. The miller, millwright and millfurnisher. ground, the finer the corrugations must bemade for a given roll diameter. It might be said that the depth of the cor-rugations must be half (or less) the diameter of the particles to be very short use the sharpness of the corrugations becomes lost, and mod-ern practice points to the employment of grooves intentionally rounded insection. Of course the great desideratum in a roller mill is to effect granulationwithout cutting the bran. It is claimed for the rounded ribs as against the saw FORMS OF CORRUGATIONS. 393 tooth that they roll the
. The miller, millwright and millfurnisher. ground, the finer the corrugations must bemade for a given roll diameter. It might be said that the depth of the cor-rugations must be half (or less) the diameter of the particles to be very short use the sharpness of the corrugations becomes lost, and mod-ern practice points to the employment of grooves intentionally rounded insection. Of course the great desideratum in a roller mill is to effect granulationwithout cutting the bran. It is claimed for the rounded ribs as against the saw FORMS OF CORRUGATIONS. 393 tooth that they roll the bran back and spill out the contents of the berry, andthat even the cockle instead of being cut or crushed is held, the whole passingoff in the final operation with the bran.* It is further claimed that the germis neither cut nor broken, but that it is crushed, passing off in one operationfrom the scalper to be finally separated from the middlings. Just so far asthese claims are borne out by actual commercial results, there is increase of. Fig. 285.—Equally Speeded Saw-Tooth Rolls. yield and small proportion of low grade flour. It is claimed for a sharptooth roll that it makes more middlings than the rounded rib ; but, on theother hand, for the rounded flutes that they make cleaner middlings than thesharp cuts. There is this comparison between the sharp and the roundtooth rolls and the millstone, that the one may be said to represent the oldmillstone dress in which there was a large proportion of cracked surface, andthe other corresponds to the more modern idea of perfectly smooth surfaceof both the land and the furrows. One of the greatest drawbacks in the introduction of roll pairs is that * This latter claim, for any corrugated rolls, strikes the author as rather too strong. 394 DETAILS OF ROLLERS AND FRAMES. while they render the hard spring wheat valuable for making better flour thanthat made from millstones from even the best spring wheat, they have notbeen able to get
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectflourmi, bookyear1882
