Cake Growth Rate

Cake growth rate is the rate at which solids accumulate on the filter medium, expressed as mass or thickness per unit area and time (e.g., kg/m²·h or mm/min). It determines the duration of a filtration cycle and influences washing and deliquoring performance. The rate depends on solids concentration, particle-size distribution, floc structure, viscosity, temperature, and hydraulic regime (constant-pressure versus constant-rate). Coarse, narrow PSDs and rigid flocs form open, permeable cakes that grow uniformly, whereas fine or sticky feeds tend to blind pores and increase differential pressure. Engineers optimise cake growth by conditioning the feed (coagulation or flocculation), controlling temperature and viscosity, and selecting media and drainage layers that maintain under-cake channels. In continuous belts, feed distribution and belt speed set the foundation for even cake build-up; in pressure filters, precoat quality and fill strategy matter. Measurement methods include mass balance and in-line thickness sensors or interpreting ∆p versus throughput at constant flux. Recording cake growth rate under defined setpoints provides a reliable fingerprint for quality assurance and process control.