Slide 1*
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Quenching System
Project on
2. Introduction to JSW Vijayanagar
3. Introduction to Coke ovens at JSW Vijayanagar
4. Introduction to coke oven 4 - Recovery ovens
5. Introduction to QC Team
6. Sarthak Quality Circle team project
a. Identification of problem
b. Selection of problem
2. Ranking Matrix
4. Pareto Diagram for selection of problem
5. Definition of the problem
6. Gantt Chart
9. Setting of Objectives
f. Data Analysis
g. Developing Solution
g. Regular Implementation
i. Benefits
k. Future Plans
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An ISO 9001:2008, ISO 14001:2004, OHSAS 18001:2007 ,TS 16949:2009
Certified Company
Steel Ltd.
VIJAYANAGAR WORKS BELLARY, KARNATAKA
Vasind and Tarapur Works
It is here that all began. A new chapter was written in the history of Indian Steel Industry when JSW made its foray at Vasind in 1982 and setup a 20 Hi CR mill. JSW then acquired a mini steel mill, which moved on to become JSW Steel Ltd.
Apart from being a leading manufacturer of cold rolled and color coated steel, Tarapur and Vasind works is today India’s biggest producer & largest exporter of galvanized steel. At Vasind Works, the Company has recently launched GALVALUME, a revolutionary product in the steel industry. Its strategic location, with access to the major ports of Mumbai, markets and raw material sources has worked to its advantage.
The total capacity of Vasind and Tarapur Works is 0.9 MTPA of Galvanised, GALVALUME & Colour Coated Cold Rolled products.
As JSW grew phenomenally, it also steered Tarapur and Vasind towards newer horizon of prosperity. Apart from providing more jobs, JSW actively participates and organizes various social and cultural activities to make lives richer. The region is now cleaner happier and even more beautiful. Better health initiative, promotion of sports & education are few of the development initiative that has gained in JSW presence
Salem Works
JSW group acquired the Company and took over the Management from November 2004. Salem Works is the only integrated steel plant in Tamil Nadu and is located at Pottaneri/M. Kalipatti villages and at about 35 kms from Salem.
The Company is having facilities for production of Pig Iron, Steel, Billet and Rolled Steel products in the long product category. The present capacity is being expanded to 1 million tones per annum. It has adopted the Sinter plant – Blast furnace – Energy Optimising Furnace – Ladle Furnace, Vacuum Degassing Continuous Casting Machine – bar and rod mill route with iron ore as the basic input material. It also has plants for generation of power and production of oxygen.
Following the commissioning of blooming mill, Salem Works is the only Indian facility manufacturing the entire range of rolled long products (5.5 mm to 200 mm).
Salem Works is highly environment conscious and the process and technology is designed for reusing and recycling the process waste. We have an expanding green belt to provide a green environment.
Products of Salem Works have the hallmark of quality and combined with competitive pricing, they are highly preferred in automobile and construction sectors.
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Group
JSW is part of US $16.5 billion O.P.Jindal Group. It has grown to US$ 9 billion in little over a decade and has presence across various sectors – Steel, Energy, Minerals, Port & Infrastructure, Cement and Aluminium.
JSW Steel, the flagship company of the JSW Group, is today an integrated steel manufacturer. JSW Steel is the largest private sector steel manufacturer in terms of installed capacity.
The Group set up its first steel plant in 1982 at Vasind near Mumbai. Soon after, it acquired Piramal Steel Ltd., which operated a mini steel mill at Tarapur in Maharashtra. The Jindals, who had wide experience in the steel industry, renamed it as Jindal Iron and Steel Co. Ltd. (JISCO). In 1994, in order to achieve the vision of moving up the value chain and building a strong, resilient company, Jindal Vijayanagar Steel Ltd. (JVSL) was setup, with its plant located at Toranagallu in the Bellary-Hospet area of Karnataka, the heart of the high-grade iron ore belt and spread over 3,700 acres of land. It is just 340 kms from Bangalore, and is well connected with both the Goa and Chennai ports. In 2005, JISCO and JVSL merged to form JSW Steel Ltd.
JSW Steel is one of the lowest cost steel producers in the world. It has established a strong presence in the global value-added steel segment with the acquisition of steel mill in US and a service center in UK. JSW Steel has also formed a joint venture for setting up a steel plant in Georgia. The Company has also tied up with JFE Steel Corp, Japan for manufacturing the high grade automotive steel. JSW Steel has acquired a majority stake in Ispat Industries Ltd. Making JSW Steel India’s largest steel producer with a combined capacity of 14.3 MTPA. The Company has also acquired mining assets in Chile, USA and Mozambique.
JSW Steel offers the entire gamut of steel products – Hot Rolled, Cold Rolled, Galvanized, Galvalume, Pre-painted Galvanised, Pre-painted Galvalume, TMT Rebars, Wire Rods & Special Steel Bars, Rounds & Blooms. JSW Steel has manufacturing facilities at Toranagallu in Karnataka, Vasind & Tarapur in Maharashtra and Salem in Tamil Nadu.
By 2020, the Company aims to produce 34 million tons of steel annually with Greenfield integrated steel plants coming up in West Bengal and Jharkhand.
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Galvanised Coils & Sheets
JSW Pragati Colour Coated Sheets Pre-Painted Products
JSW TMT Plus Bars
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Vijayanagar Works
Vijayanagar Works is India’s largest single location steel plant with 10 MTPA capacity. It was the first Greenfield project in India to use Corex technology to produce steel. With the commissioning of Blast Furnace IV with 3.2 MTPA capacity, JSW Steel became the largest private sector steel producer in India. It has also set up of 5MTPA state of the art Hot Strip Mill. The next phase of expansion taking the total production to 12 MTPA at Vijayanagar Works is also under implementation.
It’s eco-friendly approach has also led to the development of Vijayanagar into a modern township. Enveloped by acres of greenery and, maintained by JSW, Vijayanagar is prospering by leaps and bounds. Be it education, career opportunity or women empowerment, the Company’s initiative has gone a long way in making Vijayanagar the success that it is today and our quality circle comes from this place.
Vijayanagar Works is India’s largest single location steel plant with 10 MTPA capacity operating with 2 Corex and 4 Blast Furnace with capacities as mentioned below.
Corex – 1 0.9MTPA 8/Aug/99
Corex – 2 0.9MTPA 15/Apr/01
Total 10MTPA
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Process Description of By-Product plant
Gas from batteries are cooled in Gas cooling mains (GCM) to 80°C from 800°C exchanging heat from flushing liquor from gas condensate pump house in by product. Gas from GCM is sucked at 80°C, enters Gas Liquid Separator and then through primary gas coolers (PGC) in gas condensation area. In PGC gas temperature is further reduced to 22°C using water at ambient temperature and chilled water at 18°C; hence 98% of tar is removed here and then gas enters Electrostatic tar precipitators wherein final tar is removed under high ionizing current and voltage. All the condensate (ammonia liquor and tar) collected in this area is transferred to decanters where by sedimentation these are separated. Ammonia liquor is sent back to battery GCM for cooling; tar settled and sent out for selling commercially.
Gas is sucked from GCM through PGC and ETP by exhausters; hence the whole area is under suction (negative) pressure. This gas is pressurized by the exhausters to desulphurization area where wet oxidation process is used to remove and concentrate hydrogen sulphide. Gas free from hydrogen sulphide enters Ammonia scrubbing area where Ammonia is scrubbed from gas, concentrated in distillation columns to vapor form (18-20%). Ammonia vapor is then cracked in Ammonia decomposition furnace to hydrogen and nitrogen in presence of Nickel catalyst. Obtained N2 and H2 is vent to atmosphere.
Hence coke oven gas which is free of tar, ammonia and sulfur is sent to gas holder.
Part of which is used in battery for heating and remaining sent to Blast furnace, mills, power plant and other consumers of JSW.
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This is a schematic representation of our coke making process.
SINTER Plant
SILOS
A
CB
QUENCHING
PUSHING
PP
COKING
CHARGING
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This is a schematic representation of our coke making process from coal to coke.
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QUENCHING CAR
PUSHER CAR
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8.bin
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Identification of problems
Rating the problem by 1-10 scale method
Selection of problem
Defining the problem
Data Analysis
Developing solutions
Brain storming
Brain storming
Stratification / graphs
Brain storming
Flow diagram
Pareto Analysis
Brain storming
Re-occurrence preventive measure
Above diagram shows the process that we have followed for identification of problems and developing the solution.
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STEP 1
Sr.No
PROBLEM
B
15
A
2
B
18
B
5
C
19
C
21
B
22
B
9
B
23
B
10
B
24
B
11
A
13
B
27
C
14
B
28
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STEP 1
Sr.No
PROBLEM
A
41
A
42
B
44
B
46
B
35
B
47
C
36
C
48
B
49
B
40
B
52
A
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C - PROBLEMS WHICH NEEDS HELP FROM MANAGEMENT
ABC ANALYSIS
STEP 2
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RANKING MATRIX (SCALE 1-10)
5
8
3
3
4.75
8
3
7
7
6.25
5
6
6
4
5.25
5
4
5
7
5.25
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We have used a ranking matrix to find the severity of the problem considering parameters like production, quality, environment and safety.
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DGGJDFLUE BIRD
Above slide shows a Gantt chart for the schedule of our project.
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This is a schematic representation of our coke making process.
STEP 3
SILOS
A
CB
QUENCHING
PUSHING
PP
COKING
CHARGING
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This is a schematic representation of our coke making process from coal to coke.
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IMPORTANCE OF COKE MOISTURE
There are 2 types of quenching systems to quench the hot coke i.e. Dry quenching & Wet quenching.
We are using wet quenching system, wherein water is used as a quenching media.
Presently there is a variation in coke moisture which leads to:
Effects the quality parameter i.e., 2.0%-5.0%.
Effects the conveyor belts.
STEP 3
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CURRENT SITUATION OF THE PROBLEM
Low Moisture:- Leads to damages & reduces the life of the conveyor belts, which effects the production.
High moisture:-This will leads to high fuel rate in blast furnace and higher production cost of hot metal.
STEP 3
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To reduce the deterioration of conveyor belt.
To reduce the production loss.
To reduce the fuel rate in blast furnace.
To increase the customer satisfaction.
DEFINITION OF PROBLEM
THEME :
Reduction and stabilization of coke moisture by enhancing the quenching system
STEP 3
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TO REDUCE THE DETORIORATION OF CONVEYOR BELTS.
TO REDUCE PRODUCTION DELAYS DUE TO BELT CHANGING.
STEP 3
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What is the problem?
 
Hot coke is quenched with water, then it is conveyed to Blast furnace through belt conveyors. During this process There is a variation of coke moisture
STEP 4
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STEP 4
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Where does it happen?
It happens at quenching tower, where high pressure water is sprayed over the hot coke through systematically arranged Nozzles
STEP 4
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STEP 4
PROGRESS OF QUENCHING ACTIVITY BY SPRAYING THE HIGH PRESSURE WATER THROUGH NOZZLES
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When does it happen?
During quenching at quenching tower & belt conveyer system used to transport the quenched coke to blast furnace
STEP 4
BELT CONVEYING THE COKE
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STEP 4
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How does it happen?
It may arises because of Quenching of hot coke and transporting of quenched coke.
STEP 4
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IN COKE MOISTURE
Water leakages on the conveyor belt.
Online coke route tripping.
Bulging of hot coke.
Coke feeding from yards.
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COKE MOISTURE
Speed of cold pushing.
-Albert Einstein
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Control room clearance
Above is the fish bone diagram to divide the various problems that may contribute to our problem.
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Trained Operators
Trained Operators
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SOP/Constant Speed
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Zero Leakages
Found leakage
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Material, Machine & Method related causes which did not satisfy the standards were checked in all boxes.
STEP 7
25
3
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Uniform water distribution by changing the arrangements of water spray nozzles at quenching tower.
Optimization of quenching pulses.
Yard feeding of coke to be done separately.
To avoid the bulging of coke.
To avoid online route tripping, communication to be improved with RMHS and Blast furnace
Automation of emergency water spray system.
PLAN
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Optimization of quenching pulses.
Modification in quenching system to avoid inadequate quenching.
Automation of emergency quenching line to reduce the operator intervention in the system.
DO
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Anand & Halappa
10 DAYS
Halappa & Shaik Basheer
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COKE GAP
A coke gap was observed at one end of quenching car, which results in high coke moisture.
COKE GAP IN THE QUENCHING CAR
STEP 8
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STEP 8
QUENCHING TOWER
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Blocked Nozzles
Hence 2 numbers of water spray nozzle & 4 numbers of vent nozzles were blocked at coke gap area.
BLOCKED NOZZLES IN THE QUENCHING
TOWER
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OPTIMIZATION OF QUENCHING PULSES
Water sprayed for 10 seconds & stopped for 30 seconds, is called quenching 1 pulse.
Trials taken for different pulses.
We optimized the quenching to 6.5 pulses with quenching of 65 seconds of water spray.
STEP 8
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2
6
3
6.5
4
7
5
7.5
7
6
8
6.5
9
7
10
7.5
12
6
13
6.5
14
7
15
7.5
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Resistance – Maintaining the optimized quenching pulses for critical ovens.
Reason – As coal cake charged tonnage is less for critical ovens, amount of water required for quenching will be less.
Solution – There will be around 10-12 critical ovens per day, and as we cannot change the optimized pulses for the quenching of critical ovens, so high moisture coke will be pushed in open yard. After air dried, it will be sent to the respective customers.
STEP 9
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Inadequate quenching means insufficient quenching of coke.
This results in damage of conveyor belts & eventually reduces life of the belt.
If inadequate quenching happens, alarm indication is provided at quenching tower.
STEP 8
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STEP 8
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STEP 8
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STEP 8
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Resistance – Even though there is alarm for inadequate quenching, operator may push believing on the physical appearance of coke.
Reason – Frequent variation in discharge of quenching pump, leads to variation in tank level.
Solution – An inter lock is provided between coke pusher ram & quenching tank level to stop the pushing process when there is inadequate quenching alarm.
FORE SEEING PROBABLE RESISTANCE
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AUTOMATION OF EMERGENCY QUENCHING LINE
Emergency quenching line is provided on the belts to spray the water in case of tripping of the belt while conveying of hot coke.
Earlier this system was in manual mode(operator).
Manual system is converted into Auto mode.
By automation, when the belt trips water will get sprayed automatically over the belt for 10 sec, thus increasing the life of conveyor belt & reduces the coke moisture.
STEP 8
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STEP 8
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STEP 8
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STEP 8
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STEP 8
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Resistance – Difficult to maintain the constant water pressure during Emergency water Spray System.
Reason – When emergency water spray system turns ON during belt tripping, it is difficult to maintain the required pressure on all the conveyors by running single pump.
Solution – We started to run two Pumps.
STEP 9
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Material, Machine & Method related causes which earlier checked again reviewed after making modification
SR.NO
CAUSES
25
5
3
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Comparison of problem occurrences before and after QC
STEP 10
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STEP 10
Reduction in variation of coke moisture range from 6.5% to 5.0% achieved.
Belt damages has been reduced by eliminating the Inadequate quenching.
Water leakages on the conveyor belt is controlled
Quenching pulses has been optimized & pulse variation is eliminated.
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STEP 10
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STEP 10
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MISTAKE PROOFING–POKA YOKA
After automation of emergency quenching system, still there was variation in coke moisture.
Whenever belts trips, irrespective of coke present on the belt water spray get started.
To avoid this, interlock is provided between coke present on the belt & the emergency water spray.
STEP 11
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STEP 11
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(After Poka Yoka)
STEP 11
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STEP 11
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Coke Moisture %
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Preventive maintenance checklist for entire quenching pipe line system i.e. nozzles, valves and pipe leakages.
Continuously monitoring of the quenching pulse.
Periodical training given to all quenching car operators for the movement of quenching car and cold pushing techniques.
HKH,H
45T4
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CHECK LIST FOR MONITORING OF QUENCHING PULSES AFTER Q C
STEP 11
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Coke quenching pulses Optimized to 6.5 pulses i.e. 65 seconds
Periodical checking & monitoring of system established.
Emergency quenching pipe line on the conveyor belt to be cleaned & Checked on regular frequency.
To avoid bulging, charging car plate status to be reviewed
Communication system has been improved by RMHS and Blast furnace during bunker changing to avoid uninterrupted belt tripping
FOLLOWUP AND REVIEW
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TANGIBLE BENEFITS
By reducing the Variation in coke moisture Following Benefits were observed
Consistently achieving the departmental quality objectives.
Frequency of Conveyor belt changing is reduced.
Durability of conveyor belt increased.
Improved the customer satisfaction.
Which will directly reduces the Production Loss.
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By reducing the Variation in coke moistureFollowing Benefits were observed
Standard burden Moisture Maintained in Blast Furnace is 2%
For Every 1% Increase in coke moisture increase in 5 kg of coke rate in burden feeding
% of Moisture
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15
5000
15,00,000
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Cost Analysis
As the belt changing frequency reduced from 4 times per year to 3
times per year, following table shows the cost savings.
Belt Changing Cost Analysis
5000
7
40
1117600
3352800
4470400
1117600
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TOTAL COST SAVING
15,00,000
11,17,600
Total
26,17,600
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Our confidence level and presentation skills have improved.
We learned putting our thoughts into actions.
Environment
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FUTURE PLANS
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We are thankful to the JSW management for giving us the opportunity to present our project before the quality circle Bengaluru Chapter.