Roll Crusher Capacity Formula

The theoretical capacity of crushing rolls is arrived at simply by calculating the volume' of the ribbon whose cross section is the area of the discharge opening, and whose length is the peripheral speed of the roll faces per unit of time. The formula, for material weighing 100 lb per cu ft, is:

D x W x S /48 = tons per hr.

Where: D= space between roll faces, in inches;

W = width of 1'011 faces, in inches;
S= peripheral speed of rolls, in ft per minute.

This "full-ribbon" formula gives results which cannot be achieved in practice, except for special conditions of choke-feed on small material, where the rolls are forced apart by pressure of the material, thereby thickening the ribbon. For the more usual condition of regulated feed the results must be divided by a service factor to arrive at a conservative estimate of capacity. For heavy-duty rolls, a factor of 3 may be used; for light and medium-duty rolls, it is safer to divide by 4. These compensating factors may be inserted in the formula by using divisors of 144 and 192, respectively, instead of the regular divisor of 48.