Numerical Investigation of Degasification in an Electrocoagulation Reactor
Abstract
:1. Introduction
2. Materials and Methods
2.1. Experimental Setup
2.2. Numerical Simulation Setup
2.2.1. Geometry and Grid Generation
2.2.2. Solver Setup
2.2.3. Interphase Transfer Model
2.2.4. Turbulence Model
3. Results and Discussion
3.1. Verification and Validation
3.2. Hydraulic Retention Time
3.3. Velocity Vectors
3.4. Gas Holdup
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Nomenclature
A | Area |
Aαβ | Interfacial area density |
c | Continuous phase |
CD | Drag coefficient |
Ci | Ion concentration |
CL | Lift coefficient |
CTD | Coefficient of turbulence dispersion force |
CVM | Coefficient of virtual mass force |
cμ | Viscosity coefficient |
D | Drag force |
d | Dispersed phase |
db | Bubble diameter |
dH | Horizontal bubble dimension |
Eo | Eotvos number |
Eo’ | Modified Eotvos number |
F | Faraday’s constant |
f | Volume fraction |
Fb | Buoyancy force |
FL | Lift force |
Fs | Surface tension force |
FTD | Turbulence dispersion force |
FVM | Virtual mass force |
g | Gravity acceleration |
Ie | Electrical current |
ke | Specific electrical conductivity |
kαβ | Normal surface curvature |
Le | Electrical charge loading |
Mα | Interphase momentum transfer |
nb | Bubble number |
P | Pressure |
Pabs | Absolute pressure |
Pref | Reference pressure |
Prt | Turbulent Prandtl number |
Pstat | Static pressure |
Ptot | Total pressure |
Q | Volumetric flow rate |
r | Area density |
rc | Capillary radius |
Re | Electrical resistance |
S | Source term |
t | Time |
T | Tensor of mean motion |
U | Mean velocity |
u | Fluid velocity |
u’ | Fluctuating velocity |
V | Volume |
x, y, z | Cartesian’s spatial direction |
Z | Charge |
α | Phase α (Water) |
β | Phase β (Hydrogen) |
δ | Kronecker delta |
ε | Eddy |
κ | Turbulent kinetic energy |
μ | Dynamic viscosity |
μt | Dynamic turbulence (eddy) viscosity |
µtp | Particle induced eddy viscosity |
μts | Shear-induced eddy viscosity |
ρ | Density |
σs | Surface tension coefficient |
σtc | Turbulence Schmidt number for the continuous phase |
τ | Reynolds stress tensor |
ταβ | Interphase mass transfer |
ζ | Zeta potential |
ν | Kinematic viscosity |
νt | Kinematic turbulence (eddy) viscosity |
χi | Ionic conductivity |
ω | Turbulent frequency term |
ωc | Angular velocity |
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Parameters | Min Intervals | Max Intervals | Typical Intervals |
---|---|---|---|
Current density [A/m2] | 1 | 75 | 25 |
Inlet flow [L/h] | 1 | 1000 | 10 |
Hydrogen gas flow [g/min] | 6 × 10−6 | 1.93 × 10−3 | 6.62 × 10−4 |
Degassing time interval [min] | 15 | 120 | 60 |
Degassing duration [min] | 0.1 | 2 | 1 |
Water temperature [°C] | 15 | 25 | 20 |
Fluid Properties | Water | Hydrogen |
---|---|---|
Thermodynamic State | Liquid | Gas |
Molar Mass [kg/kmol] | 18.02 | 2.016 |
Density [kg/m3] | 998.2 | 0.09 |
Ref. Temperature [°C] | 20 | 20 |
BCs | Case 1 | Case 2 | Case 3 | Case 4–6 |
---|---|---|---|---|
Water inlet | 0.00278 | 0.27778 | ||
Water outlet | ||||
Spiral Cathode | ||||
Gas outlet | degassing |
Case 1 | Case 2 | Case 3 | |
---|---|---|---|
Retention time [s] water velocity | 486 | 67 | 8 |
Retention time [s] superficial water velocity | 473 | 55 | 8 |
Case 4 | Case 5 | Case 6 | |
---|---|---|---|
Gas holdup [%] before degassing | 0.3 | 3.76 | 0.22 |
Gas holdup [%] after 30 s | 0.020 | 0.028 | 0.027 |
Gas holdup [%] after 120 s | 0.019 | 0.020 | 0.020 |
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Höhne, T.; Asl, V.F.; Ople Villacorte, L.; Herskind, M.; Momeni, M.; Al-Fayyad, D.; Taș-Köhler, S.; Lerch, A. Numerical Investigation of Degasification in an Electrocoagulation Reactor. Water 2021, 13, 2607. https://doi.org/10.3390/w13192607
Höhne T, Asl VF, Ople Villacorte L, Herskind M, Momeni M, Al-Fayyad D, Taș-Köhler S, Lerch A. Numerical Investigation of Degasification in an Electrocoagulation Reactor. Water. 2021; 13(19):2607. https://doi.org/10.3390/w13192607
Chicago/Turabian StyleHöhne, Thomas, Vahid Farhikhteh Asl, Loreen Ople Villacorte, Mark Herskind, Maryam Momeni, Douha Al-Fayyad, Sibel Taș-Köhler, and André Lerch. 2021. "Numerical Investigation of Degasification in an Electrocoagulation Reactor" Water 13, no. 19: 2607. https://doi.org/10.3390/w13192607
APA StyleHöhne, T., Asl, V. F., Ople Villacorte, L., Herskind, M., Momeni, M., Al-Fayyad, D., Taș-Köhler, S., & Lerch, A. (2021). Numerical Investigation of Degasification in an Electrocoagulation Reactor. Water, 13(19), 2607. https://doi.org/10.3390/w13192607