Computational Fluid Dynamics Simulation in

the Cement Industry

Kyle CobleMaintenance Engineer

CalPortland

CFD Overview

Fluid Flows

• Fluid States• Chemistry• Boundary Conditions• Navier-Stokes Equations

Heat Transfer

• 3 Heat Transfer Methods• Cement Pyro Process

Combustion

• Proven Capabilities• Combining Flow, Heat, & Chemical Reactions

Discrete Phase Model (DPM)

• Multiple States• Particle Tracking• Coupled Solving• Evaporation

Discrete Element Method (DEM)

• Bulk Material Flows• Numerous Applications• Particle Size Distributions• Specialized Software

Steady State and Transient Analysis

• Steady vs Transient• Screw Compressor

Geometry and Mesh

• Simulation Foundation• Collection of Cells• Cell Calculations• Cell Size, Count, & Quality

Solution Method• Simultaneous Calculations• Neighboring Cells• Iterative Process• Scaled Residuals• Convergence

Residual Examples• Velocity• Continuity• Energy

Advantages of CFD in the Cement Plant

Process Energy Savings

• Process Improvements• Other Resources• Gas Conditioning Tower Example

Wear Reduction

• Identify Heavy Wear Areas• Implement Protections• Design to Minimize Wear

Process Education and Understanding

• Visualizations• Animations• Incoming Employee Education• More Complex Equipment

Equipment Design and Selection

• Compare Designs• Size Fans and Pumps• Fan Rotor Optimization

Practical Applications of CFD in the Cement Plant

Gas Conditioning TowerOverview

Flow Direction

Inlet FromTower

Water SprayerLocation

Outlet ToID Fan

• Extended Downcomer• Laminar Flow• Pressure Drop

FlowStraighteners

Old Design

Gas Conditioning TowerPareto Optimization

• Flow Straightener Removal• Pareto Front Optimization• Design Points

Gas Conditioning TowerResource Savings

• 0.4 inH2O• 20 GPM

Clinker Cooler Takeoff DuctOverview

Inlet from Cooler

Outlet to Baghouse

AmbientInlet Flow Direction

Forced Air Inlet

• Outlet Temperature Distribution• 16 Compartment Baghouse

Outlet to Coal Mill

Clinker Cooler Takeoff DuctHanging Chain Solution

Kiln Chain Cylinder ApproximationTight Corners

• Conventional Practice• Geometry Approximation• Ineffective Solution

Clinker Cooler Takeoff DuctSlanted Plate Solution

Inlet from Cooler

Outlet

AmbientInlet

• Vertical Temperature Distribution• Forced Mixing

Slanted Plate

Preheater Tower Simulation

• Understand Our Process• Replace Top Stage• Test Vessel Designs

Coal Silo Wall Stresses

• Asymmetrical Loading• Low Pressure Zone• Wall Stresses• DEM or Viscous Fluid

Dryer Design• DEM with DPM

Raw Mill Feed

Hot AirFlow

Lessons Learned

Validate and Refine the Results

• Collect Base Case Data• Anticipate Measurements• Model Base Case• Model Changes• Trend & Compare Results• Multiple Iterations

Verify the Drawings

• “Existing”• “Field Fit”• Measure• Relines

Meshing, Meshing, Geometry, Meshing

• Simulation Foundation• Many Meshing Methods• Chain Approximation

In-House vs. Contracting

Fixed vs Variable Costs

• In House Labor• Variable Pyro Process• Numerous Cases• Charge per Case

More Opportunities for Simulation

Raw MillDryer ID Fan

Design PreheaterVessels

CementStorageDome

Cross FlowHeat

Exchanger

• Applications Everywhere• Growing List

In-House Expertise

• Interpretation• Validation• Verification

Future Possibilities

Pneumatic Transport

• Wear Identification• Pressure Drop• Piping Design and Changes

Mixing of Bulk Materials

• Shoot Design• Effective Mixing• Uniform Distribution

Whole Plant Processes Linked

Coolerto

Coal Mill

TA Ductto

Calciner

• Process Changes• Accurately Predict Effects• Upstream and Downstream

Calcination

• Proven Combustion Capabilities• Calcination Potential• Large Undertaking• Immense Benefit

Thank You• Special Thanks:

o Steve Coppinger – VP Engineering Serviceso Dave Carichner – Director of Project Engineeringo Hartmut Riess – Chief Process Engineero Brandon Schirmer – Mechanical Engineer