A NEW CONCEPT OF FILTERABILITY

Abstract A dimensionless Filterability Number relates the filterability of a suspension to filter material taking into account clarification, clogging and flow rate. A simple compact apparatus requiring only 1 litre of suspension enables the Filterability Number to be measured. A series of 80 experiments are briefly described where different pretreatments of clay suspensions, various media, and flow rates have been used. Some examples of data are given in detail, presenting the calculation of Filterability Number. The application of the technique to preliminary testing before design, evaluation of flocculants, operational control in waterworks and student teaching is discussed.