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Tablets & Capsules July 2020 31 expected concentration during the emptying cycle was computed, as shown in Figure 10. All dimensions are measured from the centerline of the hopper. A dimen- sion of 230 millimeters is a position right at the hop- per wall. Note that placing the feed inlet location right at the bin wall (purple line) causes some of the material exiting the bin to be outside the allowable CU of 90 to 110 percent. Placing the feed inlet location close to the You can use the material's flow properties and the feeder bin configuration to compute the expected veloc- ity profile in the bin and then calculate the concentra- tion of key components as material leaves the feeder bin during a complete fill-and-then-empty operation cycle, as shown in Figure 9. To determine the optimal feed inlet location for the vessel shown, several positions were selected, and the Figure 9 Typical velocity pro le and emptying mode in a metering feeder device with a central auger and offset feed inlet Offset High concentration Low concentration Figure 10 Expected content uniformity during emptying mode in metering feeder device (10 percent API concentration) High level Low level 230 mm offset 160 mm offset 50 mm offset Content uniformity (%) 130 120 110 100 90 80 70 60 Percent empty 0 20 40 60 80 100