Blast furnace operation

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JNIL, SPD, SILTARA, RAIPUR

BLAST

FURNACE

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OPERATION

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A blast furnace is a type of metallurgical furnace used for smelting of iron ores to

producing generally iron .

The earth crust contains about 5% iron. However,it is present as a compound mostly

as iron oxide. Iron is extracted as metallic iron from the oxide ores of iron by reduction with a

reducing agent. the principal agent that is used is a naturally occurring carbon in the form of

coke or coal (pulverised coal).

The most abundant oxide ores of iron is hematite (Fe2o3) and magnetite is used .but

hematite is used mainly in our country iron oxide also contain oxide minerals of some other

elements such as aluminium, silicon Mn and P.

Sinter is also used in blast furnace. It is the prepared burden which is occurred by the

sintering process .this is agglomeration process which utilises the fines of iron , fluxes and

coke. 80 to 90 % of sinter is charged in our JNIL blast furnace.

BLAST FURNACE OPERATING DATA :-

Number of furnace – 01

Useful volume – 680 cub.met.

Working volume – 560

Throat diameter – 5.10

No. Of tuyers – 16

Tuyer diameter – 110 mm

Tap hole – single

Slag notch refractory lining – micropour carbon block

Top charging system – bell less top

No. Of stoves – 03

Cooling system – stave

Hot blast volume – 1,05,000Nm3/hr.

Hot blast pressure – 1.9Kg/cm2

Furnace top pressure – 0.88Kg/cm2

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INPUT – BLAST FURNACE

Raw material : -

Iron ore &sinter-(size 10 to 30)

Flux, limestone, dolo, & quartz-( size10 to 30mm)

Mn ore – ( size10 to 30mm)

Coke – (size 25 to 80mm)

Hot blast air – (Temp. 980Deg.C)

PCI – ( as injection)

OUTPUT - BLAST FURNACE

Hot metal -

Steel melting Shop

Pig Casting Machine

Blast furnace Gas –

Power Plant

Rolling Mill

Sinter Plant

Slag granulated –

Cement Plant

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HOT METAL ANALYSIS

Si% = 0.5 TO 0.8

Mn% = 0 to 0.6

S% = 0.06 max.

FOUNDRY GRADE :- BASIC GRADE :-

FROM FURNACE / BY ADD. OF Fe-Si; Si% =0.5 to 0.8

Si% = 2.0 to 2.5 Mn% = 0.5max.

Mn% = 0.5 to 1.0 S% = 0.06max.

S% = 0.06max.

GAS ANALYSIS

CO% = 25

Co2% = 17

H2% = 2.5

O2% = 0.5

CV = 750 to 800 Kcal

COKE DETAILS

FC% = 85.52

S % = 0.58

Ash% = 13

M10% = 4.6

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IRON ORE DETAILS

Fe% = 60 to 65

Al2o3% = 2 to 3.5

Sio2% = 1.5 to 3

SLAG ANALYSIS

Cao% = 32 to 34

Sio2% = 33 to 35

Al2o3% = 21 to 23

Mgo% = 10.5 to 11.05

Cao Mgo Sio2 Al2o3 Fe Mn

Limestone 48.50 1.70 4.0 0.90 0.46 -------

Dolomite 28.0 18.50 4.0 0.90 0.46 -------

Quartzite -------- -------- 96.0 1.42 -------- --------

Mn ore --------- --------- ------- -------- 28.20 26.70

Fe ore --------- --------- 1.56 -------- 66.0 --------

Sinter 8.50 2.20 4.5 2.8 58.0 --------

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INPUT< ----------------------------------------------------------------------->OUTPUT

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PROCESS

The blast furnace process is based on counter current principle. The input and output

are of modern blast furnace practice .the furnace is refractory lined and is filled with material

from the stock rod level down to bottom.

Solid raw material at room temperature or preheated furnace temp. At beginning the

process are charged from the top of the furnace .

Preheated air above 950 to 980 deg.C is blown through tuyer pipe inserted in to the

furnace wall along with injection of pulverised coal. The highest temp. Of the furnace is at

the level of tuyere. This heat is transferd from bottom to top. That result direct and indirect

reaction occurred.

PROCESS REACTION :-

OXIDATION REACTION ;--

C + 1/2O ---------------- CO

C + O2 --------------- CO2

C + CO2 --------------- 2CO

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REDUCTION REACTION ;--

3Fe2o3 + Co ------------ 2Fe3o4 + Co2

Fe3o4 + Co ------------ 3Feo + Co2

Feo + Co ----------- Fe + Co2

DIRECT REACTION;--

Feo + C ----------- Fe + Co

Sio2 + 2C ---------- Si + 2Co

Mno + C ----------- Mn + Co

H2o + C ---------- H2 + Co

INDIRECT REACTION;--

Feo + Co ---------- Fe + Co2

THE FURNACE INTERIOR IS BROADLY DIVIDED IN TO;--

STACK, where wall slops outward going downwards.

BELLY, the cylindrical portion below the stack.

BOSH, below the belly and sloping inwards going downward.

HEARTH, below the bosh and tuyere region and the cylindrical portion.

Stack : -

This zone extends from the stock line down to the metal level . it is the

zone in which the burden is completely solid. The charge gets heated from 200

deg. C at the stock line level to nearly 1100 to 1200 deg. C by the line it

descents to the bottom of the stack.

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Bosh : --

The charge materials being to soften and fuse as they come down in to

bottom of the stack. The next lower zone is called the bosh in which meeting of

the burden, except that of core takes place. The gangue & flux combine to form

two slag.

TUYERE OR COMBUSTION ZONE:--

By the time the charge descends in to the area near the tuyere , except the

central column of coke , the entire change in molten . the oxygen of the blast

burns coke to CO and several combustion zone. One in front of each tuyere,

exist in the tuyere zone .thus, there is a runway or raceway. In front of each

tuyere which is first horizontal and then smoothly changes it,s direction to

vertical while expanding over the entire cross section of the furnace.

In our furnace there are 16 tuyeres,

No. Of tuyeres = Hearth dia. * 2 +2

COOLERS:--

In our blast furnace having material of tuyeres are,

1 to 4 row cast iron coolers

5 to 9 row Cu. Coolers

10 to 15 row cast iron coolers

HEARTH:--

Although most of the coke burns at the tuyere level , small fraction

descends even in to the hearth where it dissolve in the metal to its near

saturation .the intir charge is molten and sends to stratify in to slag and metal

layer in the hearth from where these are tapped separately.

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PULVERISED COAL INJECTION

PCI (pulverised coal injection) is the fine powder of non – coaking coal .

this coal is injected in a blast furnace .

Because the reason is that , by using PCI we can decrease the rate of

coke consumption in a blast furnace.

PCI RATE:--

7 T per hour

RAW COAL BUNKER:--

Raw coal are stored in to it , the capacity of bunker has 80 T.

DRAG CHAIN CONVEYER (DCC):--

Drag chain conveyer this is the type of conveyor. But the DCC is differ

from belt conveyor because at the bottom of the raw material hopper becomes

heavy material load by far DCC is used otherwise slipping is occurred and can

not transferred.

MILL:--

Mill is used for milling the raw coal at the temp. Is 80 to 84deg, C.

Temperature is provided for the wet material ( coal) has become dried because

this condition coal is well pulverised .

Three rollers are held in to a mill for the milling purpose.rollers are rotate

through the centre axis of roller table.

SCREW CONVEYOR:--

In a PCI two numbers of screw conveyors are used for the feeding in

single connection from the two bag filter.

PC SILO:--

PC SILO is a storage tank.

Hot gas generator (H.G.G).:--

Hot gas generator is used for supply of hot gas in to the mill, because has

maintained the mill parameter or temperature apprix,80 deg C.

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RAW MATERIAL HANDLING SYSTEM(RMHS)

Raw Material Handling System(RMHS) is the main part of integrated steel plant.

This system is raw material supplied and import from the supplier or mines.

Main Equipment of RMHS

Wagon Tippler

Side Arm Charger

Stacker cum Reclaimer

LOCO

Conveyors

Wagon Tippler:-

Wagon Tippler is the mechanism through this the wagon material ( raw material form

the mines and suppliers ) are tippling or tilting in to the hoppers.

In our Jayaswal New Industries limited have one Wagon Tippler. In a Wagon Tippler

four hydraulic clamps are provided for clamping the Wagon .

58 Wagon of Iron ore 3600 T & 2600 T are required 4 hours for empting.

Side Arm Charger:-

Side Arm Charger is used for removing the interconnections of the each wagons.

By the help of Side Arm Charger wagons has positioned in wagon on table.

Side Arm Charger is worked in forward and reversed movement.

Stacker cum Reclaimer:-

This is a very big machine in Jayaswal Neco Industries Limited. Stacker cum

Reclaimer is material handling machine or mechanism.

Material to be handled:-

Iron ore _ 10-40mm

Coke _ 20-80mm

Quartzite _ 20-50mm

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Lime stone _ 20-50mm

Dolomite _ 20-50mm

Stock pile height _ 12meter

Travel length _ 412meter

Bucket Wheel –

By the help of bucket wheel material has Stacking and reclaiming through the boom

conveyor.

Stacker Cum Reclaimer is travel on the Conveyor no. -3.

Stock –House:-

It is alsop knows as raw material store section.

When the RMHS has some problem are include that condition the raw material are

required for continue operating the Blast -furnace as per condition we are provide the stock

house for Blast-furnace operating.

Stock house are connected through the Junction House-3.

Two numbers of Travelling Tipper are held in the stock house.

Travelling Tipper-1 on C5

Travelling Tipper-2 on C6

Stock house have 16th bunkers for various type of Raw Material Feeding.

Bunker capacity is 30tonne to 250tonne.

Weighing hopper are 12 in no. in this hopper the burden has weighted as per required.

Screening System:-

Vibro Screens are used for the Screening purpose and required size material are

provide for Blast –furnace.

Vibro Feeder:-

This is a feeding equipment. Which is worked on vibration, for this purpose two Vibro

Cylenders are used.

Pig Casting Machine:-

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In a Pig Casting Machine the hot liquid iron(metal) are poured in to the Pig moulds,

this complete process is known as casting process. The producyt of casting process is

called as Pig or Pig iron.

Jayaswal NECO Industries limited have two Pig casting machine.

The weight of one piss or pig iron casting has 10kg per pig.

1200 pigs are producing(casting) machine with the help of a one belt or the pig

casting machine.

Total 4800 pigs are produced in pig casting machine.

Pig Storage Yard:-

The casting pig are transferred through the wagon Pig Storage Yard. Where pigs are

accumulate and stay by the gardes.

Such as_

Foundary grade

Basic grade

Then the pigs are loaded on trunk by the Electro magnetic crane and sopplied the

customers.

Inmotion Bridge:-

It is used for the reading or taking weight of the metal by the LOCO & ladle car in

running condition.

tn this bridge 4load cells held.

This bridge has worked when the speed of loco is more the 5km/hr..

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Gas Cleaning Plant(G.C.P)

Blast furnace produce an effluent gas containing a significant proportion of carbon

monoxide. Which could not be used for iron oxide reduction. The actual CO many vary

around 20-30% nearly 900kcal/m3 . the quantity of gas produced depends upon the

amount of fuel burnt. For one tone of coke burnt nearly 4000m3 of effluent gas may be

produced.

The effluent gas from the furnace cannot directly be used as a fuel since a substantial

quantity of dust & wear in the equipment using the gas.

The gas is therefore, clean before its use & in so doing the sensible heat of the gas is

invariably lost. So here the chemical heat of the cleaned gas is utilized.

In general cleaned is carried out in three stage_

1. Coarse

2. Semi-fine

3. Fine cleaning

There are following arrangement through which cleaning of the gas is carried out in

the Gas Cleaninig Plant(G.C.P).

The effluent gases from furnace are carried out of the furnace by large vertical pipes

called up takes. Up takes are four in number.

Two adjacent uptake are joined together to form a single duict & the two such ducts,

thus formed, are connected to from only one duct which carriea the gas downwards into trhe

duct catcher . the downcoming pipe or doct is called downcomer.

A bleeder valve is a safety device which opens automatically or is opened ,to released

extre pressure developed inside the furnace and thereby eliminate the danger of explosion.

DUST CATCHER;-

The dust is contained in the gas by virtue of its velocity hence if the velocity is zero

the dust particles will be eliminated from the gas.the state of zero velocity is achieved in the

gas catcher by simply reversing the direction of the gas flow from vertically to vertically

upward diection.

The downcomer leads the gases into the dust catcher through a Vertical

pipe that flares out and extends nearly to the bottom of the dust catcher. The gases comes

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down vertically & suddenly changes its direction to vertically upwards since the outlet is

located nearly at the top of dust catcher,

The efficient of the dust catcher is usually upto 65%.

VENTURY WASHER(1&2):-

It is a vertical unit with a construction where water is injected in the form of sprays to wet the

gas moving downwards.

The coarse cleaned gas from the dust catcher enters into the ventury washer-1, where water

sprays at angle appoxemately 120 degree.

Due to venture effect & the water sprays dust particle is settle down in the B.S.P 1.

From venture-1 the cleaned & low pressure gas is fed to the venture washer-2. Where the

same way water spray is done & the clear gas upto % is done.

B.S.P(Bottom Seal Port):-

BSP is located near the bottom of venture washer-1 & cyclone separator, where the surry is

accumulated & collected bottom of BSP.

Cyclone Separator:-

From venture washer-2 the Blast furnace gas enter into cyclone separator and spun rapidly.

The centrifugal force created by the circular flow throws the dust particles toward the wall of

the cyclone. After striking the wall, these particles fall into a hopper located underneath.

When the gas travel upward in the cyclone separator, strikes with mist eliminator and hence

moister is gas is eliminated from the Blast furnace gas.

SEPTUM VALVE:-

Septum valve is use to control the clean gases. Also septum valve is used to maintain the top

pressure.

Septum valve contain five valve

2 regulating valve(1 pneumatic+ 1 motorized)

2 shutt off valve(both are motorized)

1 valve is always open having a small diameter.

FLARE STACK:-

Flare stack is a stack through which the blast furnace gas is fed into atmosphere.

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GAS HOLDER:-

Gas holder capicitty 40,000m3 hold or storage the blast furnace gas. Which are not comsume

by the plant.

BOOSTER STATION:-

Booster station is used to boost Blast furnace gas to conveyt desired place since it is used

long distance like rolling mill etc.

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MECHANICAL

&

ELECTRICAL

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BLAST FURNACE MECHANICAL

# Tap Hole Drill Machine(Hydro-pneumatic Equipment)

Supplier- Rotamech, Kolkata

Return Speed- 0.603m/s

Rotation of drill bit- 395rpm

Drill rod length- 4150mm

Drill bit dia.- 38mm-65mm

Hydraulic rated press- 100kgf/cm2

Hydraulic tank capacity- 800ltr

Hydraulic oil- HLP68

2 Hydraulic operation

With two cylinder(Big & Small)

Big cylinder- Rod dia- 90mm

Bore dia-200mm

Stroke- 800mm

Small cylinder- Rod dia- 45mm

Bore dia- 80mm

Srtoke- 335mm

3 pneumatic operation

*forward, reverse & rotation

Globe air motor & drifter

*Globe air motor

Make- Atlas Capco Model- RM310F

*Drifter

Make- Haryson Model- BBC120F

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#Mudgun

Supplier- Shougang China

Rated press- 20 MPa

Max press- 25 MPa

Hydraulic tank capacity- 800ltr

Rated flow capacity- 210ml/rev.

Min oil level- 600ltr

Hydraulic oil-HLP68

*Operational sequence

Swing, Tilt & Push

Hydraulic cylinders-

Clay pushing cylinder- Rod dia- 320mm

Stroke- 1260mm

Total pushing force- 1655kN

Tilt cylinder- Rod dia- 45mm

Bore dia- 70mm

Stroke- 500mm

Swing cylinder- Rod dia- 110mm

Bore dia- 160mm

Stroke- 1000mm

#Skip Charging system

Volume – 4.5m3

Capacity- 9 tonne

Inclination of bridge- 53 deg.

*Skip Winch

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Rated elevating capacity- 7 tonne each car

Elevating max speed- 2.5m/s

Travel time- 54sec.

Lenth of rope- 145m each

No. of rope- 2 per car

Dia of rope- 32mm

Motor – 160kW DC drive, 1200rpm

Skip winch drum dia- 1850mm

Double herringbone type gear for skip winch drum

Reduction of gear box- 26.92:1

# BLT(bell less top) system

Burden tank consist of 4 valves

3 Hydraulic

1 motorized

*burden receiving valve

Bore dia- 80mm

Rod dia- 45mm

Srtoke- 370mm

*Upper seal valve

US1-Bore dia- 100mm

Rod dia- 56mm

Srtoke- 200mm

US2- Bore dia- 80mm

Rod dia - 45mm

Srtoke - 370mm

*Lower seal valve

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Bore dia- 80mm

Rod dia- 45mm

Srtoke- 560mm

Other than burden tank it consist of 04 hydraulically operated valves

*02 equalizing valve

*02 pressure relief valve

Equalizing valve detail:

Bore dia- 80mm

Rod dia- 40mm

Stroke- 165mm

Pressure relief valve detail:

Bore dia- 100mm

Rod dia- 55mm

Stroke- 190mm

#BLT hydraulic system:

Hydraulic tank- 1200ltr

Hydraulic pump- 02 no’s

Working pressure- 9.5 to 11MPa

Accumulators- 05 no’s

#Burden flow regulating valve:

Motor – 5.5kW, 1500rpm, AC servo motor

#Disributor:

Motor – 7.5kW, 1440rpm, Induction motor

#Chute:

Motor - 7.5kW, 1440rpm, AC servo motor

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#COOLING SYSTEM

1. Bottom hearth pipeline- 23 no’s

2. Row no. 1,2,3

No. of cooling plates- 28(each row)

Two plates interconnection.

3. Row no. 4

No. of cooling plates- 32

No. of pipelines- 16

4. Row no. 5, 7, 8 & 9



5. Row no. 6




6. Row no. 10, 11, 12




7. Row no. 13 & 14



8. Row no. 15

No. of cooling plates- 28.

#STOVE AREA

No. of stoves- 03 no’s

Each stove has following valves:

1. Hot blast valve

2. Cold blast valve

3. Cold blast by pass valve

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4. Burner shut off valve

5. Gas regulating valve

6. Gas safety shut off valve

7. CA shutoff valve

8. CA regulating valve

9. Chimney valve 1 & 2

10. Chimney by pass valve

11. Branch bleeder

Other than these valves in each stove there are three valves

installed in the stove line.

1. Mixed air shutoff valve

2. Mixed air regulating valve

3. Back draft valve

# STOVE PROPER

1 Total height of stove 35.261m

2 Inner dia. of stove 7000mm

3 Dome shell inner dia. 8000mm

4 Dome brick work inner dia. 6632mm

5 Shell height 35800mm

6 Stove height to dia. ratio 5

7 Checker chamber section area 118.79m2

8 Combustion chamber section area 3.14m2

9 Overall heat accumulating area of stove 19040m2

10 Checker type 7 hole honey comb

11 Overall height of checker 27m

12 Overall weight of checker 728 tone

13 Ceramic burner type Sleeve type

14 Capacity of burner 32000m3/hr

15 No of column 18

16 Weight of each column 635kg.

17 No of grids 14

18 No of beams 24

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#GAS CLEANING PLANT

Dust catcher- Dry type

Venture 1:

Type- adjustable throat venture

Make- kirloskar AAF Ltd.

Pressure drop- 600 to 800mmwc

Water circulating rate- 110 m3/hr

Temp. at outlet- 60 to 70 deg.

Venture 2:

Pressure drop-1600 to 2000mmwc

Water circulating rate- 110 m3/hr

Temp. at outlet- 50 deg.

Cyclone separator:

Type- centrifugal


Diameter- 3650mm

Height- 13300mm

Pressure drop- 75mmwc

Mist eliminator

Type- chevron


Size- 1000*600 & 1000*400 mm2

No of passes- 2 pass

Pressure drop- 25mmwc

Flare stack:

Capacity- 90000Nm3/hr

Inlet pressure- 900mmwc

Overall height- 55m

Type- tip burning

No of pitot burner- 04 no’s

Fuel for burner- LPG

Gas holder

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Effective volume- 40000 m3

Operating pressure- 875mmwc-600mmwc

Design pressure- 1000mmwc

Design temperature- 70 deg.

STOCK HOUSE EQUIPMENT SPECIFICATION

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Weighing Hopper (WH):

WH No. Material m3 Capacity(tone) Load cell

01 to 03 Iron ore 4.5 5 Compression type 04

no’s

04 to 08 Flux 0.2 3 Single ended 03 no’s

05 to 09 Flux 1.2 3 Single ended 03 no’s

06 to 07 Coke 4.5 5 Compression type 03

no’s

Quadrant Gates (QG):

1. QG type A:

Electrical actuator operated

1000mm stroke, 1000kg thrust

QG 01, 02, 03, 10, 11, 12 – Iron ore

QG 04, 05, 08, 09 – Flux

QG 13, 14 – Intermediate hopper

2. QG type B:

Electrical actuator operated

600mm stroke, 500kg thrust

QG 06, 07 – Coke

Vibroscreen 01 to 03 & 06 to 08

Make: International Combustion

Qty: 06 no’s

Wire deck size: 1390*1035

Wire mesh size: 10mm2

Feed material: I/O

Feed rate: 200 TPH

Separation: 10mm

Motor: 11kW, 1000rpm

Coupling: U coupling

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Shaft: Carden Shaft

Bulk density: 2.5 T/m3

Vibroscreen 04 & 05


Qty: 02 no’s

Wire deck size: 1380*1130

Wire mesh size: 25mm2

Feed material: Coke

Feed rate: 110 TPH

Separation: 25mm

Motor: 7.5kW

Coupling: U coupling

Shaft: Carden Shaft

Bulk density: 0.5 T/m3

Vibrofeeders 05 to 12


Inclination angle: 10 deg

Liner: 04mm thick

Feed material: LS/DOLOMITE/Mn ore/Qtz.

Bulk density: 1.6/1.65/2.0/2.5 T/m3

Feed size: 20 - 50 mm

Feed rate: 260 TPH

Feed rate variation – 10% - 100%

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WAGON TIPPLER

Type of wagon tippler – Hydraside

Gross weight of wagon to be handled – 110 tonne

Max angle of rotation of tippler – 155°

No. of load cell provided: 06 no’s

No. of top clamp – 4 no’s

Drive Unit: Hydraulic motor powered through power pack mounted outside of the tippler

rotating body.

Gear box: Planetary

Tippler drive motor: 90kW, 1440rpm

Type of wagon clamping: Hydraulic

SIDE ARM CHARGER

Motor for power pack- 45kW, 1450rpm

Charger drive type: Planetary gear box (1:77)

Arm drive: Hydraulic cylinder 02 no’s

STACKER CUM RECLAIMER

Materials to be handled

Iron ore = 10 – 30 mm

Coke = 20 – 80 mm

Qtz = 20 – 50 mm

Limestone = 20 – 50 mm

Dolomite = 20 – 50 mm

Stockpile height – 12 m

Travel length – 412 m

Capacity

While stacking

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I/O – 1500TPH

Coke- 450 TPH

Mn ore, Qtz, LS, Dolomite – 1500 TPH

While reclaiming

I/O – 650 TPH

Coke – 130 TPH

Mn ore – 500 TPH

Qtz, LS, Dolomite - 400 TPH

Drive details:

Motor: 06 no’s, 7.5kW, 1500rpm

AC variable frequency control

Coupling: Flexible brake coupling

Gear box: Vertical gear unit

Brake: Thrust operated jaw brake

Bucket Wheel:

Type: cell less

No. of bucket: 08 no’s

Bucket capacity: 250 ltrs.

No. of discharge/min.: 28

RPM: 3.5

Motor: 45kW, 1500rpm, AC SCIM reversible

Gear box: Planetary gear box (410:1)

Boom Conveyor:

Belt width: 1400rpm

Belt speed: 1.75 m/s

Conveyor length: 33.407m

Motor: 75kW, 1500rpm, AC SCIM reversible

Gear box: Bevel helical triple reduction gear, 28:1

Brake: DC electromagnetic brake 400Ø

Slewing mechanism:

Slewing speed at centre of bucket wheel: 08 – 32 mtr/min

Slewing angle: ±105°

Motor: 02 no’s, 10kW, 150 – 1500rpm, continuously variable DC drive

Lifting mechanism for boom

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Type: hydraulic

No. of cylinder: 02

Speed: 03 m/min.

Type of cylinder: differential double acting cylinder

BELT CONVEYOR DETAILS:

Conveyors Belt Length

(m)

Belt Speed

(m/s)

Motor (kW) Belt Size (mm)

C1 36 1.75 30 1400

C2 299 1.75 200 1400

C3 1249 1.75 280 1400

C4/C4A 400 1.75 90 900/800

C5/C6 400 1.75 75 900

C7/C8 95 1.25 22 1000

C9A 54 0.5 11 650

C9B 63 0.5 5.5 650

C11/C11A 142 0.5 11 650

C12 145 0.5 30 500

BF1 165 0.75 7.5 500

PCI (PULVERIZED COAL INJECTION) EQUIPMENTS:

ID FAN:

Flow rate: 43900 – 53000 m3/ln

Pressure: 2256 – 2432 Pa

Working temp: 150 – 300°C

RPM: 0 – 1480

CA BLOWER:

Flow rate: 3963 – 4792 m3/ln

Pressure: 4256 – 4662 Pa

Working temp: 20°C

RPM: 2900

COAL MILL:

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Capacity: 15.1 TPH

Diff. pressure: 5 – 6 kPa

Inlet flow rate: 40000 m3/ln

Max inlet size: 50 mm

Inlet temp.: 300°C

Outlet temp.: 80 - 100°C

Inlet moisture: <12%

BAG FILTER:

Flow rate: 40000 m3/ln

Inlet temp.: <120°C

Filtering speed: 0.41m/min

Filtering area: 1610 m2

Density inlet: <1000 g/m3

Density outlet: <50 g/m3

PC BUNKER:

Volume of tank: 140 m3

Weight level limit: 90T max

20T min

COAL BUNKER:

Volume of tank: 130 m3

Weight level limit: 90T max

20T min

BELT CONVEYOR: NO. 01 & 02

Breadth: 650mm

Speed: 1.25 m/s

Quality: 120TPH

Length: 86.4m & 84.82m.

ELECTRICAL OF BLAST FURNACE ;

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1. SLD OF BLAST FURNACE

2. SLD OF STACKER CUM RECLAIMER

3. SLD OF WAGON TRIPPLER

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EOT CRANES –

ELECTRIC OVERHEAD TRAVELLING CRANE are used for

transporting raw material,laddle etc from one place to

another.

Components-

1. Current collector – It is mainly used for power supply

from down shop line to crane. As crane is movable,

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current collector is used which is fixed with respect

to crane but movable with respect to dsl.

2. Switch fuse unit- It is used in power panel to prevent

from short circuit.

3. Overloading relay- it is used in power panel to prevent

the motor from overloading.

4. Miniature circuit breaker and contactor

5. Transformer- A step down transformer is used in

power panel. It reduces 44o V to 110 V.

6. Motor

7. Break

8. Limit switch

9. Timer

10. Resistance box

Safety equipments for EOT cranes –

1. Counter weight limit switch- it is

present in the main hoist. When main hoist raise

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to maximum limit of height, it touch the counter

weight limit switch and entire power supply of

crane is cut-off.

2. Rotary gear limit switch- it has coupling

with the rope drum. There is the limit to revolve

the drum in both direction, when the rotation

exceed for the limitd value, then power supply is

cit off.

3. End limit switch – it is used for both long

travel and cross travel maximum limit, when

crane touch the limit switch, power supply cut-

off.

4. corner limit switch- it is situated as the

master panel. If there any fault is found in the

crane then supply is cutoff by this switch.

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INSTRUMENTATION

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INSTRUMENTS IN AGLANCE AT JNIL BLAST FURNACE

Instrumentation is used to measure many parameters (physical values). These

parameters include:

1. Temperature

2. Pressure, either differential or static

3. 3. Flow

4. Level

5. Weight

Thermocouple Theory : A thermocouple, shown in Figure 1, consists of

two wires of dissimilar metals joined together at one end, called the

measurement (“hot”) junction. The other end, where the wires are not

joined, is connected to the signal conditioning circuitry traces, typically

made of copper. This junction between the thermocouple metals and the

copper traces is called the reference (“cold”) junction.

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Figure 1. Thermocouple.

The voltage produced at the reference junction depends on the

temperatures at both the measurement junction and the reference junction.

Since the thermocouple is a differential device rather than an absolute

temperature measurement device, the reference junction temperature

must be known to get an accurate absolute temperature reading. This

process is known as reference junction compensation (cold junction

compensation.) Thermocouples have become the industry-standard

method for cost-effective measurement of a wide range of temperatures

with reasonable accuracy. They are used in a variety of applications up to

approximately +2500°C in boilers, water heaters, ovens, and aircraft

engines—to name just a few. The most popular thermocouple is the type K,

consisting of Chromel ® and Alumel ® (trademarked nickel alloys

containing chromium, and aluminum, manganese, and silicon, respectively),

with a measurement range

Type K (Chromel / Alumel)

Type K is the 'general purpose' thermocouple. It is low cost and, owing to its

popularity, it is available in a wide variety of probes. Thermocouples are

available in the -200°C to +1200°C range. Sensitivity is approx 41uV/°C. Use

type K unless you have a good reason not to

Type S (Platinum / Rhodium)

Suited for high temperature measurements up to 1600°C. Low sensitivity

(10uV/vC) and high cost makes them unsuitable for general purpose use. Due to

its high stability type S is used as the standard of calibration for the melting

point of gold (1064.43°C).

Type J (Iron / Constantan)

Limited range (-40 to +750°C) makes type J less popular than type K. The main

application is with old equipment that cannot accept 'modern' thermocouples. J

types should not be used above 760°C as an abrupt magnetic transformation will

cause permanent decalibration.

What are Rtds?

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Resistance Temperature Detectors or RTDs for short, are wire wound and thin

film devices that measure temperature because of the physical principle of the

positive temperature coefficient of electrical resistance of metals. The hotter

they become, the larger or higher the value of their electrical resistance.

They, in the case of Platinum known variously as PRTs and PRT100s, are the

most popular RTD type, nearly linear over a wide range of temperatures and

some small enough to have response times of a fraction of a second. They are

among the most precise temperature sensors available with resolution and

measurement uncertenties or ±0.1 °C or better possible in special desions.

Usually they are provided encapsulated in probes for temperature sensing and

measurement with an external indicator, controller or transmitter, or enclosed

inside other devices where they measure temperature as a part of the device's

function, such as a temperature controller or precision thermostat.

The Advantages of RTDs

The advantages of RTDs include stable output for long period of time, ease of

recalibration and accurate readings over relatively narrow temperature spans.

Their disadvantages, compared to the thermocouples, are: smaller overall

temperature range, higher initial cost and less rugged in high vibration

environments.

They are active devices requiring an electrical current to produce a voltage drop

across the sensor that can be then measured by a calibrated read-out device

Platinum RTD Output Equation

ASTM Standards E 1137 for Industrial Platinum Resistance

Thermometers specifies that the resistance-temperature relationship for

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such devices for the range 0 °C to 650°C, to within the tolerances given

below, will be described by the equation:

R(t) = R(0)[1 + At +Bt^2]

Where:

t = temperature (to ITS-90), °C,

R(t) = resistance at temperature t,

R(0) = resistance at 0°C

A = 3.9083 * 10^-3(°C), and, B = -5.775 * 10^-7(°C^2).

LOOP DIAGRAM

http://www.temperatures.com/scales.html

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Thermocouple/RTD

mV/ohm

Temperature Transmitter

4-20 mA

DCS

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PRESSURE MEASUREMENTS

DEFINITION OF PRESSURE

Absolute pressure

The pressure is referenced to zero absolute pressure and has units of psia.

Absolute pressure can only have a positive value.

Gauge pressure

The pressure is referenced to atmospheric pressure and by convention is

measured in the positive direction, i.e. 7 psig.

Vacuum pressure

The pressure is referenced to atmospheric pressure and by convention is

measured in the negative direction, i.e. -50 mm Hg.

DP TRANSMITTERS

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• DP i.e Differential pressure transmitters are used for the measurement of

flow and level. Supply: 24v dc

Output: 4-20 mA

Types of Flow meters

1. Magnetic Flow meters

2. Vortex Flow meters

3. Ultrasonic Flow meters

4. Coriolis Mass Flow meters

5. DP type flow meter

Types of level measurement

1. Radar

2. Ultrasonic

3. Capacitance

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4. Differential pressure

5. Conductive

6. RF Admittance Level Switches

Principles of Radar Level Sensor

The antenna on a radar level gauge generates millions of very short 1

Nano second microwave pulses every second. Each pulse is directed and

transmitted to and reflected from a product surface. The elapsed time

period between transmission and reception of the signal at the speed of

light is measured and calculated as a distance. This continuous stream of

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pulses gives real time level information updated and is evaluated many

times a second.

Radar level sensors work with safe, low emitted power in the c (4 to 8

GHz) and k-band (18 to 26.5 GHz)frequency range. The proven

ECHOFOX signal processing selects the correct level echo reliably.

Adjustment by filling and emptying the vessel is not necessary, it can

normally be done with simple input of vessel dimensions.

Principles of Conductive

level Sensor

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Principles of Loadcell

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Application of loadcell


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Opacity MeterOpacity meter is used for the measurement of opacity and dust concentration within

the flue gas.

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2. Measurement Principle

Consider the two identical transceiver units positioned at either side of

the flue(or duct), unit 1 and unit 2. The transmissivity of light from unit 1

to unit 2 (unit 1transmitting) can be represented by the equation :

t12 = K1 (D21/D11) where :

K1 = gain constant to produce

t = 1 (100% transmissivity, clean air condition)

D11 = the detector output at unit 1 (internal reference level)

D21 = the detector output at unit 2

The transmissivity of light from unit 2 to unit 1 (unit 2 transmitting) can

also be represented by the

equation : t21 = K2 (D12/D22)

where : K2 = gain constant to produce t = 1, D12 = the detector output

at unit D22 = the detector output at unit 2 (internal reference level)

Control valve

Control valves are used to control the process

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Parameters such as flow, pressure, temperature, level.

It works under force balance principle.

Control valve accessories include:

AFR-air filter regulator

I/p- current to pressure

Positioner.

Control valves are of two types:

Air to close

Air to open

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Flow diagram of control valve

Instrument air AFR I/P (0.2 -1 kg/cm2)

(5-6 kg/cm2) (1.5kg/cm2)

Positioner

AFR

(2-3 kg/cm2)

I to P converter• I to P converts an analog signal (4 to 20 mA) to a proportional linear

pneumatic output (.2 to 1 kg/cm2).

• Its force balance principle is a coil suspended in a magnetic field on a flexible mount. At the lower end of the coil is a flapper valve that operates against a precision ground nozzle to create a backpressure on the servo diaphragm of a booster relay.

• The input current flows in the coil and produces a force between the coil and the flapper valve, which controls the servo pressure and the output pressure.

Positioner

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• Positioner consist of air supply port , signal input port, out put port.When

positioner get input signal ,it compare with stem position and output is

generated and signal boosted sufficiently to operate the valve . It uses

force balance system.

•

•

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I/O’s defined in DCS

• DI signals – Signals Coming from swicthes,sensors,etc

DI FIM card -32 channels are used.

• DO signals - Signals given to drives,shut off valves etc.

DO FIM card-32 channels are used.

• AI Signals – Signals coming from transmitters,etc

AI FIM card – 16 channels are used.

• AO signals – Signals given to control valves,regulating power cylinders,etc

AO FIM card – 8 channels are used.

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