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ACKNOWLEDGEMENT
I am very thankful to Mr.S.S. Mohanti, Managing Director, SAIL, BOKARO for providing
me with this opportunity to work with the organization; Mr.ShankarChaudhari(GM,
HRD), Mr. S.K. Singh, Mr. Rajesh Singh, and Mr. P.K. Mishra from the training department
of HRD, SAIL, Bokaro for making all required resources available.
I would like to express my sincere thanks to all the technical experts: Mr. R.R
Kumar, Mr. A.K.Gupta, Mr.H.S Mishra, Mr.H.Nigam, Mr. R.A.P Singh, Mr. S.K Singh, Mr.
A.K Mishra, Mr. B.B.Kochgavay, Mr.K.KSrivastava, Mr.P.S Krishnamurthy who helped me
understand the various systems involved.
I would like to extend my gratitude Dr. V.I.George for his constant inspiration and
guidance. I also thank Mr. R.K.Sinha for helping the PSD for the opening of the PS station
and to all the technical experts and employees at the plant who helped us during the program.
Lastly, I would also like to thank all my PS mates for their constant support and those
involved, directly or indirectly, with me in due course of the project.
SUBODH KUMAR
ELECTRONICS & COMMUNICATION BRANCH
(08EELEC058)
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TABLE OF CONTENTS
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3
1. INTRODUCTION
1.1 Lay-out of Bokaro Steel Plant
2. DEPARMENTS VISITED :-
2.1 RMHP, CO AND SP
2.1.1 Raw Material Handling Plant
2.1.2Coke Ovens & By-Product Plant (CO and BPP)
2.1.3 Sintering Plant
2.2 BLAST FURNACE
2.2.1 INTRODUCTION
2.2.2 INPUTS
2.2.3 OUTPUTS
2.2.4 PROCESS REACTIONS
2.2.5 INSTRUMENTATION
2.3 STEEL MELTING SHOP-1
2.3.1 Raw Material
2.3.2 Sections
2.3.3 Instrumentation and Control
2.4 STEEL MELTING SHOP-2
2.4.1 Inputs
2.4.2 Outputs
2.4.3 Sections
2.4.4 Measurement and Control
2.5 CONTINUOUS CASTING SHOP
2.5.1 Sections
2.5.2 Measurement and Control
2.5.3 Advantages
2.6 HOT SRIP MILL
2.6.1 Instrumentation
2.6.2 Reheating Furnace
2.6.3 Mill Instrumentation
2.7 COLD ROLLING MILL
2.7.1 INPUT
2.7.2 OUTPUT
2.7.3 SECTIONS
2.7.4 ZONES
2.7.5 MEASUREMENT AND CONTROL 2.8 HOT DEEP GALVANIZING LINE
2.9 PLANT EXCHANGE
2.10 ECRS
3. RESULT
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CHAPTER 1.0
INTRODUCTION
Bokaro Steel Plant is located in the Bokaro district of Jharkhand. It is the fourth integrated
public sector Steel plant in India built with Soviet help. It was incorporated as a limited
company in the year 1964. It was later merged with the state owned Steel Authority of India
Limited (SAIL).
Formerly it was known as Bokaro Steel Limited (BSL). Bokaro Steel Plant is hailed as India's
first Swadeshi Steel plant. Its first blast furnace was started on 2nd October 1972. At present
it houses five blast furnaces with total capacity to produce 4.5 MT of liquid steel. The plant is
undergoing a mass modernization drive after which its output capacity is expected to cross 10
MT. The first shop of Bokaro Steel Plant got the ISO 9001 certification way back in 1994,
and its SAIL JYOTI branded products enjoy a loyal market.
Fig.1: The entrance of Bokaro Steel Plant
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1.1 LAYOUT OF BOKARO STEEL PLANT
Fig. 2: Layout of Bokaro Steel Plant
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CHAPTER 2.0
DEPARTMENTS VISITED
2.1 RMHP,CO AND SP
2.1.1 RAW MATERIAL HANDLING PLANT
The Raw Materials and Material Handling Plant receives blends, stores and
supplies different raw materials to Blast Furnace, Sinter Plant and Refractory Materials
Plant as per their requirements. It also maintains a buffer stock to take care of any
supply interruptions.
Some 9 MT of different raw materials viz. Iron ore fines and lumps, Limestone (BF and
SMS grade), Dolomite lumps and chips, hard Coal and Manganese ore are handled here
every year.
Iron ore and fluxes are sourced from the captive mines of SAIL situated at Kiriburu ,
Meghahataburu, Bhawanathpur, Tulsidamar and Kuteshwar. Washed coal is supplied
from different washeries at Dugda, Kathara, Kargali and Giddi, while raw coal is
obtained from Jharia coalfields.
2.1.2 COKE OVENS AND BY-PRODUCT PLANT (CO AND BPP)
The Coke Oven Complex at Bokaro converts prime coking coal from Jharia,
Dugda and Moonidih and medium coking coal form Kargali, Kathara and Mahuda,
blended with imported coal, into high quality coke for the Blast Furnaces, recovering
valuable by-products like Anthracene Oil, Benzene, Toluene, Xylene, Light Solvent
Naphtha, Ammonium Sulphate and Extra-hard Pitch in the process. Bokaro is situatedin the prime coal belt of the country.
The Coke Oven battery has 8 batteries with 69 ovens each, maintained meticulously in
terms of fugitive emission control, use of phenolic water and other pollution control
measures.
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Fig. 3:CokeOvensComplex
2.1.3SINTERINGPLANT (SP)
The sintering plant at Bokaro is unique in many respects. It has a very high sintering
area per machine, there is provision for partially cooling the sinter on machine itself, the
ignition furnace is of double hearth, plus extended hearth provision is there for adding extra
amount of coke on the top layer of the charge.
Sintering may be defined as the process where heat is produced by combustion of solid fuels
within moving beds of loosely packed particles, so as to agglomerate the loose particles i.e.
iron ore and other fines into a compact porous mass. This porous mass which is called sinter
is used in blast furnace as an iron bearing charge material. If there was no sintering plant then
the fines and the waste materials arising in the iron ore mines and steel plants would have
posed a problem regarding their disposal. So sintering plant helps in that not only it supplies a
suitable charge for blast furnace but also eliminates other intricate problems.
The set up of Sintering plant at Bokaro comprises of five main sections. They are
i. Stock bins and proportioning section
ii. Waste bin section
iii. Raw material section
iv. Machine building section
v. Slime thickening section
2.2 BLAST FURNACE
2.2.1 INTRODUCTION
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The purpose 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. The raw materials require 6 to 8 hours to descend to the bottom
of the furnace where they become the final product of liquid slag and liquid iron. These liquid
products are drained from the furnace at regular intervals. The hot air that was blown into the
bottom of the furnace ascends to the top in 6 to 8 seconds after going through numerous
chemical reactions. Once a blast furnace is started it will continuously run for four to ten
years with only short stops to perform planned maintenance.
Fig 4: Blast Furnace
2.2.2 INPUTS
Iron ore lump (Hematite (Fe2O3) or Magnetite (Fe3O4) and the iron content ranges
from 50% to 70%.)
Sinter
Metallurgical coke
Limestone
Manganese
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Nut coke /special coke
2.2.3 OUTPUTS
Hot Metal
BF gas (used as fuel)
Gangue material used in the form of slag
2.2.4 PROCESS REACTIONS
The coke descends to the bottom of the furnace to the level where the preheated air or
hot blast enters the blast furnace. The coke is ignited by this hot blast and immediately reacts
to generate heat as follows:
C + O2 = CO2 + Heat
Since the reaction takes place in the presence of excess carbon at a high temperature the
carbon dioxide is reduced to carbon monoxide as follows:
CO2+ C = 2CO
Carbon monoxide, is necessary to reduce the iron ore by series of chemical reaction:
1) 3 Fe2O3 + CO = CO2 + 2 Fe3O4 Begins at 850 F
2) Fe3O4+ CO = CO2 + 3 FeO Begins at 1100 F
3) FeO + CO => CO2 + Fe ( Begins at 1300 F)or
FeO + C => CO + Fe
The limestone descends in the blast furnace and remains a solid while going through its
first reaction as follows:
CaCO3 => CaO + CO2
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This reaction requires energy and starts at about 1600F. The CaO formed from in this reaction
is used to remove sulfur from the iron which is necessary before the hot metal becomes steel.
This sulfur removing reaction is:
FeS + CaO + C => CaS + FeO + CO
The CaS becomes part of the slag. The slag is also formed from any remaining Silica
(SiO2), Alumina (Al2O3), Magnesia (MgO) or (CaO) that entered with the iron ore,
pellets, sinter or coke. The liquid slag then trickles through the coke bed Calcia to the
bottom of the furnace where it floats on top of the liquid iron since it is less dense.
2.2.5 INSTRUMENTATION:
2.2.5.1 SENSORSThe main variables in the blast furnace which need to be sensed by the master
computer for comprehensive sensing and control are:
a) Composition.
b) Sizing or Screening.
c) Temperature.
d) Pressure.
e) Voltage (only in Electrical Generators)
f) Ampere (only in Electrical Generators)
g) Misc. Variables and Sensing.
a) Composition:
Composition analysis is one of the main mission critical variables to guarantee
troubleless BF Operation and Product Composition. In a typical steel product from a BF
operation the main critical elements are:
a. Carbon. (Fe3C, Solid Solution, Free Form)
b. Sulphur. (MnS, FeS, etc.)
c. Phosphorus. (Free Form, etc.)
d. Manganese. (Free Form, MnS)
e. Silicon. (Solid Solution, Free Form, Oxide)
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Table 1: Instrumentation used in the analysis are:
Methods Of Analysis Materials to be analyzed
Optical Emission Crude Steel ,Product
X-Ray Fluorescence Slags , sinters
Inert Gas Fusion Steels
Plasma Method Liquids
Ion Selective Electrodes Liquids
Mass Spectrometry Off-Take gases
Neutron Activation Solid steel
b) Sizing and Screening:
Sizing and screening is required at raw material input and sinter plant to let the desired
sized particles pass and reject the remaining. This can simply be achieved by using industrial
screens, which start from small diameter screens to large diameter screens in many steps,
electronic weighing machines permanently manufactured at the bottom of each screen can be
used to measure the weight retained in each screen and this data may be digitized and put to
an attached computer, which will feed the data to the master computer by LAN.
The attached computer besides sending the weights retained, can also be used to control
robotic arms to spread the particles uniformly on the screens and to
remove particles from the screen. The robotic arms can also be replaced by mechanicalcounterparts for cost reduction.
c) Temperature Measurement:
Temperature is the main mission critical variable especially in blast furnace, which should
be measured at all costs. The temperature in the blast furnace gives following information:
Extent of combustion of coke and oxygen in air.
The temperature distribution of the entire blast furnace gives an idea of the extent of
reactions and processes occuring in the furnace
The condition of the refractory bricks can be judged from the comparison of the
temperature of outer shell and internal temperature.
Numerous devices can be used to determine the temperature of various stages in steel making,
some of the most common methods are:
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i) Optical Pyrometer:
The temperature results in the emission of radiations of special wavelengths, an optical
pyrometer is device used to measure the intensity of these special radiations by
semiconductor photo sensors and display them as the temperature on the display. They
are usually gun shaped devices and can be used to measure the desired temperature
without any contact with the hot material.
ii) Thermal / IR Camera Systems:
Thermal / IR Cameras measuring light usually in 3 to 8 micrometer wavelength by a
thermally stable cooled Camera Array. It measures the near infrared light emitted from
hot objects by black-body radiation. These cameras usually contains built in computers or
external portable computers to make temperature distribution diagrams in real time and
also provide point temperatures at selected points without any physical contact. Thermal
Graphs or thermograms are usually obtained from these cameras. They are also used to
detect the thermal gaps in the furnace due to possible wear-off or damage of the furnace
linning.
iii)Thermo-couples:Thermo-couples are formed by joining two dissimilar metallic wires and measuring the
emf in the wires by keeping one joint at reference temperature and the other at
temperature to be measured. They are the most widely used temperature measurement
tools in metallurgy, due to their easy operation, high accuracy, high temperature stability
and rugged use.
Depending upon the metals used, the developed voltage increases between 7 and 75
micro-volt for each degree celcius increase in temperature. J-Thermocouple a junction
between iron and constantan is used to measure between -184 to 760 degree celcius.
iv)Semiconductor Temperature Sensors:
Semiconductor sensors like National's LM35 can be used to measure lower temperatures
in the range of - 55 to 150 degree Celsius. The voltage increases by 10mV for each
degree Celsius rise in temperature. The analog to digital converter usually of operational
amplifiers and the output of LM35 is adjusted to 0V for 0 degree Celsius. But due to their
lower temperature measuring capability they are not employed in metallurgy.
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v)Thermister and RTDs:Resistance Temperature Detectors and thermisters are also commonly used temperature
sensors. RTD's have capability to measure in the range of -250 to 850 degree Celsius.
These RTD's and Thermisters can be encapsulated in refractory bricks due to their low
cost. These bricks may be used to line the other most layer of the furnace to give precise
readings. The resistance is converted into voltage change and digitized by analog to
digital converter.
d) Pressure Measurement:
Pressure measurement of off-take gases, blast gases and internal blast furnace pressure is
very important variable.
i) Strain Gauges and Load Cells:
A strain gage is a small resistor whose value changes when its length is changed. It may
be made of thin wire, thin foil or semi-conductor material. These are used to convert
mechanical pressure gauges already installed in the Off-Take Gas Processing Plant into
analog electronic signals, which in turn are converted to digital signals by analog to
digital converter and integrated with microcontroller.
ii) Linear Variable Differential Transformers:
In this method the core of the transformer is moveable and the change in the voltage of
secondary coil is exploited to measure the temperature. A fixed voltage of known value
and 20KHz frequency is fed at primary coil as AC Excitation Signal. The secondary coils
are actually two coils and opposite ends of each are connected with each other, while the
remaining two are used as output. The output voltage is converted into digital signal by
special AC interface digitizer and is fed
to microcontroller.
iii) Potentiometers:
Potentiometers can be used with pressure guages to give a reading of pressure in a linear
change in resistance, which can be converted into digital signal by analog to digital
converter and fed to microcontroller.
e) Misc. Sensors:
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Various other sensors can be used in Steel Making to detect various variables which are
important for complete automation is used. Some of them are:
i) Height of Burden in Stack:
Height of burden in stack is an important factor and can be detected by a variety of
methods. One of the most easily and low cost method is the use of laser beam to detect
the height. The laser may enter the stack from a quartz window on one side and leave the
stack to be detected from another quartz window on the opposite side. A pulsing laser of
UV band may be employed to prevent it from being interfered by the light produced by
the heat in the stack. More than one laser beams can be provided at different heights to
enable the computers to detect exact height.
Another alternative which is less affected by the presence of dust particles is the use of
ultra-sound instead of laser. An ultra-sound transducer will send a signal from its
diaphram on the top of the stack and below the double bell loading system and receive
the sound waves after being reflected by burden surface and by noting the time taken to
return the sound waves will yield in the exact burden height. The only disadvantage is to
make an ultra-sound system stable enough to operate at 200 to 600 degree celcius.
ii)Gas flow detectors:
The velocity of the in-take gas or hot blast is an important factor and may be measured by
the introduction of a small turbine connected to a small low power generator just before
tuyers. The voltage generated by the generator may be converted into digital data by
analog to digital converter and fed to microcontroller or computer.
Table 2: Technical Data:
No. Of Blast Furnace 5
Volume Of each furnace 2000 cubic meter
Working volume 1756 cubic meter
Capacity of furnace 1756 cubic meter
No. Of stoves per furnace 30,300 square meter
Blast temperature 1100 degree Celsius
Max. Blast Pressure 3.2 Kg/square centimeter
Charging scheme BLT
Hot Metal Specification C=4-4.5%
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Si=0.6-1.2%
Mn=0.6-1.2%
P=0.25%
S=0.05%
2.3 STEEL MELTING SHOP I
Steel melting is a process of removal of impurities like Carbon, Silicon, Manganese, Sulphur
and Phosphorus from hot metal by oxidation and formation of basic slag. For this Hot metal
from BF is taken to LD converter after mixing in the mixture. Pure Oxygen is blown through
water cooled hence to remove impurities by oxidation and steel is made. Purity of Oxygen is
about 99.5%.
There are two Steel Melting shop, SMS-I and SMS-II. Three types are produced from
these shops:
Killed Steel
Semi-Killed Steel
Reamed Steel
2.3.1 RAW MATERIALS
Apart from the hot metals from BF the different raw material required for the production of
steel are:
Limestone
Dolomite
Aluminium
Ferro Alloys
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2.3.2 VARIOUS SECTIONS
Mixer
Converters
Pit Side
Teeming Bay
Stripper Yard
Waste heat Boiler
2.3.3 INSTRUMENTATION AND CONTROL
Distributed Control System(DCS) for Converters & Boilers
Vibro-feeder weighing System for weighing additives
Liquid Steel Temperature Measurement using throwaway type thermocouple
Weighing System in Mixer
Blow time control system
Waste Heat Boiler level measurement and control
Flow and pressure measurement and control of blowing oxygen
Lance height position measurement
Table 3: Technical Data
Capacity of SMS-I 2.5 MT/year
No. of LD Converters 5 (100/130 tonne each)
No. of Lances/Converter 2 each (280/320 NM3/min)O2
Oxygen Pressure 15-20 Kg/m3
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Mode Of Combustion Free combustion
2.4 STEEL MELTING SHOP -II
SMS-II differs from SMS-I because of blowing process and converter gas system. The mode
of combustion in SMS-II is suppressed combustion where atmospheric air is not allowed in
hood area and the combustion of converter gas is suppressed which is further used as a flue.
2.4.1 INPUTS
Hot metal from BF.
2.4.2 OUTPUTS
Semi-killed or Killed steel to continue casting m/c exclusively.
2.4.3 VARIOUS SECTIONS
Mixer: same as that of SMS-I
Two converters of suppressed combustion type
Steel refining unit
Continuous Caster: Heart of SMS-II and has following main point:
Turndish
Mould
Secondary Cooling zone
Straightening Rolls
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2.4.4 MEASURMENT AND CONTROL
PLC for realizing interlocks, monitoring various parameters and control
Lance Height Measurement
Converter Gas Analyzer for O2,CO,CO2
Liquid Steel Temperature Measurement using throwaway thermocouples
Weighing system in Mixer
Electronic Platform Weighing System for Bulk material charging and Ferro-alloy
weighing.
Waste heat boiler level measurement and control
Flow and pressure measurement and control of Blowing oxygen
Blow time control
Table 4: Highlights of Continuous Caster
Mould Straight with adjustable withdrawing
cooling
Dummy Bar System Top charging
Containment Segmental Design
Bending Continuous with 8 mm curvature
Roller Type Split DesignMetallurgical Length 29.5m
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Cooling Air mix cooling
Automation Mould level control, Turndish level
control, secondary cooling, breakout
prediction, computer aided quality
assurance, material, tracing etc.
2.5 CONTINUOUS CASTING SHOP(CCS)
The main function of Continuous Casting Shop is to produce steel slabs directly
from the molten steel coming from SMS-II and sending them to Hot Strip Mill (HSM) for hot
rolling.
2.5.1 SECTIONS
SRU
Caster
Turndish Preparation Area
Slab Area
Slab Yard
RERS(Replaceable Equipment Repair Shop)
2.5.1.1 STEEL REFINING UNIT(SRU)
In SRU the steel is refined to make it suitable for casting of desired quality. First the
steel is killed by removing O2 to
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dispatch CaSi/cafe wire is added to the ladle so as to reduce/eliminate Al2O3 choking at
caster.
2.5.1.2 CASTER
There are two twin stranded slab casters which can cast 940-1850 width of slab with a
thickness of 200,255&250 mm.
2.5.1.3 SLAB YARD
Mainly handles the slabs for despatch to Hot Strip Mill (HSM).
2.5.1.4 TURNDISH PREPARATION AREA
It is used to prepare the Turndishes for casting & RERS for repair of mould, Bender and
segments.
2.5.2 MEASUREMENT AND CONTROL
PLC based Mould Level measurement and control system
Breakout prediction system
PLC based water flow/air pressure measurement and control of different cooling of
different cooling zones
PLC based Level measurement of different water tanks
Steel temperature & Oxygen ppm measurement Electronic weighing system for hopper,
tundish, Turret and slab
Table 5: Technical Data
Type of Machine Low head machine with straight mould and
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segmented stranded guide
Length of Mould 900mm
Number of strands 2x2
Cooling bow radius 8m
Machine speed 0.2M/min-1.9M/min
Cooling Air/mist cooling
Casting Size:
Thickness
Width
Length
200mm,225mm,250mm
950-1850mm
9-10.5m
Others
Metallurgical Length
Dummy Bar
Cutting System
Average heat size
Tundish capacity
29.7m
Top charging
Torch cutting
302T
50T
2.5.3 ADVANTAGES
Higher Yield
Lower Energy Consumption
Lower operating costs
Elimination of primary mills
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2.6HOT STRIP MILL
Hot rolling refers to the plastic deformation of metal above re-crystallization
temperature by squeezing it between pair of roller. The HSM at Bokaro Steel Plant has
continuous 2000mm wide strip mill. This mill is design to roll thin and wide strip for used in
various industries such as wagon building, tube and pipe industries, drum manufacturing and
for use in CRM. The capacity of HSM is 4MT/year. The HSM is rolling different grade of
plain carbon and low alloy steel into strip 1.92 to 12mm thick and 910 to 1850mm wide in
coil form. The average rolling rate is 550T/Hrs.
Table 6: Slab Dimension
Thickness 170 to 230 mm
Width 910 to 1850 mm
Length 7.7 to 10.5m
Max.Weight 32T
Fig. 6: Layout
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Table 7: Coil Dimension
Strip thickness 1.5 to 16mm
Strip width 910 to 1850 mm
Coil inside dia 850 mmMax. Coil outside Dia 2300mm
Max coil weight 32T
Table 8: Comparison between Push Type and Walking Beam type Furnace
Pusher Type Walking Beam Type
Design Giproez Italimpianti
Specific heat combustion 0.50goal/T 0.315 Goal/T
Recuperator Ceramic Metallic
Air preheat Temperature 350 to 500 degree Celsius 650 degree Celsius
No. of Burners 57 156
Capacity 260 T/Hrs 300 T/Hrs
No. of skids 8 main 4 movable+4 fixed
Cooling system Evaporative cooling ECS
Thermal Efficiency 30 to 40% 55 to 65%
Availability 71% 95%
Burner Design Injection type Flat flame type
Slab movement Pushing action Walking Beam Action
Consumption of gas 108000NM3/Hrs 52000NM3/hrs
2.8.1 INSTRUMENTATION
Reheating Furnaces with ECS(3WB+1PT):
Principle function of reheating furnace is to heat the cold and hot slab to the rolling
temperature of 1250 degree Celsius.
Mill proper:
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a). Roughing Mill group
b). Finishing Mill Group
c). Coiler Area
2.8.2 REHEATING FURNACE
This comprises the following measurement & control system:
DCS system for measurement & control of Temperature of all zones
Gas & air flow
Mixed pressure control
Waste Gas pressure control
Upstream/Downstream Draft measurement & control
CV analyser for measurement of CV of mixed gas
O2 analyser for O2 at flue gas
pH &conductivity measurement in DM plant
10 level measurement & control, steam pressure& flow measurement & control in ECS.
2.8.3 MILL INSTRUMENTATION
A number of instruments are in use in Mill area for monitoring critical parameters:
Scanner for motor Bearing & winding Temperature at roughing, finishing stand,
combustion air fans, Roll cooling pumps & descaler pumps
Oil pressure, grease pressure, Oil level measurement
Water flow, pressure, level in distributed chamber, water level in elevated tank
Magnetic flow meter for measurement of water flow for interstand cooling
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Strip temperature measurement by infrared pyrometers in roughing stand, after/before
finishing stand, before coiler & laminar cooling area sec 1 & 2.
2.9 COLD ROLLING MILL
Cold Rolling is defined as a compressive deformation process in which there is
either a continuous or stepwise deformation with more than one rolls. Hot rolled steel is
generally cold rolled at ambient temperature to produce material of following characteristics:-
Thinner gauge material
Material with improved strength
Bright smooth and dense surface finish
2.9.1 INPUTS
Coils from HSM through HRCF (Hot Rolled Coil Finishing)
2.9.2 OUTPUTS
Sheet Gauges
SAIL Auto
SAILCOR
Galvanized Sheet
Tin Mill
Black Planets(TMBP)
2.9.3 SECTIONS
Major sections of CRM complex are:
Pickling line
Tandem Mill
Annealing zone
Hood Annealing
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Continuous Annealing
Electrolytic Cleaning Line
Hot dip Galvanizing line
Continous coil Corrugation line
Galvanized sheet shearing line
2.9.4 ZONES
2.9.4.1 ZONE 1
It comprises of Pickling Line(PL-1&2),Tandem Mill(TM-1 & 2)
2.9.4.2 ZONE 2
It comprises of:
Hood Annealing 1&2(EF Bay)
2000mm 4 High single stand non-reversing skin pass mill
1420mm 4 high stand non-reversing SPM-2
Sheet shearing lines no 1,2,3,4&5
Slitting line no.1 &2
2.9.4.3 ZONE 3
It comprises of:
Hood Annealing 3
Electrolytic cleaning
Continuous annealing line(CAL)
Double Coil Reduction Mill(DCR)
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Shipping Bay
Hot dipping Galvanizing line(HDGL)
HDGL shipping Bay
HDGC consist of following sections:
Hot dipping galvanizing line
Continuous coil corrugation line
Galvanized sheet shearing line
2.9.5 MEASUREMENT AND CONTROL
Annealing furnace temperature control through DCS/PLC
Data Acquisition System(DAS) in Annealing#2
Hydrogen and Oxygen analyser in HDGL/CAL
Infrared pyrometers in HDGL/CAL
Measurement of Ph in block of chemical& conductivity in Galvanising line
Air Gas ratio control in Ammonia cracking unit/HD
2.10 HOT DIP GALVANIZING LINE
The Hot Dip Galvanizing Complex integrated with the CRM produces zinc-
coated Cold Rolled strips resistant to atmospheric, liquid and soil corrosion. The Continuous
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Coil Corrugation Line in the HDGC produces corrugated sheets and the Galvanized Sheet.
Shearing Line produces galvanized plain sheets for a variety of applications. The first shop of
Bokaro Steel to get the ISO-9001 certification way back in 1994, this complex has maintained
a high-standard of coating quality and its SAILJYOTI branded products enjoy a loyal market.
Hot-dip galvanizingis a form ofgalvanization. It is the process of coating Iron orSteel with a
thin Zinc layer, by passing the steel through a molten bath of zinc at a temperature of around
860 F (460 C). When exposed to the atmosphere, pure zinc reacts with oxygen to form zinc
oxide, which further reacts with carbon dioxide to form zinc carbonate, a dull grey, fairly
strong material that stops further corrosion in many circumstances, protecting the steel below
from the elements. Galvanized steel is widely used in applications where rust resistance is
needed, and can be identified by the crystallization patterning on the surface.
The unit has a huge assembly of rollers and kilometers of steel strips .The strips are first
passed through series of furnaces which are divided into 14 zones. This process is termed as
Continuous Annealing and imparts hardness to the material. Then the strip is passed through
molten zinc pot where the actual galvanization takes place. Optimum composition and
temperature has to be maintained here for proper galvanization to take place. The strips are jet
cooled and cleaned. The finished products are Rolls, Corrugated Sheets and sheet.
2.10 PLANT EXCHANGE
In the field of telecommunication, a telephone exchange or telephone
switch is a system of electronic components that connects telephone calls. It is a central
office used to house the equipments inside plant e.g.:- telephone switches, which make
telephone calls "work" in the sense of making connections and relaying the speech
information.
In plant exchange, the server needs 5/12V DC supply. There are different types of
cards, which are as follows:-
1) SSC (System Supervisory Control Card)
2) MMO (Memory Card)
3) TNS (Tone Sender Card)
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4) HWIFC (High-way Interface Card)
5) POW (Power Card)
Types of tones:-
1) DT (Dial Tone)
2) BT (Busy Tone)
3) RBT (Ring Back Tone)
4) HT (Haulie Tone)
2.11 ECRS ( ELECTRONIC CARD REPAIR SHOP )
This shop is used :-
1) To test each component of the electronic cards/circuits.
2) To replace the faulted components.
3) To test the capacitors by an instrument called APPLEP.
4) To test the ICs by an software called ABI.
CHAPTER 3.0
RESULT
At SAIL, BOKARO I completed my vacational training successfully and learnt the total
procedure to manufacture the Steel.
In addition to Steel manufacturing, there I also came to know how to organize the work
and distribute the work among the workers. I visited the various shops, which are connected
to each other in the process of Steel manufacturing.
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CHAPTER 4.0
CONCLUSION
The Vacational training at SAIL, Bokaro helped me in improving my practical knowledge and
awareness regarding Steel manufacturing to a large extent.
Here I came to know about the technology and material used in manufacturing of
Steel. Besides this, I also visualized the parts involved or equipments used in the Steel
manufacturing.
Here I learnt about how the Steel is being manufactured in different forms. At
least I could say that the training at SAIL, Bokaro is great experience for me and it really
helped me in making or developing my knowledge about Steel manufacturing.