Lesson 2/Learning Event 1
avoids down-time for recalibration of the plant to produce a second size product and aids in the management of
stockpiles. This concept is most profitable when a plant must produce two sizes of product which cannot be
processed without changing the roll shells of the secondary unit for the second size (Figure 18).
For example, to produce 1-inch minus material with the 75-tph plant, a fine corrugated and smooth roll shell
combination would be used in the secondary unit. But to produce 1/2-inch minus aggregate with the same plant,
two smooth roll shells would be required in the secondary unit. To replace the