Prediction of resistance in constant‐pressure cake filtration

Methods of predicting resistance in constant‐pressure cake filtration have been classified into three groups, (1) basic particle and cake properties, (2) permeability tests, and (3) small‐scale filtration tests. Methods 2 and 3 involve the concept of specific filtration resistance, a property characteristic of each unit mass of deposited cake, and these methods were extensively investigated in the laboratory. Specific resistances for three chemical slurries were determined by laboratory filtrations and filter‐ and compression‐permeability tests. Results of these investigations showed that specific filtration resistance could be predicted from compression‐permeability test data. Filtration tests made on commercial‐scale equipment operating on pearl cornstarch illustrated the correlation between predicted and actual specific resistance values, the resistance predicted from compression‐permeability test data agreeing very well with the actual resistance of the prefilt.