Screens material balances over

The equations derived from consideration of material balances over a screen are found to be useful in calculating the ratios of feed, oversize, and underflow from the screen analysis of the three streams and knowledge of the desired cut diameter. Let F stand for the mass of the feed flow, D for the mass of the overflow flow, B for the mass of the underflow flow, mF for the mass fraction of material, A in feed, mD for the mass fraction of material A in the overflow and mB for the mass fraction of material A in the underflow. The mass fractions of material A are shown in Figure 2.13 (C). The mass fractions of material B in the feed, the overflow, and the underflow are 1 - mF, 1 - mD, and 1 - mn respectively. Since the total material fed to the screen must exit either as underflow or as overflow,... 

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