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"A Real Time Process To Optimize The Blast Furnace Burden To Improve Quality Productivity And Cost Involvement"

Abstract: This invention relates to a process established for real time estimation of the optimum raw material distribution of a running blast furnace at any stage of operation for improving production control. This process uses the raw materials of blast furnace burden as an input and an evolutionary method towards that combination of raw materials that minimizes the burden cost and maximizes the production, in process real time. The computational solution itself brings out the best possible combination of raw materials that can improve the production in the blast furnace.

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Notices, Deadlines & Correspondence

Patent Information

Application #
Filing Date
14 January 2013
Publication Number
29/2014
Publication Type
INA
Invention Field
METALLURGY
Status
Email
Parent Application

Applicants

TATA STEEL LIMITED
RESEARCH AND DEVELOPMENT AND SCIENTIFIC SERVICES DIVISION, JAMSHEDPUR-831001, INDIA

Inventors

1. DEBJANI SAMBASIVAM
C/O. TATA STEEL LIMITED AUTOMATION DIVISION, JAMSHEDPUR - 831001, INDIA.
2. ARYA KUMAR BHATTACHARYA
C/O. TATA STEEL LIMITED AUTOMATION DIVISION, JAMSHEDPUR - 831001,INDIA.
3. ABHIK ROY CHOWDHURY
C/O. TATA STEEL LIMITED AUTOMATION DIVISION, JAMSHEDPUR - 831001,INDIA.

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