Dilute-phase riser transport

Dilute phase riser transport. As the gas velocity is increased still further, the dilute phase riser transport regime is reached. The particle hold-up in this regime is of the order of 0.05 or smaller. 

The spout is like a riser through which particles are being transported in a dilute phase, with the added features of a decreasing gas flow and an increasing solids flow along the height. The spout voids are therefore determined by interaction between the gas and solids flow patterns. 

Bermti et al [13], for example, used the term CFB to generically describe systems like fast fluidized bed, riser reactor, entrained bed, transport bed, pneumatic transport reactor, recirculating solid riser, highly expanded fluid bed, dilute phase transported bed, transport line reactor and suspended catalyst bed in co-current gas flow. 

The fast fluidization regime is represented by a dense region at the bottom of the riser and a dilute region above it. The inter-relationship of the fast fluidization regime with other fluidization regimes in dense-phase fluidization and with the dilute transport regime is... 

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