1. Structural Modeling and Meshing of Blast Furnace Using HyperMesh
And Tcl/Tk.
Debiprasad Ghosh Bhaskar Sengupta Shyam Kr. Maitra Sujan Hazra
Sr. Manager, Tech cell Head, Tech cell Consultant, Tech cell Sr. Engineer, Tech cell
M&M, L&T Construction M&M, L&T Construction M&M, L&T Construction M&M, L&T Construction
th th th th
6 Floor, Technopolis, 6 Floor, Technopolis, 6 Floor, Technopolis, 6 Floor, Technopolis,
Saltlake-700091, India Saltlake-700091, India Saltlake-700091, India Saltlake-700091, India
Abbreviations: FEA- Finite element analysis.
Keywords: Blast furnace, TCL/Tk, CDB format, Ansys
Abstract
The generation of geometry and meshing is done automatically using HyperMesh with the help of Tcl/Tk scripting language, with a
means to conduct iterative analysis of a blast furnace (an industrial structure) using finite element method. Material properties,
boundary conditions, loading and other input parameters are also given automatically to the script for iterative solution requirements.
Mesh-refinement is generally required at the critical locations for more accurate results. The proposed script in this study will be useful
to analyze any dimensions of blast furnace, material properties, loading and at different orders of discretization. These results are taken
by a designer to design a safe and economical blast furnace for an industry.
Introduction
More than 85% of the world steel production is through the blast furnace route. Blast furnaces continue to
be the prime choice on account of versatility of operation, large production volume and lower cost of
production. However, Blast Furnaces are not only capital intensive, they also require significant time for
design & erection of the various components comprising the Blast furnace shell, its refractory cooling
arrangements, charging equipment, gas cleaning plant, cast house equipment, blast furnace hearth
refractory etc. This paper discusses an approach where the Blast Furnace is designed on the basis of a set
of empirical rules applied to a handful of parameters. As a first attempt, some components of the Blast
Furnace have been ignored - cooling arrangement, up-comers, charging equipment & blast equipment.
Because of the huge financial impact, all efforts are made to design a reliable & economical Blast Furnace,
one that will have a long campaign life and achieve a throughput in excess of 8500 t/day.
In the present paper we are using Ansys for finite element analysis (FEA) and HyperMesh for FEA meshing
of blast furnace [Figure 1]. The function of a blast furnace is to chemically reduce and physically convert iron
oxides into liquid iron called "hot metal". The blast furnace is a huge, steel stack lined with refractory brick,
where iron ore, coke and limestone are dumped into the top, and preheated air is blown into the bottom [1,
2, 3]. The raw materials require 16 to 18 hours to descend to the bottom of the furnace where they become
the final product - liquid slag and liquid iron. These liquid products are drained from the furnace at regular
intervals. The hot air that is blown into the bottom of the furnace ascends to the top in 6 to 8 seconds after
reacting with the raw materials. Once a blast furnace is started it will continuously run for four to ten years
with only short stops to perform planned maintenance.
Simulation Driven Innovation 1

2. Process Methodology
Geometric modelling of blast furnace is created in HyperMesh with required material properties, boundary
conditions and loading. Finite element meshing is obtained from HyperMesh, which is then exported to a
text file of Ansys CDB format. Finally, Ansys-mechanical solver performs the finite element solution and
provides result in “.rst” format, which is imported from HyperView for iterative modification. These repetitive
modelling, meshing and solution are performed using HyperMesh TCL/Tk programming integrating with
HyperMesh GUI.
Figure 1: Overview of program flow
3
This program requires a handful of input parameters (Blast Furnace Effective Volume: 4000 M ), and on the
basis of a few empirical rules [Ref 1], the program generates the list of tentative Blast Furnace dimensions
(Total Height, Belly Diameter, Hearth Diameter, Tuyere Height, Hearth Height, Blast Furnace top diameter
etc…). Based on experience these dimensions can be edited from HyperMesh UI Tab, and then TCL/Tk
program will generate a “.cdb” file, wherein the geometrical dimensions as well as the mechanical & thermal
loads and the boundary conditions are created in an input file. The iterative steps are outlined in the
schematic, where we check for the maximum seismic and pressure deflections & thermal stresses, and
make changes to the dimensions (Tuyere height 4600 mm), and the loading conditions (the location of the
Simulation Driven Innovation 2

3. cooling staves and the cooling water flow rates), then generate a new input file for the next Ansys
simulation.
Total modeling is performed in six stages - solid modeling; meshing; application of boundary condition;
export to CDB format; solution; and Import from HyperView
; HyperView.
Solid Modeling: Solid modeling of blast furnace is constructed using a set of solid cones extracted from
other set of solid cones. Different parts of a iron making blast furnace are Hearth, Boss, Belly, Stack, and
an rth,
Throat. The lower part of blast furnace, the hearth consists of a packed bed of coke particles through which
hearth,
liquid hot metal flows during tapping. In the present model only Firebricks are modeled a
and internal hot
metal/cokes/ore are considered as load.
Outer steel shell of the blast furnace is not solid modeled, which is face extracted from 3D brick elements to
eel
get nodal coincidence between brick and shell elements.
For simplicity with mapped meshing, tapholes, tuyeres and staves are not considered in the model.
uyeres
Figure 2 Interactive modeling of blast furnace using Tcl/Tk
2:
Meshing: Solid modeling of blast furnace provided 3D geometry of the blast furnace. To g response of
get
blast furnace under structural and thermal loading using finite element analysis, required meshing of this
loading,
solid model. Mapped meshing is used to get good quality hexagonal brick mesh. Once 3D elements are
created, 2D shell elements for outer steel shell of blast furnace are face lifted from 3D elements. Such
technique will generate shell elements even for internal, top and bottom surfaces as well, which are deleted
afterward. This deletion of extra shell elements i done using following steps
etion is
Simulation Driven Innovation 3

4. 1. Get nearest node from a particular point
2. Get the elements connected on face
3. Delete the elements.
Now material and real constant properties are provided for both brick and shell elements.
are
Figure 3: meshing of blast furnace using Tcl/Tk
Application of Boundary Condition: Application of both thermal and structural boundary condition can be
applied either on solid modeling, or on the generated mesh. In the present paper boundary conditions are
paper,
applied in the mesh. Nodes at the bottom of blast furnace are considered as structurally fixed. The seismic
e
load is taken as 25% of the self weight in the horizontal direction, where the self weight includes the weight
of the structure as well as the weight of the internal burden in the furnace. The second important loading
condition is due to the internal pressure, typically 2 atmospheres in the modern furnaces. Similarly, different
e
temperature boundary conditions are applied at bottom, internal, and external wall of the furnace. These
give rise to thermal stresses because of the unequal expansion of the refractory lining and the steel shell.
ive
Modern Blast Furnaces have extensive cooling arrangements, and the operational heat loads can fluctuate
2
by an order of magnitude over their nominal values (40 mJ/m /Hr). These give rise to severe temperature
.
fluctuations with their attendant thermal stresses, and these also have been ignored in the model to arrive
model,
at a preliminary design.
Export to CDB Format: Once Model is ready with nodes, elements, materials, boundary conditions, Ansys
profiles, and Ansys solution commands, these can be exported in Ansys CDB format.
Simulation Driven Innovation 4

5. Solution: Solution is fired from TCL script using “exec AnsysRun.bat” command within a “try block”, where
“AnsysRun.bat” file contains Ansys batch solver command for finite element solution. Ansys solver which
writes results in Ansys “.rst”/”.rth” file.
Import from HyperView: To view and take design decision, generated Ansys “.rst” or “.rth” file is opened
from HyperView.
Results & Discussions
Figure 4 shows the stress contour of the blast furnace shell for structural and thermal loading.
Figure 4: Stress contour from HyperView
Benefits Summary
Manual repetitive modeling of blast furnace is time consuming as well as prone to manual error. Present
technique reduces the requirement of man power and gives opportunity to concentrate on the other
important design issues of blast furnace (design parameters, several alternative cooling stave
configurations) easily, which should be examined before a satisfactory arrangement can be finalized.
Challenges
First challenge we have faced in our project is regarding interoperability between HyperMesh/HyperView
and Ansys, where Altair India and USA technical team had helped to overcome the difficulty. Another
challenge is regarding the TCL/Tk language; as not being an object oriented family. Programmers with big
projects are mostly available for object oriented (Java, C++, C#), or more recently multi-paradigm, functional
languages (Python, F#). Even after development, big projects using other family of languages are difficult to
maintain, extend and test. Anyway, extensive uses of namespaces are applied to overcome this challenge.
Although ScriptView is not yet mature, it also helped a lot.
Simulation Driven Innovation 5

6. Future Plans
SolidThinking can be used for solid modeling of blast furnace with tuyeres, and staves. Moreover, these
design technique can be extended using solver and optimization features of Altair software like OptiStruct,
RADIOSS etc…
Conclusions
A computational framework is created to model blast furnace in HyperMesh, Analyze in Ansys APDL and
viewing results in HyperView using TCL/Tk programming. Automatic modeling technique had given
opportunity to concentrate on important design related issues.
ACKNOWLEDGEMENTS
The authors would like to thank Subir Roy, Anand Ronad, Dev Anand, Shashi Kumar, Sujatha K G, Jyotsna
Naveen, Rajas Majumdar, Nitin Chirdeep, Ramesha B S, Shashi Mantrawadi, Vishwanath Rao; Anshuman
Panda, Kiran Chakravarthy of Altair Engineering for their kind help during the development of project and
submission of paper in the HTC2012.
REFERENCES
[1] Eu. F. Wegmann, "A Reference Book for Blast Furnace Operator," Translated from the Russian by V. Afanasyev, Mir publishers
Moscow.
[2] M. Geerdes, H. Toxopeus, C. van der Vliet, “Modern Blast Furnace Ironmaking”, Verlog Stahleisen GmbH.
[3] Anil K. Biswas, “Principle of Blast Furnace Ironmaking”, Cootha publishing house.
Simulation Driven Innovation 6