STARTING FROM THE LOCAL EQUILIBRIUM
OR COMING FROM THE DYNAMIC END:
A COMPARISON OF METHODOLOGIES IN
PROCESS MODELING1))
1) as suggested by K. Hack
R. Emler – University of Leoben
Starting from the local equilibrium or coming from the dynamic end: A comparison of methodologies in process modeling
Contents
1. Introduction
2. Simulation of the cement clinker burnung process
3 Simulation of tunnel kiln firing of refractories
3.
1
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
1. Introduction
What do we need to describe a process sufficiently?
Global (Local) Equilibrium
Cement clinker burning
P. Monheim, 2002
Tunnel kiln firing of refractories
M. Weghaus, 2006
Fluid Dynamics Kinetics
2
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
2. Cement clinker burning process
Project objectives
Determination of the chemical loading of refractories
Calculation of the infiltration profiles of volatiles in the lining
Tl
Ts
Corrosion of refractory lining
Thermal spalling during cooling
3
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
PHT gas
375°C 98 464 mN3·h
98.464 h-1 2. Cement clinker burning process
Retznei – Kiln audit summer 2008
PHT Dust
357°C
357 C 10
10,2 t h-1
2 t·h
Raw mix
83°C 98,37 t·h-1
9803 mN3·h-1
Input streams
Air iinleakage
e
Air
Ai
Output streams
ByPass
1132°C gas
25°C
2.969 mN3·h-1
ByPass dust
1132°C
1132 C t h-1
0,63 t·h
SNCR Air inleakage
Ø 4 m x 58 m 35°C 677 mN3·h-1
25°C
25 C 0
0,55 t h-1
55 t·h
Solid fuel Fuel
38°C 6,50 t·h-1
25°C 1,67 t·h-1 Cadence fans Primary
y air
40°C 4.300 mN3·h-1
43°C 6.791 mN3·h-1
Air inleakage
25°C 2.310 mN3·h-1 Clinker
Secondary
C 3,90air
865°C
865 t hdust
t·h-1
1420°C 61,2 t·h-1
Secondary air
865°C 56.167 mN3·h-1
4
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
2. Cement clinker burning process
Retznei – Total process model
Setup of reactors
g
4 Preheater stages
58 Kiln segments (à 1 m)
Facts and figures
complexity similar to FE-simulations
~ 12 500 Si
SimuSage
S components
t
~ 2 500 000 calculated equilibria
~ 12 · 1015 floating point operations
5
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
2. Cement clinker burning process
Retznei – Simulation results – Preheater tower gas
6
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
2. Cement clinker burning process
Retznei – Simulation results – Longitudinal section of kiln
Clinker
Material buildup
Refractory lining
Steel shell
7
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
2. Cement clinker burning process
Retznei – Simulation results –Phase composition material bed in the kiln
Clinker
Tgas
Ts,top
s top
Ts
8
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
2. Cement clinker burning process
Retznei – Condensation of alkali salts in the kiln lining
9
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
2. Cement clinker burning process
Retznei – Condensation of alkali salts in the kiln lining
10
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
3. Tunnel kiln firing of refractories
Introduction
11
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
3. Tunnel kiln firing of refractories
Introduction
P h ti
Preheating zone B
Burning
i zone C li
Cooling zone
Exhaust gas
Pushing
g Air
G
Gas / Ai
Air
Air inleakage
11
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
3. Tunnel kiln firing of refractories
Project objectives
Determine the influence of process parameters on
product quality
process control
Some examples of process parameters of interest
Burner position
Kiln car pushing frequency
Kiln car setup scheme
Make use of OpenFOAM
p
Local process model
12
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
3. Tunnel kiln firing of refractories
Reference setup – Opposite position at the bottom
13
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
3. Tunnel kiln firing of refractories
Reference setup – Opposite position at the bottom
14
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
3. Tunnel kiln firing of refractories
Modified alterated positioning of top and bottom burners
15
1. Introduction 2. Cement clinker burning process 3. Tunnel kiln firing of refractories
3. Tunnel kiln firing of refractories
Modified alterated positioning of top and bottom burners
16
