Uniformity of fluidization on a multi-orifice gas distributor

As the gas flow rate is increased through a bed of particles lying on a multi-orifice gas distributor, several gas pressure maxima arise in the plenum chamber which correspond to the occurrence of fluidization in different sections of the bed. The gas pressure at the distributor orifices may considerably exceed the quantiy ρ_sg(1 ? ?₀)H. A formula has been derived for the complete-fluidization index at which all caps come into play.