Transactions . is that the energy applied per pound of pulp at various points along thecone is inversely proportional to about the sixth power of the means that half way toward the apex of the cone, only 1 64 as muchwork is done as at the cylindrical portion, while three-fourths of theway toward the apex, only 1/4000 is done This means that thlenergy applied along the cone is so small that the force exerted by HARDINGE MILLS VS. CHILEAN MILLS. 61 the falling or rolling pebbles is not sufficient to break the coarser par-ticles, with the result that the work in the cone is largely
Transactions . is that the energy applied per pound of pulp at various points along thecone is inversely proportional to about the sixth power of the means that half way toward the apex of the cone, only 1 64 as muchwork is done as at the cylindrical portion, while three-fourths of theway toward the apex, only 1/4000 is done This means that thlenergy applied along the cone is so small that the force exerted by HARDINGE MILLS VS. CHILEAN MILLS. 61 the falling or rolling pebbles is not sufficient to break the coarser par-ticles, with the result that the work in the cone is largely done on thelines! This is as logical as the generally accepted explanation. But the Hardinge mill is not run at such speeds that the effect ofthe large diameter is obtained; it runs at such a speed (750 ft. perminute peripheral speed for the 8-ft. diameter size, according to ) that centrifugal force at the periphery is about timesthat of gravity and therefore at least one layer of pebbles in the. Fig. 3.—Active and Dead Zones in the Hardinge Mill. periphery is useless except for the purposes of lining. For at least afoot in, the possible fall of the pebbles is so slight as to be valuelessfor crushing. The result is, neglecting part of the apex of the conewhere the energy is too small to be effective, the Hardinge millresolves itself automatically into a short tube mill, the 8-ft. size pro-ducing about the same effect as a 5 by 5 or 6 by 6 ft. tube mill, as inFiff. 3. 1 Tram., xlv., 201 (1913). 62 HARDINGE MILLS VS. CHILEAN MILLS. Perhaps I am like the sailors mother who could credit his storyabout the mermaids, but refused to believe what he told her about theflying fish. The segregation of the pebbles is entirely reasonable, thesurvival of the most energetic, but how can the fines separate them-selves from the coarse in the turmoil taking place within the crushingzone ? The particle has got to go where it is knocked, the agitationis too great for it to follow
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
