iiii How to Reduce Production Costs and Environmental Impact Steel

i Steel®: Tenova Innovative Technologies:
How to Reduce Production Costs
and Environmental Impact
MMMM 2012 – Resurgent India: Vision 2020 in
Metals & Minerals Sector
New Delhi, September 29th , 2012
Davide Masoero
Area Manager i Steel Melt Shops
Tenova S.p.A.
Iron&Steel Division
Vision 2020
Drivers to face the challenge of the next decades:
Flexibility
Environment friendliness
Continuous data collection
Real time process analysis
Dynamic control
Are we ready?
YES
Tenova i Steel Technologies
2
i Steel® - Tenova Innovative Technologies
The philosophy
Increase steel making process efficiency
•
Exploit energy input inside EAF
i EAFTM
Dynamic process control system through
real-time measurements
•
Recover wasted energy exiting EAF
i Recovery®
Steam production through
offgas energy recovery
The i EAF®
The i EAFTM
4
i EAF® - Definition
i EAF® Technology is a modular program that provides savings and productivity
improvements by optimizing and dynamically controlling the EAF process.
It is a system for dynamic, real-time control and optimization of the electric arc
furnace that uses sensors, models and real time advanced control algorithms.
Module 1 – EFSOP® System Description
Patented Probe
Patented water-cooled probe
continuously samples the off-gas
exhaust for the Goodfellow
EFSOP™ gas analyzer
Gas Analyzer
Measures levels of O2,
CO, CO2 and H2 and sends the data
to the operator screens and to the
Goodfellow EFSOP™ computer in
the furnace control pulpit
EFSOP™
HMI & SCADA
.
Plant PLC
Plant PLC network communicates
with the EFSOP™ analyzer and
computer to receive new setpoints for dynamic furnace control
Goodfellow EFSOP™
computer (closed loop
control) and/or operator
send process
adjustments to the plant
PLC network
6
Module 1 – Off-Gas Losses
Unburnt chemical energy (CO and H2). Up to 70% of chemical energy
added is wasted. Ideally, these gases are combusted mostly in the furnace to
help lower kWh.
In poorly balanced furnaces, a portion of these gases are combusted even
further downstream leading to higher temperatures in the fume system. In
severe cases, baghouse fires and explosions occur.
C h e m ic a l O ff-G a s H e a t L o a d
40
S e n s ib le O ff-G a s H e a t L o a d
35
30
25
20
15
10
5
0
T im e (M in u te s in to h e a t)
40
35
30
25
20
15
10
5
0
Time (Minutes into heat)
7
Module 1 – EFSOP® Off-Gas Chemistry
EFSOP® measures CO, O2, CO2 and H2 continuously at
the fourth-hole.
8
Module 1 – Chemical dynamic control
Closed loop control based on offgas composition
Module 1 – Proven EFSOP® Economic Savings
MacSteel **
Deacero **
Customer Verified Savings
Nucor Auburn
For installations allowing public
disclosure. Savings based on:
Nucor Seattle
Hylsa
Electricity
Fuels
Charge & Injected Carbon
Oxygen
Yield **
Productivity **
Cape Gate
Thamesteel
POSCO
Topy
CMC-AL
Dongkuk
$0,00
$1,00
$2,00
$3,00
$4,00
$5,00
Customer Verfied EFSOP® Savings US$ per tgb
10
Module 2 – i EAFTM New Advanced Sensors
Sensors:
EFSOP Off gas composition
Off gas flow sensor
Off gas temperature sensor
Off gas pressure sensor
Measurements:
CO, CO2, H2, O2, H2O*
Temperature
Flow
Pressure
* under testing
Module 2 – i EAF® advanced process models
Advanced sensors
information
cooling water circuit
information
chemical electrical real
time data
plant bucket information
Off gas, cooling panels,
furnace bottom losses
Net bath oxidation and
decarburization
Oxidation energy
Net energy transferred to
charge
Melting progress
The MP defines the progress of the heat. It is the ratio between the
liquid formed over the total amount of charged material.
MP = (Net energy to charge)/(specific energy required to melt * charge
weight)
Module 2 – MP control innovation
Electrical and Chemical closed loop control based on MP
Module 2 – Installations and Results
6 M2 i EAFTM installation
4 M2 i EAFTM underwork:
TenarisDalmine
Riva Verona (2 EAFs)
ArcelorMittal Dofasco (2EAFs)
Beltrame Vicenza
Tenaris Tamsa (Summer 2012)
Ternium Siderca (Summ. 2012) – i DRI®
Ternium Puebla (Summ. 2012) – i DRI®
Sidor (December 2012) – i DRI®
Plant 1
Plant 2 (2EAFs) Plant 3 (2EAFs)
Electrical Energy kWh/tgb
- 2,30%
- 2,50%
- 3% ÷ - 5%
Fuel (CH4)
Nm3/tgb
- 3,70%
- 16,3%
- 5% ÷ 0%
Oxygen (O2)
Nm3/tgb
- 0,20%
+ 0,30%
- 1% ÷ - 1%
Productivity
tgb/h
+ 2,40%
+ 5,20%
In addition to the EFSOP Savings
Module 3 – T&C prediction
Once MP =100%, the Bath & Slag model
will use the calculated specific net energy,
to evaluate in real time the bath
temperature and composition behavior.
The predicted temperature is the average bath temperature. It has to be
carefully compared with the local immersion thermocouple measurement.
The predicted carbon is statistically corrected to the errors in the carbon in
and out evaluations. In addition it is corrected once the first ppm reading is
taken.
Module 3 – Temperature prediction
Temperature error std
deviation: 24.9 Celsius.
The i Temp®
i Temp® - Tenova Patent EP1440298-B1
Patented technology for optical measurement
of the temperature of the liquid steel
Optic pyrometer installed on
a KT lance
Easy equipment integration
FOV through the main
oxygen
Nitrogen supersonic injection
for slag surface opening
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Pyrometer signal during nitrogen shoot
Average spectral radiance ratio during the nitrogen shoot
0.55
The nitrogen shoot opens the
slag surface, the signal
decreases because molten steel
is colder than slag
0.45
0.4
0.35
0.3
0.25
0.2
0.37
0.15
0
2
4
6
8
10
12
Refining time (min)
Nitrogen shoot cycle
takes 1sec
Nitrogen introduced in
the EAF is 0.577Nm3
14
0.32
Spectral radiance ratio, N1/N2
Spectral radiance ratio, N1/N2
0.5
0.27
0.22
0.17
0.12
Shooting time 1sec
0.07
0.02
8.18
8.2
8.22
8.24
8.26
8.28
8.3
Refining time (min)
19
i Temp® Vs Immersion thermocouple
Immersion Thermocouple
iTemp
1800
1750
Temp (°C)
1700
1650
1600
1550
1500
1450
300
310
320
330
340
350
360
370
380
EE (kWh/ton)
20
TAT® - Tenova Auto Tapping
TAT® - Tenova Auto Tapping
Automatic Tapping
TAT® - Tenova Auto Tapping
Automatic EBT refilling
TAT® - Tenova Auto Tapping
Robot for EBT Cleaning
TAT® - Tenova Auto Tapping
Lance for EBT Opening
The i RecoveryTM
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i RecoveryTM - Description
100 t/h EAF from 14 t/h to 28 t/h steam produced
20 – 25 % of primary energy can be recovered
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i Steel technologies - Installations
Davide Masoero
[email protected]
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