The estimation of filtering rate from the clearance of suspensions

The indirect method of determining the filtering rate requires that a suspension feeder be allowed to feed for a given time in a volume of suspension. Six equations have been published by which the filtering rate can be calculated from the observed depletion of the suspension. By applying a standard notation throughout, it is shown that these 6 equations are identical. A graphical method is described by which the filtering rate can be obtained directly from the ratio between the initial and final concentration of suspension, obviating the need for individual calculations.