“ Best Practices in Sesa Sterlite, A Case Study on Energy

“ Best Practices in Sesa Sterlite, A Case Study on
Energy Conservation in Anode Baking Furnace”
Workshop on “Knowledge Exchange Platform”
on 26th Feb 2015 at
DRDO HQ Bhawan, New Delhi.
By – Praveen Kumar R
Madhu Mynampati
1
About Us…,
Vision, Mission & Values
Entrepreneurship
Mr Anil Agarwal
Chairman, Vedanta Resources Plc
Growth
Sustainability
VISION
“We will be the world’s most admired
company that consistently defines the
leading standards in our businesses,
making our stakeholders proud to be
associated with us”
MISSION
“Our mission is to be a world class,
diversified resources company that
provides superior returns to its
shareholders,
through
high-quality
assets,
low-cost
operations
and
responsible corporate citizenship.”
VALUES
Trust
Excellence
2
Our Global Presence
3
Sesa Sterlite - Jharsuguda
5 LTPA Aluminium Smelter
1215 MW CPP
12.5 LTPA Aluminium Smelter
2400 MW IPP
4
Making of Aluminium
5
Aluminium Electrolysis Cell
6
About Our Plant…,
Aluminium Smelter Overview
GREEN ANODE
PLANT
GREEN ANODE
INGOT
WIRE ROD
BILLET
BAKE FURNACE
CAST HOUSE
MOLTEN
ALUMINIUM
BAKED ANODE
CAPTIVE POWER
PLANT
ALUMINA
RODDED ANODE
RODDING SHOP
POT LINE
POT
ALUMINA HANDLING
7
SYSTEM
About Our Plant…,
Bake oven Plant Overview
GAP
Stacking Area
Green
Anode
Baked
Anode
Grouping Station
FTA Crane
Packing Coke
Furnace
FTP
Heavy F/C Oil
Rodding Shop
Stacking Area
Ungrouping
Station
FTA Crane
8
About Our Project Area…,
Project Area - Anode Baking Furnace(ABF)
Furnace Design Details
 Technology: GAMI
 Firing Equipment: Five Solios
 Fume Treatment Plant: Chalieco
 No of Furnaces: 4 (36 Section, 8 pits,
9 flue walls each)
 No of Fires: 8
 Designed Fire Cycle: 28 Hr
 Designed Capacity: 987 Anodes per Day
9
About Our Project Area…,
ABF Operation Pics
Green anode packing into the pit
by FTA crane
Packing coke padding on top
of the green anodes
10
Fire Process
Cross Sectional
View
Fire Process
– –Cross
Sectional
View
S – Section, T – Temperature, P – Pressure, ER – Exhaust Ramp, HR – Heating Ramp,
BR – Blowing Ramp, CR – Cooling Ramp
ER-CM
ER
BR
TPR
S1
4 3 2 1
HR1
HR2
S3
S4
S5
S2
Pre-heating
zone
HR3
S6
S7
S8
Blowing
zone
Heating
zone
CR
ZPR
S9
S10
S11
S12
S13
Cooling
zone
T°
P1, T1
T4
T5
T6 P6
Fire direction
Time
11
Thermal Balance of Furnace
Furnace Oil
Air
Surface
Loss
Pitch
Volatiles
Thermal Balance of
Open Top Furnace
Stack Loss
Packing
Coke
Anode
Baking
Refractory
&
Others
 Furnace oil
contributes
50-55% of
energy
 Pitch Volatile
combustion
gives 40-45%
of energy
12
Why We Choose This Project
Sesa Sterlite is the First ISO 50001 Certified Aluminium
Smelter in Asia.
Our Prime focus is on
DC Energy in Smelting Process
HFO Consumption in Carbon Plant.
13
Six Sigma - DMAIC Approach
D
M
A
I
C
Define: The purpose of this step is to clearly articulate the business problem, goal,
potential resources, project scope and high-level project timeline.
Measure: The purpose is to objectively establish current baselines as the basis for improvement
and also for a data collection step, of which is to establish process performance baselines
Analyze: The purpose of this step is to identify, validate and select root cause for
elimination
Improve: The purpose of this step is to identify, test and implement a solution to the
problem; in part or in whole.
Control: The purpose of this step is to sustain the gains. Monitor the improvements to
ensure continued and sustainable success
14
Project
Charter
Business Case
& Problem
Project
CharterStatement
D - Define
Cost Drivers in Baked
Anode
Heavy Fuel Oil Consumption
75
70
kg/ mt of Baked Anode
M - Measure
A - Analyze
63.8
65
60
Manpow Admin
6%
er
16%
Mfg cost
11%
55
50
45
40
HFO
59%
35
Power
4%
30
I - Improve
Yr Avg Sp Cons
Month Sp Cons
Packing
Coke
4%
Problem Statement :
C - Control
 Year average oil consumption was 63.8 kg/mt of baked anode
 Reduction in furnace oil consumption to 48 kg/mt will reduce
cost of baking by INR 20.92 crore in 2013-14
15
D
Project Scope, Timelines & Sign Off Sheet
PROJECT SCOPE
INSIDE SCOPE
M
1) Bulk Storage
2) Day Tank Area
3) Furnace Floor
4) Firing Equipment
5) FTP
6) Refractory Maintenance
7) Maintenance
8) Firing Operations
NA
PROJECT MILESTONES
A
Project Steps
I
OUTSIDE SCOPE
Date
Project Charter
16-Aug-13
Define phase
Measure phase
15-Nov-13
15-Dec-13
Analyze phase Improve phase Project closure
15-Jan-14
15-Feb-14
15-Mar-14
SIGN OFF SHEET
C
Signatures:
Project Leader
Process-owner:
Process- sustenance owner:
Sponsor
Finance:
Black Belt:
Unit Business Head
Madhu Mynampati
Harshvardhan Pande
Praveen Kumar R
Kamal Kumar Dewangan
Piyush lunawat
Sunil Srivastav
Dayanidhi Behera
16
Project Financial Impact Calculations
D
Sl No
M
A
PARAMETER
UNIT
VALUE
1
Cost of HFO
Rs/MT
42000
2
Current Sp Consumption
Kg/MT
63.8
3
Target Sp Consumption
Kg/MT
48
4
Reduction in Sp consumption
Kg/MT
15.8
5
No of Anode Production for 2013-14
MT
315360
6
Absolute HFO Reduction
MT
4982
Total Saving per Year in Cr
Rs
21
I
C
17
SIPOC Chart
D
M
A
I
SUPPLIER
1. Operation
2. Maintenance
3. Refractory
INPUT
1.Madhu - Shift I/C
2. Jyoti – Elect I/C
3. Shift Crew
Khitish Das
Soumya
Bhagwan
PROCESS
OUTPUT
During the baking process
unwanted heat transfer
processes
1. Coke covering around
the burner stand.
2. Heat loss from top
surface of peep hole
cover
HFO
Consumption
CUSTOMER
Head Bake
Oven
C
18
Process Mapping
D
HFO
Start
B
oil
M
A
Anode
Preheating
(PH 1)
Anode
Grouping
Hot Air
Hot AIr
Anode
Preheating
(PH 2)
Anode
Packing
Hot Air
Anode
Preheating
(PH 3)
Fume
Fume
Treatment
Plant
Baked Anode
Unpacking
Oil
Hot Air
Oil
Heating of
Anodes(HR 2)
Hot Air
Heating of
Anodes(HR 3)
Quality Check
Y/N
Reject Baked
Anode
Y
Baked Anode
Sampling for
Quality Testing
Forced Cooling of
Anodes And
Blowing of Hot Air
Fume Treatment
Plant
Baked Anode
Transfer to
Storage
Pre Heating
Zone
Air
Furnace Operation
Natural Cooling
of Anodes
Quality Check
Y/N
Y
C
N
Hot Air
Draft
I
Heating of
Anodes(HR 1)
Monitoring Points:
1. Preheating
Temp
2. Draft
3. Anode
Preheating rate
4. Heating Temp
5. Final Anode
Temp
6. Soaking Time
7. Soaking Temp
8. ZPR pressure
B
Baked Anode
Supply to
rodding
N
Reject Baked
Anode
Heating Zone
Blowing Zone
Cooling Zone
End
19
SIPOC Parameters
D Define
Input Variables, Xi
Process Variables, Xp
M Measure
•
A Analyze
•
•
I Improve
C Control
•
•
•
•
Leakage from side
Flue Walls/Head
Walls
Cleaning of Flue
Walls
Size of degassing
gaps in flue walls,
mm
Firing Operations
Pitch content in
green anodes, %
Burner Maintenance
Firing Operations
•
•
•
•
•
•
•
•
•
Flue wall
temperature, °C
HR1 Stoppage time
Soaking Time
Pressure and
Temperature of Oil
Size of degassing
gaps in flue walls
Final TPR
Temperature
Draft settings
Pitch front
progression
Baking Curve
OutputVariables,
Variables,
Output
Y
Y
• Reduced
HFO
1.
HFO
Consumption
Consumption
2. Anode
• Temperature
Anode Temp
20
D
Operational Definition of “Y”
What to measure :-
M
1. Total absolute HFO consumption in kg
2. Total anode production in MT
A
I
C
Total absolute HFO consumption in kg
Specific HFO Consumption : - ---------------------------------------------------Total anode production in MT
21
D
M
A
Causes identified from Brain storming
 Idea Generation
conducted
session
 60 Employees from
Operations, Maintenance,
Process Control &
Associated Partners.
 Total 62 Ideas were listed
I
C
22
D
Cause & Effect Diagram
M
A
I
C
23
Cause & Effect Matrix
D
Causes
M
Level 1
Oil temp & Pressure setting
Pitch Burning
Baking Level
A
I
C
Level 2
Method
Improper oil-air mixture
Temp. loss in fire-movement
Improper Top Layering
improper Packing
Temp. loss in fire-movement
Low calorific value of HFO
Improper granulometry of
packing coke
Material Improper burner stand,
casting ring, burner windows,
peephole covers
Improper injector spares
Environm
Atmospheric Temperature
ent
Training Gap
Poor operational skill
Man
Lack of motivation
TPR final Temp
HR1 Initial Temp
HR1 Stoppage Time
Soaking Time
Soaking Temp
Low Air Input
Input/
Process
Indicators
X1
X2
X3
X4
X5
X6
X7
X8
X9
X10
X11
X12
Output 1
Output 2
HFO
Anode Temp
Consumption
Correlation of input to output
10
5
9
1
9
9
9
9
9
3
3
9
3
9
3
1
3
3
3
3
1
3
3
3
1
1
Total
95
135
135
105
75
75
35
45
45
25
45
15
X13
1
3
25
X14
9
3
105
X15
9
3
105
X16
1
1
15
X17
X18
X19
3
3
1
3
3
1
45
45
15
24
Cause & Effect Matrix
D
Causes
Level 1
M
Faulty Injectors
Faulty thermocouples
A
Refractory
Machine
I
Cold air ingress
C
Level 2
Backpressure in nozzles
High response time
Nozzle jam
Leakage from Injectors
Inconel tube Damage
Element Damage
Poor maintenance skill
Cable Damage
Leakage from U- Plate
Leakages from Side walls
Leakage from Head walls
Peep Hole cover damage
Improper cleaning
Top Block Damage
Insulation Wall Damage
Air Ingress ZPR sheath
Air ingress through HR T/C
sheath
Air ingress Through shut off
Gate Dampers
Air Ingress through TPR
Sheath
Air Ingress through ER hatch
Air Ingress through Burner
stand
Output
Output 2
HFO
Input/Proc
Consumptio Anode Temp
ess
n
Indicators
Correlation of input to
10
5
X21
9
3
X22
3
3
X23
3
3
X24
9
3
X25
3
3
X26
3
3
X27
3
1
X28
3
1
X29
3
1
X30
9
1
X31
3
1
X32
3
1
X33
9
1
X34
3
1
X35
3
1
X36
3
1
Total
105
45
45
105
45
45
35
35
35
95
35
35
95
35
35
35
X37
3
1
35
X38
3
1
35
X39
3
1
35
X40
3
1
35
X41
3
1
35
Factors having score more than 80 are considered for actions in first
phase
25
D
Operational Definition of Inputs(Xs)
Performance Measure
M
A
I
C
Operational Definition
Oil Temp and pressure is the measure of Oil used in the Ramp.
Oil temp & Pressure setting Unit of measurement is Degree Celcius
Measured with RTDs at the oil line in the heating ramp
Temperature of Flue wall at the TPR before fire change
Temperature Pressure
Unit of measurement is Degree Celcius
Ramp(TPR) final Temp
Measured with Thermocouples at the TPR Ramp
Temperature of Flue Gasses at the First Peep Hole of the Pre Heating Section No 3
Heating Ramp(HR) Initial
Unit of measurement is Degree Celcius
Temp
Measured with Thermocouples at the HR 1 Ramp
Heating Ramp Stoppage
Duration of time the HR is stopped during the baking process
Time
Unit of Measurement is Hours
Improper burner stand,
Condition of the equipment to insulate heat from escaping from the furnace
casting ring, burner
Unit of Measurement is No
windows, peephole covers Measured by physical inspection
Condition of the Burners used to inject oil in the furnace. Represents the health of the
burners.
Improper injector spares
Unit of Measurement is No
Measured by physical inspection
This is a physical condition observed in the Injector systems wherein flames are
Backpressure in nozzles
observed in the Burner Base inspection Windows.
Measured by Physical inspection
This is the condition observed in the Furnace where in inpite of High Draft in the Pipe
Leakages from Side walls
Opening, very less draft is observed in the Side Flues.
Unit of Measure is Pa and Measurement is done by Pressure Gauges
Condition of Flue Wall Surface wherein Pitch and Coke mixture is found deposited on
Improper cleaning
the Flue Wall surface clogging the Degassing Gaps
Measure by Physical Inspection
26
D
MSA - GRR Study on Oil Consumption
Gage R&R Study - ANOVA Method
M
A
I
C
Two-Way ANOVA Table With Interaction
Source
Parts
Operators
Parts * Operators
Repeatability
Total
DF
7
2
14
48
71
SS
116.689
0.001
0.002
0.004
116.696
MS
16.6699
0.0004
0.0002
0.0001
F
110700
3
2
P
0.000
0.096
0.103
α to remove interaction term = 0.05
No of Parts: 8;
Total Trial Runs: 72
Instrument Used: Dip Gauge
P – Value < 0.05 so Gage R&R study is well accepted
27
D
Stability Test
M
A
I
C
As all the 4 P – Values are greater than 0.05 so the process is
stable
28
D
Normality Test
M
A
I
As PValue is
greater
than
0.05, so,
data is
normal
C
29
D
Process Capability Test
M
A
I
C
ZBench+1.5 =0.69
30
Causes Shortlisted from C & E matrix
D
Sl No
M
A
I
LIST OF FACTORS TO BE VALIDATED
1
Oil Temperature and Pressure
2
TPR final Temperature
3
HR1 initial Temperature
4
HR Stoppage Time
5
Improper Burner Assembly
6
Nozzles Problem
7
Leakages from Side walls
8
Improper cleaning of Flue Wall
C
Factors having more than 80 score are listed down
31
D Define
Data Analysis – Regression for validated causes
M Measure
A Analyze
I Improve
C Contro
l
From the above regression analysis, it shows that the two factors are
contributing the most in HFO consumption
32
FMEA
D
Additional exploration/prioritization of X’s through FMEA done with middle
management and senior management
M
A
Process
Step
Potential
Effect(s) of
Failure
Fluewall
Cleaning
Improper pitch
burning
High HFO Consumption
8
Regular fluewall
cleaning not done
10
Random inspection of
Fluewall cleaning
9
720
Refractory
Maintenance
Side fluewall
(1&9) leakages
High HFO Consumption
due to low temp in
Fluewall 1&9
8
Improper sectional
refractory
maintenance
9
No inspection from
operation team
9
648
Cold air ingress
High HFO Consumption
to maintain the
temperature
7
Damaged burner
stand, cast iron ring,
burner windows, peep
hole covers
9
No inspection before
usage of burner stand,
cast iron ring, burner
window, peep hole
7
441
Delay in achieving
Interruption while
Heating Ramp
desired temp leading to
pulsing of fuel
high HFO consumption
7
Nozzle choke
9
Only existing old nozzles
replacing by cleaning
7
441
6
Optimization of
stoppage time not done
8
Currently 8 Hrs
stoppage tome optimized
3
144
7
Non-availability of
sufficient draft for
pitch burning
7
Online monitoring of
individual draft
1
49
Baking process
I
Potential
S
O
D
Cause(s)/
Current Process
e
c
e
Mechanism(s)
Controls
v
c
t
of Failure
Potential
Failure
Mode(s)
Heating curve
Extra fuel
injection
Heating curve
Low initial temp
at HR1 due to
improper pitch
burning
C
High HFO consumption
Additional fuel input
R
P
N
In first phase total RPN score which are having above 144 considered for implementation
33
List Of Total Significant Factors
D
Sl No
M
A
Root Causes
1
Regular flue wall cleaning not done
FMEA
2
Improper sectional refractory
maintenance
FMEA
3
Damaged burner stand, cast iron ring,
burner windows
REGRESSION
ANALYSIS
4
Number of peep hole cover replace
REGRESSION
ANALYSIS
5
Low initial temperature at HR
FMEA
6
Nozzle choke
FMEA
7
Optimization of stoppage time not
done
FMEA
I
C
Methods
34
D
Solution Prioritization
SOLUTIONS
M
A
I
C
Impact on Time
parameter Impact
Scale
3
Run all dampers in Remote mode for draught optimization
3
Heating curve optimization
3
All settings in Heating Ramp to be lock
1
Proper placement of protection tube
3
Manual adjustment in Ring main damper
3
Ensure optimum draught availability(60 to 125Pa) in Exhaust ramp
9
Ensure final TPR temperature reaches in all fluewall
9
Anodes should not touch the fluewall inside the pit
3
Ensure GCV, Moisture,Density
3
Ensure air tight inside the HFO circuit
3
Ensure proper functioning of tightening rod, replacing heavy oil hose with normal hose
3
Replacement of cleaned nozzles before fire change
3
Ensure quality of coke receive from GAP as per specification(0.8 to 6 mm)
3
Double polytene covering in preheating section
9
Leakage points to be sealed with ceramic wool
9
9
Relayering of preheat3 before fire change
Replace the burner stand and TC sheet with repaired ones
9
Even coke padding from corner to corner
3
Emptying the HFO buckets and trays regularly
3
Connect hose to the drain point
3
Bucket or funnel arrangement around the coupling
3
Emptying the HFO drum regularly
1
Replace all terminal ball valves with gate valves
1
Ensure proper tightness in flanges of HFO circuit line
3
Scale: 0 = None, 1 = Low, 3 = Moderate, 9 = Strong
7
3
3
1
3
3
1
1
1
3
3
3
1
1
1
3
1
1
1
1
1
3
1
3
1
Cost
benefit
impact
10
3
3
3
9
1
9
9
3
3
9
9
9
3
9
9
9
9
3
3
3
3
3
3
3
Total
Rank
60
60
40
120
40
124
124
46
60
120
120
106
46
124
138
124
124
46
46
46
60
40
54
46
11
12
24
7
23
5
4
20
13
8
9
10
21
3
1
2
6
16
17
18
14
22
15
19
35
Selected Solutions
D
Sl No
M
A
Solutions
1
Leakage points to be sealed
2
Relayering of preheat3 before fire change
3
Double polythene covering in preheating section
4
Ensure final TPR temperature reaches in all flue wall
5
Heating curve optimization
6
Replace the burner stand & TC sheet with repaired ones
7
Proper placement of protection tube
I
C
36
Pilot Plan
D
Impleme
ntation
Number
M
1
Leakage points to be
sealed
1
1.Checklist prepared for
inspection of flue wall refractory
maintenance 2. Adherence
verified in A&B shift
2
Nimanand
05.03.14
Implemented
Currently this practice has
implemented
Madhu
Implemented
Implemented
3
Currently this practice has
implemented
Soumya
Implemented
Implemented
4
Ensure final TPR
temperature reaches
in all flue wall
4
Improve TPR temp from 780 deg
C avg in Flue Wall 2-8 to 810 deg
C & from 620 deg C avg in flue
wall 1 & 9 to 700 deg C
Madhu
Monitoring
Monitoring
5
Ensure Heating
curve optimization
5
HR1 initial temperatures to be
cross check
Parijat
6
Replace the burner
stand and TC sheet
with repaired ones
6
No of damaged TC sheets and
burner stands to be audit and to be
replace with repaired one
7
Proper placement of
protection tube
7
SOP compliance to be ensure
2
A
Solution
Responsible Target/
Control
Current
Individual/ Actual
Action Improvement Action
Status/
Solution Complete
Number
Comments
Owner
Date
3
Relayering of
preheat3 before fire
change
Double polythene
covering in
preheating section
I
C
Monitoring
Monitoring
Sushant
09.03.14
Damaged TC
sheets changed
and burner stands
changing by daily
requirement basis
Soumyajit /
Bhagawan
Implemented
Implemented
37
D
Solution 1 - Air Ingress Prevention
Before
After
M
A
Gap between flexible base and cast iron ring
Cerawool covered the flexible base
I
C
Gap between burner stand & ring
Gap covered with packing coke
38
D
Solution1 - Heat Loss Prevention
Before
After
M
A
I
C
Head wall gaps not filled
Head wall gaps filled with
Cerawool
39
Solution1 - Heat Loss & Cold Air Ingress Prevention – Peep
hole cover design modification
D
•
•
M
•
•
A
Covers were modified from the original
design as shown in the figure
Metallic cylinder and nets were replaced
with ceramic wools and holding plates
Redesigned covers saves nearly 73°C from
the original design
Modified covers were 700 Rs cheaper than
the original design.
Top Surface Temperature (°C)
I
346
•
C
•
Peep hole cover were damaged with
increased age. This resulted huge
heat losses from the furnaces.
Cost replacement of entire lot of
5200 number covers were too high.
258
185
Damaged
Designed
Modified
40
D
Solution1 - Heat Loss & Cold Air Ingress Prevention
Problem
M
•
Cast iron rings were deformed at high
temperature
•
A
Resulted gaps between rings & cover because of
misalignment
Metallic Ring as per design
•
I
•
•
C
•
Modified refractory castable ring
Solution
Refractory castable made rings were introduced
Castable rings did not deform under high
temperature
Reason for misalignment was eliminated
Castable were cheaper than the prior metallic
rings
41
D
Solution1 - Refractory Maintenance Initiatives –
Flue Wall Repair & Rebuilding
•
Based on the final pre heat
temperature the side flue
walls were mapped.
•
Total 35 flue walls with lowest
temperature were identified.
•
Top 5 layers are being
replaced with top 10 layers of
side insulation wall.
•
An average increase in draft
around -20 pa was observed
•
An increase in flue wall
temperature around 200°C
was achieved
M
A
I
C
42
D
Solution2 - Relayering in Preheating3
Before
After
M
A
I
C
Packing coke layer which is less
than 150mm from fluewall top
Packing coke layer which is
maintained at 150mm from
fluewall top
43
D
Solution3 - Double polythene covering
Double Layer Polythene Covering in Preheat Zone
Effect of Double Polythene Covering on Draft
M
0
1
2
3
4
5
6
7
8
9
-20
Single
Polythene
-40
-71
-80
-80
-120
-114
-122
-106
-105
-78
-89
-92
-96
-100
I
-60
-60
Draft (Pa)
A
-54
-99
-101
-108
-120
Double
Polythene
-140
-144
-151
-160
C
Flue Walls
Single Cover
Double Cover
44
D
M
A
Solution 4 - Preheating Curve Modification
Preheating curve optimisation done
to ensure complete pitch volatile
combustion.
After several trials following
modification was done :
•
I
Final preheating temperature
was increased from 740°C to
800°C
Note: Anode heating rate < 10°C/hr
was maintained to avoid micro
cracks
C
45
D
Solution 5 - Heating Curve Modification
Heating curve also experienced step
by step change:
M
A
I
C
•
Initial temperature was increased
from 790°C to 810°C
• Oil injection was started after 8
hours of fire change (initially it
was 4 hours)
• Oil injection continued till 76
hours of total 96 hours heating
(initially it was 78 hours)
• Final temperature was reduced
from 1145°C to 1140°C.
Fixed Parameters: Soaking period
@34 hours ; Final anode temperature
@1100°C
Heat loss was significantly reduced
because of the shorter duration curve.
46
D
Solution6 – Modification of Thermocouple Sheet
M
•
Thermocouple sheets were
damaged with increased age
•
Heat loss was noticed from the
top of these sheets
A
•
Frames were restructured with
ceramic wool
•
Resulted nearly 70°C temperature
saving at the top surface
•
Modification was also very cost
effective
I
C
47
Pilot Results And Analysis
D
M
Experiments started fSpecific HFO Consumption Trend
58
month
57
Experiments started
56.3
55.85
56
from this month
A
Kg/MT of BA
55
54
53
52
51
I
50
54.22
53.9
53.43
52.53
51.32
50.15
49.74
49.5 49.47
49.9
49.5
49
49
48
47.57
47.25 47.15
47
C
46
48
D
Result Validation – Hypothesis Test
H0: Sp. HFO Consumption achieved is same as base line
Ha: Sp. HFO Consumption achieved is lower than the base line
M
A
I
C
Conclusion: P value = 0.828 > 0.05 (α = 0.05).
So, in 95% confidence interval it can be said that the data are normal
49
Result Validation – Hypothesis Test
D
ividual Value Plot of Specific Cons (Kg/mt)_Past, Specific Cons (Kg/mt)_pres
75
Two-Sample T-Test and CI: Specific Cons (Kg/mt)_Past, Specific
Cons (Kg/mt)_present
70
Two-sample T for Specific Cons (Kg/mt)_Past vs Specific Cons
(Kg/mt)_present
65
60
Data
M
N Mean StDev SE Mean
Specific Cons (Kg/mt)_Pa 118 54.82 5.99 0.55
Specific Cons (Kg/mt)_pr 121 50.88 2.80 0.25
55
50
45
A
40
Specific Cons (Kg/mt)_Past
Specific Cons (Kg/mt)_present
Boxplot of Specific Cons (Kg/mt)_Past, Specific Cons (Kg/mt)_present
75
70
I
65
Difference >= μ (Specific Cons (Kg/mt)_Past) - μ (Specific Cons
(Kg/mt)_present)
Estimate for difference: 3.940
95% CI for difference: (2.741, 5.139)
T-Test of difference = 0 (vs ≠): T-Value = 6.49 P-Value = 0.000
DF16
Data
60
Conclusion: P value = 0.000 < 0.05 (α = 0.05).
So, in 95% confidence interval it can be said that
the sp. HFO consumption achieved is lower than
the base line value
55
50
C
45
40
Specific Cons (Kg/mt)_Past
Specific Cons (Kg/mt)_present
50
D
Process Capability Test – Post Improvement
M
A
I
1.18
C
Sigma Level improves from 0.69 to 1.18.
51
Results Realized
D
59
57
55
KG/MT OF BA
M
 Initiatives taken in
the year 2013-14,
helped to reduce the
oil consumption
drastically from the
level of 63.8 to 49.74
kg/ mt of baked
anode
Specific HFO Consumption
Trends
53
51
49
A
47
Specific HFO cost, rupees per anode
Nov/14
Oct/14
Sep/14
Aug/14
Jul/14
Jun/14
Apr/14
Mar/14
Feb/14
Jan/14
Dec/13
Nov/13
Oct/13
Sep/13
May/14
2331
2013-14
C
2718
2012-13
I
Aug/13
Jul/13
45
 There were a bit
upward trends
during the period of
September,13 and
October,13 due to
process optimisation
experiments.
 This improvement in
oil utilisation
provides nearly INR
19 crore savings
52
D
Project Financial Benefit Calculations For 2013-14
Sl No
M
A
I
C
PARAMETER
UNIT
VALUE
1
Cost of HFO
Rs/MT
42000
2
Current Sp Consumption
Kg/MT
63.8
3
Target Sp Consumption
Kg/MT
49.74
4
Reduction in Sp consumption
Kg/MT
14.06
5
No of Anodes to be produced
MT
315360
6
HFO saved per annum
MT
4434
Total Saving per Year in Cr
Rs
19
53
Intangible Benefits
ay Forward...
Team Spirit
Sense of Entrepreneurship
Conservation of natural resources
Learning of six sigma methodology
Way Forward:
 A Six sigma project has been taken to achieve furnace
oil consumption of 45 Kg/Mt of baked anode
 Installation of flow meters in individual ramps
 Trial with oil additive
54
Acknowledgement
Abhijit Pati
COO - Metal & Power
Srinivas Narkedamalli
Head - Carbon
Dr. Rajeev Nayan
Head - HR (VAL)
Kamal Dewangan
Head - Bake Oven
Dayanidhi Behera
Head - Plant 1
Sunil Srivastav
Head - L & D, TQM
55
This is an ongoing game; there can’t be a Number One
or Two. But we always aim to enhance our capacities
to its maxim…!!!
- Anil Agrawal
“Little Drops of Water Make a Mighty Ocean….”
These drops of oil will make our BAKE OVEN to
A BAKE HEAVEN”…
Thanks a Lot….
ANY
QUERIES?