Pro Report Sidhi cement

7/31/2019 Pro Report Sidhi cement

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GUJRAT SIDDHI CEMENT LIMITED

INDEX

Sr Subject Page

1 Acknowledgement 2

2 Introduction 3

3 Production flow Diagram 6

4 Mines 7

5 Crusher 11

6 Stacker & Declaimer 14

7 Rawmill 16

8 C.F Silo 18

9 Preheater 19

1

0

Kiln 24

1

1

Cooler 28

12

Clinker storage 29

1

3

Cement mill 32

1 ESP 33

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4

15 Packing plant 34

16

Instrumentation used incement plant.

36

1

7

Plant Interlocking diagram 48

1

8

Heartily thanks to 51

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ACKNOWLEDGEMENT

This is the acknowledgement for those

personalities who have helped me directly or indirectly

to organize my training, helped me during my training

period and to make my training report. I am alsothankful to all staff members of automation division,

who have helped me to clear my doubts & concepts.

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Preheater

Kiln

Cooler

Clinker Storage

Cement Mill Clinker yard

Cement Silo

Packing Plant

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2 MINES####################################################

2.1 INTRODUCTION:

The lime stone

2.2

MINING:

Here in the GSCL Lime Stone Mine mining is done in two

methods:

1. Conventional Mining

2. Surface Mining

1. CONVENTIONAL MINING

These explosives and detonators are stored is called the

magazine. First of all the top soil is removed with the bulldozer.

This soil is transported to the mines only when ordered, otherwise it

is heaped at the mines.

The drilling machine is used to make holes upto the depth of

10 m and 150 mm diameter. It also takes samples of soil at various

levels for the assessment of the soil. According to the kind of earth

i.e., soft or hard the placing of explosive is decided.

If the soft earth is charge with an explosive, then the gases

pass through the porous soil and hole is not blasted, hence

explosive is wasted.

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It is very important to ram and compact the earth after piling

explosive. Otherwise it might explode in the air. Even the rock

develops the cracks, so if the drilling machine is used in the area it

might get stuck up in crack.

The blast explosive is of 125 mm and 83 mm Diameter. It is

class 2 explosive weighting 6.25 kg. The 83 mm Diameter

explosive is Aqua dyne, also manufactured by IDL Chemicals. It

has weigh of 2.77 kg.

The explosive have following compositions:Nitrate - 60 %

Ag Powder - 10 %

Water - 10 %

Nitroglycerine - 20 %

These explosive are Nitroglycerine based explosive and they

are in a thick paste form and contains salver. The cost is Rs.18/kg.

When we observed the blasting there were 19 holes of depth

10 m each, so 35x15x10x1.5 tons of limestone is acquired against

the usage of 1500 kg of explosive used.

Here the holes blasting affective area are 34 m long and 15 m

wide. The power factor ranges from 3 to 5 which are consideredless.

A detonating chord is used to connect these holes to each

other. These are made up to Penta Ethylene Tetra Nitrate coater

with plastic. A one meter long chord contains 10 gm of PETN. This

is used in a chord form so that the contact is not broken. It fires at

the rate of 6000 m/sec.

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A detonator is used to connect these holes and complete the

circuit. The wire is made of steel which is covered with plastic.

This wire is ignited. An Ohms meter is used to check whether the

circuit is completed or not. Then the dynamo is charged and the redlight on it lights frequently and fire button is pressed, and blast

occurs.

The place where the stone and it is 60 cm thick stacking of

explosives and detonators are done separately. In the case of

accidents if explosives ignite, they just burn, but if detonators

ignite, they explode.

The explosives are stacked on a wooden platform, 6 inch

above the ground, so that no harm is caused by rats also. Special

care is taken not to use any iron material in the magazine, instead of

iron, Cu is used. The stacking is done only upto 1.2 m. A red line is

marked almost about 2.5 m above the ground which marks themaximum storage capacity. A passage is left between the stacks, so

that if one starts burning the others might be removed.

These magazines have special Z type ventilators for the

purpose of security. These are also made from Cu.

The vehicle used for carrying the explosives is made from Al.It has a partition between back part and front part and also a

silencer in front, so there will not any chance of fire.

2. SURFACE MINING:

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Mining lime stone with surface miner is of very recent origin

in India and it has got definite advantages over conventional

mining.

First of all the mining with surface miner eliminates totally

drilling and blasting. Surface miner performs in site crushing while

mining, which cases out the problems encountered in transportation

of limestone to crusher.

The system needs no separate loading arrangement and the

machine loads the material directly to he trucks or dumpers. Theneed for haul road maintenance is drastically reduced, since the

mine surface with the surface miner is very gradual and uniform.

The biggest advantage with surface miner is that it eliminates

primary crushing, since the product size will be maximum 150 mm

and 50 % will be less than 75 mm.

Surface miner provides scope of selective mining and hence

gives greater opportunity for exploiting the reserve where

contamination is more and where conventional mining is not

possible. The elimination of drilling and blasting provides

environmental friendly mining operations with utmost safety for the

mine operators.

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3 CRUSHER##########################################

Apron Feeder

It comprises of specially fabricated frame on which two heavy

duty endless link assemblies are wounded. The apron flights are of

rolled steels and are bolted on the chains and are used for conveying

the material. The drive arrangement is a D.C. motor and a gear ox

connected to the drive shaft of the apron feeder. The link assembly

and the flight are supported and guided on the top of the frame by

deck rollers. The drive shaft has two sprocket hub assemblies which

mesh with the link assemblies and drive the apron feeder. On the

return end of the apron conveyor is the tail wheel assembly for

guiding the link assembly.

1. Scraper Chain Conveyor

The scraper conveyor consists of a trough assembly within

with a scraper chain assembly travels. The round link chain and

fabricated scraper flight runs on scraper trough while conveying the

spillage load on trough support assemble while returning.

Actual conveying of spillage is done by the bottom strand by

scraping material alone the trough bottom plate. The drive

arrangement consists of an A.C. electric motor and shaft mounted

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reduction gear box which directly rotates the drive shaft. At the rear

end, the scraper tail wheel assembly guides the round ling chain

assembly.

2. Impactor

The crusher is Impactor Cursher. Crushing is done by impact

and it is a dynamic operation.

The main size reduction is carried out by striking i.e., by

impact of the impeller bars to the crusher feed. The purpose of thebreaker plates arranged inside crusher is to function as deflecting

plated. The material thrown against them is reflected back into

crushing compartment, where it is again hit by the impeller bars,

until it leaves the crusher through slot between rotor and lower edge

of breaker plate.

By the impact of material against roller plates and materialgets crushed and then material is supposed to crush by chunking

against each other. The material is ground to the size of 50-60 mm

in first phase.

There are three types of impact plates

1: front impact2: rear impact

3: grinding lower

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CONVEYOR BELT:

The crushed material from is convening through many

numbers of belt conveyor.

The material is feeded to stacker through conveyor BC 4A

and BC 4B.

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3 STACKER & RECLAIMER####################################################

3.1 STACKER :

The stacker type SU is used to stack raw material at the yard.

The stacker runs on the rails fixed at the right hand side of the pile

in longitudinal direction. The material are stacked with a certainhomogenizing effect normally according to Chevron method or

longitudinal stack piling method, with help of Boom stacker.

Chevron method is a roof like stock piling method.

The stacker consists of two main parts:

1. Tripper

2. Jib

1. TRIPPER:

Tripper and jibs are linked together and are provided with

RBCs. For the traveling of stacker four drive motors are provided

which are attached with jibs rollers through gear boxes. The tripperis fitted with four wheels which are mounted in wheel casing.

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1. JIB:

The stacker consists of a mobile rotable frame and a stacker

capable of lifting in the vertical plane. The hydraulic equipmentserves to move the stacker jib in step from the lower to the upper

working position. While the stacker lift the stacker jib according to

the height of the pile.

3.2 RECLAIMER:

The bridge scraper is used for homogenization of particular

materials at longitudinal store and for conveyance of material from

piles to outgoing conveyor belt.

Reclaimer has a long scrapper chain through which

homogenized material is transported to outgoing conveyor. Harrow

carriage has cross conveyors on it and cross conveyors have

horrows on it. Horrows move horizontally by horrow carriage. The

horrows cut the stack horizontally and material falls down and from

the stacker chain material gets collected. The scrapper chain moves

ahead and material comes on conveyor belt and further goes to

additive silos.

Thus, reclaimer has an important role for homogenization ofmaterial. And it helps to achieve good quality of final product.

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4 RAW MILL####################################################

4.1 INTRODUCTION:

Lime stone, clay, Iron ore fed into mill. The chemical

composition of raw materials is controlled by computer calculations

based on analyses of raw materials, as well as actual amount of

compositions of meal in the homogenizing silo.

During transport to mill inlet, magnetic objects are removed by

a magnetic separator, which is mounted over belt conveyor. Metal

detectors are also built in as further protection. If a metal is

detected, a pneumatically operated gate is activated for discharge of

a portion of materials containing metal piece. Another metal

detector is placed near box feeder, where belt stops for manualremoval if a metal is detected.

The box feeder at mill inlet operates as a buffer and as an air

sluice to reduce false air intake. After box feeder, raw material

drops on rotary grinding table. Here, they are thrown under rollers

by rotary movement of table, and ground. The grinding table is

driven by mill main motor.

The material might contains some moisture upto 4%. This is

dried by hot kiln exit gases supplied through nozzle ring

surrounding grinding table.

The reflected material from mill is returned to mill inlet. The

ground and dried materials i.e., raw meal are carried by air flow to

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dynamic separator. Here, coarse particles are returned to grinding

table while finer particles pass for separator in dedusting cyclones.

There are a number of oil pumps for Lubrication and cooling

of gr unit and bearing of grinding table. Grinding pressure between

three rollers and grinding table. A constant and correct lubrication

of bearing in three rollers.

There are nozzles installed in front of rollers and on grinding

table, for use when temperature or grinding process makes it

necessary. Here, in raw mill hot gas blow is taken from kiln string.It helps material to dry and thus to less moisture content. Yet

moisture content remains 0.5%, which is necessary for easy

operation.

The mill is automatically stopped when very strong vibrations

occur. The air flow to mill is supplied by fan. A gas recirculation

duct with damper is also installed to ensure sufficient constant air

flow. The air from mill fan is drawn through ESP.

The raw meal produced is carried by fluxosides and elevators

to C.F. silo for storage. The dust precipitated in ESP and

transported to C.F. silo.

The most important feature of raw mill is that instead of balls,it has rollers. There are three rollers of 50 tons each around centre

shaft. The production of a ball mill cant exceed more than 150

tons, where as the kiln needs 450 tons of raw meal. The production

of raw mill is 500 tons/hours.

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CONTROLLED FLOW SILO :

FLS have developed a new, continuously operated silo for

blending and storage of cement raw mix, called C.F. silo. It extractsmaterial simultaneously at different rates from a number of outlets

in silo bottom.

The C.F. silo bottom is divided into seven identical hexagonal

sectors. Each of these sectors is divided into six triangular sub

sectors. Thus, the bottom consists of a total of 42 sub sectors. These

sub sectors represent 42 individual areas from which are provided

with aerating units. These 42 separate sub sectors represent 42

individual areas from which material can be extracted accurately to

a predetermined program.

In actual operation, homogenization is performed by using

three of seven discharge outlets simultaneously, each bloweraerating only one sub sector at a time.

The raw meal flow stream from extraction points of part silos

is then blended in a tank placed after silo.

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5 PRE-HEATER####################################################

5.1 PREHEATER AND CALCINER:

A decisive factor in heat economy of cement dry production process

was development of preheater. With this, it was possible to obtain very low

exit gas temperature of about 250oC which were not attainable before.

ADVANTAGESOF PREHEATER:

The kiln dimensions can be considerably reduced.

The calciner can be supplied with combustion air from clinker

cooler at a temperature of approximately 900oC. Since control

devices are located in gas stream behind preheater.

The process control allows for a suitable margin of safety

against overheating, even at a calciner stage of 90-95%.

The high degree of calcinations and regular feeding of kiln

ensure stable kiln operation without kiln upset conditions.

The characteristic feature of calciner is through blending of

raw mix and fuel prior to introduction of combustion air and

subsequent initiating of combustion process. The combustion air isdrawn from clinker cooler at a temperature of about 900oC. The air

flows from inlet to outlet of calciner, with only a low pressure drop.

The heat generated in calciner is utilized partly to raise raw

mixture temperature to calcining level and to implement actual

calcining process. The preheater here has a double string-kiln string

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and calciner string 6-stage preheater with low pressure type

cyclones.

Kiln string: 3x6 m + 3x6.3 m cyclone.

Calcining string: 1x2x5.4 m + 1x7.5 m + 2x7.8 m + 2x8 m

By using separate strings for kiln and calciner important

operational advantage of independent and accurate draught control

is obtained.

The raw meal feed is extracted from the C.F. silo into feed bin.The feed control is based on schenck impact weigher concept. The

feed bin is placed on load cells.

After the feeding system, raw meal is transported to the

preheater inlet by means of elevators and air slides. At preheater

inlet, feed is split into two preheater strings in such a way that

outlet temperatures are equalized.

The preheater is operating as a counter current heat exchanger

with raw meal passing downwards by gravity and air going

upwards by the INDUCED DRAUGHT (ID) fans.

After fifth stage of the calciner string and sixth stage of kilnstring, combined raw meal enters calciner vessel. Here, about 55%

of fuel is fired. The combustion for the calciner is hot atmosphere

air drawn from coolax cooler through a separate tertiary air duct

mixed with combustion has from kiln. The calciner is designed for

a gas retention time of more than 3 seconds. In calciner, raw meal

will be calcined to about 90-95%.

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The material from calciner is routed onwards to four cyclone

stage of calciner string from where it slides into kiln.

Part of gases leaving top stage of preheater cyclones is taken toraw mill for drying and transporting raw material before it is taken

to bag house.

5.2 BAG HOUSE:

Reversible air bag house has an important role to deal with

environmental pollution problems. As the whole pre heater system

works on the negative draft system by ID Fans, the air goes upward

direction.

These gases contains material or particle form material and if

they are directly send or vented out on the air, then pollution

problems will occur and even lot of material loss will be there in the

manufacturing process, so it is very necessary to do something with

this.

The system consists of a sixteen compartments bag houses

with associated safety device.

Support structures By using separate strings for kiln and

calciner important operational advantage of independent and

accurate draught control is obtained.

The raw meal feed is extracted from the C.F. silo into feed bin.

The feed control is based on schenck impact weigher concept. The

feed bin is placed on load cells.

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After the feeding system, raw meal is transported to the

preheater inlet by means of elevators and air slides. At preheater

inlet, feed is split into two preheater strings in such a way that

outlet temperatures are equalized.

The pre heater is operating as a counter current heat exchanger

with raw meal passing downwards by gravity and air going

upwards by the INDUCED DRAUGHT (ID) fans.

After fifth stage of the calciner string and sixth stage of kiln

string, combined raw meal enters calciner vessel. Here, about 55%of fuel is fired. The combustion for the calciner is hot atmosphere

air drawn from coolax cooler through a separate tertiary air duct

mixed with combustion has from kiln. The calciner is designed for

a gas retention time of more than 3 seconds. In calciner, raw meal

will be calcined to about 90-95%.

The material from calciner is routed onwards to sixth cyclone

stage of calciner string from where it slides into kiln.

Part of gases leaving top stage of preheater cyclones is taken to

raw mill for drying and transporting raw material before it is taken

to bag house.

These gases contains material or particle form material and ifthey are directly send or vented out on the air, then pollution

problems will occur and even lot of material loss will be there in the

manufacturing process, so it is very necessary to do something with

this.

Reversible air bag house has an important role to deal with

environmental pollution problems. As the whole preheater system

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works on the negative draft system by ID Fans, the air goes upward

direction.

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6 KILN####################################################

6.1 INTRODUCTION:

The kiln is 75 m long and it have 4.75 m diameter. The kiln is

supported on three types of 2 rollers each. It rotates at a speed of 3

to 4 rpm. The burning zone temperature in kiln is around 1400-

1500oC. Pulverized coal is used as fuel in kiln and calciner. The

fuel supply rate to kiln installation is determined on basis of an

evaluation of clinker quality and current status of kiln.

The exit gas analysis is done for evaluation of combustion

process. The smoke gases must not contain any unburnt substances

i.e., C or Co. They may cause fire and also waste latent heat of

unburnt part of gases. A certain surplus air is supplied during thecombustion process, because of inadequate air is supplied, smoke

may contain unburnt gases.

There are alarm limits set up to monitor CO and O2 levels in

exist gases. If due to any reason there is a blockage in cyclones, kiln

is shut down.

The lubrication between supporting rollers and kiln type must

be provided by means of dry graphite lubrication. Providing an oil

bath can prove fatal as kiln is almost floating in air.

Usually refractory lining of kiln is replaced if the thickness of

bricks is reduces to half of its original size due to wear. Hence, kiln

shell must not be overheated. If kiln shell temperature rises above

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400-500oC, affected area must be cooled by means of fans. There

are 14 fans for this purpose.

In event of a further rise in temperature kiln must be shut

down for a repair of lining. A radiation pyrometer (scanner) has

been installed for purpose of checking condition of kiln lining

during operation.

If there are any hot spots observed, kiln motor is run at lowest

speed until temperature of hot spot has been reduced. In burning

zone, the temperature reaches upto 1400oC and clinkerization

occurs.

BURNING PROCESSIN KILN:

For burning purpose firing is done in kiln. The firing is done

through nozzle, coal is fired, reaching temperature of flame upto

1800oC and maintaining temperature in kiln upto 1400-1500oC of

material.

KILN SPEED:

Slowing kiln will heat kiln up through out its length. It will

also increase draft, which will tend to reduce rate of heating in

burning zone and increase temperature at feed end.

Speeding kiln up will have opposite effect. When a kiln is

slowed down for longer period of time, increase in draft should be

controlled by regulating damper, to avoid overheating of feed end,

fuel rate is decreased.

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The kiln should be controlled by change in fuel rate, as sight

increase in fuel which is not enough to overheat burning zone will,

if left on long enough, heat up feed end and correct slowly dropping

back end temperature.

CHEMICAL PROCEDURE:

During burning and decarbonation of carbonates of Mg and Ca

and removal constitutional water, there are schematically three

consecutive stage of clinker mineral formation. During burning of

first stage upto 990oC all aluminium oxide reacts with lime,generating monocalcium alluminate silica also starts to combine

with lime generating dicalcium silicate. At this phase of clinker

compounds dicalcium silicate concentration is low.

At second stage of formation, when the material is heated to a

range from 1190oC to 1400oC, monocalcium alluminate formed

during first stage is further saturated with lime reacts with iron

oxide creating dicalcium alluminoferrit which is also called

browmmillerite. Formation of dicalcium silicate which started first

stage is now being completed.

At third stage, material reaches temperature above 1285oC, at

this stage of clinker formation, known exothermal effect occurs,which produces generally 120-150 kcal/kg clinker. The rapid

heating of material by this effect causes clinker to behave in this

kiln section similar to fluidized material, thus increasing the

transport velocity of material which can disturb the regular kiln

operation. The partially fused condition of material permits one part

of dicalcium silicate to be saturated with remainder of the

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uncombined lime, and thus be converted to tricalcium silicate. The

formation of clinker is completed with third stage.

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7 COOLER

####################################################

7.1 COOLER:

The cooler receives approximately 145oC. Hot clinker from

rotary kiln, cooling clinker down to a temperature which is

approximately 80oC at a production of 6500 t/day.

Some of thermal energy contained in clinker is simultaneously

recuperated. The thermal energy is transmitted to cooling air which

is subsequently utilized in kiln and calciner.

Grate-1 is designed as CFG system while grate 2 and 3 are

designed as RFT system. From kiln outlet, clinker drops down onto

the inclined grate plates, latter being alternately stationary andmoveable.

CONTROLLED FLOW GRATE:

The airstreams to first grates is very powerful so that clinker is

well distributed across the entire width of the grates. This will

prevent clinker from being backed together at very hightemperature.

The air flow is adjusted so that clinker is kept bubbling on

surface of layer. Hence, heat recuperation will be optimized.

A controlled flow means that air is fed to grates, individually

controlled to smaller units of grate. This is accomplished by means

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many cases, high temperature of clinker leaving cooler does not

allow direct grinding, because hot clinker causes high grinding

temperatures, which impair not only mill operation but also cement

quality so, far cooling and as a production buffer clinker is stored invarious storage facilities.

The storage time of a good quality clinker, stored in protected

facilities does not influence grinding process nor the quality of

cement. Even clinker stored for many years in dead space of clinker

holes did not show a drop in quality.

Here, for purpose of clinker storage, they have a clinker yard

erected with aluminium sheets and a clinker silo of R.C.C. The

bottom diameter of silo is 80mts and capacity is 400,000 tons. From

the clinker yard, it is taken to cement mill with help of trucks,

whereas from silo, it is taken via conveyor belt, clinker is also

stored in open space. Size of clinker is 2 to 25mm.

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8 CMENT MILL

####################################################

8.1 INTRODUCTION:

Cement clinker and 2-5% raw gypsum is ground together to

form cement. The purpose of grinding mills:-

Creation of larger reactive surface, so that clinkerminerals can react with water.

Controlling of setting properties of cement by adding

gypsum.

At L&T, there are four cement mills of capacity 133 t/hr. It

consists of two chambers divided by double wall. This wall allows

particles of 4 mm size to pass through. About 27 % of volumeconsists of grinding media. The first chambers has high chrome ball

of 60 to 90 mm diameter whereas second chamber has 15-20 mm

diameter high chrome balls In first chamber grinding takes place

due to impact and in second due to attrition. The product is taken to

air separator where coarse particle are recirculated to mill. The mill

converts majority of energy input into heat. Gypsum is dehydratedat 130oC at high temperature. Gypsum loses its property as cement

setting retarded and becomes false set cement. Hence temperature

inside mill is 70-80oC. For this water is injected into hottest part of

mill where it evaporates instantly. Water is carried into mill by

compressed air through a simple nozzle which breaks up water into

very small drops; from where material goes to air separator.

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8.2 ELECTOSTATIC PREICIPITATOR:

In plate type electric precipitator, only electrical precipitation

is employed. This ESP is used after and Cement Mill.

In addition to precipitation by action of the electrical dust

collection also precipitation of a certain quantity of dust particle by

action of gravity as well as direction and by impact. During the

elimination of every supply, the electrical precipitator works as thedust settling chamber with collection of 30 to 70 %.

The size and velocity with which the dust is attracted by the

collecting electrodes is of importance for the collection efficiency.

High resistivity and is difficult to remove from the collecting

electrodes and often it may cause a detrimental operating condition

known as return throw of sparks or as back ionization.

ESP is less efficient than bag house, as it fails to work at high

temperature.

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9 PACKING PLANT####################################################

9.1 INTRODUCTION:

A rotary packing machine is used here having 6 filling spouts.

This machine completes 2.5 rotates per minute. Hence filling 30

bags/minutes or 1800 kg/hour.

The spouts are mounted at the bottom of cylindrical container.

The manual work comprises of placing the empty bags on the

spouts as they pass it. Fluidized cement flows into the rotating

container. At the bottom of the container. Certain amount of

fluidized air is added to the cement to increasing flowability

through the filling spouts into the bags.

Each spout has its own weighing device. By the time the spout

finished one rotation 50 kg of cement is filled into the bag. It is

dropped off on the conveyor belt. All the extra cement falls in the

hopper from where it is transported to the cement silo.

In case of transportation by ship, they are carried to the jettythey are slide down and loaded in to the trucks standing underneath.

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10 INTRUMENTATIONUSEDIN

CMENTMANUFACTURINGPROCESS####################################################

1) Lime Stone Crusher and stacker :

As the control material is required to feed the crusher. Apron

feeder is used and the speed of apron feeder is controlled by VFD

(Variable Frequency Drive) and discharge of the crushed material

flow to the belt is measured by belt wave. The material is taken to

the lime stone stacker through number of belts proximity type

speed monitors are provided in each belt.

There are three micro logic 1000 mini PLCs has been used

for controlling the stacker for making the limestone pile.

2) Limestone Reclaimer & raw mill grindings :

Limestone stacker is used to reclaim the material for pile for

feeding to raw mill for fine grinding. Reclaiming speed iscontrolled by 2 dc motor which is controlled by thyristor control

panel and skewing of Reclaimer is controlled by varying the

correction speed by field weakening system of dc motor and

required reclaimed material can be controlled by varying the

speed of these dc motors which can be vary from 0-3m/hr. for

cutting the material the hydraulic harrow having to & fro motion is

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there which is controlled by hydraulic system and the cylinder

having four meter stroke length for string and on the moment the

proximity switches are used harrow speed can also be varied with

the hydraulic proportional valve which is controlled system.

There are three mini PLCs used for logic control for lime stone

reclaiming and as there two harrow are used, one each side which is

controlled by min PLCs. There is online redundant PLCs are

supervised in case operational PLCs fails. The materials are cuts by

harrow slides down which is dragged by chain drive. It leaves

discharging material on the belt proximity type speed monitoring

is provided for monitoring the speed of bucket chain drive. The

chain drive discharge the materials on the belt & to the third.

Finally the material discharges into raw mill box feeder hopper. All

the three belts which is carrying the material from reclaimer to raw

mill to raw mill hopper and provided by proximity type speedmotors. The function of these motors is to stop the system in case

the belt jamming and belt is getting shared of to avoid further

damages of the system. Box feeder hopper is having capacity of 70

tones which is weigher by three load cells having the capacity of

47 tones each and they are 120 degree apart in the periphery of the

hopper. In order to have equal load distribution on all three loadcells. As shielding cables is connected across three load cells. To

protect three load cells shielding cable is connected by across each load

cell against the welding current. Care is also taken during welding jobs on

such places by giving earthen point directly to the place where welding is

done. The required quantity of the material on volumetric basis is fed to the

vertical raw mill by controlling the box feeder speed. Box feeder speed is

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controlled by 11 kw VFD. The grinding capacity of vertical raw3 mill is 325

tones/hr.

As the raw mill is vertical beam. Raw mill consists of a gear box, a

grinding rollers and 2000kw dry motor(ac induction motor).

Motor:motor rating is 2000 kw induction sleeping motor. 6.65 Kv H.T

motor which is during the grinding table through gearbox.

Gear box: Gear box is very heavy duty gear box hence sufficient lubrication

is required. In case of failure of this oil lubrication system the gear and

bearing can get damage hence bearing temperature are measured by pt100rtd

which trips the system. If oil flow to the gear box becomes less than the

desired value.

Grinding table: Grinding table is rotating on six static show bearings and

these bearings oil supplied by two high hydraulic pressure pumps in

order to maintain the continuous oil film between static show

bearing and grinding table go down surface in order to avoid metal

to metal contact to ensure the required pressure and flow to these

static show bearing six thermal type oil. Oil flow transmitter and

six pressure switches. On oil flow monitor and one pressure

switch for each vein. This system ensures the continuous oil flow

and pressure to the static show bearing in case of abnormality inthe oil flow and pressure & the system trips in order to protect the

static show bearing. The oil show discharged temperature is also

monitored in order to maintain the required viscosity. There are

three grinding rollers placed 120 degree apart connected by yolk at

the centre and outer end of each roller is connected to hydraulic

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cylinders. The complete hydraulic system is provided to control

the moment of the roller against grinding table.

Pumping starts up in the roller which is in varied condition. Thematerials before rollers are brought down. Sufficient quantity of

material is fed which is judged by differential pressure across the

mill. For grinding the material the rollers are brought down to the

table and as the table are rotating rollers are also free to rotate so

whatever comes in between roller and the table gets crushed down.

The crushed material flies up also with the hot gases connected tothe inlet and going inside the mill at the periphery of grinding mill

through mill. The crushed material is lifted along with hot gases

which possess through static separator where the converse material

is separated out and travel further and coarse material comes down

for further grinding. The outlet temperature is measured by

pt100rtd.

3)C.F silo

As consistent quality of material is required for stable operation

C.F silo is used for homogizing the material in the top layers are

getting discharged from 7 extraction points. As quantity of

materials from 10-20% this discharging phenomenon converts its

different quality of horizontal layers into vertical layers hence we

are getting different quality of layers into vertical layers from

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different extraction points. These extracted material goes to wave

bin where again it is getting mixed with the help ofcompressed air

supplied from the bottom of wave bin. Therefore we are getting

consistent quality from the bin.

OPRATION:

For the homogenizing the C.F silo there are 7 air slides connected

to each discharged points getting air in sequence which is

programming. Controlled by PLC there are 7 pneumatic gates at the

discharge point which are also operated in sequence and are being

controlled by PLC for level measurement of C.F silo on eco type

radar has been put. There is one more pedal type level switch which

is provided for monitoring high level of C.F silo.

4) KILN FEEDING SYSTAEM :

There are 2 outlets at the bin from where controlled desired

material flow is fed to kiln pre heater one for P.C stream and

one for P.H stream to sank impact flow meter are used for the

system. The capacity of P.C feeder is 130 tones/hr where as

the capacity of P.C feeder is 240 tones/hr. Dozing valves are

provided as final element to control the flow.. Before the

dozing valve to pneumatic gates are provided for total material

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cut off the material discharge from these feeders fed to the P.C

& P.H stream by conveying through air slides and elevators at

the discharge of the elevator there is one y-shoot diverter

which can feed the material towards the C.F silo back to the

system when it is in operation or to the system hence the total

material from P.H & P.C feeder is carried by elevator there is

one splitter gate is provided by which the material again splits

to P.H & P.C streams in the same ratio from deferens. t feeder

4) PRE HEATING SYSTEM:

In the P.H stream ,flame is second the gases light from cooler

through the kiln and P.H & P.C duct cyclones. The material flow

is from top to bottom and hot gases flow in the P.H system is

from bottom to top hence the heat exchange takes place and the

material is separated out from the cyclone and goes to the P.Cstream & P.C stream goes to P.C where again the burn coal fixed

to maintain the temperature around 900 degree Celsius. The total

material from P.C goes to the

Cyclone of P.C stream and to the kiln inlet during this process

80-90% of calcinations takes place before it reaches to the kilnand if material comes into. The extreme temperature of

1400degree Celsius is maintained for burning process. So after

the burning process in the kiln the material from powder to

nodules. Finally it drops to the cooler. There are number of

instruments used in the process. Each stage material temperature

ad gas temperature are measured with the k-type thermocouple

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down to the transmitter. From here mV generated by the

transmitter is converter to 420 million. After each transmitter

repovided to PLC analog input cords. Each stage is also provided

,2 pressure points ,2 draft points, One at the cyclone outlet

number order to know stable flow of material if any restriction

forms into the coating formation into the system can be deducted

by pressure defense at outlet of each strings.

CO & O2 analyzers have been provided know the proper

combustion of the gases in the P.C for getting the sample fromthe stream to gas analyzers probes are provided to have the

continuous sampling to the analyzer and cleaning panel, O2

analyzer is based on the principle of infrared observation.

The entire kiln rotated from 0-4.5rpm with the help of 670kw

D.C motor which is being controlled by thyristor based 6 pulseD.C drive. The kiln is driven by the mechanism of gear box,

pinion and pair of this continuous lubrication girth system where

it is controlled by mini PLC mounted in the local plc mounted in

the local panel there is one kiln thruster driven by hydraulic

power system to control the float of kiln. In normal operation the

float of kiln is controlled + - 5mm in abnormal condition if floatof kiln is rises to + - 10mm as alert alarm is generated to system

and when it is reached to + - 15mm system is given the rippling

command to the kiln to know the float of the kiln. Assembly is

provided which is attached to one of the leveling of the kiln

through roller. Emergency limit switch is also provided to quit

the kiln operation in switch assembly there are 3 supporting

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roller is moving through bearing which has the controller oil

lubrication temperature of each bearing is also measured with pt

100rtds Abnormal rising temperature rising on any of its roller

bearing trip the kiln operation for safety of the roller bearing

there is one kiln same scanner is provided which scans the entire

kiln 8 times a second. Hence the temperature of each point of its

kiln surface, each recorded or stored into the computer. For the

system coating thickness as the condition of kiln linings is

monitored on continuous basis. Kiln lining migration is measured

on continuous basis with the help of proximity switch at each

lining which gives 1 pulse in the complete rotation is continuous

indication. In case of hot zone forms just below the lining which

can not be deducted by kiln. Shell temperature scanner red spot

forms just below the lining which cannot be deducted by kiln

shell temperature scanner which will result very local k liningmigration which can damage or crack the kiln lining if in

condition continuous for longer period.

5) GRATE COOLER :

The entire cooler is divided into three moving grates. Each

grete is having the number of fix end moving plates which can

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conveyor. The speed of gratecooler is controlled by under

grate pressure in order to have proper bed of material over the

grate. In order to have proper distribution of cooling air to

grates. Each fan flow is controlled by damper and VFD. The

excess air to the cooler is a part of hot gas from cooler is taken

to the vertical coal mill for raw cool grinding.Excess air to the

cooler is taken out through cooler ESP. This is done by

maintaining killer hood draught at the desired level by

controlling cooler vent fan. Speed which is controlled by

thyristor control panel to know or to monitor the burning zone

temperature on continuous basis pyrometer is used. Condition

inside the kiln and the momentum of kiln by CCTV camera

burning flame is also being monitored. The secondary air to

kiln temperature and the tertiary air to P.C vessel temperature

is also measured and the third drive water spray. Steam is alsoprovided which controls the excess air exit temperature and

that clinker temperature at the discharge of the cooling.

6) CEMENT GRINDING AND PACKING:

There are two ball mill type cement mill. Each mill is

having three hoppers. One for clinker, second for gypsum and

third for fly ash. Feeding of cement mill is controlled by belt

wave feeder and for PPC grinding with clinker 2-5% gypsums

fed with clinker . The quantity of gypsum is maintained in

order to have setting time of cement. For manufacture PPC 20-

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30% fly ash is also added. There are two chambers in the

cement mill. In first chamber mix of 80mm, 60mm,70mm

manganese balls are used as grinding media for coarse of

grinding and in the second chamber 10-15mm diameter

slippers are grinding media or finer grinding. Flow of air

through mill is created by cement mill ESP fan. Cement mill

discharges the material for the cement in the screw conveyor

carrid through belt conveyor through lift. From the air lift is

carried to the cement silos. Cement temprature in the mill is

controlled by internal water spray in the cement mill. Jamming

of cement mill is controlled by phosphate which detects the

jamming by sound level which is created by grinding process.

For both the cement mill tuning bearing temprature

measurement is provided. In case abnormal high temprature of

tuning bearing it trips the system continuous oil lubrication forcement mill tuning bearing is also provided and to ensure

continuous sufficient oil flow to the bearing being monitored

with the help of capacitance type proximity switches which

ensure the oil level on oil flow tray over the bearing the mill is

driven by 3600kw ac induction motor through symmetric gear

box and the rotation of cement mill is around 22rp.in the gearbox oil lubrication is also ensured by oil switches. Bearing

temperature of oil box is also measured on continuous basis.

There is continuous vibration monitors at the input shaft of

symmetric gear box. The grinded cement by cement mill

stored in four silos having capacity of 5000tonnes. Each and

every fine cement goes to the air collected in ESP is also fed

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back to belt and to the cement silos. For packing there are five

fourteen spouts mechanical type of packing machines are

there. These machines are packing the cement in 50kg bags

which are loaded on the trucks through the belt conveyor. The

speed of packer (rotary packer) is controlled by D.C drive.,

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11 BLOCK DIAGRAM OF PLANT

INTERLOCK

#####################################

######

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1. Crusher.

2. BC 4A, BC 4B.

3. Stacker.

4. Reclaimer.

5. BC 8.

6. Raw mill.

7. ESP.

8. Drag chain.

9. Air Slider.10. PC & PH.

11. Kiln.

12. Air slider.

13. LO 2 & LO 5 (Coal Silos).

14. Coal mill.

15. Cooler.

16. Clinker Silo.

17. Clinker storage yard.

18. Cement mill 1.

19. Cement mill 2.

20. LO-1& Lo-2(Cement Silos).

21. LO-3& LO-4(Cement Silos).

22. Packing plant.23. Gypsum feeding.

24. Fly ash feeding.

25. Bucket elevator.

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DESCRIPTION-

Same color indicates same group of interlocking. If any

One unit in the same group will shut of, Then all the unit from

The same group will be shut of .

GRUPS -

1. Crusher, BC 4A, BC 4B, Stacker

2. Reclaimer, BC 5, BC 8, Raw mill, ESP, Raw mill hydraulic

plant.

3. PC, PH, Cooler, Bucket elevator.

4. Coal mill, Air slider.

5. Cement mill-1.

6. Cement mill-2

7. Packing plant.

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Documents

Pro Report Sidhi cement