Upload
duongkiet
View
259
Download
3
Embed Size (px)
Citation preview
Steel Melting Shop
Electrical Energy Reduction thro’ process innovation
Presented by : Bidhan Mondal
Chiranjib Das Date: 4 th March 2016
2
CONTENTS
a) Introduction
b) SMS : Process Flow Diagram
c) EAF features.
d) Data Sheet.
e) Need is the mother of invention.
f) Innovation.
g) Process Steps.
h) Results - Data Sheet.
i) Cost Saving & Energy Saving.
j) Horizontal Deployment.
Usha Martin Ltd.
Globaly Second Largest Co. in the manufacturing of
“ Steel Wire Ropes ”
Wire Ropes For :
Shipping Mining
Cranes Bridges
Fishing Oil & Gas
Elevators Rope Ways
Tyre cord
3
Usha Martin Ltd. - Key Facilities
1. Iron Making
Blast Furnace 600,000 MT (245 m3, 380 m3)
DRI Plant 500,000 MT
Sinter Plant : 800,000 MT
Coke Oven: 400,000 MT
Pellet Plant: 1,200,000 MT
2. Captive Power Plants
82.5 MW Waste Heat Recovery type
55 MW Thermal power plant
3. Oxygen plant and lime kiln plant
•70 Ton per day, 150 Ton per day, 125 Ton per day Oxygen Plants.
•2 x 50 Ton per day & 1 x 100 Ton per day Lime Kilns
6
Iron Making Facilities
Pellet Plant DRI Plant
Coke Oven Sinter Plant
Blast Furnace
Steel Making
3 EAF
• 40 T capacity
• 40 T capacity
• 70 T capacity
5 Ladle Furnaces
3 VD units
Casters
• CCM1, CCM 2: 3 Strand; 6/11 m radius
130 mm x 130 mm
150 mm x 150 mm.
• CCM3: 2 Strand, 12/16.5/30 m radius
360 mm x 300 mm
240 mm x 200 mm
• CCM4: 4 Strand, 9/16 m radius
200 mm x 200 mm
150 mm x 150 mm
Rolling Mills
• Wire Rod Mill : 400,000 T/year.
• Blooming Mill : 300,000 T/year.
• Bar Mill : 75,000 T/year.
Size Range
Wire Rods: 5.5 – 25.40 mm
Bars/Round: 28 – 160 mm
Bars/RCS: 55 – 150 mm
Flats : Thickness (11-20 mm )
Hex : 23.5 A/F – 34.0 A/F
Rectangle : various sizes
7
Usha Martin Ltd. - Key Facilities
Steel Making and Rolling Facilities
EAF Bloom Caster Reheating Furnace
Bloom Mill Bar Mill Wire Rod Mill
MANAGEMENT SYSTEM CERTIFICATES
ISO / TS 16949:2009 ISO 14001:2004 EMS ISO 9001:2008 QMS
MANAGEMENT SYSTEM CERTIFICATES
TPM OHSAS 18001:2007
VD
EAF VD
LRF
LRF
HM LADLE
FEATURES : EAF : 1 No. • F/C CAPACITY : 40 T • TXN CAP : 20/21 MVA • TECHNOLOGY : EASTERN METEC • REGULATION : DIGITAL SIEMENS • P ON TO TAP TIME : 45 MIN • TAP TO TAP TIME : 60 MIN • OXYGEN BLOWING : 2 INJECTORS ( AIR LIQUIDE) • CHARGE MIX: * HOT METAL : 50-55% * DRI : 35-45% * SCRAP : 10-20%
• PRODUCTIVITY : 0.25 MILLION TON
LRF (2 Nos.) FEATURES : • CAPACITY : 40 T • TXN. CAPACITY : 6 MVA VD ( 01 No.) • CAPACITY : 40 T • EJECTOR : VAI SIEMENS
DRI / FLUX FEED
CCM : 02 Nos. (FLEXIBILITY OF USING BOTH CASTERS ) • TECHNOLOGY : CONCAST INDIA • RADIUS : 6/11 Mtr. • SECTION : 130 SQR. & 150 SQR. • CASTING THROUGHPUT : 1T / MIN. • AMLC / AUTO START • EMS
SMS-1 &2 : PROCESS FLOW DIAGRAM
SCRAP BKT.
BILLET INSPECTION / RECTIFICATION &
DESPATCH
LIQUID METAL
VD
EAF VD
LRF
LRF
HM LADLE
FEATURES : EAF : 1 No. • F/C CAPACITY : 70 T • TXN CAP : 60/65 MVA • TECHNOLOGY : SARRALE (SPAIN) • REGULATION : DIGITAL SIEMENS • PON TO TAP TIME : 45 MIN • TAP TO TAP TIME : 60 MIN • OXYGEN BLOWING : 2 INJECTORS ( SARRALE) • CHARGE MIX: * HOT METAL : 50-55% * DRI : 35-45% * SCRAP : 10-20% • PRODUCTIVITY : 0.5 MILLION TON
LRF (2 Nos.) FEATURES : • CAPACITY : 70 T • TXN. CAPACITY : 14 MVA VD ( 01 No.) • CAPACITY : 70 T • EJECTOR : VAI SIEMENS
DRI / FLUX FEED
CCM : 4 TECHNOLOGY : CONCAST INDIA • RADIUS :9/16 Mtr. • SECTION : 200 SQR. & 150 SQR. • CASTING THROUGHPUT : 1.7 T / MIN. • AMLC / AUTO START • EMS
SMS-3 : PROCESS FLOW DIAGRAM
SCRAP BKT.
BILLET /BLOOM INSPECTION /
RECTIFICATION & DESPATCH
LIQUID METAL
CCM : 3 TECHNOLOGY : DANIELI • RADIUS : 12/16.5/30 Mtr. • SECTION : 200x240 & 300x360. • CASTING THROUGHPUT : 0.8T / MIN. • AMLC / AUTO START • EMS
Usha Martin 12
Electric arc Furnace :
EAF is basic melting unit which –
Converts solid scrap ( combination of solid scrap , DRI & hot metal
from MBF ) in to liquid .
Reduces harmful elements like “P”,“C” from the melt .
Maintains desired temp. required for further processing.
All these activities are carried out with the help of electrical
energy , Oxygen & use of different fluxes.
Electrical energy converts into heat energy , O2 gives chemical
energy which ultimately converts in to heat energy .
Usha Martin 13
Electric Arc Furnace
Usha Martin 14
EAF-II Features
Features:
40MT – EBT furnace
16 MVA transformer.
Oxygen lance from side panels and through slag door along with
coke injection system
Average tap to tap time = 65 - 70 mins.
Usha Martin 15
EAF Working :
This EAF is working with electrical energy, oxygen blowing from
side panels & thro’ slag door along with coke injection.
Processing Steps :
Combination of Liquid PI , DRI , solid scrap is charged in to the
Furnace .
Converts completely in to liquid form – reducing P & C
Removing the slag
Raising the temp to ~ 1650 0C .
Tapping ( at 1620 – 1660 0C ) in to the ladle .
Usha Martin 16
Need is the mother of invention
On 5th February 2015 , EAF transformer winding failed & resulted
in stoppage of production.
Usha Martin 17
Innovation :
As transformer is failed – no electrical power.
So entire working of energy calculation is done .
Steps followed :-
1. Electrical energy required to be replaced is calculated.
2. Decided to replace this electrical energy by chemical energy.
3. Source of chemical energy - O2 , C , Si.
4. With existing mix – 54 % hot metal found that chemical
energy is not sufficiently generated .
5. Decided to increase equivalent hot metal & reduce solid
scrap like DRI & scrap .
6. Fixed the hot metal to 70 – 75 % .
7. Designed the O2 blowing parameters .
8. Taken the trial , fine tuned the process & freezed the process.
Usha Martin 18
Data Sheet (Arcing & Oxygen Blowing)
Sl.
NoDescription Dec'14 Jan'15 Average
a) Charge Mix
DRI (%) 31.62 23 27.31
Hot Metal (%) 53.39 54 53.70
Scrap (%) 14.98 23 18.99
b) Tap to Tap Time (Mins) 68 63 65.50
c) Oxygen Nm3/Mt 47.79 57.65 52.72
d)EAF-II Power Consumption
(Kwh/Mt)209.19 194.11 201.65
e) Yield (%) 76.91 77.08 77.00
Usha Martin 19
Process Steps
1. Charge Mix DRI : 20 – 22 %
Hot Metal : 70 – 75 %
Plant return : 3– 5 %
2. Oxygen Blowing Practice :
Stage Side Lance (2 Nos.) Door Lance
Initial 5 Mins 400 - 600 Nm3/hr 800 - 1000 Nm3/Hr
5 - 15 Mins 400 - 600 Nm3/hr 1000 Nm3/Hr
15 - 25 Mins 1600 - 1700 Nm3/hr 1600 - 1700 Nm3/Hr
DRI Feeding 1600 - 1700 Nm3/hr 1600 - 1700 Nm3/Hr
Slag Off
Typical Tapping Temperature 1650°C
Usha Martin 20
Sl.
NoDescription Nov'15 Dec'15 Jan'16 Average
a) Charge Mix
DRI (%) 22.77 20.52 22.86 22.05
Hot Metal (%) 75.51 76.68 74.79 75.66
Scrap (%) 1.73 2.9 2.35 2.33
b) Tap to Tap Time (Mins) 68.82 73.78 66.81 69.80
c) Oxygen Nm3/Mt 79.77 78.55 68.95 75.76
d)EAF-II Power
Consumption (Kwh/Mt)0 0 0 0.00
e) Yield (%) 79.46 79.82 80.62 79.97
Data Sheet (Only Oxygen Blowing)
Usha Martin 21
Result : Comparative Data
65.5052.72
201.65
2.60
77.0069.8075.76
0 0
79.97
0
20
40
60
80
100
120
140
160
180
200
220
Tap to Tap Time Oxygen (Nm3/Mt) Power (Kwh/Mt) Electrode (Kg/Mt) Yield (%)
With Arcing Without Arcing (Only on Oxygen Blowing)
Usha Martin 22
Cost Saving
442
0
0
100
200
300
400
500
600
700
800
900
1000
With Arcing Without
Arcing (Only
on Oxygen
Blowing)
465
0
With Arcing Without
Arcing (Only
on Oxygen
Blowing)
907
0
With Arcing Without
Arcing (Only
on Oxygen
Blowing)
Electrical Energy Electrode Total
Rs/Mt
Usha Martin 23
Cost Saving
Energy reduced to ‘Zero’
Electrode consumption reduced to ‘Zero’
Additional oxygen required 23.04 Nm3/Mt = 23.04 x 7 = 161 Rs/Mt
Cost Saving :
Energy = 201 x 2.20 = 442 Rs/Mt
Electrode = 2.6 x 179 = 465 Rs/Mt
Cost saving = 442 + 465 = 907 Rs/Mt
Net Cost saving = 907 – 161 = 746 Rs/Mt
Apart from this, reduction in flux consumption and increase in the life of EAF.
Challenges & Opportunities
1. Due to increase of hot metal CO2 emission is increased by
approx. 1100 kg/heat
2. Life of oxygen lancing nozzle reduced from 600 heats to 500
heats
3. Needs to clean roof top position as it is getting jammed due to
splashing
4. Refractory consumption due to refractory delta is reduced to
zero as refractory delta is replaced by water cooled
Usha Martin 24
Usha Martin 25
EAF-3 Started on oxygen blowing and with no arcing power
from 25/11/2015.
Horizontal Deployment
Usha Martin 26
THANK YOU