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A small cluster of mineral particles separating into evenly dispersed individual particles within a controlled liquid jet and fine bubble cloud.

Reactors & equipment

Cavitation-Assisted Particle Dispersion

Dr. Oleg V. Kozyuk

okozyuk.com

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Nomenclature

Symbol Definition SI unit or status
a Particle radius m
as External particle area per unit mass m² kg⁻¹
AH Hamaker constant J
b(d|d′) Daughter size distribution from parent size d′ Model dependent
Br Breakage number Dimensionless
cl, cs Sound speed in liquid and solid m s⁻¹
Cd Discharge coefficient Dimensionless
CR Structural coefficient in agglomerate strength relation Dimensionless
cp Specific heat capacity J kg⁻¹ K⁻¹
da Agglomerate characteristic size m
db Load bearing building block size m
dh Hydrodynamic particle diameter m
dp Particle diameter m
D10 Diameter below which 10 percent of the stated distribution occurs m
D43 Volume weighted mean diameter m
D50 Median diameter m
D90 Diameter below which 90 percent of the stated distribution occurs m
DB Brownian diffusion coefficient m² s⁻¹
e1 Specific hydraulic energy for one pass J kg⁻¹
ecum Cumulative specific energy input J kg⁻¹
e Elementary charge C
FA van der Waals attractive force N
Fb Characteristic interparticle bond force N
Fcap Capillary force N
g Gravitational acceleration m s⁻²
h Surface separation distance m
I Ionic strength mol m⁻³ or stated concentration basis
k Polytropic exponent or pass index, as defined Dimensionless
kB Boltzmann constant J K⁻¹
L Characteristic length or settling height m
ms Mass of solid kg
mdisp Estimated dispersant mass kg
n(d,t) Number density distribution Model dependent
NA Avogadro constant mol⁻¹
Np Nominal number of passes Dimensionless
pB Pressure inside bubble Pa
pg Noncondensable gas pressure Pa
pls Liquid solid impact pressure Pa
pref Reference pressure for cavitation number Pa
pv Saturation vapor pressure Pa
p∞ Far field or recovered pressure Pa
Ph Hydraulic power W
Pmotor Motor power transferred to process W
Pes Sedimentation Peclet number Dimensionless
Q Volumetric flow rate m³ s⁻¹
Q˙HX Heat exchanger duty W
R Instantaneous bubble radius m
R0 Initial or maximum bubble radius m
RD Percent reduction in selected diameter %
S(d) Breakage frequency s⁻¹
SPSD Particle size distribution span Dimensionless
St Stokes number Dimensionless
t Time s
tR Rayleigh collapse time s
T Absolute temperature K
uj Liquid microjet velocity m s⁻¹
U Characteristic mean flow velocity m s⁻¹
Vb Batch volume m³
VA, VR, VS, VT Interaction potentials J
vs Settling velocity m s⁻¹
AFM Atomic force microscopy Abbreviation
CFC Controlled flow cavitation Abbreviation
CFD Computational fluid dynamics Abbreviation
CMP Chemical mechanical planarization Abbreviation
DLS Dynamic light scattering Abbreviation
ICP Inductively coupled plasma analysis Abbreviation
PSD Particle size distribution Abbreviation
SEM Scanning electron microscopy Abbreviation
TEM Transmission electron microscopy Abbreviation
Fd Deagglomeration factor, initial selected diameter divided by final selected diameter Dimensionless
f(d) Relative probability density of plant particle diameter in Equation (8.2) mm⁻¹
dm Fitted mean plant particle diameter in Equations (8.2) and (8.3) mm
dx,0; dx,f; dx,∞ Initial, final, and asymptotic value of selected particle size metric m or stated unit
kx Empirical pass response constant in Equation (8.5) Pass⁻¹
Re Reynolds number Dimensionless
IPA Isopropyl alcohol Abbreviation

Greek Letters

Symbol Letter name Meaning SI unit or status
αc Alpha Empirical coefficient relating jet momentum to effective collapse stress Dimensionless
ΓA Gamma Adsorbed dispersant mass per unit area kg m⁻²
γ Gamma Liquid surface tension N m⁻¹
Δp Delta p Pressure drop across cavitation device Pa
ΔTad Delta T Adiabatic temperature rise K
γ˙K Gamma dot Kolmogorov strain rate s⁻¹
ε0 Epsilon zero Vacuum permittivity F m⁻¹
εr Epsilon r Relative permittivity Dimensionless
εa Epsilon a Agglomerate porosity Dimensionless
εt Epsilon t Turbulent energy dissipation rate per unit mass m² s⁻³
ηh Eta h Overall hydraulic efficiency Dimensionless
ηK Eta K Kolmogorov microscale m
θ Theta Contact angle rad or degree
κ Kappa Inverse Debye screening length m⁻¹
κ−1 Kappa inverse Debye screening length m
μ Mu Dynamic viscosity Pa s
ν Nu Kinematic viscosity m² s⁻¹
ρl, ρp, ρs Rho Liquid, particle, and solid density kg m⁻³
σc Sigma Cavitation number Dimensionless
σagg Sigma Agglomerate tensile strength Pa
τc Tau Effective collapse induced stress Pa
τf Tau Characteristic flow time s
τK Tau Kolmogorov time scale s
τp Tau Particle relaxation time s
τext Tau Applied external stress Pa
τin Tau Inertial turbulent stress Pa
τvis Tau Viscous turbulent stress Pa
ψ0 Psi Surface potential V
λ Lambda Cavitation stage used in the plant raw material study Dimensionless
σd Sigma d Standard deviation of plant particle diameter distribution mm
τ Tau Cavitation processing time in the plant raw material model min

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