BOWL- CHOPPER: ONLY ONE KNIFE OR MAXIMALLY TWO KNIVES CUT BATTER DURING CHOPPING

摘要

The observation, that when working with a 65 L- bowl chopper, operated at 14 revolutions per minute [rpm] of the bowl and at 3000 rpm of the shaft, only the first two of 6 knives sheared batter, was not erroneous. It could be shown mathematically, that with this chopper at 3000 and 6000 rpm of the shaft neither the second nor the third knives- level - with two knives each - could contribute to a shearing of the batter. Because of the distance between the knives or because of their thickness, only one knife cold shear batter between the inner filling height of the bowl and its middle height, if the rpm of the bowl was 3739 or higher. If the rpm of the shaft were higher and up to 6000, the shearing of the batter began more and more towards the outer filling height of the bowl. By that less and less batter war sheared. In so far, publications about the interaction between the chopper knives and the batter are in question. After calculations with different linear speeds of the bowl and different rpm of the shaft it became apparent, that the distance between the first and the second knife, which allows a shearing of the batter by the second knife, is equal for all sizes of choppers. If the sides of the knives, which showed to the batter, were 3 mm or further apart, only the first knife sheared batter on the inner filling side of the bowl. This holds for sizes of choppers between 30 and 1000 L. Distances between the first two knives of more than 8 mm made in no case sense, if the second knife should shear batter between the inner filling height and the middle height of the bowl. That holds for all sizes of bowl choppers, if the rpm of the shaft is 3000 or more and for speeds of the bowl of 0.8 m/sec or less.