs o, and passes out through the balls into an air current drawn in through the lips k2, k3 and thence through g2 into the passage r1 into the separator. The worm wheels d, hare driven by shafts t, t1 which may be geared together through wheels t2, t3. The casing g is perforated for the admission of air to the mill.