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ACKNOWLEDGMENT:
I wish to pay my sincerest regards to the following personnel’s for their wholehearted
guidance and cooperation, which enabled to me to gain valuable knowledge about
technologies and their application, during my in plant Training.
Mr. Rakesh Sinha(Plant Head)
Mr Rajender Thakur(HR Head)
Mr. P.K. Chauhan(Engineer)
Mr. Sanjeev Gautm(Supervisior)
I also wish to thank, Mr. Ajay Sharma (Training Head) for his whole hearted support
enabling me to prepare a training report in the most efficient manner.
I also wish to thank whole H&R Department members to give their support during the
training.
I wish to pay my word of thanks to each and every individual of plant helping me to
finish my training successfully.
Aman Sharma
Mechanical Engg
i
DECLARATION
I hereby declare that the Industrial Training Report entitled “Six Months Industrial
Training at ACC, Barmana” is an authentic report of my own work as a requirement of
6-months Industrial Training during the period from 1st July,2014 to 31st Dec 2014 for
the award of the Degree of B.Tech (Mechanical Engineering),BAHRA
U NIVERSITY, SHIMLA HILLS (Waknaghat Distt. Solan) under the guidance of
Aman Sharma
2013UGME012
Date :
Certified that the above statement made by the student is correct upto the best of my
knowledge and belief.
Signatures
Examined by:
1. 2. 3. 4.
HOD/DEAN
(Signature and Seal)
ii
CONTENTS:
Introduction 2.
Gagal Cement Works – An Overview 3.
Organization Chart 5.
Raw material 6.
Specification of the Product 8.
Cement manufacturing Process (In brief) 11.
Detail of different departments : 13.
1. Quarry 14.
2. Stacker & Reclaimer 19.
3. Raw mill 23.
4. Homogenisation system 31.
5. Preheater 33.
6. Kiln 38.
7. Cement mill 44.
8. Packing House Workshop. 47.
9. Workshop 49.
10. MIPS 51.
Material handling equipment (Mechanical & Pneumatic) 52.
MIPS Department 63.
Quality control technique 65.
Research & Development 68.
Inventory management 69.
ISO 71.
Gagal Cement Works a unit of the Associated Cement Companies Limited, has two
unites Gagal I and Gagal II. Gagal I was set up in the year 1984 and Gagal II was set up
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in the year 1994. Clinker production of Gagal I is 2800 TPD and of Gagal II is 3300
TPD. The total annual capacity of the plant is around 2.2 million tonnes. Both units are
located at BARMANA in District BILASPUR of H.P.
KIND OF PRODUCT :
Ordinary Portland Cement (OPC) in different grades i.e. 33GR, 43GR, 53GR and
Portland Pozzolona Cement (PPC).
The quality of the cement is in accordance with specification as per BIS (Bureau of
Indian Standard). The company has registration to ISO 9002 & ISO 14001.
CEMENT:
The present definition of cement as given in DIN 1164 is as follows:
Cement is finely ground hydraulic binding medium for mortar and concrete, consisting
substantially of compounds of CaO with SiO2, Al2o3 and ferric oxide which have been
formed by sintering or fusion. ‘Sintering’ means burning at a temperature which cause
partial fusion of the material. When mixed with water cement hardens both in air and
under water and retains its strength under water; it has to possess constancy of volume
(soundness) and attain a compressive strength of at least 25N/mm2 at 28 days.
Portland cement is manufactured by burning a calcareous material, such as,
limestone, chalk, shells or marl and an argillaceous material such as clay, shale etc. at a
high temperature of 1450-1500ºc and grinding the resultant product called ‘Clinker’ with
the addition of the small quantity of the Gypsum.
The ordinary portland cement consists of four major components i.e.
Tricalcium Aluminate (C3A)
Tricalcium Silicate (C3S)
Dicalcium Silicate (C2S) and
Tetracalcium Alumino ferrite (C4AF).
ORGANIZATION STRUCTURE:
PLANT HEAD
iv
GM TECH -- MGR. MINES MGR COMM SR.MGR HR MGR FIN MGR HS MGR W HRS
DY MGR DY.MGR DY MGR DY MGR DY MGR
ASST. MGR ASST .MGR ASST. MGR ASST.MGR
MGR MAINT. MGR.PRODN MGR. E& I
DY MGR DY MGR DY MGR
ASST.MGR ASST.MGR ASST.MGR
v
RAW MATERIAL:
Minerals of natural origin as well as Industrial products can be used for the
production of cement.
The main component of cement: Lime, Silica, Alumina and Iron oxide.
Lime stone:
Calcium Carbonate (CaCo3) is wide spread in nature. The purest grades of
limestone are calcspar (calcite) and aragonite. Calcite crystallizes hexagonally (specific
gravity 2.7) and aragonite is rhombic (specific gravity 2.95). The hardness of the lime-
stone is between 1.8 & 3 of the Mohr`s of hardness. Only the purest varieties of
limestone are white. The total carbonate in limestone is minimum 80%. The limestone
provided to ACC is of grade 86 to 89 by nature. Chalk and Marl are other lime
component but not used by ACC plant.
Clay:
Clay is formed by the weathering of alkali and alkaline earth containing aluminium
silicate and their chemical conversion products.
Corrective Ingredients:
If an essential chemical component needed in the cement raw mixture is not present
in the required amount, corrective ingredients are used as additives i.e. Iron oxide.
Auxiliary Components:
Magnesium oxide (Mg2O) up to 2% by weight, K2O and Na2O up to 0.6% should
present in the Portland cement. Sulfur appears predominantly as sulfide in all cement raw
material. The alkali sulfate combined by the clinker is of advantage for the early strength
of the cement.
To control the setting time, cement needs a minimum amount of calcium sulfate,
mostly in the form of gypsum added to the clinker.
Proportioning of raw material per unit clinker (dry base):
Limestone: 1359 kg per 1000 kg of clinker
Shale : 105 kg per 1000 kg of clinker
Iron Ore : 12 kg per 1000 kg of clinker
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Total : 1476 kg per 1000 kg of clinker
Gypsum : 30-40kg per 1000 kg of cement
FUEL: Kind of fuel: coal
Total moisture content: less than 3%
Volatile matter : not less than 27%
Ash : 32%
Calorific value : 4200 kcal/kg (net on wet).
SPECIFICATION OF THE PRODUCTS:
[1]-P.P.C. (Fly ash based):
SCOPE: This standard controls the manufacture, physical and chemical requirements of
Portland Pozzolona Cement using only fly-ash pozzolona.
TERMINOLOGY: Pozzolona is a silicious material which in itself possesses little or no
cementitious properties, it will be in finally divided form in prerence of water, It reach
with calcium hydroxide at ambient temperature to form compounds possessing
cementitious properties. Term includes natural volcanic material having pozzolana
properties and also other natural and artificial material.
Setting time: P.P.C when tested by vicat`s apparatus method shell be as follows-
Initial setting time (minimum): 30 minutes
Fineness: When tested by air permeability method specific surface of ppc shall not less
than 300 m2/kg.
Drying shrinkage: In accordance with IS4031:1998, shall not be more than 0.15%
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Soundness: When tested by Le Chatelier method and autoclave test described in IS4031,
and a rated ppc shall not have an expansion of more than 10 mm and 0.8% respectively.
Compressive strength:
1- At 12 +/- 1h : 16 Mpa, minimum
2- At 168+/- 2h : 22 Mpa, minimum
3- At 672+/- 4h : 53 Mpa, minimum
Chemical requirements:
Loss of ignition % fineness (maximum) – 5.0
Magnesia % by mass (maximum) – 6.0
Sulphuric anhydride %by mass (maximum) – 3.0
[II]-O.P.C. (43 Grades):
1)-Chemical Requirement:
a)-Lime saturation factor CaO 0.7SO3 : Not greater than 1.02
2.8SiO2+1.2Al2O3+0.65Fe2o3 & not less than 0.66
b)-Ratio of percentage of Alumina : Not less than 0.66
to that of Iron oxide
c)-Insoluble residue, percentage by mass : Not more than 2.0
d)-Magnesia percentage by mass : Not more than 6.0
e)-Sulfuric anhydride percentage by mass : Not more than 2.5
f)-Total loss on ignition percentage by mass: Not more than 5%
g)-Total chloride content : max 0.05%
h)-C3A percentage by mass : Not more than 5%
viii
C3A=2.65(Al2O3)-1.69(K2O3)
2)-Physical Requirements:
a)-Fineness-
Specific surface (Blaine) : Not less than 2250 m2/gm
b)-Soundness-
Le-Hotelier expansion : Not more than 10 minutes
Autoclave expansion : Not more than 0.8%
c)-Setting time- Initial : Not less than 30 minutes
Final : Not more than 600 minutes
d)-Compressive strength- 3Days : Not less than 230 kg/cm2
7Days : Not less than 330 kg/cm2
28Days : Not less than 430 kg/cm2
ix
CEMENT MANUFACTURING PROCESS [IN BRIEF]:
The raw materials used are lime stone, shale, iron ore and gypsum. The lime stone
provided by nature and Iron-ore comes from BIHAR and RAJASTHAN. Firstly we get
the 70mm size limestone with the help of crusher and stock it with the help of stacker
through belt conveyor. Reclaiming of the blending bed stockpiles is carried out by means
of a movable Reclaimer system. The limestone goes to the hopper connected to weigh
feeder, within proportionate quantity through belt conveyor. Clay and Iron ore are also
goes to the weigh feeders with the help of belt conveyors.
In Raw mill / VRM section, limestone, shale, quartzite & Iron ore are fed in
measured quantity through weigh feeders. In the mill the mixture further reduces the size
to the desired fineness. The finer product separated by air separator is goes to the
Electro-static precipitator & then to the blending silos and coarse material is fed back
into the mill Inlet. Raw mill / VRM s controlled by central control room. The set point
for chemical composition of the raw meal and fineness of the material is given by the
Laboratory department.
From raw mill the raw meal is fed to the blending and the storage silos .In the
blending part of the silo, further homogenization of raw meal takes place so that a
constant quality is maintained. In storage part the raw meal is stored so that it may be fed
at the desired rate. From there the material is fed to the low lift pumps (L.L.P.s) with the
help of bucket elevators. Low lift pumps feed the material or raw meal to the preheated
cyclone. To reduce the requirement of heavy coal injection in the kiln, 95% of the
calcination occurs in the M.F.C., D.D.F. vessels and cyclones of preheating zone. About
60%of the coal firing is done at pre-calciner section itself. Raw meal which is almost
calcined enters from the one end of the kiln. From the other end of the kiln the
pulverized coal is fired. Various chemical reactions occurs as the raw meal progresses
from feed end to the burning zone , where intermediate phases consisting of CaO, Al2O3,
Fe2O3 become liquid and because of the rotation of kiln CaO and silica combine with
liquid to form nodules called clinker.
At the lower end of the kiln the temperature reaches to about 1450 degree
centigrade. Due to such high temperature the physical and the chemical characteristics of
the raw meal changes. Clinker that comes out of the kiln is at a very high temperature
and has to be cooled to facilitate handling and grinding. Hence, the clinker is passed
through the cooler where cooling takes place by means of fans. Hot air is used for
x
combustion inside the kiln and calciner. In cooler circuit the ESP has also been installed
to control the air pollution. With the help of the drag chains and bucket elevators the
clinker is fed to the clinker silos. There a pneumatic based roller press installed next in
the circuit to decrease the size of clinker and increases the efficiency of the cement mills.
Clinker and the necessary additives like – gypsum, Pozzolona, slag etc. are fed to the
cement mill in proper proportion. Grinding is done to desired fineness as in the raw mill.
Then, the final product cement is conveyed to cement storage silo. Cement is then sent to
packing machines for final packing and then dispatched.
DETAIL OF DIFFERENT DEPARTMENT:
01-Quarry
02-Stacker and Reclaimer
03-Raw Mill [Ball Mill / Vertical Roller Mill]
04-Homogenisation system
05- Preheater
06-Killn
07-Cement Mill
08-Packing House
09-Workshop
10-MIPS
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[01]-QUARRY:
We can divide in three divisions –
I-Mining –a) Drilling
b) Blasting
c) Loading
d) Transportation
II-Garage—[Maintenance of heavy earth material machine and provided them to mining]
III-Crusher [Reduce the size of material up to required size]
[I]-Mining:-
Mining department provide the limestone to the plant. This department follows the
rules of DGMS (Director General of Minning Safety). There are limestone as well as
dolomite but no use of dolomite in cement plant so its throw. For blasting, the hole depth
maintained up to 9, 10 or 11m with 6inch diameter. The blasting materials are NH4NO3
& Accuadoine (as booster). In 10m hole, 6m depth is fill up by NH4NO3 & Accuadoine
in which Accuadoine is 18-20% and then above the blasting material, rest 4m fill by soil.
To fire the booster use detonator, It is AL tube (high explosive) detonator attached to the
DTH wire. TLD use to interconnect the holes and then safety fuse wire used to fire the
hole. In 10m hole 100 kg NH4NO3 & 15-20kg Accuadoine required.
Loading and Transportation-The blasting material is of very big size stones. To
load them and transport to the crusher, equipment used as follows-
1-SHOVEL: Shovel used to load the Dumper. It is hydraulically operated and can
rotated at 360º. There are four shovels, their specification are as follows-
Make : Telco Tata Make : BEML
Model : EX700 Model : PC650
Capacity: 4.5m3 Capacities: 3m3
Total No. : 2 Total No. : 2
2-DUMPER: Dumper used to transport the big size stone from blasting place to the
crusher. It total hydraulically operated. There are total 9 dumpers in which 7 dumper of
773B and 2 dumpers of 210M which are of latest technology. Their specification are as
follows-
Make : BEML Make : Hindustan motors
xii
Model : 210M Model : 773B
Capacity : 44tonnes Capacity: 50tonnes
6- Cylinder engine, V-type 12-Cylinder engine, V-type
3-POCLAIN,
4-DOZARS,
5-PAYLODERS.
[II]-GARAGE:
Garage is related to automobile, there are only maintenance of the heavy earth
material machine (i.e. shovel, poclain, dumper, dozers and payloders) and provided them
to the Mining. Only regular maintenance of these machines carried out there.
[III]-CRUSHER: There are two crushers-
1-L &T Impactor (capacity 1000 TPH)
2-Hammer Crusher (capacity 400 TPH)
1]-L & T Impactor: General information-
Make : Larson & Tubro Limited
Type : Single rotor impactor
Size : APPM2022
Feed material : Limestone
Feed size : 0-1600mm×1300mm×1100mm maximum
End product size: 90-95 % min, 75mm
Capacity : 1000 TPH
Motor rating : Slip ring Induction motor
1200kw, 100 rpm
Description of the machine:
The single Rotor Impactor, also known as primary Impactor is designed to achieve
maximum reduction ratio in a single pass-particular features of the machine are its
cubical product, largely free of tension and cracks, and the ease with which the servicing
can be carried out.
Design and Operating Principle –
xiii
The housing of the impactor is of welded plate construction, within this housing the
rotors is installed on rigid bottom housing.
The cross sectional view shows the rotor working in conjuction with impact arms
and a grinding path in the rear side. The impact arm are adjustable and they are
supported material enters or over feeding takes place. The easy adjustment of impact
arms & grinding path allows for constant product control and limitation of over size.
Main component of the impactor are as follows –
HOUSING: Housing of the impactor is of sturdy steel fabricated construction and
consists of three parts: bottom housing, front top housing and rear top housing. The rotor
and grinding path assembly is housed in bottom housing. The rear top housing can be
opened and closed with the help of hydraulic cylinders.
ROTOR: The rotor in the impactor is of S type construction, secured to the shaft by
locking assemblies.
BLOW BARS: The blow bars mounted in the rotor are made of high alloy steels. Their
shape is symmetrical and are secured against lateral movement.
DRIVE ARRANGEMENT: Power to the rotor is given through jack shaft arrangement.
The driven V-belt pulley is fixed on to the rotor shaft by means of ring feeder locking
assembly. The drive pulley is secured on the jack shaft by a pair of ring feeder. The jack
shaft assembly is supported on two bearing blocks (spherical roller bearing with adapter
sleeve-SKF23036CKC3+H3036) and it is coupled to motor shaft through a Resilient
coupling (Bibby size H556 or GBM size 125 type S). Impactor rotor bearing is spherical
roller bearing with adapter sleeve – FAG23264 BKMBC3+H3264HG.
2]-HAMMER CRUSHER: - Unit : 1 No.
Make : Hammer Mill Co.
Size : 7272
Capacity : 400 TPH.
Total hammers : 18; 6 on each shaft.
Material of hammers: Maganess steel.
xiv
Description:-
These are used for the size reduction of hard to medium hard limestone and for raw
marl crushing. Reduction ratios are as high as 1:40. Depending upon crusher feed this
can be reduced to 1:60. Generally two types of the hammer crushers are manufactured:
Single shaft hammer crusher.
Double shaft hammer crusher.
These work with the impact effect of the hammers according to the formula,
P=mv²/2. Mass of hammers in hammer mill was reduced to minimum while increasing
the velocity as far as possible, resulting in greater impact force combined with reduced
wear. Rim speed of the hammers is in the range of 5000 to 7000 rpm. Power demand of
single hammer crusher is between 1.3 to 2.8 HP h/t.
Weight of the replaceable is between 155 to 440 lb, depending on the crusher.
Throughout capacity (Q) = (30/40)*D*L
Where, D =Rotor diameter, L =Useful length of rotor in meters.
[02]- STACKER & RECLAIMER:
xv
Gagal I –
Type: Portal
Make: TRF
Span: 42M
Gagal II--
Type of storage : Open Longitudinal
Make : CIMMCO.
Stacking capacity : 1000 TPH, designed for 1300
Width of stockpile : 32250mm
Height of stockpile : 12245mm
Total length of stockpile: 300000mm
Storage capacity : 2×25000M.T.
Reclaiming capacity : 600 TPH
The blending bed consist of two equal material stockpile which are arranged in
line. These material stockpile are used both for storing and also for prehomogeniation of
the material to be stacked. The material stockpile of one pile can be reclaimed while the
other stockpile is stacked.
Stacking of the blending bed:
Stacking of the blending bed is carried out in the ‘Chevron method’ by means of a
stacker with loop car. The stacker with loop car is moved into its starting position in
‘manual mode’ with the boom raised its highest position. The boom is lowered to its
lowest position after reaching the starting position.
The stacker starts the operating process after the commands for automatic mode of
stacking are given from a central control room. The stacker now throws off the incoming
material to the yard as it travels from one end of the stockpile to the other, until a
material probe which is mounted to the boom tip sends a single material height reached’.
Then a command is given to the luffing gear to lift the boom by one lifting step. This
process is repeated until the boom, after 20 lifting steps, has reached its maximum lifting
height and the stockpile is stacked to its maximum volume.
Stacker consist of the following units:
a)-Travel gear – fixed side:
with built in bogie wheels, complete with travel drive and pressure rollers.
xvi
b)-Travel gear – pendulium side
c)-Bogie car: for supporting the two travels gears and the linking of the loop car.
d)-Luffing gear: for stepwise adjustment of the stacker boom. The hydraulic lifting gear
consists of the hydraulic cylinder with electro hydraulic pump unit.
e)-Stacker boom: mechanical construction, comprising belt drive and standard parts.
Technical data- Conveying capacity: 1000 TPH
Centre distance : 23500mm
Belt width : 1200mm
Belt speed : 2.5m/s
Power : 55kw
Boom ascent : +18º
Boom descent : -15º
f)-Loop car: has the function to feed the conveying material arriving from the stacking
belt to the boom belt. Mechanical parts of the loop car are-
Pulley : Ø630×1400
Reverse pulley : Ø500×1400
Transition idler : Ø139.7×465×10º
Throughing idler: Ø139.7×465×30º
g)-Electrical Accessories: Electrical house, control panel, cable reels, cable duct
covering, limit switch support and speed control support.
h)-Lubricants: Oil lubrication and Grease lubrication.
Reclaiming of the blending bed stockpile:
The material is reclaimed from the stockpile by the forward movement of the
scraper travel gears in connection with the reversible rake car on the scraper bridge, the
rakes mounted to the car on the scraper bridge, the rake mounted to the rake car and the
material discharge by the scraper chain drive.
Reclaimer consists of the following units-
a)-Travel gear – fixed side
b)-Travel gear – pendulum side
c)-Scraper bridge
xvii
d)-Rake car: The two rake car-side section are bolted on to the slide of the rake car-
upper section.
e)-Scraper chain: Technical data –
Power : 90kw
Chain speed : 0.51m/s
Bucket width : 1800mm
Centre distance: 32000mm
The scraper chain runs in the chain guide which is bolted to the scraper bridge from
beneath. The scraper buckets are bolted to the scraper chain with a spacing of 670mm.
The scraper chain is laterally guided by guide rollers. Every second scraper bucket is
equipped with a guide roller.
f)-Rails: Complete with plats, rail fastenings and buffers.
For trouble free operation of the machine, it is necessary that the laying of the rails
is carried out skillfully and within the tolerances stated below –
1-The maximum height tolerance must not exceed ±10mm on length of 25m.
2-The maximum permissible rail cant must not exceed 1:150.
3-The gauge of the rails in parallel must not exceed ±10mm.
g)-Electrical Accessories.
[3]- RAW MILL [BALL MILL / VRM]:
xviii
THE DEPARTMENT:
Activity of Raw mill department start from feeding the raw materials (Limestone,
Shale, Quartzite and Iron ore) to the mills and ends at filling the raw meal to silos.
Limestone feeding: Limestone feeding to Raw mill / VRM is through sequence of belt
conveyers of different hoppers. Feed size of limestone is up to 90mm.
Additive feeding: Iron ore and shale feeding is from the gantry to the respective hoppers
through sequence of belt conveyors. Shale feeding is through reclaimer or payloder and
Iron ore / quartzite feeding is by payloder.
GAGAL I: RAW MILL [BALL MILL]:
To close circuit two chambers ball mills are performing the grinding of raw mix.
Raw mill is a tube construction of thick mild steel plate with steel liners and the
compartments are separated by double diaphragm for improving the retention time and
transfer of material in second chamber for further grinding. Mill is charged with hyper
steel balls. Mill product and teritiary crusher output is fed to the elevator. Ball mill is air
swept mill.
In Ball mill section limestone, shale, quartzite and iron ore are first fed to the
tertiary crusher in measured quantity through weigh feeders. Tertiary crusher is single
rotor reversible impact crusher which is further reduces the size of mix. The finer
product separated by air separator is fed to the blending silos and coarse material is fed
back in to the mill inlet. The raw mill are operated through control room operators by
miller.
Detail of major component installed in Gagal I Raw Mill:
a] Type of Raw Mill : Ball Mill
Make : ABL
Size : 3.8 M dia x 9.5 M Length.
Motor details : 1875 kw, 2500 HP, 1420 RPM.
Gear box : Elecon, ratio 1500/24
xix
No. Of Units : 2 Nos.
Both the raw mills are two chamber tube mill lined with Mn steel liners, chambers
are separated by intermediate diaphragms and charged with Hyper steel balls. Size
reduction of the mill feed is performed by motion of the grinding media. Rotation of the
mill cylinder raises the pile of mill feed and grinding media to an optimum height,
necessary for grinding operation. Grinding is performed by impact and friction between
the grinding balls which hit one against another, as well as between the grinding media
and the mill lining itself.
Detail of Internal is given below:
First chamber Second chamber
Liners : Mn steel Liners Mn steel segregation Liners
Diaphragm : Mn steel Intermediate Mn steel single Diaphragm
GR.media : Hyper steel Hyper steel
Grinding media pattern : 90mm-10TS 60mm-17TS
75mm-34TS 50mm-15TS
60mm-20TS 40mm-26TS
b] Tertiary crusher : ABL Make
Type : Reversible Impact Hammer
Size : 1200 x 1200
Motor details : 225 Kw, 750 RPM.
c] Turbo Separator : ABL make
Type : ‘U’ type mechanical separator
Motor details : 350 HP, 750 RPM.
This separator is furnished with an auxiliary fan driven by a separate drive
arrangement. Hollow shaft and core shaft are attached to a common motor, totally
enclosed spur gear drive.
Rotating parts are not freely floating but are held by a flexible two point support
arrangement, one on the top in gear casing and down on the shafts end. This is
accomplished by a structure inside the separator. Special arrangement has been
xx
developed to improve the separation process by uniform distribution of separator feed
from the distribution plate into the circular separating space area.
The effect of the droplet size is related to the surface area of the volume ratio. This
means that a droplet of twice the diameter will have four times the evaporation time.
Regarding the temperature driving force relationship the rate of evaporation is increased
by a high inlet temperature, decreased by lower outlet temperature and also decreased by
a higher initial gas moisture content. The critical aspects of the evaporation gas cooler
design are as follows:-
1. ATOMISER:-
The higher performance atomizer is required. It should give fine atomization over
the whole of its flow range and should good turn down ratio. It should be capable of
withstanding the process conditions of temperature, corrosion and abrasion.
2. CONTROL SYSTEM:-
It must maintain a constant outlet gas temperature with an acceptable tolerance and
cope up with reasonable fluctuations in the process and gas conditions. It must ensure
that the atomizers are always operating at the optimum pressure whatever the water flow
rate.
d] Mill Vent Fan : Make Andrew Yule
Flow Rate : 1500 m3/minute.
Fan diameter : 2195 mm
Motor details : 225 Kw, 1000 RPM.
e] Mill Vent Dust Collector: Make Andrew Yule
Type : Pulse Jet 264 - 4 –10.
Total Filtering area : 644 m²
f] Weigh-feeders : Limestone Additives
Make : J&N make J&N make
Size : 1200x8m 800x7.46m
Hopper capacity : 212 M.T. 155 M.T.
xxi
g] Desired Product : 2% reside max. (on 212 micron sieve)
Particle size : Micron sleeve.
GAGAL II: RAW MILL [VRM] –
In VRM section raw material are directly fed to the mill through feed belt and
ground to the desired fineness. The ground material is stored in continuous flow silo
from where it is fed to the kiln. These mill utilize the hot air from the kiln exhaust to dry
the raw mix.
Detail of major components installed in Gagal II Raw Mill:
Type of Mill : RM 46/26 Vertical Roller Mill [VRM]
No. of Unit : 1 No.
Output capacity : 280 TPH
Make : Krupp Polysius
Feed material size : 80% Passing 75mm and 90mm max.
Moisture content : 1-2% normal, 5%max
Product size : 12-14% on 90micron
Power : 2500Kw.
Grinding Bowl dimension : 4750mm dia. X 1580mm height.
External diameter of Roller: 2600mm.
Raw mill fan : Type – Backward curve
Volume rating : 600000m³/hr.
Fan speed : 600-990 RPM
DESCRIPTION:-
A vertical roller mill has two vertical rollers, which are provided with roller tyres
and are mounted on the axle. The axle is mounted on the roller support. Each roller has a
bearing inside it. One side of one bearing is provided with oil/grease for lubrication
while the other side has the air seal to prevent the dust from entering the roller body. The
body has R.T.D. and an oil probe to detect the unusual increase in temperature of the oil
and also the amount of oil present. The rollers are placed in the grinding bowl. The
grinding bowl is rotated by a drive present below it. When the grinding bowl rotates the
xxii
roller rotates along with it. The material entering from the side of the housing will get
grounded when in between the rollers and the bowl. The nozzle rings are provided along
the side for the gas entry. The cross-section of the nozzles and the velocity of hot gases
can be adjusted. These gases will carry the grinding solid to the top in he separator,
which will feed the coarse particle back to the grinding bowl and will carry the fines in
the exit side
b]-: SEPOL SEPARATER (DYNAMIC SEPARATER):
Gas volume : 4, 60,000-5, 40,000 m³/hr.
Rotor diameter : 4000mm
Housing diameter : 7500mm
Speed : 7-70 RPM
Description:
The material that has been ground & entrained by the air flow is fed into the
separator through the outer adjustable guide vanes. The rotating rotor separates the
finished material from the portion of material, which is still too coarse– which are
centrally returned to the mill through the tailing return cone.
The external mill circulation material is fed into the separator from above and
scattered by the distributing disc rotating with the rotor. The circumferential zone of this
distributing disc is provided with a number of evenly distributed openings. These
openings in the form oblong holes bordered outside by guide elements. The fed in
material falls through the openings and is uniformly spread outward into the ring shaped
space between the tailing cone and the external housing. The material is flushed by
vertical directed gas flow, so that the fines contained in external circulation material are
also separated.
Fineness can be regulated by varying the rotational speed of the rotor. More the
speed more will be the fineness.
Hydrostatic drive for VRM Sepol:
It consists of the hydraulic drive station, Hydrostatic motor, electric motor and
accessories. Drive work in closed circuit which is designed for one direction of the
rotation of the radial piston motor only. The axial piston pump is driven by the electric
motor via a flexible coupling. Oil returning from the radial piston motor is fed into the
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axial piston pump again. In the hydraulic drive station a heat exchanger or a radiator
serve to help the hydraulic oil at operating temperature.
c] - BUCKET ELEVATOR:
Feed partical size : up to 50mm
Capacity : 540 TPH
Bucket width : 1400mm
Elevating speed : 1.4m/sec
Shaft centers : 31m.
d] - RAW MILL / KILN ELECTROSTATIC PRECIPITATER:
Size : M400 LC4F 3.45 x 12-19-36+PC.
No. of Unit : 1 No.
Make : Orient Engineering
Gas before ESP : 247500Nm³/hr.
Gas temperature : 90-100ºc
The Precipitator system is configured to achieve the following process for solid-gas
separation:
Corona Generation,
Particle Charging,
Particle Collection &Removal.
The basic configuration consists of collection plates and discharge electrodes
forming flue gas ducts through which the gas is passed for treatment. High voltage DC
power is applied to the discharge electrode while the collecting plates are grounded. The
presence of strong electric field in the vicinity of the discharge electrode and the free
electrons available in the gas generates corona. Also an electrostatic field is established
between discharge electrode and collecting plates. Particles which travel between the
discharge electrode and collecting plate get charged and collected on collecting plates.
The rapper mechanism provided for the collecting plates shear away the collected dust
into the dust hoppers for onward disposal. Rapper mechanism provided for discharge
electrode dislodges the dust gathered on these electrodes.
E] - AEROPOL:
Diameter of conveying vessel: 2500mm
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Height of vessel : 5500mm
Capacity : 380 TPH
Conveying height : 80m
Conveying pipe size : 600NB
f] - RAW MATERIAL HOPPERS:
Hopper capacity; Limestone: 1 No. 900T.
Shale : 2 No. 300T.
Iron ore : 1 No. 300T.
Weigh-feeder capacity; Limestone: 35 to 350 TPH
Shale : 4 to 40 TPH
Iron ore : 1 to 10 TPH.
Critical Operating Parameters:
Except raw meal composition and fineness, following are the control parameters-
Mill feed is kept in auto mode w.r.t. bucket elevator drive Amps,
Vibration level at gear box,
Roller bearing temperature,& Mill outlet temperature,
Differential pressure across mill,
Mill hydraulic pressure.
[04]- HOMOGENISATION SYSTEM:
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Gagal – I
a] Blending Silo : No. of Units 2.
Size : 13m dia.x 24m height.
Capacity : 1500 M.T. each.
b] Storage Silo : No. of units 2.
Size : 13m dia.x 40m height.
Capacity : 3100 M.T. each.
Gagal – II
Blending-cum-storage silo: Type – Multi-flow silo [C.F. silo]
Make : Krupp Polysius
Size : 22m dia.x 52m height.
Filling height : 50m
Effective Volume : 16500m³.
Capacity : 18000 M.T.
Air quantity : 10m³/min.
Air pressure : 1.6 M.bar.
BLENDING SIL0:-
In continuous blending system the feeding and the discharging of the material to
and from the silo is done simultaneously and continuously. Homogenization is achieved
either by pneumatic means inside the silo or mechanically as in cascading and recycling
system. Two or more silos are used in series and the overflow from one silo is fed into
the next silo and the material discharged from the silo is discharged into the inlet stream.
In the mixing chamber the material is fed from the top and distributed over the top of the
silo at the several points across the cross – section to ensure the uniform layer deposition
in the silo. Both the mixing chamber bottom and the outer ring bottom are aerated. Low
pressure air is admitted to the section of peripheral silo ring. This partial aeration creates
the fluidized material layer that passes below the un-aerated material through the
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peripheral opening into the mixing chamber where it freely expands. Alternated sectional
aeration initiates the gravity pre-blending inside the main silo compartment. The pre-
blending material entering into the mixing chamber is subjected to the intensive cycle
quadrant blending. The material is then discharged through one lateral discharge socket.
[05]- PREHEATER:-
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Gagal –I
No. of Streams –3
a] Four-stage, twin string type MF Calciner Make: ABL
Size – CY1 - Ø2925mm
-- CY2 - Ø5m
-- CY3 - Ø5m
-- CY4 - Ø5m
MFC size - Ø5.1m x 16.5m length.
Make - Mitsubishi
b] Five stage preheater, single string with DD Furnace
Size – CY1 – Ø3.244m x 8.65m height.
-- CY2 – Ø4.45m x 8.57m height
– CY1 – Ø4.45m x 8.57m height.
--CY1 – Ø4.45m x 8.57m height
DD Furnace size – Ø 4.20m x 8.41m.
Make- Nihon
c] Kiln ESP MFC Stream;
Make -- ABL
Nos of ESP – 2 Nos.
Design – Dry Horizontal.
Height of Electrostatic field – 10.5m
Length of Electrostatic field – 8.64m
d] Kiln ESP DDF Stream;
Make – Voltas
Nos of ESP – 1 No.
Size – IP, IC, 17 G.P. [16”x29”x29.2”]
2F [2x14.6”]
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Gagal – II
Nos of Stream – Round two string.
a] Five stage preheater with PREPOL –AS precalciner.
Make – Dopol, Krupp Polysium AG, Beckum.
Volume of calciner - 660 m³
Cross section of calciner – 14m²
DESCRIPTION:-
Basic function performed by a cyclone are:-
1-It heats up the raw meal in the gas stream,
2-It separates the raw meal and discharges it via the meal chute.
PREHEATER & IT’S COMPONENTS:-
A TYPE CYCLONE:-
It is arranged between the calciner and the B type cyclone. It is fed from above.
The exit gas containing the raw meal when leaving the calciner flows via the calciner
bend to the cyclone. Here the cyclone meal is separated and passed in via the meal chute
to the kiln inlet .The exit gas flows through the dip pipe and intermediate piece into the
next higher gas duct .
B TYPE CYCLONE:-
One or more of the B type cyclone stages are installed in the preheater between A
and C type cyclone stage. B type cyclone is fed from below.
The raw meal which fed into the gas duct is conveyed into the cyclone by the
exhaust gas. In the cyclone the raw meal is separated passes through the meal chute and
the dispersing box to the gas duct of the next lower cyclone stage. The dispersing box
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hereby effects the uniform distribution if the raw meal in the gas duct. Exhaust gas flows
into the dip pipe and the intermediate piece into the next higher gas duct.
C TYPE CYCLONES:-
It is the last cyclone in the DOPOL 90 Preheater. It may consist of one or more cyclones
per string. It is designed for high degree of raw meal separation.
The raw meal fed into the gas duct is conveyed into the cyclone by the exhaust gas.
In this cyclone the raw meal is separated and passes through the meal chutes and the
dispersing box to the gas duct of the next lower cyclone stage. The dispersing box hereby
effects the distribution of raw meal in the gas duct. Exhaust gas flows through the dip
pipe into the exhaust gas duct.
CALCINER:-
It is mounted between the kiln inlet and the lowest cyclone stage of the pre-heater.
The raw meal, fed into the transition piece, The fuel and the tertiary air are conveyed into
the exhaust gas through the calciner to the cyclone of the lowest stage of the preheater.
Combustion of the fuel takes place in the calciner. Raw meal is heated up by the heat
exchanger.
M.F.C. VESSEL:-
Mitsubishi Fluidized Calciner suspension preheater consists of a regular raw mix
suspension preheater working in conjugation with fluid bed calciner. The calcining of the
raw meal is performed in a separating fluid bed reactor which is located in between the
suspension pre-heater and the rotary kiln.
D.D.F. VESSEL:-
Dual combustion and de-nitration calciner was developed by the Nihon Cement
Company in 1973 to cope up with the soaring prices of heavy oil.
MECHANISM:
Coal firing capacity of the D.D.F. kiln is 3600tpd. D.D.F furnace is divided into four
zones:-
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Reducing zone:-
This is the inverted conical shaped part at the lower side of the D.D.F furnace
whose main function is to reduce NOX the kiln exit gas.
Fuel cracking and burning zone:-
This is the cylindrical part of the central lower side of D.D.F., whose main function
is to vaporize, crack and partially burn the fuel injected into this oxygen rich zone.
Main burning zone:-
This is that part of the orifice in the central part of D.D.F. where Main function is
to burn the fuel and to transfer the heat generated to the raw material.
Complete burning zone:-
This is the top cylindrical part of D.D.F. whose main function is to burn the
remaining fuel gas and to accelerate the calcining of the raw material.
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[06]- ROTARY KILN:
Gagal – I
a] Kiln Make : ABL
Size : Ø 4.11m x 64.0m length.
Capacity : 2800 TPD
Inclination angle : 3.5%
Motor : 475 HP
Feeding device : Sank weigh feeder
b] Grate Cooler, Make : ABL
Size : 829 H/ 1050 H
No. of fans : 8Nos.
Cooler ESP : Make Flakt
Size : FAA 2 X 45 M 152110 A2
Nominal Flow : 8000 m³ / minute.
c] Coal Mill : 1 No.
Type : 8.5 E Type
Coal Mill ESP Make : ABL
ESP Design : Dry Horizontal
Height of Electrostatic field: 4.5m
Length of Electrostatic field: 8.64m.
d] Type of Clinker storage : 2 No. Silos
Capacity : 10000 M.T. each.
Gagal –II
a] Kiln Make : KRUPP POLYSIUS
Size : Ø4.4m x 65m length
Capacity : 3300 TPD
Inclination angle : 3.5%
Motor : 600Kw, 1500 RPM
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Feeding device : POLDOS-SR,
capacity – 300tn/hr
b] Grate cooler make : Krupp- Polysius.
Type of grate cooler : Repol,
Size : SR3130 / III,
grate width-3044mm&
grate length- 30350mm,
grate surface- 92.4m²
No. of fan installed : 10
Cooler ESP Size : M.400 LCS 3 F 4, 6 x 12.19-34.
ESP Make : Orient Engg.
c] Coal Mill : 2 nos.
Type of mill : 8.5 e 9 coal mill.
Make : ABL
Capacity : 20 TPH
Coal mill ESP Nos. : 2, size- 15/6/2 x 9/0.3
d] Type of Clinker storage : Circular clinker stockpile
Storage capacity : 60000Tonnes.
The rotary is designed for the burning of the pulverulent, small size or sludge feed
material. For this purpose the kiln hood at the outlet of the rotary kiln accommodates a
special rotary kiln burner. The hot secondary air coming from the downstream cooler and
entering the rotary kiln via the kiln hood is mixed with primary air of the rotary kiln
burner and passed through the rotary kiln in the counter-flow to the feed material.
The inclination and the rotation of the rotary kiln make the feed material in the
rotary kiln inlet to flow towards the outlet. The downstream kiln hood serves as an air
seal and as a connection to the cooler.
For the protection of the rotary kiln shell and the attached parts as well as for the
preventation of the excessive heat losses, the rotary kiln is provided with a special
refractory lining which is adjusted to the requirements of the individual zones.
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The rotary kiln pipe consists of the individual pipe sections which can be welded
together depending upon their size and transport possibility, either in workshop or at the
site and the pipe is provided with a refractory lining. The plate thickness fulfil the
requirement of the calculated stresses in the respective zones.
The material quality has to be chosen according to the temperature stresses in the
respective zones.
The rotary kiln rests on the tyres or the supporting rollers the axial guidance is
effected via a hydraulically longitudinal guides or thrasher blocks. The driving torque is
transmitted via the rotary kiln drive and the rack and pinion drive to the rotary kiln pipe.
The rack and pinion drive is protected against influences by a guard and provided with a
lubrication device.
A transition piece is to the downstream cooler the outlet end is equipped with kiln
hood provided with the manholes for entering the rotary kiln and for introducing the
rotary kiln burner.
Seals at rotary kiln inlet and outlet serve as to prevent any entry of any infiltrated
gases.
FUNCTIONAL DESCRIPTION:
The feed material enters the rotary kiln through the inlet housing. The inclination
and the rotation of the kiln cause the material to move in counter-flow to the hot gases
towards the outlet and from there into the cooler.
In this process the feed material passes through the following reaction zones:
1. Preheating zone (subject to kind of preheater )
2. Calcining zone (subject to the kind of preheater )
3. Clinkering zone
4. Cooling zone
The presence and the length of these zones is mainly dependent on the composition
of the material to be burnt, the preheater and the downstream cooling system.
Diameter and the length of the rotary kiln depends upon the desired output and are
considerably influenced by the chosen preheater and cooling system.
The quality of the refractory lining of the rotary kiln pipe is adjusted to the length
of the reaction and temperature zone and is specifically determined for every individual
plant.
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The heat quantity required for different reaction stages is generated by the rotary
kiln burner at the rotary kiln outlet. The combination air is high temperature secondary
air coming from the cooler section. The hot gases flow through the rotary kiln and reach
the inlet housing via the rotary kiln inlet. The heat is transmitted to the feed material by
the contact between the hot gases and the material and by its contact with the refractory
brick lining.
RECIPROCATING GRATE COOLER:
SPECIFICATIONS:-
1. Type of the grate cooler : REPOL
2. Grate width (nominal) : 3040 mm
3. Grate length : 30350 mm
4. Grate surface : 92.4 m2
5. Number of single grates : 3
6. Grate inclination : 3 degree
7. Type of drive : Mechanical
8. Type of crusher : Hammer
9. Number of fans : 9
DESCRIPTION:-
The reciprocating grate cooler serves for the cooling of the small sized or
granulated burned material. An excellent cooling effect is achieved in that. The cold air
is blown through the cooler grate and through the burned material lying on the grate.
FUNCTIONAL CHARACTERISTICS OF THE COOLER:
The burned material discharged from the kiln falls through the inlet shaft of the
cooler onto the entry to the grate. Due to the special design to the grate entry the material
to be cooled forms a uniform bed. Over the stationary and movable grate plate rows, the
burned material is transported by the forward movement of the movable grate plate rows
to the end of the cooler.
The oscillating frame with the movable grate plate rows is driven on both the sides;
the number of the strokes per minute is infinitely variable. The cooling air is generated
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by the several fans. Normally, one fan is allocated to each air chamber, thereby providing
the targeted aeration to the grate and the material to be cooled.
The heated up cooling air is captured in the upper section of the cooler and is
available for the further use as secondary air for the kiln or as the tertiary air .The grate
riddlings are reclaimed from the collecting hoppers installed under the air chambers,
which are equipped with the dust tight discharge elements.
On leaving the reciprocating plate the cooled material is screened and the oversize
particles are fed into the crusher using a grate bar chute. The crusher throws the crushed
material partially back into the reciprocating grate.
The bearing and the lubrication points of the cooler are supplied with grease by
automatically working central lubrication systems.
The outlet opening of the running axle in the lower housing walls are encased with
sealing air housings. These have an over pressure towards the inside cooler area and
protect the bearing arrangements of the axles against dust and over-heating.
The reciprocating grate cooler is equipped with an automatic control system.
Proceeding from the pressure of the first and the second air chamber of the first grate, the
reciprocating speed of the cooling grates is controlled.
The reciprocating grate consists of -
The upper housing with the inlet shaft,
The lower housing,
The cooling grate,
The clinker crusher,
The cooling air fans,
The compartments with collecting hopper for the grate riddlings,
The discharge elements,
The material conveying system.
[07]- CEMENT GRINDING MILL:
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SPECIFICATIONS:
Capacity
Gagal 1 : 75 to 90 tph
Gagal 2 : 140 tph
Shell inside diameter : 4.4 mm
Shell length : 15.15 mm
Compartments : 2
Length of first compartment : 4.76 m
Length of second compartment : 9.41 m
Rated output : 115 tph
Operating mill speed : 14.11 rpm
Ball charge
First chamber : 28 %
Second chamber : 28 %
Recommended number of motors : 2
Power : 2200 kW
Speed : 990 rpm
DESCRIPTION:
Final processing step in the manufacture of the cement of the cement is grinding a
mixture of clinker and additives into a finished product Object is to create a particular
fineness of the product to achieve some predetermined physical characteristics in the
cement. When in concrete, Main ingredient used in cement is the clinker. Clinker is
ground with gypsum to produce Portland cement. Grinding mill is the main component
used in finish grinding system. A ball mill is horizontal cylindrical drum with two
compartments having steel balls of the different diameter. as grinding media. Clinker is
ground by a closed circuit grinding system where mill product is routed through the
dynamic air separator and the material coarser than the required grain size is returned to
the mill. Thus, separator removes the coarser and the fine particles, which are fed back to
the mill.
xxxvii
Sufficient new feed is added to the mill as required to maintain the charge within
the mill capacity. Heat generated in the mill is always present since the majority of the
energy imparted to the mill is converted into heat. Although nothing happens to the
clinker at 220 degree farenhite, but raw gypsum at that temperature begins to degenerate
loosing retarding effect on the setting of cement and thus rendering the cement for false
setting. Mill product temperature is maintained by water injection system, which
improves the grinding efficiency also and eliminates the problem of cement setting.
Further air vented through the mill is used to remove some of the heat generated during
mill grinding. Dust laden air vented through the mill is passed through the grit separator,
bag filters and ESP where fine dust is collected and clean air is vented to the atmosphere.
FLY- ASH HANDLING:
DESCRIPTION:
For higher production rate of fly-ash based cement, it was necessary to develop
silos with higher capacity and lower operating cost for both fly-ash and cement. Flat
bottom system is the result of Research and Development in American cement industry.
Several discharge gates placed at the bottom of silo, opened one or two make the fly-ash
flow downwards near the central aeration pad.
Silent features of fly-ash silo:-
Vertical silos wall avoidance of material, bridging by proper silo internal
construction, nearly total discharge.
Controlled discharge of the material flow, several aeration sections are fluidized
alternatively by motorized six ways distributor appertaining valves in the air supply
lines.
Minimum amount of the air is supplied which is necessary to locally fluidize and
discharge the required amount of the fly-ash.
Lowering the material level in the silo is controlled by dozing valve.
Easy availability for maintenance of all the components in the bottom.
High availability because there are four discharge spouts used on specific
requirement.
xxxviii
[08]- PACKING HOUSE:
xxxix
Packing Plant is the place where cement is stored, packed and dispatched to various
destinations.
Gagal Cement Works Packing Plant has six cement silos with a total storage
capacity of 35200tonnes. There are one mechanical and two electronic Rotary Packers at
Gagal I Packing plant of capacity 60 TPH (for mechanical packer) and 100 TPH (for
each electronic packers) and two electronic rotary packers at Gagal II Packing plant of
capacity 180 TPH each.
All the packers have the truck loading facility because the cement from Gagal is
transported to different destinations by road only.
33 Grade OPC (Ordinary Portland Cement) as per IS : 269
43 Grade OPC (Ordinary Portland Cement) as per IS : 8112
PPC (Portland Pozzolana Cement) as per IS : 1489(part II)
PPC (Portland Pozzolana Cement) super
Separate bags Godown is available in Gagal plant I and Gagal plant II, Where up to
40 lakhs and 80 lakhs can be stored respectively. Packing plant is close liason with
cement Dispatch section and Laboratory.
Function of the Department:
Cement packing and dispatch is done through road transported by trucks only.
Cement dispatch section receives order from CMD Chandigarh and accordingly
they place demand of trucks to the truck unions, destinations wise. Then the trucks are
placed in accordance to demand for loading of cement. The silo from which the cement
is to be extracted for loading depends upon the type of cement and type of cement filled
in the silos.
Rated Capacity of the packers are as follows:
Packer-1 : 60 TPH
Packer-2 : 100 TPH
Packer-3 : 100 TPH
Packer-4 : 180 TPH
Packer-5 : 180 TPH
The main parts in the packing plant:
Compressor for packer and dust collector,
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Dust collector fan,
Rotary screen,
Elevator,
Spillage screw conveyor of packer hopper,
P.G. Blower,
P.D. Blower of respective cement silo,
Loading machine,
Belt.
[09]- WORKSHOP:
Workshop department deals in repairing of the jobs inside the plant as per the
requirement of different departments, for the performance of their function at optimum
xli
return on investment in machinery. Whenever some job (i.e. fabrication or machining –
smaller in nature) is required by any department, he sends a job order to the workshop
and the job is completed by workshop maintenance gangs.
Workshop has three major sections:
Machine shop,
Welding shop,
Maintenance of Positive Displacement Blowers, Reciprocating compressors and
High horse power gearboxes of whole plant (Gearboxes of more than 150hp or
100kw).
The following machines & machine tools are available in the workshop –
Lathe: Make: VICO; unit nos. : 6
Make: HML; unit nos. : 2
Column Drilling machine:
Make: HMT; unit nos. : 2
Type: CD
Table size: 630 x 500mm.
Table travel (vertical): 200mm.
Milling machine:
Make: HMT; unit nos. : 1
Type: KNEE
Feeds: 18 nos. (16 – 1800mm/min).
Table clamping area: 1350 x 310mm
Planer machine:
Make: Punj steel. Batala
Bed : 3000 x 1000mm.
Boring machine:
Unit nos. : 1
Shaper machine:
Unit nos. : 2
Power hexa:
xlii
Unit nos. : 1
Grinder:
Unit nos. : 2
There are no special purpose machine or extraordinary machine in workshop
because no newly production, only maintenance and repairing are there. All new parts of
machine are purchased from other companies.
Routine maintenance is done by the department-gangs individually by their own
maintenance gangs.
MATERIAL HANDLING EQUIPMENTS:
There are two categories: Mechanical conveying equipments and Pneumatic
conveying equipments. Mechanical equipments consumed less power in comparison of
Pneumatic equipments, but maintenance is higher. Pneumatic conveyer conveyed only
Pulverized material.
Mechanical Conveying Equipments Installed in Gagal I & II:
1. Belt conveyer,
2. Screw conveyer,
3. Bucket Elevator,
4. Deep Bucket conveyer,
5. Drag Link Chain conveyer.
Pneumatic Conveying Equipment Installed in Gagal I & II:
1. Aeropol vertical conveyer,
2. Fluidor Pneumatic Trough Conveyer (P. G. Conveyer),
3. Poldos S-R Proportioning Feeder,
4. Fuller-Kinyon Pump (FK Pump),
5. Low Lift Pump (LLP).
DESCRIPTION OF THE MECHANICAL CONVEYORS:
[1]- BELT CONVEYORS:
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CONVEYING OF A VERITY OF MATERIAL:
The size of materials that can be conveyed is limited only by the width of the belt.
Materials can range from very fine, dusty chemicals to large, lumpy ore, stone, coal or
pulpwood logs. Because rubber belts are highly resistant to corrosion and abrasion,
maintenance cost are comparatively low when handling highly corrosive materials or
those that are extremely abrasive, such as alumina and sinter.
ADVANTAGES:
Belt conveyors operate automatically and continuously without loss of time.
Without loss of time for loading, unloading or empty return of trips.
Low labour cost, low power cost, Low maintenance cost.
Belt conveyors provide a continuous flow of material while avoiding the confusion,
delays, and safety hazards of rail and motor traffic in plants and other congested areas.
For these reasons, belt conveyors are capable of handling tonnage of bulk materials that
would be more costly and often impractical to transport by other means.
They neither pollute the air nor deafen the ears. They operate quietly and do not
contaminants the air with dust or hydrocarbons. At transfers, dust can be contained
within transfer chutes or collected with suitable equipment, if necessary.
The conveyor equipment itself can be protected from overload and malfunction by built-
in-mechanical and electrical safety devices.
Long-distance transportation.
Conveyor component are – troughed conveyor belt, tail pulley, head pulley & drive,
closely spaced idlers at loading point (impact idlers, if required), return idlers, vertical
gravity take-up, loading skirts, discharge chute.
After the conveyor belt tension requirement in pounds per inch of width, the conveyor
belting must be selected on the basis of the tension rating of multiple-ply belts & their
trough ability. The maximum allowable inclination of the belt conveyor is 14º.
Specification of the belt used in the plant –
800/4 (Capacity-800kg/cm², 4-ply rating)
1800/5 (Capacity-1800kg/cm², 5-ply rating)
Belt width: 1000mm
Belt length: as per requirement.
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[2]- SCREW CONVEYOR:
Specification:
Diameter of screw: 70mm
Geared motor : BAUER Type-DO54SZ2-212/170
Motor rating : 0.25kw
Motor speed : 23RPM
Container capacity: 5 litres.
Consisting of:
The conveying screw in semi-open tube,
the reversible geared motor driving the screw conveyor,
the chute at the outlet end of the screw conveyor,
the sample collecting device,
the sample container with level indicator,
the control system for the screw conveyor.
No sample being taken, the screw conveyor is reversed, in order to always convey fresh
sample material. The scope of supply includes the welded pipe socket accommodating
the sampler.
[3]- BUCKET ELEVATOR:
DESCRIPTION:
The Bucket Elevator is used for the continuous vertical handling of bulk materials having
a peak temperature of approximate 300ºc and a grazing range from 0-50mm.
The Bucket Elevator consists of:
The boot with return sprockets,
The casing,
The head with drive sprocket,
The chain with round steel links,
The buckets,
The casing doors.
The Bucket Elevator boot is placed on the supporting structure. Adequate clearance must
be left on one side of the boot, to allow for the dismantling of the return sprockets. Its
casing consisting of individual sections are erected. All casing joints must be sealed with
the sealing cord, the cord being placed between the row of holes and the inside edge of
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the connecting flange. Spacer plates must be inserted between the two casings spaced
about 6m apart. The Bucket Elevator head may now be placed on the erected casings,
aligned and fastened.
The buckets are fixed onto the U-links of the chain. When making the two chains
endless, make sure that the return sprockets are in their highest possible position. In the
outlet of the bucket elevator head, an adjustable tongue is provided to guide the material
flow.
Generally speaking, the drive unit consists of:
a flexible coupling between machine and gear unit,
the speed reducer with backstop,
a hydraulic starting and overload protection coupling or a flexible coupling between gear
unit and motor,
and the motor.
[4]- DEEP BUCKET CONVEYOR:
The Deep Bucket Conveyor is a unit for continuous handling of bulk materials with a
lump-size not exceeding 150mm and a peak temperature of 500ºc.
The Deep Bucket conveyor works horizontally as well as on an incline up to an angle of
60º. In principle, the bulk material must be proportioned according to the maximum
quantity conveyed.
The machine consists of:
the drive station,
the frame with running track,
the supporting frame,
the take up station,
the two-strand bushed chain,
the deep bucket,
the bucket guide shoes and feed guides and the inlet chute.
The drive unit normally consists of:
- a flexible coupling between drive shaft and gear box, the speed reducer with anti-
run-back device,
- a hydraulic starting and overload coupling between gearbox and motor,
and the motor.
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[5]- DRAGLINK CHAIN CONVEYOR:
DESCRIPTION:
This conveyor is used for the continuous handling or distribution of bulk material at peak
temperature of 280ºc with chain links of manganese alloy steel, and up to 500ºc using
chain links of chrome – nickel alloy steel. This conveyor works horizontally as well as
on an incline. The material to be handled is fed onto the lower strand, i.e. the conveying
strand, if possible from both sides.
The conveyor consists of:
the drive station,
the return station,
the conveying chain,
the slide rails,
the guide shoes,
the support rollers,
the stripper plate, and
the trough of concrete or steel, as required.
Drive Unit: A chain drive with shear pin sprocket between machine and gear unit, slide,
rails, speed reducer with motor bracket, V-belt drive between gearbox and motor, and
electric motor. The gearbox is filled with the prescribed quality and quantity of oil.
DESCRIPTION OF PNEUMATIC CONVEYORS:
[1]- AEROPOL VERTICAL CONVEYOR:
DESCRIPTION:-
The AEROPOL vertical conveyor is a device for the continuous vertical transportation of
finely granular bulk materials. The conveyance is performed Pneumatically and is based
on the principle of lean-phase conveyance. The conveying medium is oil-free and
waterless compressed air of maximal 1 bar over pressure. The standard design conveyer
is suitable for non-combustible pulverulent to granular bulk materials with temperatures
of up to 120ºc.
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DESIGN:-
The AEROPOL vertical conveyer consist:
- The conveying vessel with bracket or supports as well as air supply ducts and
control
lines;
The conveying pipe with expansion tube as well as sliding and fixed anchorages;
The pipe branching or the separator.
The conveying vessel consists of the pressure vessel with material inlet connection piece,
riser pipe socket, and deducting pipe-socket, manhole with manhole closure and brackets
or supports. The air supply ducts and control lines including pressure gauges are
mounted according to the local conditions.
The expansion of the conveying pipe owing to thermal stresses is compensated by
expansion tubes. The separator serves for the separation of carrier gas and material.
FUNCTIONAL DESCRIPTION:
The material to be conveyed is continuously fed to the AEROPAL vertical conveyor
through the material inlet connection piece. For conveyance and aeration purposes the
conveying vessel must be charged with compressed air which is free from dust, oil and
water.
The aeration flows through the textile fabric belt in the aeration floor and fluidizes the
material conveyed. Tanks to the pressure of the material column the fluidized material
flows as dense phase to the riser pipe inlet where it is diluted by the conveying air and
carried away. The quantity conveyed is proportional to the intensity of pressure
generated by the material column in the conveying vessel and thus also proportional to
the conveying air pressure and the pressure on the bottom.
It is possible to mount a measuring diaphragm on to the pressure-measuring flange in
order to control the material feed and thus the throughput quantity by means of the
pressure on the bottom (POLDOS system).
The air quantity required for aeration of the material conveyed depends on the kind of
material conveyed and is adjusted by the throttle valve. The shut-off flap serves as safety
valve. If the conveying air supply is switched off or fails, the flap will shut immediately
in order to prevent material returning into the conveying air duct.
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[2]- FLUIDOR PNEUMATIC TROUGH CONVEYOR (P.G. CONVEYOR):
DESCRIPTION:
It is also named as Pneumatic Gravity Conveyor. It is a conveying unit of dust free
operation and low-wear design; its purpose is to transport all kinds of bulk material-from
dry, Pulverulent to fine grained or granular material.
DESIGN:
The FLUIDOR Pneumatic trough conveyor of the following components:
trough section
support
flexible joint
trough flow bow
fan
aeration piping
Fluidor shut off slide valve
Fluidor semi rotory isolating valve.
Trough upper section & through lower section are permanently screwed up with the
fabric floor insert-usually a textile fabric or polyster fabric-situated between the
longitudinal flanges. If required, the fabric may be protected by a laid-on wise cloth in
order to prevent the wear of the intermediate bottom.
The trough inlet can be flange-mounted to the trough section or welded in the trough
section. Flexible joints at the trough inlet and at the trough outlet compensate the
horizontal and vertical trough expansions.
The aeration air is supplied via aeration sockets welded in the trough lower section and is
removed via dedusting sockets in upper section or in the trough outlet. Fan is connected
to the aeration via the aeration piping consisting of hose line, pipe and throttle valve.
FUNCTIONAL DESCRIPTION:
The functional operation of the P.G. Conveyor is such that aeration is supplied from the
trough lower section via the fabric floor insert ventilates the material to be conveyed thus
producing its free-flowing condition. Thanks to gravitational force the inclination of the
trough has the fluidized material in the trough upper section flow to the outlet.
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The aeration air is supplied to the conveyor via the aeration socket at the trough lower
section. The quantity of air is adjustable by means of an upstream, mainly operated
throttle valve. The air to be used must be dry and clean. This air may be produced by
fans or taken from compressed-air mains. For exhausting the aeration air each conveyor
must be connected via dedusting pipe socket to a dust collector.
[3]- POLDOS S-R PROPORTIONATING FEEDER:
Material to be conveyed : Raw meal
Bulk density : 900 kg/m².
Temperature : 80ºC
Diameter of conveying pipe : 4954mm.
Vertical length of conveying pipe : 100mm.
DESCRIPTION:
The POLDOS S-R Proportionating feeder is a device for proportional and continuous
conveying of the fine grained bulk materials through horizontal and vertical piping.
Inclined piping either upwards or downwards is not allowed. Flow bows are not
permitted, as they cause different pressure drops and pulsations to those of pipe bends.
Conveying occurs pneumatically and is based upon the principal of lean-phase
conveying. It is suitable for non-inflammable; dusty to granular bulk materials at the
temperature up to 80ºC.The conveying rate can be varied within wide limits.
Consists of:
the pressure vessel which consists of the conveying vessel and the storage vessel;
the riser pipe which is fitted centrally in the pressure vessel;
the anchorage frame, a welded construction made of steel section;
three suspension fittings which contain the load cells;
the necessary control fitting and piping.
Functional Description: For conveying and aeration, the pressure vessel must be fed
separately with compressed air which is free of dust, oil and water. The aeration air flows
through the fabric in aeration floor and fluidness the material to be conveyed. The
fluidized material flows to the riser pipe inlet as a dense phase by means of pressure of
the material column and, there, is diluted and conveyed away by conveying air.
The through rate of material being conveyed is proportional to the pressure of the
material column in the conveying vessel and, consequently, also proportional to the floor
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pressure. The control valve in breather pipe of storage vessel regulates the top pressure in
the storage vessel. When the control value is fully open, there is same pressure in both
conveying and the storage vessels. The material columns automatically adjust themselves
to the same height. When control valve is throttled, aeration air serves to build up a top
pressure in storage vessel, which presses the fluidized material to be conveyed out of the
storage vessel and into the conveying vessel. In this condition maximum material column
height in the conveying vessel corresponds to the maximum output.
[4]- FULLER-KINYON PUMP:
PRINCIPLE OF OPERATION:
Material to be conveyed enters the hopper; the screw advances the material through the
barrel to the discharge body. In the discharge body, the material is compressed to form a
material seal. The material seal prevents a reverse flow of conveying air from the mixing
chamber. After the material is discharged into the mixing chamber, compressed air-
entering the mixing chamber through the nozzles-fluidizes it sufficiently to permit
pumping through the transport line connected to the end of the mixing chamber.
The free-floating flapper valve, located in the discharge area of the pump, is a
mechanical seal which assists in preventing the reverse flow of air from the mixing
chamber through the pump Barrel. The external flapper valve lever serves as a visual
indication that the free-floating valve is operating satisfactorily. A counter-weight is
attached to the flapper valve handle to aid in maintaining a material seal. Each pump is
supplied with one spacer ring located behind the flapper valve assembly.
The pump screw consists of a solid steel shaft and flight made from rolled mild steel
welded in position. All screws are dynamically balanced in two planes to improve
bearing life and ensure vibration-free pump operation. The pump screw is coupled to a
drive motor by either a shaft coupling or a V-belt drive. This pump uses angular contact
bearings. The bearing located at the discharge end of the pump screw is fixed to absorb
both radial and thrust loads. The bearing located at the drive end is not fixed to the screw
shaft and absorbs radial load only.
MIPS:
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MIPS is abbreviated form for Maintenance Inspection Planning System. As the name
suggests, the prime-function of the department is to prepare planning and scheduling of
carrying out various inspections, maintenance job and to record and update the
inspection result, maintenance remark for corrective action. Equipment inspection /
maintenance planning is the result of visual inspection / running hours or upon the result
of condition monitoring equipments etc.
The various techniques used for condition monitoring equipments are based upon the
diagnosis of the change in behavior pattern of sound, temperatures, heat, vibration,
viscosity etc.
MIPS department also coordinates in planning the maintenance activities of various
departments so as to get optimum utilization of stoppage duration of main equipments.
Whenever the equipment is remarked on unhealthy condition by the condition
monitoring equipments, analysis is carried out. MIPS department prepares the downtime
analysis of the main equipments such as mills, kiln etc.
Function of MIPS department:
Vibration measurement
Girth gear / Pinion profile & teeth impression
Wear measurement (mainly of E-mill grinding rings & balls, VRM table & roller liners,
wear of Roller press rollers).
Creep measurement – The live ring migrations or creep is the relative measurement
between the live ring and the kiln and it is measured in mm/revolution.
Shell thickness measurement – Shell thickness of kiln, mills are measured by ultrasonic
thickness gauge D-meter.
Kiln alignment reading.
Dynamic balancing.
Breakdown analysis.
Compact schedule – Compact stands for computerized maintenance planning and control
system.
Down time analysis.
QUALITY CONTROL:
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Daily outputs and intermediates of different departments at different stages and final
product are analyzed on a regular basis by the laboratory to achieve the set target. This
department provides the feedback for the relative departments. To maintain the quality as
per BIS Norms.
1-Limestone from quarry: Some samples are analyzed at works Laboratory, to get the
advanced information of the quality of the limestone proposed for mining.
The fresh limestone is carried out at stacker and Reclaimer, to control the carbonate
percentage. The desired characteristic normal operating range are-
Particle size: 3"
Total carbonate: 82% minimum.
CaO : 44.5% minimum.
Coal sample from coal stacker is analyzed to produce clinker of consistent quality.
2-Raw meal: Periodic samples of raw mill are collected for total carbonate and residue
and checked at Laboratory. The total carbonate and residue is conveyed to central control
room operator who according to the deviation if beyond to tolerance limit, take the
necessary action to obtain the targeted values as per BIS Norms and ACC’s Internal
norms. Periodic samples are also collected from discharge of blending silo and checked
for homogenization.
3-Final coal for Kiln: coal received from reclaimer is fed to raw coal hoppers. The final
coal sample from fine coal hoppers are collected in desired frequencies for residue, ash
and moisture. M.F.C. & D.D.F. coal sample are collected and checked for moisture,
residue and ash content.
Moisture : 6.0% maximum : To control flame temperature.
Residue on 90 micron,
Kiln : 25% maximum : To monitor the proper combustion
Pre calciner : 40% maximum and fineness control.
4-Clinker:
a) - Liter weight (gms) To control the quality of clinker.
1000 to 1350
b) - Free lime % maximum 2.5
Chemical analysis
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% CaO 63.0 to 66.0
% SiO2 20.0 to 23.5
% Fe2O3 3.5 to 4.5
% MgO 1.0 to 4.0
% LiO 0.2 to 1.5
5-Cement Grinding: According to the parameters of clinker, the gypsum and pozzolona
material are adjusted. Samples of cement at the cement mill out let is collected every
hour and check for different characteristic as required as chemical composition, strength,
fineness etc.
OPC PPC
Specific surface (m2/kg) : 240 to 350 min. 320 To maintain the quality
% So3 : 1.8 to 2.7 2 to 2.9 as per BIS Norms.
Setting time (minutes) :
Initial : 60 to 150 60 to 150
Final : 140 to 225 140 to 225
6-Packing House: Sample are drawn at every packing stage from all the running packers
and tested for key quality parameters for to access the quality of cement. In case, any
deviation is observed corrective action are taken.
ACC`s Internal norms on quality of cement manufactured at Gagal Cement Works-
Physical Parameters 33GR 43GR 53GR PPC
Seeting time (minutes) -
Initial (minimum) : 60 60 60 60
Final (maximum) : 225 225 225 225
Compressive strength (minimum) in MPa-
03 Days : 24 26 30 24
07 Days : 34 36 41 34
28 Days : 44 46 57 45
Specific surface (minimum) –
(m2/kg) 250 270 290
RESEARCH AND DEVELOPMENT:
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In all the dynamic and versatile companies Research and Development forms the hub of
new activities and is a constant partner, innovator, and evaluator. In 1964, the central
research station was established in Thane, MAHARASTRA. The Research station spread
over an area of 8000sq.m has modern Laboratory, with the latest technique equipment
and manned by highly qualified scientists and technologists, who carry out research in
cement and other fields. The thrust is on the process of optimization in cement plants,
utilization of low grade coal, development of special purpose cements, and special
varieties of dense and insulating bricks for rotary kiln lining; computer modeling and
simulation unit operation in cement manufacture; and watching brief on the plant quality
control and innovation aimed at its further improvement. The facilities at CRS are used
as the reference laboratory in terms of continual evaluation and monitoring of operations
and assistance to the factories in specific trouble shooting assignments.
INVENTORY MANAGEMENT:
There are three types of inventories: Raw material, Work in progress and Finished goods.
Raw materials are materials that are inputs in making the final product. Work in progress
refers to goods in intermediate stage of production and finished goods consists of final
products ready for sale. Manufacturing firms gradually hold all the three types of
inventories.
The goal of offertory inventory management is to minimize the total cost. Thus,
management is constantly confronted with the taste of attempting simultaneously.
To meet an ever-increasing demand for prompt customer services.
To maintain smooth flow of production operation.
The effective management of Inventory involves a trade off between having too much or
too little inventory. ACC’S Inventory consists of raw material, work in progress, finished
goods, stores and supplier.
Detail of Inventory in ACC:
Limestone, Gypsum and other raw material,
Coal, bags, stones, spares etc.
Loose plant and tools,
Stock in trade,
Work in progress
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Raw material, stock in trade and work in progressed is valued, whichever is lower coal,
packing materials, stones and spares are valued at cost, cost is determined on a weighed
average basis.
The ACC stores are classified as-
Regular: For items which are used regularly.
Sporadic: For items which are used once or twice in a year.
ESP (Emergency Stock Pool): For items having high value and are used in more than one
plant.
Discounted: For items not in use.
A class: For items which are very costly.
Generally in stores Inventory are broken in two parts-
a- General Items: Items which are common for different departments like electric
bulbs, paint etc.
Machinery parts: Spare parts as per drawing no. / part no. used for various
Machinery in plant.
ISO:
ISO is a specialized international organization whose members are the national standards
bodies of 111 countries. ISO was founded in 1946 to develop manufacturing, trade and
communication standards. The goals of ISO standards to facilitate the efficient exchange
of goods and services.
ISO develops standards in all industries except those related to electrical and electronic
engineering. Standard in these areas is developed by the Geneva – based International
Electro technical Commission (IEC).
ISO 9000:
The ISO 9000 series are generic standards for quality management and quality assurance.
The Standard in the series that are used for registration purposes include ISO 9001, ISO
9002 and ISO 9003. ISO 9001is the most comprehensive and covers all elements, from
design and development, through production, installation and servicing. Other standards,
such as ISO 9000 and ISO 9004, provide guidance for using the standard and for
implementing their element internally.
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More than 70,000 company facilitates worldwide have achieved registration to one of the
three standards in the series ISO 9001, ISO 9002, or ISO 9003.
For some companies, registration to ISO 9000 is a legal requirement to enter regulated
market. Companies have, implemented ISO 9000 to maintain market share, keep up
with, or get ahead of their competition. In addition, ISO9000 registered companies have
realized internal benefits, better operating efficiency, higher quality, reduced cost and
greater productivity.
ISO 14001:
The ISO 14001standard describes the basic requirements of an environmental
management system. ISO 14001 contains only those requirements that may be
objectively audited against for registration purposes and / or for self-declaration
purposes.
An ISO 14001 registration will not guarantee that a particular facility has achieved the
best possible environmental performance. Only that it has the basic elements of an EMS
in place and the continual improvement.
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