Specification
FIELD OF THE INVENTION
The present invention generally relates to a real-time process to optimize the
blast furnace burden to improve quality, productivity and cost-involvement.
BACKGROUND OF THE INVENTION
In Blast Furnace (BF) production, the properties of raw materials including
selection of combination of raw materials in the 'charge' has a significant bearing
on the quantity, quality and cost of hot metal. The solid charge, as it descends
further down into the furnace, is called the "burden". Traditional burden
calculations are either by hand, or Excel sheet, which are error prone. Therefore,
to maximize BF production, it is of practical significance to make a best use of
the advantages and minimize the disadvantages of different burden materials in
order to guide the operator towards burden optimization. With a variety of
options of iron-bearing materials, flux and fuel, it is another emphasis on the
rational use of these, to find an appropriate balance point between optimal
properties and lowest cost by burdening. Therefore, it is of vital significance to
find a reasonable burden structure.
A number of earlier models are available which aim to predict BF burden
optimization and real tie control based on mutual reactivity of the iron bearing
materials at high temperature. Some of the prior art are based on the gas flow
through the layered structure, solids and liquid flows, heat transfer between
different phases and with walls, ore softening and melting in the cohesive zone
including the predominant chemical reactions. All the above mentioned prior art
have been modeled as a steady state condition i.e. none of these models
predicts the opti8mized burden composition under running condition. Hence, it is
mandatory to arrive at a model, which can predict an optimum burden
distribution for a running BF to ensure lower cost of burden and maximize
production of modern blast furnaces.
A Blast furnace (BF) is a type of metallurgical furnace used for smelting to
produce industrial metals, generally iron. In a BF (Fig.l), fuel, ore, and flux are
continuously supplied through the top furnace, while hot air is blown into the
bottom, so that exothermic chemical reactions take place throughout the furnace
as the materials move downward. The end products are usually molten metal
and slag tapped from the bottom and flue gases exiting from the top of the
furnace. The downward flow of the ore and flux in contact with an upward flow
of hot, carbon monoxide-rich combustion gases form a countercurrent heat and
mass exchange process.
The hot air blast to the furnace burns the coke fuel and maintain very high
temperatures that are needed to reduce the ore to iron in subsequent stages
according to the reactions below:
Boudouard Reaction:
CO2+C = 2CO;
Subsequent Stages of Reduction:
Fe203 + CO = 2Fe304 + CO2;
Fe304 + CO = 3Fe0 + CO2;
Fe0 + CO = Fe + CO2;
Because the furnace temperature is in the region of 1500°C (iron melting
temperature being around 1200°C), the metal is produced in a molten state and
this runs down to the base of furnace. The furnace temperature is also high
enough to decompose limestone into calcium oxide, which subsequently
produce slag that floats on top of the molten iron.
In the upper part6 of Blast Furnace evenly sized Sinter, Coke & Pellet are
charged. The proportion of ore and flux to fuel, in the charge of a blast furnace
is called burden. The charge descends regularly, without sticking, because
narrow range of particle sizes make the gas flow evenly, enhancing contact with
the descending solid. While descending, metallic part of the burden reacts with
the rising reduction gases. Hence, the burden gets heated and the iron oxides
are partially reduced. At high temperature iron and its oxides are softened and
eventually melt. The melt (iron and slag) and the remaining coke are collected in
the lower part of furnace (Hearth). The hearth is mostly filled with a porous bed
of coke called the dead man wherein the formative liquid iron and slag
accumulate. By drilling a tap hole through the furnace wall, the hearth is drained
of the liquid metal and slag at regular intervals.
The materials discharged from the BF are Hot metal is produced into a torpedo
car, where it is subjected to hot metal pre-treatment, and then transferred to the
steelmaking plant. Molten slag is crushed after solidification and is recycled as a
material for construction. Top gas, after dust removal, is used as a fuel for hot
stove.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a real-time process to
optimize the blast furnace to improve quality productivity and cost-involvement.
Another object of the invention is to propose a real-time process to optimize the
blast furnace burden to improve quality productivity and cost-involvement which
is implemented in a burden control system adapting a differential evaluation
method.
SUMMARY OF THE INVENTION
According to the invention, there is provides a system and process for estimating
the blast furnace burden of a running Blast Furnace at any stage of operation.
The process uses the relative weights of different raw materials of blast furnace
burden as degrees of freedom to device an evolutionary model which minimizes
the cost of burden and maximizes the production in real time process. The raw
materials of BF are categorized into three different types i.e. Fe bearing, Fuel
and Flux. Further, each such category has sub-categories as well. The raw
materials are taken in real-time as input to the technical solution directly from
the existing level 2 systems.
A "fitness function: is created using minimization of burden cost and
maximization of production in real time process, which drives a differential
evolution (DE) to manipulate the burden of BF using the various degrees of
freedom. This has appropriately been co-related into the DE chromosomes in
order to obtain the burden profile that optimizes the fitness function.
Each member of the DE population is a combination of raw materials in every
generation. It evaluates all combinations of raw materials under given
constraints to maximize the production and minimize the burden cost. In every
generation, it attempts to improve the fitness value and compares fitness values
of other generations and the best chromosome is stored. After a certain
generation, when fitness value no longer changes generation to generation i.e.
the solution converges to a best possible optimum value within the solution
space, DE provides the best possible fitness value that corresponds to the
optimum raw material distribution that suits the real time blast furnace
operation.
It must be understood in context of the present invention, the models referred
herein constitutes one of an application specific integrated circuit (ASIC), an
electronic circuit, a processor including a memory that execute one or more
software or firmware programmes, or a combinational logic circuit that provide
the described functionality.
The system of the invention can be realized but not limited to, in the form of a
processor with memory enabled to implement instruction from a differential
evaluation software, and operably connected to the plant control system.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig 1: Schematic of blast furnace burden.
Fig 2: Schematic of the work flowchart.
Fig 3: Process Flowchart
DESCRIPTION OF A PREFERRED EMBODIMENT
The raw materials of BF i.e. components of the burden, are categorized into
three different types:
Iron/Fe bearings, Fuel and Flux. Each of the three types is having subsets as
follows:
1. Fe Bearing materials:
A. Sinter from Sinter Plants - (i), SP1, (ii) SP2, (iii) SP3 and (iv) SP4.
B. Iron Ore from (i) Joda and (ii) Noamundi (These are mine locations)
C. Pellet from palletizing plant.
D. Sponge Iron (DRI).
2. Fuel
A. Coke
B. Pulverized Coal: - Indigenous: Jamadoba and W Bokaro (mine
locations).
C. Tar
3. Flux
A. Dolomite.
B. Dunite
C. Pyroxinite
D. Quartzite and
E. Limestone etc
To determine all combinations of a burden, i.e. the amount of each component,
raw materials are expressed as a set of each category i.e.
Source of Fe bearing raw materials are basically from SPI, SP2, SP3, SP4, Joda
Ore Naomundi ore, Pellet and Sponge Iron. So Fe bearing is a set of above
mentioned sources i.e. if we consider Fe bearing material as a raw material 1
(RMI) then we can say
RMI = {SP1, ..., sponge iron}. Similarly for Fuel (RM2) we can write, Subset of
RM2 = {Coke, ,Tar} and for Flux (RM3) = {Dolomite,...,Lime Stone}.
Now each source {SPI, ,Lime Stone} contains {Fe, FeO, C, Mg0, Si02,
A1203, CaO. S, and Si}.
The total Fe, FeO, Fe203, Fe304, C, CaO, Mg0, Si02, Al203, Si, and S coming from
RM1, RM2 and RM3 are estimated in the burden control system through their set
respectively and the inputs {SP1, , Lime Stone} are obtained directly from
the level 2 systems in real time. The complete data is shown in a tabular form in
Table 1 where {X1, , Xm} = {SP1, , sponge iron}, {Y1,.....,..., Yn} =
{Coke, , Tar}, Z1,..., , Zk} = {Dolomite, , Lime Stone}. Therefore,
the total degrees of freedom or the total solution space for this problem is
determined in the control system which is represented by (m + n + k)
where m, n, k represents total number of source of raw materials of RM1, RM2,
RM3 respectively.
Now a random combination of {X1, , Xm, Y1, ,..., Yn,Z1, ..., , Zk},
within a specific range, is generated in the control system. Further, the
corresponding values (Fe, Fe203, FeO, Fe304, Ca0, Mg0, Si02, Al203, C, Si and S)
are calculated from a loop-up table and the (table 1) calculated values, as stated
below, are evaluated:
1. B1 = Cao/Sio2; 0.85 < B1 < 1.15 (1)
2. B21 = (Al203/Slag Volume) *100 (Kg/THM)
18.0 < B21 < 25.0 (2)
3. B31 =(Mg0/Slag Volume)*100 (Kg/THM)
6.0=0.3135
5. B5 = Slag Volume (Kgs)=(Ca0 + Mg0 + Si02 + Al203)*100;
0.25
Documents
Application Documents
| # |
Name |
Date |
| 1 |
43-Kol-2013-(14-01-2013)SPECIFICATION.pdf |
2013-01-14 |
| 1 |
43-KOL-2013-Correspondence to notify the Controller [08-07-2022(online)].pdf |
2022-07-08 |
| 2 |
43-Kol-2013-(14-01-2013)GPA.pdf |
2013-01-14 |
| 2 |
43-KOL-2013-US(14)-ExtendedHearingNotice-(HearingDate-08-07-2022).pdf |
2022-06-09 |
| 3 |
43-KOL-2013-Correspondence to notify the Controller [08-06-2022(online)].pdf |
2022-06-08 |
| 3 |
43-Kol-2013-(14-01-2013)FORM-3.pdf |
2013-01-14 |
| 4 |
43-KOL-2013-FORM-26 [08-06-2022(online)]-1.pdf |
2022-06-08 |
| 4 |
43-Kol-2013-(14-01-2013)FORM-2.pdf |
2013-01-14 |
| 5 |
43-KOL-2013-FORM-26 [08-06-2022(online)].pdf |
2022-06-08 |
| 5 |
43-Kol-2013-(14-01-2013)FORM-1.pdf |
2013-01-14 |
| 6 |
43-KOL-2013-PETITION UNDER RULE 137 [08-06-2022(online)].pdf |
2022-06-08 |
| 6 |
43-Kol-2013-(14-01-2013)DRAWINGS.pdf |
2013-01-14 |
| 7 |
43-KOL-2013-REQUEST FOR ADJOURNMENT OF HEARING UNDER RULE 129A [08-06-2022(online)].pdf |
2022-06-08 |
| 7 |
43-Kol-2013-(14-01-2013)DESCRIPTION (COMPLETE).pdf |
2013-01-14 |
| 8 |
43-KOL-2013-US(14)-HearingNotice-(HearingDate-09-06-2022).pdf |
2022-05-18 |
| 8 |
43-Kol-2013-(14-01-2013)CORRESPONDENCE.pdf |
2013-01-14 |
| 9 |
43-Kol-2013-(14-01-2013)CLAIMS.pdf |
2013-01-14 |
| 9 |
43-KOL-2013-Proof of Right (MANDATORY) [19-03-2019(online)].pdf |
2019-03-19 |
| 10 |
43-Kol-2013-(14-01-2013)ABSTRACT.pdf |
2013-01-14 |
| 10 |
43-KOL-2013-Proof of Right (MANDATORY) [05-03-2019(online)].pdf |
2019-03-05 |
| 11 |
43-KOL-2013-FORM 4(ii) [06-12-2018(online)].pdf |
2018-12-06 |
| 11 |
43-KOL-2013-FORM-18.pdf |
2013-08-06 |
| 12 |
43-KOL-2013-DRAWING [05-12-2018(online)].pdf |
2018-12-05 |
| 12 |
43-KOL-2013-FER.pdf |
2018-06-06 |
| 13 |
43-KOL-2013-FER_SER_REPLY [05-12-2018(online)].pdf |
2018-12-05 |
| 13 |
43-KOL-2013-OTHERS [05-12-2018(online)].pdf |
2018-12-05 |
| 14 |
43-KOL-2013-FER_SER_REPLY [05-12-2018(online)].pdf |
2018-12-05 |
| 14 |
43-KOL-2013-OTHERS [05-12-2018(online)].pdf |
2018-12-05 |
| 15 |
43-KOL-2013-DRAWING [05-12-2018(online)].pdf |
2018-12-05 |
| 15 |
43-KOL-2013-FER.pdf |
2018-06-06 |
| 16 |
43-KOL-2013-FORM 4(ii) [06-12-2018(online)].pdf |
2018-12-06 |
| 16 |
43-KOL-2013-FORM-18.pdf |
2013-08-06 |
| 17 |
43-KOL-2013-Proof of Right (MANDATORY) [05-03-2019(online)].pdf |
2019-03-05 |
| 17 |
43-Kol-2013-(14-01-2013)ABSTRACT.pdf |
2013-01-14 |
| 18 |
43-Kol-2013-(14-01-2013)CLAIMS.pdf |
2013-01-14 |
| 18 |
43-KOL-2013-Proof of Right (MANDATORY) [19-03-2019(online)].pdf |
2019-03-19 |
| 19 |
43-Kol-2013-(14-01-2013)CORRESPONDENCE.pdf |
2013-01-14 |
| 19 |
43-KOL-2013-US(14)-HearingNotice-(HearingDate-09-06-2022).pdf |
2022-05-18 |
| 20 |
43-Kol-2013-(14-01-2013)DESCRIPTION (COMPLETE).pdf |
2013-01-14 |
| 20 |
43-KOL-2013-REQUEST FOR ADJOURNMENT OF HEARING UNDER RULE 129A [08-06-2022(online)].pdf |
2022-06-08 |
| 21 |
43-Kol-2013-(14-01-2013)DRAWINGS.pdf |
2013-01-14 |
| 21 |
43-KOL-2013-PETITION UNDER RULE 137 [08-06-2022(online)].pdf |
2022-06-08 |
| 22 |
43-Kol-2013-(14-01-2013)FORM-1.pdf |
2013-01-14 |
| 22 |
43-KOL-2013-FORM-26 [08-06-2022(online)].pdf |
2022-06-08 |
| 23 |
43-Kol-2013-(14-01-2013)FORM-2.pdf |
2013-01-14 |
| 23 |
43-KOL-2013-FORM-26 [08-06-2022(online)]-1.pdf |
2022-06-08 |
| 24 |
43-Kol-2013-(14-01-2013)FORM-3.pdf |
2013-01-14 |
| 24 |
43-KOL-2013-Correspondence to notify the Controller [08-06-2022(online)].pdf |
2022-06-08 |
| 25 |
43-KOL-2013-US(14)-ExtendedHearingNotice-(HearingDate-08-07-2022).pdf |
2022-06-09 |
| 25 |
43-Kol-2013-(14-01-2013)GPA.pdf |
2013-01-14 |
| 26 |
43-KOL-2013-Correspondence to notify the Controller [08-07-2022(online)].pdf |
2022-07-08 |
| 26 |
43-Kol-2013-(14-01-2013)SPECIFICATION.pdf |
2013-01-14 |
Search Strategy
| 1 |
43KOL2013_16-01-2018.pdf |