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Bangladesh steel re rolling mill (bsrm)
1. Bangladesh Steel Re-Rolling Mill
(BSRM)
HASAN SHAHRIAR SAJIB
Studying B.Sc. Engineering
Mechanical Engineering
Bangladesh University of Engineering & Technology (BUET)
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2. STEEL SECTOR IN BANGLADESH
Bangladesh has more than 400 steel mills
Total production capacity 80 lakh tons
Country demand 40 lakh tons
Steel consumption 25 kg/capita
Leading steel companies: BSRM, KSRM, AKS, RSRM, GPH, PHP etc.
BSRM and AKS provide 50% of country demand
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3. INDUSTRY OVERVIEW: BSRM
First fully automated Re-rolling mill in Bangladesh
Operated since 1952
Was sister concern of Meghna Engineering Works Ltd
BSRM Steels Ltd. Started operation since April 1,2008
Initial production 3.75 lakh tons per year
At present production is about 7 lakh tons per year
Industry was fully conceptualized by Forni Industriali Bendotti (Italy) and
Denieli group (Belgium)
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4. INDUSTRY OVERVIEW: BSRM
Main product in Xtreme 500w, also produces 400w, 300w, 200w, 60 grade, 40 grade
1984 Introduced high strength cold-twisted steel bars to the
construction industry.
1987 Introduced ASTM 615 grade 60 reinforced steel bars.
1996 Commissioned the largest billet making plant in the country.
2006 Introduced micro reinforcement wires for low cost rural
construction.
2008 Introduced grade 500 steel bars, the current international standard
for modern construction-BSRM Xtreme 500 W.
2008 BSRM group contributed nearly tk.100 crores to the national
exchequer in taxes, levies, duties and vat.
2009 The largest billet making plant of the country nears completion
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5. THE ADMINISTRATIVE INFRASTRUCTURE OF
BSRM STEELS LIMITED
The entire work schedule of the industry
is divided into 11 departments. They
are:
Accounts
Admin
HR and IR (Human Resources and
Industrial Relationship)
Inventory
CSD (Customer Service and
Development)
Production Department
workshop
Electrical
Mechanical
QA (Quality Assurance) and
T&D (Technical and Development
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7. WATER TREATMENT PLANT (WTP)
WTP supplies required water in the mill, and treats the used water for re-
circulation
Two types of water used-
• Contact (used in mill)
• Non-contact water ( used in QTB and heat exchanger)
Total pumps: 31
Total filter: 5
• 3 sand filters (used for filtering Contact water)
• 2 anthracite filters (used foe removing iron particles)
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9. WATER TREATMENT PLANT (WTP)
Water filtration process: 3
• Manual
• Chemical
• Filtering
Backwash method is done in every 8 hours for removing scale from filter
Chemical used : NaOCl, anti corrosive chemical, coagulants, dispersants etc.
Cooling tower:
• total 7, forced induced drafts
• Reduces temperature almost 8 degree Celsius
• Total capacity : 3000 m3/hr.
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10. FURNACE
Furnace type:
Pusher Billet type Re-heating Furnace
Dimension:
• Length: 22m
• Width - 15m
• Height - 7m
Burner number: Total 22
• 10 in heating zone, 12 in soaking zone
Air-Fuel ratio: 10:1
Fuel used:
Duel fuel:
• Natural Gas
• Light Diesel Oil (LDO)
Pressure: 0.3 bar
Temperature: 1200 degree Celsius
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11. FURNACE
3 zones:
• Pre-heating zone (billets are heated by pre-heated air up to 400˚ C)
• Heating zone (billets are further heated up to 1200˚ C)
• Soaking zone ( maintains the temperature gained in heating zone)
Peel bar :
Used to push the billet out of furnace
Billet detector ;
2 billet detectors are used for positioning the billets inside the furnace
Recuperator:
Used to pre heat air
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12. MILL AREA
Heated billet goes through a shape changing process by rolling
Two types of rolling stand:
• Vertical: 8
• Horizontal: 12
Three area:
• Roughing area: 8 stands
• Intermittent area: 6 stands
• Finishing area: 6 stands
Looper: max. 6 (use to reduce tension of heated rod)
Slitter: use to split the billet for less dia. rod
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13. MILL AREA
QTB (Quenching and Tempering Bath)
Use for uniform cooling of heated rod
Martensite formation
Direct contact of water, rapid cooling
Temperature is reduced by 200̊̊ C
Shear Machine:
Detach the billet in head & tail position
Three shear machine
• Shear 1 (between stand 6&7, cuts the head portion)
• Shear 2 (between stand 12&13, cuts the tail portion)
• Shear 3 (placed after QTB, cuts the billets according the cooling bed size)
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14. FINISHING AREA
The quenched rod after shear-3 moves through here
The main components operating in Finishing Area are:
• Inclined Apron Roller Table
• Cooling Bed
• Cold Shear
• Tying Machine
Inclined Apron Roller Table
• 72 motor-driven rollers: imparts motion to the discontinuous rods
• 71 Lifting Aprons: shifts the rods lengthwise to the cooling bed
• 5 interconnected hydraulic cylinders: controlling simultaneous opening and
closing of the aprons
• 3 Magnetic Stoppers: stops the rods moving at high velocity
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15. FINISHING AREA
Cooling Bed
Two types of racks; Fixed and Movable: shifts the rods along transverse direction
These Movable jaws are driven by a single motor.
Two gear boxes having worm gear transmits power from motor.
Eccentric cylindrical cams are connected in series in the driven shafts.
Cams have counterweight adjusted at 180 degree.
Hydraulically driven arms transfer the rods from the cooling bed to a rolling trolley
The rolling trolley transfers them in their longitudinal direction to Cold Shear
Belt pulley
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16. FINISHING AREA
Layer Chain Transfer
Vertical Chain Transfer
Tying Machine
Tying Machine:
• 5.5mm wire is spool fed
• Hydraulic Mechanism with Hydraulic Motor ,oil storage tank for hydraulically
driven small rollers or flap.
• 8 steps controlled either automatically or manually
1. Feed wire- by hydraulic motor.
2. Clamp wire- by hydraulic cylinder.
3. Binding unit up- by hydraulic cylinder.
4. Stretch wire- by reversing hydraulic
motor.
5. Twist knot- by hydraulic motor.
6. Wire clamping off- by hydraulic cylinder.
7. Reset twisting head- by hydraulic motor.
8. Binding unit down- by hydraulic cylinder.
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17. OVERHEAD CRANE
4 Bays
12 Overhead Cranes
Magnetic Type
A-B Bay :
• 3 cranes
• Girder Capacity: 29 tons
• Lifting Capacity: 8 tons
B-C Bay:
• 4 cranes
• Girder Capacity: 24 tons
• Lifting Capacity: 8 tons
C-D Bay:
• 3 cranes
• two of 10 tons, one of 20 tons
D-E Bay:
• 2 cranes
• 10 tons and 20 tons
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18. OVERHEAD CRANE
Types of Motions:
1. Long Travel
2. CROSS travel
3. Hoisting Travel (Lifting and lowering)
4. Rotational Travel
5. Telescopic motion (A-B Bay only)
1.
2.
3.
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19. UTILITIES
Supports the entire mill to run smoothly.
Consists of :
• Hydraulic drive system
• Pneumatic drive system
• Lubrication system
• Greasing system
Hydraulic Drive System
4 central hydraulic unit
Furnace central hydraulic unit
• Used in driving pusher & peel bar.
Milling central hydraulic unit
• Used in driving pinch roll, chain transfer system, hood(up-down movement)
Finishing area central hydraulic unit
• Used in movement of QTB, apron lifting operation, tying machine.
Workshop central hydraulic unit
• Assembly operation of Robot, band saw up-down.
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20. UTILITIES
Hydraulic system contains
• Tank
• Hydraulic oil( vg46 or vg68)
• Energy Converters
• Control Devices
• Accessories (Float valve, Accumulator etc.)
• Connecting device
• Electrical & Electronic components
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21. UTILITIES
Pneumatic drive system
Application:
• Peel bar upper pinch roll
• Peel bar entry door
• Furnace exit upper pinch roll
• Billet Detector
• Looper roller up-down
Pneumatic system contains
• Compressor
• Drier
• Receiver
• FRL( Filter-Pressure Regulator-Lubricator)
• Control Valves
• Actuators
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22. UTILITIES
Lubrication
Force lubrication is used in this industry
Has 3 units
• Roughing Stand Lubrication Unit
• Intermediate Mill Lubrication Unit
• Finishing Stand Lubrication Unit
Lubrication system contains
Reservoir
Pump
Heat Exchanger( Remove moisture content)
Filter( Remove metal & dirt particles)
Lubrication oil(vg 220)
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23. UTILITIES
Greasing system
Grease generally consists of a soap emulsified with vegetable oil.
A central grease unit is present to pump grease into required places keeping
the time gap to 30 minutes.
Has 3 greasing units
• Rolling Mill Central greasing unit
• Finishing Area greasing unit
• Shear 1 greasing unit
• Cold shear central greasing unit
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24. BENDING MACHINE
Bending machine is used to bend 12 m rods into 6 m rods for carrying in trucks
Driven by electric motoring
4 rollers to bend the rods smoothly.
A rotating jaw bend the rods.
A movable arm driven by pneumatic power helps to slide the rods into delivery
chain transfer
9 men are required to work on a Binding machine
• 3 for counting
• 3 for tying
• 3 for delivery
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25. QUALITY ASSURANCE (QA)
Main Purpose is to ensure the product quality.
BSRM always try to improve product quality with best techniques of the world.
They ensure ISO 9001:2000
One set of rebar is checked in every hour.
For 500W
• Yield strength is 500MPa.
• Ratio of tensile and ultimate strength is not more than 1.15
Testing Instruments:
• Bar bending mandrel
• CNC roll turning lathe
• Universal testing machine
• Computer attached with UTM
• Spectrometer
• Microscope
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26. REBAR
Three layers
• Martensitic case
• Transition zone
• Ferrite-Pearlite core
Martensitic case provides hardness of steel.
Ferrite-Pearlite core provides ductility of steel.
Controlling the amount of water flow of QTB, we can control the marten site layer
thickness.
Martensitic layer should not be more than 40% of total rebar x-section area.
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27. WORKSHOP
The workshop of BSRM is very much enriched. The performance of the workshop
machines makes the industry self- dependent. Excelled engineers and technicians
maintain the workshop.
The work shop instruments:
• Shear Machine
• CNC-Roller notching Machine
• CNC-Lathe Machine
• Manual Lathe Machine
• Bench Drill Machine
• Radial Drilling Machine
• Surface Grinding Machine
• Robot
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28. WORKSHOP FACILITIES
Dressing of gear teeth
Surface grinding operation
Repairing mechanical equipment
Interchanging between horizontal and vertical stands
BSRM does all kind of repairing and maintaining works in their workshop. This saves a
large amount of money of the industry and enhances the profit.
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