2. 2
CONTENTS
TOPIC PAGE
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
ACKNOWLEDGEMENT
CERTIFICATE
ABSTRACT
INTRODUCTION
CEMENT MANUFACTURING PROCESS
MANUFACTURING OF KONARK CEMENT AT OCL-
A BIRD'S EYE VEIW
Raw material mining/procurement
Lanjiberna Quarry
Raw material handling
Crusher
Wagon trippler
Stacker & Reclaimer
Raw mill grinding
Vertical Roller Mill
Electrostatic Precipitator(ESP)
Gas Conditioning tower
Raw Mill Blending Silo
Coal Grinding
Coal Crusher
Coal Mill
Pyro-processing / Clinkerisaton
Preheater / Pyroclone
Dry Process Rotary kiln
Grate Cooler
Cement Formation
Overhead Crane
Hopper
Cement Ball Mill
Cement Vertical Rolling Mill (CVRM)
Bag Filter
Packing & Dispatching
Packing House
Roto Packer
ENVIORNMENTAL PROTECTION ACTIVITES
CONCLUSION
3
4
5
6
8
12
13
14
15
21
22
26
32
34
35
3. 3
ACKNOWLEDGEMENT
I, Sudhanshu shekhar of KIIT UNIVERSITY had a great time
working under the supervision of the members of OCL. I would like
to thanks all the members who guided me throughout my training
period and share their knowledge about the production process and
instruments used in cement factory. My sincere thanks to Mr. Debi
Prassad Das of OCL India Ltd. for his encouragement and valuable
suggestion during period of my training and report preparation. I
would also like to thanks Mr. Rohan shome and Mr. P.K.Rout
(Manager, HRD) for their extreme help and guidance under which
training was completed easily.
No word would suffice to express my regard and gratitude to
all the members of line-2 department Mr. dillip panda sir, Mr. bakshi
sir, Mr. rohan sir and also the attainder of various section of line 2
department, Mr. krishna, Mr. amit kumar for their constant
encouragement and valuable timing throughout the course of our
training.
I express my gratitude to all the mentors for their valuable
suggestion and guidance, without their cooperation this report is
incomplete.
-Sudhanshu shekhar
4. 4
CERTIFICATE
This is to certify that the vocational training report on OCL
India ltd. is submitted by Sudhanshu shekhar of KIIT
UNIVERSITY, Bhubaneswar towards partial fulfillment for the
award of the degree of bachelor of technology in the branch of
Mechanical Engineering is a bona fide record of the work done in
oue supervision and guidance.
It is a faithful record of bona fide training report cared by
Sudhanshu Shekhar under our supervision & guidance. It is further
certified that no part of this report has been submitted to any other
university or institute for award of any other.
.......................... ........................
Mr. P. Murlimohan Mr. D. P. Das
(A.E.D./ Engg.) (Mgr./ Mech)
(Engg. Head)
5. 5
ABSTRACT
OCL India Ltd. better known as OCL is a public limited company located
at Rajgangpur, a small village in the district of Sundargarh, Orissa in India. It
was established in the year 1951, having a single wet process Kiln with a
capacity of 4 Lakh tons of cement per annum. Subsequently it was converted
into a five stage pre-heater with pyroclone and dry process Kiln. The present
capacity is 2.9 million ton per annum. Its product KONARK brand cement
enjoys over the years a premium brand name and has been the market leader
in the state of Orissa.
Though initially the cement unit was established for catering cement for
the construction of HIRAKUD dam but subsequently hardly there is any
prestigious construction of national and or international repute in Eastern
India wherethe KONARK cement contribution is not there.
The company produces as many as seven varieties of cement in its
single unit at Rajgangpur through its state of the art technology having most
modern computerized control and monitoring system right from raw mix
preparation up to finished cement grinding, packing and dispatch system.
Fig - i
6. 6
INTRODUCTION
OCL’s Cement plant is one of the most modern dry process cement plants in
India. It was founded by Late Sri Jaidayal Dalmia. ’Konark’ brand cement
manufactured by OCL is the market leader in the state of Odisha and has
emerged as a brand synonym of premium quality cement.. It has got three
units at Rajgangpur presently:
1. Cement Works
2. Refractory Works
CEMENT WORKS:
Cement Division was established in 1949. Its initial capacity was 4 lakh
tons per annum having wet process at that time. It was expanded in 1988 to 7
lakh tons per annum following dry process & computerized central control
system. It was again expanded in March’1997 to 10 lakh tons per annum,
employing a Vertical Roller Mill (VRM),a giant clinker grinding unit.
Clinkerisation capacity 9.0 lakh ton per annum had been achieved by taking
preprocess modification and installing twin low pressure pre-heater in year
2004. Installed capacity of 2 million ton of cement production had been
achieved in the year 2005 after completion of installation of installation of
3rd
CVRM. Annual turnover of cement unit – 400 crores (approx.). It has got
ISO -9002 Product certification for oil well cement had been from API in year
2004.
Types of Cement Manufactured at Orissa Cement
OCL is presently manufacturing the following under the brand name of
KONARK CEMENT.
Ordinary Portland Cement (OPC)-33 Grade, 43 Grade,53
Grade[Gypsum-4% & restClinker with Fineness (Blains) 325 m2
/Kg]
Portland Slag Cement (PSC)[Gypsum-4%,Slag-30 to 40% & rest is Clinker
with fineness(Blains) 325 m2
/Kg]
Special Cement (IRST-40) [Gypsum-4%, Clinker-96% with Fineness
(Blains)-370 m2
/kg
Sulphate Resisting Portland Cement (SRPC) [same as PSC except that
variation in somechemical composition]
Portland Pozzolona Cement (PPC) [Gypsum-4%,Fly ash - 25% & rest is
Clinker with Fineness(Blains) 325 m2
/Kg]
Oil well cement -Class -G-HSR
8. 8
CEMENT MANUFCTURING PROCESS
CEMENT:
Cement is a substances applied to the surface of solid body to make
them where firmly or more specifically a powdered substances which made
plastic with water in used in a soft and pasty state (which hardens on drying)
to bind together bricks, stone etc. in binding Portland cement is a calcined
material composing lime and silicate which mixed with sand & stone and upon
hydration form a plastic material which sets & hardens to a rock like material
called CONCRETE.
For cement, clinker is the main product of the rotary kiln (furnace) & is
hard, light black in color. After grinding clinker (95%) with gypsum (5%), we
get ORDINARYPORTLAND CEMENT(OPC).
a) 45% slag + 5% gypsum + 50% clinker = PSC Cement(PORTLAND SLAG
CEMENT)
b) 25% fly ash + 5% gypsum +70% clinker = PPC Cement(PORTLAND
POZZOLANA CEMENT)
Slag is the waste product of steel plant i.e. from blast furnace and fly
ash is the waste product of thermal power plant. These two slags & fly ash are
materials which are not they cementation but are latently hydraulic content
same CaO. The central govt. has given order to all the cement plant to use the
waste like slag & fly ash in cement industry compulsorily. Therefore, they are
saving clinker & producing more cement to the market. Now from cement
concrete roads are manufactured instead of pitch road which are
environmentfriendly and gives long life with good quality finishing.
The most expensive component when producing cement is fuel (Coal) &
power (Electricity). So, most of the plant are taking foreign plants are using
latest technology with good quality latest foreign equipments for producing
cement.
Indian coal is relatively of poor quality with higher ash content i.e. low
calorific value but easily available in large quantity.
Because of the high temp. Existing a kiln (950o
C to 1450o
C) and pre
heater tower (340o
C to 900o
C) and cooler (1250o
C to 200o
C) during clinker
manufacturing system to protect the steel shell of the kiln, preheater & cooler
with refractory bricks & castable inside the system with good quality. OCL is
using their OCL refractory bricks & castable to protect the steel shell. Most of
the cement plants are also taking OCL refractory bricks & castable.
9. 9
For manufacturing cement the main raw material is LIMESTONE (95%).
The clay is suitable for low silica & alumina. In raw mix cinder used for
alternative to clay, which is burntcoal (80%).
By grinding limestone with additive like clay cinder, morrum in a vertical
roller mill to convert in dry powder form is called raw mill or raw mix for
rotary kiln. It always keeps in Big Silos or Tank. In OCL line-2, one raw mix
keeping silo are present and its capacity is 5000 tons having 45mts height. In
every hour the main raw mix grinding material from vertical roller mill
collected for laboratory testing in XRF for better result to maintain quality raw
mix. The capacity of the vertical roller mill of limestone grinding of line-2 is
450 tones per hour.
The limestone comes from Lanjiberna mines after blasting the
limestone during night duty & it converts into 75mm to 100mm size crushing
it into the limestone crusher. Then it is carried to OCL by conveyor belt.
The limestone comes to OCL inside and makes a big stock pile for
grinding in vertical roller mill. The capacity of one stock pile is 15000 tones.
We have two stock piles for keeping lime stone. Then, after reclaiming the
limestone through reclaimer it goes to limestone hopper through belt
conveyor.
In VRM section of limestone grinding, we havefour hoppers:
a) One for keeping limestone
b) Second one for keeping Clay or Cinder
c) Third one for keeping Morrum(Fe2O3)
d) Fourth one for keeping Sweetener which is nothing but high grade
limestone only high CaO content
Coal is the prime input for firing or burning the raw mix inside the kiln
and pre heater for making clinker. Coal fishes into a kiln and pyroclone as dry
powder only having good fineness.
In OCL line-2 there is only one vertical roller mill for grinding coal. Inside
the mill there are three hydraulic rollers for grinding. The capacity of the coal
vertical roller mill is to produce 30 tons per hour of fine coal. The coal
generally comes from Gopalpur, Korba,Meghalaya, and South Africa etc. as
raw coal.
Coal is composed of carbon, hydrogen, oxygen, nitrogen, and sulphur with
very small amount of also other elements. The composition is 80%-90%
Carbon, 4%-5% hydrogen, 5%-10% oxygen, 1.5%-2% nitrogen and 1% of
organic Sulphur. The calorific value of the coal is the most important and it
10. 10
depends on the content of volatiles, ash and the moisture. The good quality
coal having high calorific value and low ash content.
From our raw mix or raw mill silo the dusty material gone to the
preheating tower (nearly about 135mt height) through bucket elevator at the
top floor. The pre heater tower consists of cyclones having five stages hollow
inside to give the raw mix and hot gas in cyclonic motion for proper
calcinations. The material (raw mix) reaches within 30sec from pre heater top
to the kiln furnaceinside (inlet area)
During that 30sec period, near about 90-95% calcinations should be
done at pre heater which is called flameless firing and 60% coal used(fine
coal) at the pre heater, rest 10% calcinations and burning of the raw mix done
inside the rotary kiln(furnace) have firing from kiln inside from the kiln outlet
platformarea with fine coal 40%.
Pre heater cyclones are dust separation units, which are separated the
heated raw mix from the hot gases in the gas duct. Heat transfer takes place
in the pre heater cyclones between the gases and the raw mix at user duct
point. The gases leave the cyclones through the top and material spiral down
to the kiln. One big pre heater fan runs for doing this calcinations job well. At
the top the gas temps. Remain 320o
C to 380o
C and at bottom of preheater
means entering to the kiln remain 900o
C to 990o
C. The raw mix color changes
fromash color to milky tea color that enters to the kiln.
The chemical reaction of the raw mix starts at 500o
C from preheater to
1450o
C inside the kiln. From kiln end point the raw mix enters into the rotary
kiln (furnace) at 990o
C and goes on rotating to come faster. Evolution of CO2
from Calcium Carbonate started from 815o
C. Then from inside the kiln the
temp. Gradually increases in each step by producing C2S, C3S, C3A, C4AFetc. At
near about 1250o
C the hot raw mix powder slowly melts to liquid state. Then
the liquid raw mix temp. Fall from 1400o
C to 1200o
C by converting it to solid
red hot clinker balls. So, max. temp. of the kiln is on the 1/3rd
of the total kiln
length. The total kiln length of line-1 is 56mtand diameter is 3.8mt.
The red hot clinker granules fall on the cooler having perforated plates.
The max. Air given by a no. of fans (nine fans) from the bottom of the plate to
cool down the clinker from 1250o
C to 150o
C only. The steel plate’s move like
shaking conveyors very slowly and it take 25-30 min inside the cooler for
proper cooling. Then the cooled clinker became light black in color and pass
11. 11
through the clinker crusher to become small size for storing in clinker silo. But
in kiln clinker produced within 20 – 25minutes only.
Every hour the cool small clinker collects for x-ray laboratory testing to
get the C3S strength and all other detail result for taking further action. This is
a continuous process for 24hrs. In line-2 of OCL (new plant) the clinker
production capacity is 4000 tons per day in 24hrs.
Both line-1 and line-2 plant have been designed by KHD Germany and
its technology is the best in world. limestone grinding VRM are fromGermany.
For storing the final product cement there are 17 silos (Big Tank) and
two other silos also having total capacity of 36000 tons cement.
The cement packing done through rotor packer. Automatically in each
bag having 50 kg capacities. The transporting of cement bags done through
the trucks and railway wagons to outside.
The Central Control Room (CCR) is the heart of the cement plant and
from CCR all the units are operating by the expert operators regularly.
Through the computerizing modern technology system, through monitors all
the dates are coming continuously. The start, stop, increases, decreases etc
i.e. everything’s controls only fromthat controlroom through the keyboards.
In OCL Cement Plant, there are a few bag filters, ESP (Electro Static
Precipitators) for controlling the dust emission for keeping the environment
good and greenery. Since, the 60 years OCL has been producing cement in
India at Rajgangpur which is marketing at the name of “KONARK BRAND
CEMENT”
Use and purposeof cement:
1. The first and foremost use of cement is to act as main ingredient in
concrete. it is used for walls, roofs, bridges, concrete roads, flooring,
etc.
2. Used for railway sleepers.
3. Used in foundations
4. Used for pillars, piers and columns.
5. Oil well cement is used for oil well dugs, water tank .
12. 12
MANUFACTURING OF KONARK CEMENT AT OCL
A BIRD’S EYE VIEW
Fig – iii
The manufacturing process consists of the following stages: -
1) Raw material mining /procurement.
2) Raw material handling/proportioning.
3) Raw material grinding.
4) Coal grinding.
5) Pyro processing/Clinkerisation.
6) Cement formation.
7) Packing and dispatch
13. 13
Raw materials mining / procurement
Main constituent Lime stone is produced form its captive mines at
Lanjiberna Quarry, which is 10 Km from the cement works. Other raw
materials i.e. Clay, Laterite, Hard Morrum are procured from outside sources.
Blast furnace Slag is procured from Steel Plants at Rourkela, Vizag, Bhilai, etc.
Fly ash is procured from the power plants at Rourkela Steel Plant, INDAL
Sambalpur and other nearby thermal power plants.
Raw material mixtures for cement manufacturing should have following
constituents by percentage:
CONTENTS RANGE IN %BY WEIGHT AVERAGE IN % BY WEIGHT
CaO 60-69 65
SiO2 18-24 21
Al2O3 4-8 6
Fe2O3 1-8 3
MgO Less than 5 2
K2O Less than 2 1
Na2O Less than 2 1
SO3 Less than 3 1
TABLE - i
LANJIBERNA QUARRY
This is the captive mines of OCL .It is about 10 Km from the works. It is an
open cast mines. After quarrying operation, the limestone boulders are
crushed to a nominal size of 75 mm by an impact type crusher. Thereafter, the
crushed limestone are transported up to JAMPALI exchange yard in 10 ton
box type wagon pulled by a diesel locomotive from where electric locomotive
carry them to RAJGANGPUR cement works.
14. 14
Raw material handling / proportioning
CRUSHER
INTRODUCTION
Previously, there were two secondary Crusher units (Hammer Mill)
which have been already taken out. Now, function of the section is to unload
limestone procured onto hoppers and transportup to stacker/reclaimer unit.
MAIN EQUIPMENT:
1. WINCHES
Unidirectional type - 2 No’s
Reversible type - 2 No’s
FUNCTION:-Forshunting loaded wagons up to tipplers
2. WAGONTIPPLERS -2 No’s
• Tippler No.1 —90 tph
• Tippler No.2 —180 tph
FUNCTION: To unload Limestone from wagon onto existing hoppers by
tilting.
Fig - v
15. 15
WAGON TIPPLER
A wagon tippler is a compact machine and discharges limestone from
open top rail wagon by inverting the wagons over a track side hopper. It is
driven through two numbers of Pinions connected to the gear by pinion shaft
and jack shaft, maximum angle of rotation is 155 degree.
In line-1 it has two wagon tipplers supplied with winches which shunt the
wagons to the tipplers. The wagons are unloaded to the limestone hopper.
Then the lime stones are carried by laminated conveyer belt which at last is
connected to stacker belt.
STACKER & RECLAIMER
INTRODUCTION:
The intermediate storage of raw materials between Quarry & Raw Mill
is required to form the stock pile from where a steady supply of materials for
processing in the cement works is maintained. In addition, it has, in recent
years, become increasingly important for the purpose of pre-blending or pre-
homogenizing of the crushed limestone for process.
By stacker limestone procured in different trips having varying
constituent is stacked longitudinally layer by layer spread over the entire
width .At the time of reclaiming transversely, all the layers from a particular
section goes together thereby ensuring blending.
TECHNICAL SPECIFICATIONS:
Type of stock pile :Chevron type
Type of stacker unit :Boom type
Type of reclaimer unit : Scrapper typewith Harrow attachment
Stacker feed rate :600 tph
Reclaimer capacity :500 tph
Storagecapacity :15,000 MTx2 No’s
Blending efficiency :1:10
Size of Stock pile :98m (L) x 25m(W) x 9.8m(H).
Raw material grinding
Reducing the raw meal to a fine powder form conventionally called raw
meal is necessary in order to produce a homogenous mixture which will be
quickly converted in the kiln into a homogenous clinker containing no free
lime.
16. 16
MAIN EQUIPMENT:
Vertical Roller Mill (VRM)
Electrostatic Precipitator (ESP)
Gas Conditioning Tower
Raw Meal Blending Silo
VERTICAL ROLLER MILL (V.R.M)
GENERALINTRODUCTION:
The LOESCHE mill belongs to the species of roller mills. The mill is
designed with three rollers. Each roller together with the rocker arm, in which
it is rigidly clamped, the pedestal in which the rocker arm is mounted and the
hydro pneumatic spring system, represents a power unit. This power unit is a
building block or module which can be arranged two fold, threefold or four
fold around the grinding table.
VRM:LM 46.4.2
LM– LOESCHEMILL,
46– TABLE DIA (46 DECIMETER)
4– NO. OF ROLLERS
2– ROLLERDIA (1 METER)
METHOD OF OPERATION:
The rotation of the grinding table distributes the grinding stock
uniformly over the horizontally arranged grinding plate. The tapered grinding
rollers draw the grinding stock in and crush it.
When the grinding rollers come in contact with the grinding stock, the
piston of the hydraulic cylinder is lifted during crushing process via rocker
arm and the connecting rods and the fluid of the upper chamber of the
cylinder is displaced into gas filled hydraulic accumulator. This compresses the
gas which functions as a spring. Centrifugal forces throw the crushed material
from the grinding table into the upper portion of the Louvre ring which
surrounds the grinding table. The stream of the hot gases being sucked from
the grinding mill blower moves the crush material upwards to the classifier
through the mill body. The intimate contact of the grit with the hot gas
evaporates the moisture in the grinding stock spontaneously. The residual
moisturecontent will be approximately 1%.
17. 17
Material which has not been crushed to the specified size is rejected by
the classifier. The rejected material falls in the internal grit return for
recycling.
Fig - vii
SPECIFICATION:
1. MILL TYPE :LOESCHE Mill LM 46.4.2
2. MILL OUTPUT : 450 TPH
3. FEED SIZE : (0-75) mm.
4. RAW MILL FINENESS : 20% residueon DIN0.09
5. RAW MILL MOISTURE : Max 2% H2O.
6. MILL GEAR BOX : Itconsists of special design as bevel
Helical gear with horizontalinput shaft
and vertical output flange.
(A) TYPE : STK-170H
(B)MAKE :RENK
7. CLASSIFIER :FLENDER GERMANY
(A) POWER :170KW
(B) RPM : 120
8. WATER INJECTIONUNIT :Capacity 8 m3
/hr at a pressureof16 bar
9. FAN DETAIL :Capacity-383000m3
/hr
(A) TEMPERATURE :100 degree centigrade
(B) SPEED :980 rpm
(C) POWER :1900kw
10.MAINMOTOR
18. 18
(A) POWER :1120 KW
(B) RPM :750
(C) FR. No. : IRS 7567-8P
11.CLASSIFIER : LSKS-52
(A) POWER : 75 KW
(B) RPM :94
12. CLASSIFIERMOTOR:
(A) POWER :170 KW
(B) RPM :450 to 1000
(C) TORQUE :600 N.M
13. MILL FAN MOTOR
(A) POWER :1900KW
(B) RPM :600 to 980
(C) FREQUENCY :50Hz
14.TABLE
(A) DIAMETER : 4.6m
(B) RPM : 40
15.DAMRING HEIGHT : 80mm
16.ROLLER DIAMETER :2m
17.GRINDING PRESSURE:(70-90) Bar
LUBRICATION USED IN V.R.M
1. MAINGEAR BOX DRIVE : SMSP-320
2. HYDRAULICPANNEL : S.S-68
3. ROLLER PANNEL : SMSP-460
4. CLASSIFIERGEARBOX : MOBILEXMP-320
5. TRIPPLEFEED GATE
HYDRAULICOIL : 361 LP1
6. GREASE USED IN
CLASSIFIERBRG : 361 GP1
7. GREASE USED IN
TRIPPLEFEED GATE BRG : SERVO JEM EP-2
8. GREASE USED IN
ROCKER ARM BRG : SERVO JEM EP-2
19. 19
Electrostatic Precipitator
The Electrostatic Precipitator applies the effects of gas ionization in a
strong electric field. The plates on which the dust is collected are
grounded and high voltage wires are hung between the plates. The wires,
connected to a high voltage power supply, create an electrostatic field
between the plates. The gases passing through are ionized and impart a
negative charge to the dust particles. The negatively charged dust particles
are attracted to the positively charged plate on which they are precipitated
and lose their charge. The plates are rapped and the particles fall into
collection hoppers for removal. Some of the dust particles become positively
charged and are attracted to the discharge wires which, therefore must also
be rapped.
TABLE–ii
Fig - viii
ESP(Location) TYPE FAN DRIVE(kW FAN RPM NO’S.
Raw Meal VRM Horizontal 2100 0 – 1000 1
Pre-Coal ESP Horizontal 75 975
1
Coal ESP Vertical 240 735
1
Mill House ESP
Horizontal
200(I & II) 0-1000 1
315 (III & IV) 0-1000 1
20. 20
Gas Conditioning Tower (GCT)
In order to dry up moisture present in the raw meal VRM,some
exhaust gas from Preheater is directed to it(VRM).But this gas sucked from
Preheater by preheater fan has got temperature of about 300-3500
C whereas
VRM inlet temperature should be 150-200o
C.So, in order to maintain this
temperature, a Gas Conditioning Tower is arranged in between. The function
of the GCT is to reduce the high temperature of hot gas to required
temperature i.e. 150-2000
C by spraying water whereby water is evaporated
with the heat of gas and the gas temperature is reduced while the dew point
temperature is increased. Inlet Temp -3800
C & Outlet Temp.-120±100
C.
Fig - ix
Raw Meal Blending Silo
It is the intermediate storage device which can store powdered raw
meal from VRM (Raw) which is fed to the kiln later on. Raw meal VRM output
is 150 to 160 TPH, whereas preheater intake is 120 TPH. So, if raw meal from
VRM will be continuously fed to preheater directly, then it will arise a problem
of overloading due to the difference in output of VRM and input of preheater.
Properly blending and necessary quality correction in raw meal is also done in
these silos.
There are one raw meal blending silo in line 1 plant.
21. 21
SPECIFICATION:
Capacity of silos : 15000 Ton
Height of silo : 75 m
Equivalent height : 45 m
Dia. of Silo : 20.8 m
Coal grinding
Pulverized coal is used as the fuel for firing in kiln as well as preheater,
which is finally converted into ash and absorbed in the clinker processed. At
OCL, graded coal is procured from outside sources like MCL and stored in a
coal pit at works. A legged crane feeds this coal to a hammer crusher, which
crushes these lumps to a definite size i.e. less than 25mm. This crushed coal is
carried to the grinding unit, a vertical roller mill which grinds it to pulverized
form of fineness 90 micron & 212 micron. Then ground coal is stored in four
storage bin & transported to kiln by pneumatically conveying system for firing
purpose.
MAIN EQUIPMENT:
Coal crusher
Coal mill
COAL CRUSHER
This is nothing but a single rotor hammer mill, which is used for
crushing coal from 200 mm to less than 25 mm size. Main feature of the
crusher is the rotor which carries a series of pivoted hammers. When the
rotor is running ,the centrifugal forces cause the hammers to point radically
22. 22
outwards in the upper crushing chamber, the feed material is subjected to a
combination of impact and percussive action by the hammers and by
repeated collision with the breaker plate, together with " autogenously"
action by coal lamps colliding with one another. Output product size is
controlled by adjusting the gap between the hammers & breaker plate.
TECHNICAL DATA
Type : Hammer Mill
InputSize : Less than 200 mm
ProductSize : Less than 25 mm
Capacity : 75 TPH
Raw Coal Hopper Capacity : 70 TPH each
COAL MILL
This is nothing but a vertical rolling mill. It comprises of three roller on a
circular bed like raw mill roller. crushed coal came from line-1 via conveyor
belt. That crushed coal feed into coal mill via control gate. There is a magnetic
detector placed in the transportation way, if some magnetic material sensed
by that detector automatically gate closed and material exhaust via another
gate.
TECHNICAL DATA
Type :Vertical rolling mill
No. of roller : 3
Power required : 460 kW
Capacity : 50 TPH
Diameter of roller : 1.8 m
diameter of bed : 2.8 m
Coal Bin Capacity : 180 ton
Pyro-processing/Clinkerisation
Introduction:
Being extracted from blending silos by bucket elevator/air lift, the
homogenous portion of raw meal is fed to the preheater. The preheater is
two stream, 5-stage cyclones with ILC (In line Calciner). The kiln feed is feed
to the preheater by the bucket elevator. A diverting gate separates the feed
to the kiln string & Pyro string. In the preheater tower it gets heated up & by
23. 23
the time it comes out of preheater,it is about 90 % calcined. Temperature
varies from stage to stage, however it is 8500
C at 5th
or final stage. From the
cooler outlet hot waste gas supplied through Tertiary Air Duct (TAD) up to
preheater cyclone for utilization purpose. About 60 % of total fuel is also fired
at Pyroclone of preheater. Then partly calcined raw meal from preheater goes
into the dry process rotary kiln. Inside rotary kiln, about 40 % of coal is fired.
This causes burning zone temperature about 14000
C .Raw meal which enters
into the inlet of kiln is burnt and changed into grayish clinker, which
subsequently gets discharged onto clinker cooler. After necessary cooling
inside cooler the clinker is carried by Deep Drawn Pan Conveyor into clinker
storagehall.
Main Equipment:
Preheater
Kiln
Grate Cooler
Clinker crusher
The different equipment fulfill various functions as listed below:
Drying and heating up of the kiln feed takes place in the preheater.
De-carbonation (up to 90%) of the kiln feed takes place in the
PYROCLON calciner.
The fuel is ignited and burned out in the combustion zone.
The sintering process and the formation of clinker occur inside the
rotary kiln.
The hot clinker is cooled in the clinker cooler.
The main process going here is the conversion of calcium carbonate to
calcium oxide.
CaCO3 CaO + CO2
Clinkerisation occurs at temperature between 13500
C to 14000
C. The time
required for the material to pass the rotary kiln is about 20 minutes.
The major reactions taking place in the kiln are as follows:
C 3 + A C3A A=AI2O3
C4A + F C4AF C = CaO & F = Fe2O3
C2 + S C2S S = SiO2
C2S + C C3S
24. 24
Fig - xii
PREHEATER / PYROCLONE
With pre calcining almost the entire decarbonation in process is
effected in the Calcined, one result of which is that thermal conditions to
which the refractory lining in the kiln is exposed become much less severe.
This, in turn means that for equal clinker output, the diameter and length of
the kiln can be correspondingly reduced. The significant feature is that the
calcined is separate from the kiln and that part of the thermal energy required
for the clinker manufacturing process is utilized in the calcined and not in the
kiln. Unless, otherwise, the length & diameter of the kiln for the purpose
would have been unexpectedly large. Besides, the heat contained in the
exhaust air fromthe clinker cooler is also utilized.
25. 25
TechnicalData:
Manufacturer : CROMTONGREAVES
Type : 3-Ф AC SCRINDUCTIONMOTOR
Preheater Fan
Capacity : 6600 m3/min
Drive(kW) : 2200 kW
Firststage temperature : 3500
C
Final Stage temperature : 8500
C
RPM : 992
DRY PROCESS ROTARY KILN
The raw meal decarbonated/ calcined in the 5 stage cyclone preheater
enters into the SHORT ROTARY KILN at a temperature about 8500
C. The kiln is
driven by electric drive (DC shunt motor) & shell is supported by rollers. Also
thrust rollers arrangement is provided to compensate the floating of rotary
kiln during rotation. 40 % of pulverized coal is fired in the kiln which raises
burning zone temperature up to 15000
C, whereby calcined raw meal burns
down to grayish granules of clinker and discharged to the grate cooler at
outlet. It takes 30 minutes for passing raw meal from inlet up to outlet of kiln
for processing.
TechnicalData
Type : Short Rotary Kiln
Capacity : 4000 TPD
Dimension : 4.2 m Dia. x 65 m Length
Inclination : 3.5% of kiln length
Revolution : 5.2 RPM (Max.) & 0.54 RPM(Min)
Temperature of Burning Zone : 14500
C(Approx.)
Weight : 400 Ton
Power required : 220 kW
Power installed : 220 kW
Motor types : DC Shunt motor
26. 26
Fig - xiii
GRATE COOLER
Clinker manufactured in the rotary kiln is cooled in the Humboldt Grate
Cooler to temperature level required for further processing. The Humboldt
Wedag Grate Cooler is a reciprocating grate cooler with a continuous grate
having inclination of 5%. It basically consists of the housing bottom section
with supports & drive for the grate system, the plate covering & the brick
lined housing top section. The fire cooling air fans and the clinker crusher for
commuting the outsize are connected to the grate cooler. The cooling air is
heated up while flowing through the clinker (Cross current flow). A portion of
the heated cooling air is routed to the kiln system for reducing the rotary kiln
air requirement. Depending on the kiln system and its specific air requirement
from the grate cooler air temperature of approximately 7500
C may be
reached. A portion of the cooling air is withdrawn from the cooler outlet after
passage of the clinker deducted and released into the atmosphere via a stack
or recycled to the process.
TechnicalData
Manufacturer : KHD/Cimmco
Type : Grate Cooler
Dimension : 3.5 m (width) x 20.7 m (Length)
Power required : 0.85 kWh/Ton of clinker
Power installed : 40 kW/1500 rpm
Revolution of Cooler outlet Shaft : 300 RPM
Capacity : 3000 TPD with cooling air 3.7 m3/Kg of
Clinker
Temperature of Clinker at Inlet : 14500
C
At Outlet : 650
C
27. 27
Cooler Exhaust Fan:
DrivePower(kW) :315kW
Deducting system : Multi clone
Clinker conveyor : Drag chain conveyor &
Deep Drawn Pan Conveyer
(DDPC)
Clinker crusher:
Type - Hammer Mill
Drive : 90 kW
Productsize : 0-30 mm
Fig - xiv
CEMENT FORMATION
After Clinkerisation seasoned clinker from storage halls fed to the
existing cement mills(4 ball mills) along with Gypsum & other materials like
slag etc. by means of overhead crane depending upon type of cement to be
manufactured. The plant has got the world’s first vertical roller mill LM 46.2+2
C/S for clinker and slag grinding. The reason for this option is because it is
more energy efficient and gives higher output. Three vertical roller mill are
installed for grinding cement to which clinker is fed directly from cooler
discharge by DDPC (Deep Drawn Pan Conveyor), also having provision for feed
28. 28
by crane from storage hall. In Ball mill gypsum, clinker (& slag) are ground
together to obtain cement of desired quality. In CVRM, slag and Clinker &
Gypsum are ground separately and stored in separate compartments of buffer
silo from where OPC or PSC (by inter mixing by means of a paddle mixer) is
obtained.
A new generation classifier has been introduced with advanced design
at the mill internals for high grinding efficiency.
According to the type of cement required, ingredients are taken and it
is done:
1) by mixing all the ingredients together and then grinding,
2) By grinding ingredients individually and then mixing them.
Then the finished cement is stored at the silo for despatch.
Recent addition to the capacity addition OCL has commissioned world’s
largest vertical roller mill for grinding clinker and slag from LOESCHE,
Germany. (LM56.3+3 C/S).
Main Equipment
Over Head Crane
Hopper
Cement Ball Mills(4 No’s)
Cement Vertical Roller Mills (CVRM)
Bag Filter
Over Head Gantry Grab Crane
There are two overhead gantry type grab cranes in our clinker storage
hall for handling clinker as well as raw materials (morrum, clay, laterite,
sweetener etc.) to the respective hoppers, which are subsequently conveyed
to respective mills for grinding purpose.
In the Over Head Crane, the longitudinal bridge drive is effected by a
motor through reduction gear box installed at one side of bridge and
transmitting motion or the drive to the other side wheels through a long
shaft. The traversing of trolley is attained by another individual motor.
Similarly, hoisting of the grab along with material opening as well as closing of
the grab are effected by two individual motors respectively.
Technicalspecification
Span of the crane : 98'
Width of bridge : 8'
Distance between wheel centre : 20'
29. 29
Capacity : 7.5 Tons
(Grab wt.: 2 Tons & weight of material lifted: 5.5 Tons)
HOPPER
The hopper capacity of the various hoppers in CVRM are:
Gypsum Clinker Slag Wet-Flyash Additive
CVRM 1&2 170T 420T 327T 100T 85T
CVRM 3 153T 791T 540T 135T 99T
Cement Ball Mills
Cement mills are nothing but horizontal ball mills made of M.S. mill
shell inside which Mn. Steel liners are provided to prevent wear & tear caused
due to impact & attritional force between material & grinding media during
operation. It is driven by a motor through reduction gear box. The ball mill
shell has got two chambers. There is an intermediate screen called diaphragm
between primary & secondary chambers. Material i.e. Clinker + Gypsum or
Clinker + Gypsum + Slag after being ground in first chamber goes to the
second chamber through this screen. Then in this chamber, it is ground to the
fine powdered form and subsequently goes to the outlet through outer-gate
screen, then to the inlet of elevator. For proper control of fineness,
mill has been provided with O-separator which controls fineness. Fine
material, due to centrifugal action inside separator and suction of ESP Fan
goes to ESP and comparatively courser particles come back to cement mills for
further grinding. Thereafter, process is cycled.
TechnicalData:
Items
MILL NO. 1 2 3 4
Make FLS FLS FLS FLS
Type of Drive Central Central Central Central
Size [m] 2.6x12 2.9x10.4 2.6x13 2.9x10.4
(Dia x Length)
Capacity in TPH
(i) OPC 24 26 24 25
(ii) PSC 22 23 22 23
Mill Speed (RPM) 18.80 18.00 18.80 17.9
30. 30
DRIVE
Motor
Make Crompton FLS Crompton FLS
Parkinson Parkinson
KW/HP 900/1300 1040/1400 900/1300 925/1250
RPM 750 750 750 750
Gear Box
Make FLS(Symetro) FLS(Symetro) FLS(Symetro) FLS(Symetro)
Ratio 40:1 42:1 40:1 42:1
Fig - xv
Cement Vertical Roller Mill (CVRM)
Vertical Roller Mill technology for grinding cement raw materials
developed recently is being accepted all over the world because of
advantages over the centrifugal ball mill technology. The main reasons for
such a wide acceptance of this technology are higher throughputs, savings in
specific power consumption, there capability to handle both dry as well as raw
materials up to the moisture level of 15-18 % and better dependability and
availability.
In constructional feature, Our Cement VRM is the same as raw mill VRM
except that Raw VRM has got 3 hydraulic pressed rollers whereas CVRM has
31. 31
got 4 such rollers, out of which 2 are slave rollers (non-hydraulic) for leveling
the bed of material & 2 master rollers (hydraulic) for grinding purpose.
Fig - xvi
Technical Data
CVRM (1 & 2)
MAKE : Loesche, Germany
TYPE : LM 46.2+2 C/S
SIZE : Dia of table : 4.6mor 4600 mm
(i) No of Master Rollers : 2
(ii) No. of SlaveRollers : 2
(iii) table speed : 25.53 RPM
Buster Fan (i) Drive : 400 kW
(ii) Speed : 1000rpm(Max.)[Variablespeed
Motor]
CVRM-3
TYPE : LM 56.3+3
Size : Dia of table : 5.6mor 5600mm
No. Of master roller : 3
No. Of slave roller : 3
Drive Data
MOTOR
(i) Make : BHEL
(ii) Power required : 3100 kW
(iii) Power installed : 3150 kW
32. 32
(iv) Inputspeed (motor) : 990 RPM
GEAR BOX
(i) Make : Flender
(ii) Type : Bevel helical gearing(3 stages)
(iii) Ratio : 38.775:1
Raw material & performance Data
CLINKERGRINDING
i) Feed Size
Clinker: 80 % 80 mm & 20 % 150 mm
(i) Gypsum : 0-40 mm
(ii) Specific Surface : 3400 (Blaine) cm2/gm
(iii) Productrate : 117 TPH (OPC)
SLAG GRINDING
Feed material : Granulated blast furnaceslag
Feed size : 90 % 25 mm & 10 % 150 mm
Specific surface : 3400 (Blaine) cm2/gm
Productrate : 92 TPH
STORAGESILO(CVRM)
Capacity : 10,000 Tons
No. of compartment : 4No’s.
Size :Dia-18 m & Height - 52 m
Bag Filter
Bag filter is a deducting unit which is used to arrest the dust (cement
particles) from the dusty air and releases only clean air to the atmosphere
thereby preventing air pollution.
Working Principle
Dust filter comprises of chamber inside which a number of filter bags
are hung row- wise from the top. The dusty air sucked by a centrifugal (vent)
fan when passes inside this chamber, dust particles are deposited on these
bags and only clean air is released to the atmosphere through stack. Then
purging is done row-wise by compressed air operated by solenoid valves set
33. 33
timingly. Then dust drops down to the hoppers and conveyed through rotary
airlock.
TechnicalData
Drive (kW) : 2100 kW
Mill Fan speed : 1000 RPM
Fig - xvii
Packing & Dispatch
The cement is dispatched by rail and road using wagon loaders and
truck loaders respectively. The entire product is packed by high capacity
electronically automatically controlled16 nozzleENEXCO rotopackers.
Packing House
It is the final or terminal unit of our cement factory where finished
product i.e. cements is packed in bags, subsequently dispatched by wagons or
trucks. For temporary storage of various quality prior to being packed by
packing M/C, there are 17 No’s. of cement silos in which cement is stored and
thereafter it is conveyed to the packing machine hoppers through air slide and
34. 34
elevators via vibrating screen for packing purpose. There are 5No’s. of
Rotopacker M/C in our packing house and each has 16 spout for feeding and
packing empty bag. Naked cement from hopper is fed to packing M/C at
controlled rate and packed in bags containing 50 Kg .Then packed bags are
conveyed to the points of loading by means of belt conveyor arranged in
respective routes from where they are loaded to the wagons or trucks by
wagon loaders or truck loaders respectively.
Main Equipment:-
Roto Packer : 5 No’s
Wagon loader :8 No’s
Truck loader : 8 No’s
Compressor : 4 No’s
Vinnar Conveyor : 12No’s
Cement Silo : 17 No’s
Roto Packer
This is a 16 spout packing M/C .This machine rotates by a variable speed
belt drive arrangement at a speed of 2.5 rpm. Naked cement after being
extracted from storage silo is filled into the packing M/C hoppers via vibrating
screen. Two persons are standing and feeding the valve bags onto the filling
nozzles. The bags are caught by pneumatically catching system and the bulk
material (cement) from hoppers is passed through filling impellers (driven by
individual motors) into valve bags with courseand fine flow control .
35. 35
Environment Protection Activities
The company has adopted Zero discharge concept.
LIST OFENVIRONMENTAL SAFEGUARD ACTIVITIES TAKEN IN AND
AROUND THE SURROUNDING
Control of Stack emission
Control Fugitive dust emission
Control of SO2 and NOx gas emission
Management of solid & Hazardous waste
INITIATIVETO CONSERVENATURAL RESOURCES
Utilization of minimum quantity of clinker in PSC by maximizing slag
consumption.
Use of flyash from Sponge Iron plant as raw material.
Reduction in power consumption through various techniques.
Installation of rain water harvesting systems in the plant & colony.
Recycling of ETP treated water in water treatment plant for machinery cooling
and dust suppression.
Fig - xix
NEW INITIATIVES TOWARDS ENVIRONMENT
Installation of Clinker silo for clinker storage.
Covered shed for raw materials with Stacker & Reclaimer working inside.
Covered conveyor belts for raw materials transportation.
Deployment of Vacuum Suction Road Sweeping Machine to control fugitive dust
on the roads of plants and Colony.
Installations of Bag house in Kiln & VRM
36. 36
CONCLUSION
It was a great experience working under the supervision of
such great dignitaries who gave me ample time and made me
understand every bit of the process and clarified all my doubts. It
was great experience to be under the guidance of the members of
the KHD dept.
OCL, believes and aim at total quality in their products and
services to satisfy their Customers. They are committed to
continuously improve performance of the Environment and
Occupational Health and Safety Management System For
sustainable development.
OCL India believes sustained growth of business lies on triple
bottom line that is growth of people around there operation,
protection of environment where they operate and profit from their
business. They understand wellbeing of the community around
there business which helps in growth of business and hence they
value people around their operational locations and promote
inclusive growth.
The knowledge gained during the training would help me in
future and cherish my life.
