Measures to Improve Blast Furnace Coke Quality...
Transcript of Measures to Improve Blast Furnace Coke Quality...
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Measures to Improve Blast Furnace
Coke Quality and Yield
By :- PRASHANT KUMAR
DM- CO&CCD
SAIL-BHILAI STEEL PLANT
49th Coal Operating Committee Meeting
STATUS OF COKE OVEN BATTERIES IN BSP
4.3 mt tall Batteries
(8 nos.having 65 ovens each)
Batteries: 1 to 8
Oven Dimensions
Length: 14 mt
Avg Width: 407mm
Volume: 21.6m3
7 mt tall Batteries
(3 nos. having 67 ovens each)
Batteries: 9,10 & 11
Oven Dimensions
Length: 16 mt
Avg Width: 410 mm
Volume: 41.6 m3
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IMPROVING COKE QUALITY & YIELD
Coal Blend consistency
Uniform Heating & Thermal Regime
blend properties
Calibration of APD
Coal briquettes
Quenching Process
Consistent Pushing
Routine Cleaning
Monitoring CVT, EVT, CWT, FST
Coke Mass Temperature
Regulation
Stoichiometric ratio
Raw gas leakage
Coefficient of Pushing
Availability of equipments
Planning scheduled maintt.
Wet Quenching
Dry Quenching
Coal stock management
COAL BLEND CONSISTENCY
Continuous monitoring of coal blend
monitoring of crushing index
Monitoring of coal moisture
Coal stock management
Periodic drop test & Calibration of Automatic Proportioning Device (APD).
Addition of coal briquettes to improve Bulk Density in smaller batteries- thus to improve quality and yield
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Uniform Heating & Thermal Regime
Regulation – Monthly or as required
Control Vertical Temperature (CVT) - Once in A shift
Maintained as per daily pushing target
Kb ….. coefficient of battery above 0.98
End Vertical Temperature (EVT)- Monthly
(CVT – EVT) ~ 1200C
Cross wall temperature (CWT)- Monthly
should be uniform along the heating wall
Free space temperature Monthly
850 ± 500C at oven roof
Regenerator Temperature – Bimonthly
Coke Mass Temperature- Physically in all shifts
by pyrometer- weekly
Charge Level measurement bimonthly
and adjustment 300 mm free space from oven roof
Raw gas leakage Monthly
Stoichiometric ratio (A/F ratio) Weekly
For BF gas . . . 1.25
For CO gas . . . 1.45
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Consistent Pushing
Maintaining Coefficient of Pushing (+15 min of scheduled pushing time) above 0.9
Availability of equipments is high- more than 98%
Wireless Based Oven Identification, Machines Positioning & Interlocking, Scheduling Systems
Quenching process
Wet quenching- 10 out of 11 batteries uses wet quenching process
Optimum quenching and drainage time
Uniform receiving of Hot Coke Coke stabilization time in wharf
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Dry Quenching facility- Coke Dry Cooling Plant (CDCP)
Battery 11 is equipped with dry quenching facility
Better coke quality - as the coke is cooled gradually in the cooling chamber, it is free from internal cracks and surface pores.
Post carbonisation soaking in cooling chambers
Coke Quality Comparison
Parameter Wet Quenching Dry Quenching
M-10 7-8 5-7
M-40 79-81 84-86
Moisture Content 3%-5% 0.1%-0.8%
Coke Reactive Index
22-23 21-22
Coke Strength After Reaction
64-65 65-66
Volatile Matters 0.9% 0.8%
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THANKSTHANKS