major project report final
TRANSCRIPT
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VISVESVARAYA TECHNOLOGICAL UNIVERSITY
BELGAUM-590014
A major Project Report on
“Debottlenecking of HMDS unit in SMS-2 (JSW Steel)”
A project report submitted in partial fulfillment of the requirement for the award of degree of
MECHANICAL ENGINEERING
Submitted by
Shivanna 2BV10ME106
Shouvik Das 2BV09ME107
Shreyas Kari 2BV09ME108
Yatiraj Singi 2BV09ME110
Under the guidance of
DR. Sanjay Kotabagi
ACADEMIC YEAR 2013-2014
KLE SOCIETY’S
B.V.BHOOMARADDI COLLEGE OF ENGINEERING AND TECHNOLOGY, HUBLI-31
(An Autonomous Institution Affiliated to VTU, Belgaum)
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KLE SOCIETY’S
B.V.BHOOMARADDI COLLEGE OF ENGINEERING AND TECHNOLOGY, HUBLI
(An Autonomous Institution Affiliated to VTU, Belgaum)
2013-2014
DEPARTMENT OF MECHANICAL ENGINEERING
Certificate
This is to certify that the project titled “Analysis of HMDS unit in SMS-2 (JSW Steel)” is a work
carried out by 1)Shivanna 2)Shouvik, 3)Shreyas, 4)Yatiraj, bonafide students of B.V.B College of
Engineering and Technology in the partial fulfillment for the award of Bachelor of Engineering in
Mechanical Engineering of the Vishvesvaraya Technology University, Belgaum during the year
2013-14. The project report has been approved as it satisfies the academic requirements in respect
of the project work prescribed for the above said course.
PROJECT GUIDE PROJECT GUIDE (JSW) HOD PRINCIPAL
Signature of Examiners
Name Signature with date
1.
2.
3
ACKNOWLEDGEMENTS
A sincere gratitude to all the kind and noble souls who blessed us and guided
us in the partial fulfilment of the course project. It gives immense pleasure in
acknowledging them; the following is the list with lots of thanks:
The Team MPB4 cordially expresses its acknowledgement to Dr. Sanjay
Kotabagi, for his guidance throughout the execution of our project and continued
support for the same.
We are thankful to our beloved Principal Dr. Ashok Shettar, for his support,
cooperation, and motivation provided to us during the field visits for constant
inspiration, presence and blessings.
It gives us immense pleasure in acknowledging our beloved HOD Dr.
P.G.Tewari, for providing us an opportunity to work on such practical based
projects.
Lastly, we would like to thank the almighty and our parents for their moral
support and our friends with whom we shared our day-to-day experience and
received lots of suggestions that improved our quality of work.
DEC 2013 MPB4
BVBCET,
Hubli
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ABSTRACT
In Hot Metal Desulphurisation Station, sulphur impurities are removed from hot
metal by a process. This metal is then taken to Basic oxygen furnace for charging.
Over a period of time this complete process got slowed. The converter at furnace
had to be kept idle for a long time. This resulted in heavy losses. The problem
has to be identified and analysis has to be carried on. Complete process steps
have to be verified for errors. Debottlenecking has to be removed from the
process so that the complete process goes on smoothly and at rapid rate. The hot
metal ladle is placed into a treatment chamber. The treatment chamber is closed
by a cover or a hood, dedusting is activated and the injection lance or the impeller
is lowered down to the final treatment position. After having injected or stirred
in the required amount of desulphurisation agents, the lance or the impeller is
retracted and the desulphurisation step is finished. Afterwards the top slag is
removed by a slag skimmer. The treatment chamber is opened and the ladle
transferred to the BOF shop.
Keywords: HMDS, BOF, hot metal, slag
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TABLE OF CONTENTS
Sl no. Topic Page No.
Plan of Action 6
2. Customer Need 7
3. Problem Definition 7
4. Learning Aspects 8
5. Process 8-9
6. Data Collection 10-11
7. Tilting car Problems 11-13
8. Problem Root Causes 14-22
9. Ansys Analysis 22-25
10. Load Calculation 26-28
11. Progress So Far 29
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12. Problems Identified 29
13. Flow Diagrams 30-31
14. Problems Identified 32
15. Solutions Suggested 32
16. Bill Of Materials 33-35
17. Operating Values 36
18. Cylinder Calculation 36-38
19. Changes Made 39-52
20. Comparison Of Breakdown Minute 53
21. Increase In Availability 54
22. Economics Of Maintenance 55
23. Cost Analysis 56
24. References 58
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PLAN OF ACTION
7th Sem
• Problem Identification
• Data Collection
• Problem Analysis
• 2D drawing review
• Search for solution
8th Sem
• Detail solution to each problem
• Implementation of solution
• Check for effectiveness
• Possible alternate solution
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CUSTOMER NEED/ CLIENT NEED
• At JSW Steel Limited the charging time of hot metal to the basic oxygen furnace has
reduced drastically over the span of time.
• The client needs to identify the reason causing the delay in the supply time and suggest
proper rectification.
• Delay in charging time is directly linked to the production rate.
PROBLEM DEFINITION
• The charging of desulphurised metal from HMDS to converter at BOF is slow.
• As a result of which the downtime is more and converter at BOF is idle for a long period
of time.
• The direct impact is in production cost and it`s productivity.
• All the electrical equipment's are at run for a longer time decreasing the overall
efficiency.
SPECIFICATIONS/LEARNING ASPECTS
In our project we would be basically involved with the following parameters of the plant:-
• Process flow
• Hydraulic equipment’s involved
• Production downtime
• Cost Benefit
• Productivity
PROCESS
The hot metal ladle is placed into a treatment chamber. The treatment chamber is closed by a
cover or a hood, dedusting is activated and the injection lance or the impeller is lowered down
to the final treatment position. After having injected or stirred in the required amount of
desulphurisation agents, the lance or the impeller is retracted and the desulphurisation step is
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finished. Afterwards the top slag is removed by a slag skimmer. The treatment
chamber is opened and the ladle transferred to the BOF shop.
Hot metal desulphurisation (HMD) is effected by a powder deep injection system
with refractory lined immersion lance(s). The unit consists of one or more
treatment chambers with movable covers, connected to a dedusting system. A
slag skimming device including a ladle tilting frame can be integrated or provided
in a separate position.
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The desulphurised metal is carried from HMDS unit to the BOF converter by means
of overhead cranes and rails. This desulphurised metal on reaching the vertical spot
above the converter is tilted so that it`s poured into the converter for steel making.
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DATA COLLECTION
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TRANSFER CAR PROBLEMS
TILTING CARS 15%
SRM 25%
H1S1 8%H1S2
7%H2S1 1%
H2S2 4%
H3P1 2%
H3P2 5%
H4P1 9%
HOODS 15%
UNLOADING STATION
9%
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Drive bogie shaft cut
14%
Hose leakage puncture leakage
7%
Tilting problems
38%Hyd Coupling
damage12%
Cylinder damage
29%
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HYDRAULIC TANK CONTAMINATIONS
• In the above figure shown, there are no filters. So this is the reason why the
hydraulic tank is getting contaminated.
• 8 microns of dust flows. Hence there is no smooth flow of oil.
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INTERNAL LEAKAGE LINE OPENINGS PROVIDED BY THE SUPPLIER WITHOUT ANY
PROPER SEALING
• In the above figure, the oil filter is not sealed properly, and hence the dust is
getting settled in the oil filter.
• Due to damaged oil filter there is no smooth flow of oil and dust gets enter
in the filter.
Damaged Oil Filter
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RETURN LINE FILTERS AND SUCTION LINE FILTERS ARE MISSING
There are no filters provided in the above case and oil does not enters
back to the hydraulic tank.
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DRIVE BOGIE SHAFT CUT
Transfer cars hitting to the rail stoppers because of no limit switches
and brakes to stop the car.
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CYLINDER DAMAGE
Under discussion with the suppliers to reduce the stroke of the hydraulic
cylinder.
Cylinder bottom hose fittings modifications to avoid the hose damages.
Cylinder trunions modifications.
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ROOT CAUSE:
Tank, pump and motor are mounted on a single structure. Existing clearance
is 235mm. A small jam may disturb the allignment. This leads to the
breakdown.
Now we are modifying the hydraulic systems supporting flames. So that we
will get 600mm bottom clearance.
HYDRAULIC MOTOR COUPLING DAMAGE
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TILTING CARS BEAMS CRACKS
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CRACKS OBSERVED IN FRAME INDICATED ON BEAMS
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HOOD DAMAGING
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ANSYS ANALYSIS OF BEAMS
Max deflection : 1.321mm
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Max Shear force : 146.193 KN
Min Shear force : -108.67 KN
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Max Bending Moment: 214.833 KN-m
Min Bending Moment: 0.146E-10 KN-m
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WHEEL LOAD CALCULATION 280t
Technical parameter of the car
• Load capacity – 280t
• Dead weight – 69t
• Speed – 3-30m/min
• Wheel diameter – 1100mm
• Bearing axle hole diameter – 180mm
• Quantity of wheels – 4 Nos.
Wheel Load Calculation:
• Material – C55Mn75
• Diameter – 1100mm
Wheel tread fatigue load:
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Pr = (2Pmax*1.10+Pmin*1.10)/3
= (2*1266.0*1.10+422.50*1.10)/3=1083.3KN
Pmax – max. wheel load (with filled ladle during tilting)
Pmin – min. wheel load (empty ladle)
1.10 – impact coefficient
Wheel tread fatigue strength calculation:
K1 DLC1C2>=Pr
Where,
K1 is a constant relevant to the material
D is a wheel diameter
L is the effective contact length of wheel and railway, contact length of wheel and
railway is about 110mm
C1 is the speed factor
C2 is work class factor
So we have ,
K1DLC1C2=7.2*1100*110*1.13*1=984456N=984.5KN<Pr=1083.3KN
Result of calculation:
The 1100mm material C55Mn75 forged wheels cannot meet the requirement of the
wheel load.
Suppose wheel diameter – 1200mm
k1DLc1c2=7.2*1200*110*1.13*1=1073952N=1073.95KN<Pr=1083.3KN
Wheel diameter 1200mm also cannot meet the requirement of the wheel load.
So the tilting transfer car must be designed with 8 wheels.
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Progress so Far
• New cylinder calculations with reduced stroke length and maintaining the
basic required parameters have been done. Cylinder specs and operating
conditions have been approved for manufacturing by Danieli Corus.
• Cost for transfer car modification was approved and implementation of
design changes has started.
• Changes in Filter design has already been implemented.
Problem Identification
• Silos placed at Steel Melt Shop wasn`t delivering required set point ratio of
Magnesium and Calcium Carbide.
• The set point ratio was 1:5 but the achievable ratio was 1:10.
• This led to a lot of wastage of Magnesium resources.
• 1 tonn of Magnesium costs 2 lakh rupees.
• Improper ratio led to two problems:
1. Process time of the complete process increased drastically for each cycle of
treatment.
2. Improper desulphurization process.
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Flow Diagrams
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FLOW DIAGRAMS
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Problems Identified
• Several problems were identified after going through the complete process
in detail. Few of them are:
1. Heavy vibration during raking.
2. Faulty reading by Load cell installed for weight calculation.
3. Improper Plant Layout.
4. Raking at only one side .
5. Also, the slag accumulated led to increased local temperature and damage to
load cells and other critical components.
Solution Suggested
• Improvements suggested are:
1. Rubber padding to be used surrounding the load cell to reduce the vibration .
2. Turn buckle to be applied to every dispenser/silo.
3. Flow in pipe was severely affected because of sharp T- shaped pipes. So
smooth bends have to be provided to allow unrestricted flow.
4. Also, use of purging was suggested to immediately unblock the obstruction
caused in the pipelines emerging from silos.
5. Pressure of N2 should be increased for Magnesium silo so that proper ratio
is maintained.
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BILL OF MATERIALS
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BILL OF MATERIALS
N105
2"QC01-1501
4"QC01-1502
PSE 1504 (Set @ -18mm WC & 5.2 kPa) Vacuum/Pressure relief valve
6" KN01-1501 Knife gate valve
2" : 1-1/2" Reducer
2" : 1" Reducer
1-1/2" : 3/4" Reducer
1-1/2" : 3/4" Reducer
1-1/2" : 3/4" Reducer
1-1/2" : 3/4" Reducer
3/4" : 1/2" Reducer
3/4" : 1/2" Reducer
3/4" : 1/2" Reducer
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BILL OF MATERIALS
36
OPERATING VALUES
• Magnesium total mass flow: 62 Kg
• Calcium Carbide total mass flow : 504 Kg
• Mass flow rate of Magnesium: 7.6 kg/min
• Mass flow rate of Calcium Carbide: 53.3kg/min
• Calcium Carbide pre injection: 40 Kg
• Magnesium injection pressure: 324.7 Kpa
• Calcium Carbide injection pressure: 464.4 Kpa
• Nitrogen flow pressure: 983 Kpa
• Nitrogen gas temp: 320 c
• Duration of Magnesium flow: 8:4 min
• Duration of calcium carbide flow: 9:27 min
CYLINDER CALCULATIONS
Given:
Bore dia r = 280mm
Rod dia R = 140mm
Length l = 81.1023inch
Stroke = 43.3inch
Working Pressure P = 100bar
Formulas:
• Cylinder Blind End Area = pi*r2 = 3.14*(140)2
=95.48 inch2
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• Cylinder Rod End Area = Cylinder Blind End Area -(pi*R2) = 61602.8- (pi*
702 ) = 71.6134 inch2
• Cylinder Output force (In pounds):
For Push: Pressure*Cylinder Blind End Area
= 100*14.508*95.48 = 138446 pounds
For pull: Pressure*Cylinder Rod End Area
= 100*14.508*71.6134 = 103839.43 pounds
• Fluid pressure in PSI to lift load (in PSI) :
For push: Pounds of force needed/Cylinder area
= 138446/95.48 = 1450 PSI
For pull : 138446/71.61 = 1933.33 PSI
• GPM Of Flow Required For Cycle Speed:
(Cylinder Area x Stroke Length in Inches) ÷ (231 x 60) ÷ (Time in
seconds for one stroke)
= (95.48*43.3)/(231*60)/10= 3.5 GPM ( for extension)
= (71.61*43.3)/(231*60)/10= 2.51 GPM ( for retraction)
• Cylinder Speed (inch/sec):
(231*GPM)/(60*net cylinder area)
= (231*3.5)/ (60*95.48) =0.35 inch/sec ( for extension)
= (231*3.5)/ (60*71.61) =0.47 inch/sec ( for retraction)
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SNAPS
39
Changes Done:
1.Increase of ground clearence for rail cars:
Before- 235mm ground clearence
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After- 600mm ground clearence
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2. Beam cracking improvement
Before-
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After- Ribs of 20mm were welded to make the structure strong.
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3. Slag Raking machine: Turning of slag raking machine about its axis used to
cause damage as it used to collide with the rail car below
Before: (Straight Frame)
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After: ( Zig-Zag Frame)
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4.Hydraulic Tank Modification: Internal leakage port without any proper sealing
lead to hydraulic fluid contamination.
Before:
46
After: ( New sealed port provided)
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5.Modification of Cylinder Piston: 1498mm of stroke length used to bend the
piston rod because of excessive load.
Before-
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After- Piston stroke was reduced to 1390 mm without reducing the bore. The
reduction in piston stroke also increased the ground clearence as seen.
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6.Return line filters added: Earlier there was no filters provided on return line
because of which the dirt of piston used to flow into the hydraulic tank and thereby
contaminating the hydraulic fluid.
Before-
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After: A new filter fitted into the return line.
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7.Hood jamming: Because of larger thickness of the lance hood, slag of the hood
and slag of laddle used to hit each other and cause structural damage.
Before:
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After: ( thickness is reduced by 3mm)
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Comparison of Breakdown minutes
0
200
400
600
800
1000
1200
1400
1600
Dec Jan Feb March April
Before 1300 1400 1350 1230 1500
Post Car repair 0 463 550 432 440
Post completion 0 0 200 130 120
Bre
akd
ow
n M
inu
tes
Months
Pre Implementation VS Post Implementation
Before Post Car repair Post completion
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Increase in availability
Probability of equipment availability = Up time/ (up time+down
time)
Probability ( before) :
Up time= 4260 mins for 4 stations
Down time= 1500 mins
So, probability of availability = 4260/ (4260+1500)
= 0.73
Probability ( after):
Up time=4260 mins
Down time= 200mins
So, Probability of availability= 4260/ (4260+200)
= 0.95
Therefore, it is evident that after the structural changes were brought in
the equipment availabilty increased from 73% to 95%. This ensured
continous and smooth production process.
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Economics of Maintainance
Breakdown time/month= 1555.2 mins
Breakdown maintainance cost= Rs.75/min
Total cost=Rs. 1,16,640
Preventive maintainance cost=Rs. 20,00,000
Breakdown time/month post preventive maintainance= 288 mins
Total cost incurred for breakdown maintainance= Rs.21,600
So, the question now is was the preventive maintainance done economical?
Number of months required to recover the cost incurred for preventive
maintainance:
Cost of maintainance /month= 116640+21600 = Rs. 1,38,240
Months required to sum to preventive maintainance cost= 2000000/138240
= 14.46 months
So, the cost will be recovered in just 1year 3months. This project can thus be
considered to be very economical.
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Cost Analysis
The next important factor after time is the cost factor. Will this project be
able to save company funds?
A simple analysis based on previous obtained results will show the
following:
Previous monthly maintainance cost: Rs. 1,16,640
Current monthly maintainance cost: Rs. 21,600
% savings: (116640-21600)/ 116640 = 81.48%
Initial67%
1st Phase21%
Final Phase12%
Maintainance cost
Initial 1st Phase Final Phase
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Timeline of our project
Start Date- 8th September 2013
End Date- 25th April 2014
PROJECT START
PROBLEM STATEMENT
INVESTIGATION
COLLECTION OF DATA
BRAIN STORMING
ALTERNATIVE IDEAS
DESIGNING
APRROVAL
IMPLEMENTATION
TESTING AND MODIFICATION
PROJECT END
8 Sep 8 Oct 8 Nov 8 Dec 8 Jan 8 Feb 8 Mar 8 Apr
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References
www.jsw.in
www.sws-demag.com
www.google.com
Strength of Materials by Bhavikatti
Ansys tutorials
JSW supplier data
JSW technical library