Underloaded Thickener

When the feed concentration Cp is less than the critical concentration the thickener is said to be underloaded. This situation is depicted in Figure 3.16. Here the feed flux, FCp/A, is less than the maximum flux due to bulk flow and settling which can be provided by the downflow section. The flux in the upflow section is again zero (Cp = Cy = 0 VCy/A = 0). The graphical mass balance shown in Figure 3.16 enables Cb and Cp to be determined (feed flux = downflow section flux = underflow flux). 

Figure 3.16 Total flux plot for an underloaded thickener...

In an underloaded thickener, the concentration in the bottom section of the thickener is (when the total flux plot does not go through a minimum) ... 

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