Criterion

Homogeneous

Bubbling

Reference

For estimation of fluidization state

F r m f = u m f 2 g d p

Frmf < 0.13

Frmf > 1.3

Wilhelm and Kwauk [2]

R = F r m f R e m f ( ρ p ρ f ρ f ) ( L m f D c )

R < 100

R > 100

Romero and Johanson [3]

N t r = R e F r 0.5 ( ρ p ρ f ρ f )

Ntr < C1

depending on ε and εmf

Ntr > C1

Verloop and Heertjes [4]

N f = A r m ( ρ a ρ f ) 0.5

ρa: average density of particulate phase

Nf < C2

m and C2 depend on range of operation

Nf > C2

Doichev et al. [5]

U e = 1 F r t 0.5 ( ρ p ρ f ρ p ) 0.5

U ε = 0.56 n ( 1 ε b ) 0.5 ε b n 1

F r t = u t g d p

Ue < Ue

Ue > Ue

Foscolo and Gibilaro [6]

D n = ( A r R e m f ) ( ρ p ρ f ρ f )

Dn < 104

Dn > 106

Liu et al. [7]

F G * = A r R e 2 ρ *

F G * > 11.3

F G * < 11.3

Kogane et al. [11]

For estimation of minimum bubbling fluidization velocity

u m b = 100 d p

u0 < umb

u0 > umb

Geldart [1]

u m b = 2.07 d p ρ f 0.06 μ f 0.347 exp ( 0.716 F 45 )

F45: mass fraction of particles having a diameter less than 45 μm

u0 < umb

u0 > umb

Abrahamsen and Geldart [8]

R e m b = 0.263 ρ 0.553 A r 0.612

Re < Remb

Re > Remb

Kuwagi et al. [9]

R e m b = 0.297 ρ 0.5 A r 0.5

Re < Remb

Re > Remb

Kogane et al. [11]