Cement plant components & their construction method

1. Indian Institute Of Technology Delhi

2. Case study
Project:3750 TPD(Tonnes per Day)
Pyro Project
Loctaion:Dabok(nearUdaipur),
Rajasthan
Client: J.K.Lakshmi Cements Ltd.
Civil Consultant:M/S Magcons
Consulting Engineers Pvt
Ltd,Mumbai
Civil Contractor:M/S K.B.Mehta
Construction Pvt Ltd,Ahmedabad
Equipment Supplier:M/S LNVT
Sinoma,China

3. Project Overview
• Dabok Cement Factory used to be a part of
Udaipur Cement Works Limited(UCWL) some
years back.This cement factory got down and was
sold to J.K.Lakshmi Cement Company Limited.
• J.K. Lakshmi currently has the facility of grinding
the clinker and a packing plant but cement
production is not done here.
• J.K.Lakshmi decided for starting the production of
cement at the current location.

4. Existing Coal mill Existing Packing Plant

5. Components of A Cement Plant
• Quarry
• CS Silo/Blending Silo
• Preheater
• Kiln
• Cooling Tower
• Clinker Silo
• Grounding Mill
• Packing Plant

6. Current Status of Project
• The construction of the Blending Silo(85 m) is
completed from outside.Preparation for the
staging for the construction of the cone inside the
blending silo is going on.
• The first two floors of the preheater are
completed.Beam level of the 3rd floor(46 m) is
almost reached.
• Foundation of the preheater boiler is going on.
• Piers for the installation of the kiln are aready
constructed.

7. • Foundation work of the cooling tower is
almost over.The tunnel for the transport of
clinker from the cooling tower to the clinker
silo is under construction.
• Construction of the clinker silo has reached
almost upto the completion of the second
floor.

8. Site Soil Conditions
• The site is situated in Udaipur,Rajasthan which has got
hard,rocky soil conditions.
• All the foundations are Raft foundations.
Foundation of Preheater Shaft Cooling Tower Foundation Slab

9. Quarry
• The cement production plant
should be located where the
raw material for the
production is available nearby.
• The dark coloured rock in the
picture contains limestone and
two kinds of shale, all of which
are used in producing cement.
The light coloured material is
called over-burden, which is
not used in manufacturing, but
is set aside to be replaced
later during reclamation after
the quarry has reached the
end of its permit period and is
closed.

10. • The flat area in the quarry wall,
called the lift or bench, is the
depth to which holes are drilled
before charges are set for
blasting. Because of security
requirements, most quarries
subcontract the blasting
operations.
• After blasting, the waste stone is
brought to the end of the quarry
where quarrying first began. It
will be the first material to be
filled back in as part of the
reclamation process. Usable
stone is hauled by truck and
either dumped into the primary
crusher or piled nearby.
• The roads and piles must be kept
watered to reduce airborne dust.

11. •After the stone is dumped into the feed
chute from above, gravity moves it down
through the crusher, which reduces it to
about 3 inches in diameter. A bag filter
helps reduce airborne dust.
•From the crusher, the stone moves onto
a conveyor belt that carries it to the
manufacturing plant about 6 kms away
in our case.
•Long conveyor belts must be kept
adjusted to the proper tension. This is
done by using steel cables to suspend
concrete weights inside the towers.
•At each point where the conveyor
changes height or direction, another bag
filter helps to remove dust from the
crushed stone and from the air.
•The limestone and shale are finally
stockpiled at the far end of the
production line.

12. SAFETY PRECUATIONS UNDERTAKEN IN
MINING AREA
• Only the authorized employees are permitted to handle the
explosives.
• There are demarcations around the blast location like barricades,
flag signs etc.
• The blast holes are being loaded under the control and supervision
of the designated competent person.
• The controlled blasting technique is being adopted.
• Cellular phones are not allowed in the blasting zone.
• The explosive vans speed should not exceed 25km/hr.
• Warning signals are given within a radius of 500 meters from the
place of firing.
• After the blasting a siren is blown as signal if it is all clear and safe.
• As the blasting is very dangerous for the eye at some distance also,
safety glasses should be provided and used at the blasting site.

13. CS Silo/Blending Silo
• The stone is loaded with a
front-end loader one
bucketful at a time onto a
conveyor that carries it
into the blending silo.
• Limestone and shale is
blended inside the
blending silo.
• Blending silo consists a
concrete/steel cone
inside.

14. CS Silo/Blending Silo
• Blending silos are gravity blenders. Another
prevailing term is homogenising silos instead of
blending silos.
• Often the creation of horizontal layers with
differing quality can be observed when silos are
in batch production.
• Depending on the product characteristics and
flow properties, different blenders are used in
order to achieve a higher grade of homogeneity.

15. Types of Blending Silos
1. Blending silo with pipe blender
• The pipes, arranged on the outer wall of the blending silo, have different nominal
diameters. Because of the specially constructed product inlets, the product is pre-
mixed both when it flows in and out of the mixing pipe.
• The different pipe diameters and lengths create a varying speed and flow profile
in the pipes. This results in further product homogenisation.
2. Blending silo with central pipe blender
• The product is concentrically drawn from various levels and fed into the mixing
chamber via a central pipe located in the middle of the silo.
• Due to the specially constructed material intake zones, the product is already pre-
mixed when it flows in from the various zones.
• The resulting crosswise mixing of the product has a significant and therefore
reinforcing effect on the efficiency of blending.
• Furthermore, the product is guided concentrically to the blending pipe. This
prevents the development of asymmetrical flow zones to the greatest extent
possible.

16. Types of Blending Silos(contd.)
3. Blending silo with cone blender
• A blender fitting integrated in the silo cone serves to distribute the product evenly.
The product is mixed via various flow zones and is guided to the outlet of the
blending silo.
• Due to the conical shape of the blender, the product flows from top to bottom
with increasing speed. Due to the different flow speeds, there are varying
residence times for the product. This increases the blending effect.
• The blender is suitable both for the continuous and discontinuous blending of bulk
goods. Thus existing silos can be retrofitted quickly and easily.
4. Blending silo with screw mixer
• The intensive mixing takes place in the lower silo part. The product is continuously
collected from the cone by a central vertical mixing screw and conveyed upwards
through the mixing pipe to the roof of the silo.
• The blended material is picked up by an ejector which distributes it in fine layers
over the container's entire width.
• The silo can be filled or discharged at any time irrespective of the blending
process.
• The mixing screw is powered by a gear motor which is located in the middle of the
silo roof.

17. General Layout of CS Silo

18. Construction of Blending Silo
• PCC of raft
• RCC of raft
• Starter of the shell
• Erection of slip form assembly
• Slipping (75 mtr)
• Thickness reduction of shell
• Dismantling of slip form system
• Backfilling outside and inside plinth
• PCC & RCC of floor slab
• Staging of inverted cone

19. • Shuttering and reinforcement of
inverted cone
• Concreting of inverted cone
• Dismantling of staging
• Erection of roof girder 80 mtr
level
• Erection of rolladeck
• Tying of reinforcement
• Shuttering of roof slab
• Casting of roof slab

20. STAGING FOR THE CONE INSIDE THE BLENDING SILO:
1. Welding of iron brackets to the
inner wall of the silo
Triangular iron brackets
2. Erection of purlins and support
Purlins

21. Winch MachineGirder attached to winch machine
by pulley system

22. 3. Erection of girder on the bracketsGirder carried to the silo with the
help of crane

23. 4. Finished platform for the construction of cone

24. Embedded plates on the surface
of the silo
Embedded Plate(EP)
Openings in the silo
Openings

25. Construction of Preheater
• PCC of raft
• Casting of raft including tying of
reinforcement bars
• Shuttering etc. Complete
• Casting of ‘l' column till + 6 m lvl
• Backfilling & pcc in plinth
• Erection of hydraulic jumpform
rigs - 8 nos.
• Casting of ‘l' column upto 1st
• Casting of ‘l’ column till + 6 m lvl(
conventionally)
• Casting of 1st slab @ 8.5 m. Lvl.

26. • Casting of 'l' column from
2ndslab to 3rd slab
• Casting of 'l' column from 1st
slab to 2nd slab
• Casting of 2nd slab @ 31.0 m. Lvl
• Casting of 3rd slab @ 46.5 m. Lvl
• Casting of 'l' column from 3rd slab
to 4th slab
• Casting of tie beam @ 21.0 m. Lvl
• Casting of 4th slab @ 61.0 m. Lvl
• Casting of 'l' column from 4th
slab to 5th slab
• Casting of 5th slab @ 73.0 m. Lvl.
• Casting of 'l' column from 5th
slab to 6th slab
• Casting of 6th slab @ 85.0 m. Lvl

27. General Layout of Preheater

28. Operating Characteristics of
Preheater
• High-efficiency cyclones with low pressure drop resulting in low fuel
and power consumption
• Lowest NOx emission from unique high-temperature reduction
zone
• Simultaneous low CO emission specially due to calciner notch and
outlet loop duct
• Uncomplicated operation with single entry locations of calciner
fuel and tertiary air
• Suitable for firing both traditional and alternative fuels

29. Preheater Components
Cyclones
• Preheaters are based on proven low
pressure loss (LP) cyclones. The unique
design of the LP cyclone ensures high
thermal efficiency and low pressure drop
while enabling a flexible and space-saving
layout.
• LP cyclones have no horizontal surfaces on
the inside for material to accumulate,
thereby securing stable operation.
• The top stage has a special geometry to
provide the lowest dust loss while
maintaining low pressure drop. Typical LP Cyclone

30. Central Pipes
• Central pipes (thimbles) are standard in all cyclone
stages to provide high separation efficiency.
•The lowermost cyclones feature a cast, segmented
design with a hanging suspension system and common
elements throughout. This enables easy installation and
maintenance.
Cast Segmented
Central Pipe
• To prevent gas from bypassing up through the
material pipes between the cyclone stages, the
pipes are equipped with sluice flaps (tipping
valves) designed for full opening.
• Good meal distribution in the cyclone riser
ducts is ensured by adjustable spreader plates
in the distribution boxes.
Sluice Flaps & Distribution Box
Material Pipe Sluice Flaps

31. Dividing gates
• Robust dividing gates are used to precisely and
consistently distribute meal to the different sections
of the riser duct and calciner.
• One gate is capable of dividing meal into two, three,
or four different streams.
Meal dividing gate
Tertiary Air Duct Damper
• To balance the combustion air flow between the kiln
and calciner, a tertiary air duct damper is provided for
reliable regulation of the tertiary air gases.
• The damper design features a solid refractory blade
for long, reliable life.
Tertiary air duct damper

32. Preheater Operation
• Raw meal is introduced at the inlet gas duct to the Stage I (top)
cyclones. It is subsequently preheated by hot, counter current gas
flow as it is continuously collected and passed down the other
cyclone stages in the preheater to the calciner. Fuel is burned in the
calciner to achieve 92-95% of the total material calcination before
collection in the bottom cyclone and entrance into the kiln.
Combustion air for the calciner is taken from the kiln via the riser
duct and through a separate tertiary air duct from the cooler.
• Design is based on dividing the meal from the second-lowest stage
cyclone to the kiln riser and the calciner. These feed points are
separated by an expanded riser duct that forms a NOx reducing
zone. That is, the calcining chamber is built into the kiln riser. All of
the calciner fuel is introduced to the kiln riser duct with less oxygen
than required for complete combustion, thereby forming a reducing
atmosphere.

33. Preheater Operation(contd.)
• Above the reduction zone is the main calciner vessel, which
is divided into two or more sections separated by a notch.
The changes in cross-sectional areas create turbulence that
ensures effective mixing of fuel, raw meal and gas,
improving heat transfer and combustion. The calciner
outlet loop duct ensures optimum gas retention time,
further mixing and complete fuel combustion.
• Optionally, the second or third-lowest stage cyclone
material can be further split to allow for diversion of a
portion of the meal directly into the upper section of the
calciner. This creates a “hot zone” in the lower section of
the calciner that is conducive to burning difficult fuels and
further NOx reduction.

34. Jump Formwork used in Preheater construction Preheater Construction

35. Rotary Kiln
• The rotary kiln consists of a tube
made from steel plate and lined
with firebrick. The tube slopes
slightly and slowly rotates on its
axis at between 30 and 250
revolutions per hour.
• Raw mix is fed in at the upper
end, and the rotation of the kiln
causes it gradually to move
downhill to the other end of the
kiln. At the other end, fuel in the
form of gas, oil or pulverized solid
fuel is blown in through "burner-
pipe“ producing a large
concentric flame in the lower part
of the kiln tube.

36. Rotary Kiln(Contd.)
• As material moves under the
flame, it reaches its peak
temperature, before dropping
out of the kiln tube into the
cooler.
• Air is drawn first through the
cooler and then through the
kiln for combustion of the fuel.
In the cooler the air is heated
by the cooling clinker, so that
it may be 400 to 800 °C before
it enters the kiln, thus causing
intense and rapid combustion
of the fuel.

37. General Layout of Rotary Kiln

38. Cooling Tower
• Clinker cooler has two main
function to perform.
1. To cool the hot clinker quickly.
2. To provide necessary air for
burning of coal in pre-calciner
and kiln.
• After introducing of red hot
clinker into the cooler,
mechanically driven gates
moves it to the rear end of
cooler. Three pair of gates are
installed inside the cooler. A
single pair consist of fixed gate
and movable gate. To and fro
moment of movable gate
pressurized which cools it
quickly.

39. Cooling Tower(Contd.)
• Clinker cools down gradually
as it moves, due to the air
blow by the fans which is
taken from the atmosphere.
Air falling over clinker is highly
pressurized which cools it
quickly. Clinker escaping out of
the cooler is fed to a hammer
crusher, since lumpy material
requires crushing.
• Crushed material is
transported to clinker silo
through deep bucket conveyor.
Temperature of clinker
escaping out of cooler is about
208 degree celcius.

40. Grate Cooler Operation
• The grate cooler operates with a cross current principle in which the
clinker is moved across the grate while cooling air blow in from below
through the grate and clinker layer.
• The hot clinker falls from kiln and forms clinker bed on the grate and
transported through the cooler over alternatively fixed and reciprocating
grates. At the inlet of first great clinker is quenched and spread across the
cooler width by the increased cooling air.
• The grate is fabricated to be as possible to obtained a thick clinker layer
and a uniform distribution of air through the clinker bed in the interest of
heat recovery.
• During the clinker transport from the cooler a part of dust and small size
clinker is falls from the grates and collected into hoppers under the grates.
The drag chain and rotary air lock system fed these clinker and dust in
clinker transport system. A dust collection ESP is also installed beside the
cooler known as cooler ESP. Exhaust gases from collection is fed to the ESP
for dust collection.

41. Grate Cooler Operation(Contd.)
• Grate cooler consist of
1. Cooling grate Plates
2. Standard Plates
3. Cooling housing
4. Drive unit
5. Grate aeration system
6. Clinker crusher
7. Conveying unit
8. Cooling fan

42. Tunnel Construction under cooling tower Columns construction of Cooling Tower

43. Coal Mill
• The coal mill works for producing the pulverized
coal for burning to increase the temperature of
kiln, pre-heater, raw mill .It works as same as raw
mill for lime-stone grinding & the coal mill grind
& transfer the coal to the furnace for burning.
• The raw mill is grounded dried swept away by fan
through the separator to bag filter or ESP. finally
it is stored in to the fine coal bin hot air for coal
mill is supplied by cooler exhaust hot gases or
pre-heater outlet gases before GTC circulation.
The function of coal mill is to ground suitable
grate coal and for feeding the same in to the kiln
and calciner in fluidized form.
• Coal from stock yard is fed for stacking and
reclaiming in to the stacker and reclaimer. Pre-
homogenized raw coal is feed in to the coal mill
hopper with the help of belt conveyer.

44. Coal Mill(Contd.)
• The raw is then fed to the coal mill VRM via
weigh feeder, drag chain and screw conveyer.
• Coal Mill is an important integral part of cement
plant. Here large size of approx size 600mm, is
ground fine to the size of 90 micron. Coal from
coal mill is used to feed kiln and calciner. Outlet
temperature of coal from coal mill is different in
different seasons.
• Coal from mines is initially crushed at crusher
site. Coal is then sent to stacking making mixture
homogenized. Reclaimer picks up the coal and
coal is fed to the coal mill hopper through belt
conveyer.
• Coal taken out from hopper is feed inside VRM
with the help of a screw conveyer which is
mounted just below the hopper.
• Coal inside VRM is grounded between roller and
table.

45. Coal Mill(Contd.)
• Hot air from cooler ESP fan is taken inside VRM and
is used for drying of coal.
• Fine coal from VRM moves to the cyclone, where
most of the coal is separated from air and the coal
which does not get collected due to ultra fine size is
separated with the help of ESP. LV separator is for
separating coarse and fine particles.
• Coal is fed to screw conveyer through rotary lock,
which transport it to the FK pumps. Two FK pump
delivers material to the storage bins. There are two
Storage bins
1. Kiln Bin
2. Pre-calciner Bin
• Fine Coal is then transported to the kiln and pre-
calciner by kiln firing FK pump and pre-calciner FK
pump respectively.

46. Clinker Silo
• Storage of cement clinker is a prerequisite for continuous
kiln operation. Constantly increasing kiln capacities ensure
storage volumes of 200,000 cubic meter or more.The
situation on site as well as the specific properties of the
material determine the configuration of the storage and
handling equipment. Above all the following aspects need
to be taken into consideration here:
• Available space
• Statics, soil bearing capacity and groundwater situation
• Bulk material temperature and flow properties
• Environmental regulations and aesthetics
• Investment and operational costs
• Capacity and unloading capacity (in automatic
operation)

47. Construction Of Clinker Silo
1. PCC of angular raft
2. RCCof angular raft
3. Shell wall (1100 mm thick) From
top of raft to GL by conventional
method
4. Backfilling in foundation
5. Casting of shell wall (600 mm thick)
From GL to +6.00 mtr by
conventionally
6. Erection of self climbing hydraulic
system
7. Casting of shell from +6.0 mtr to
35.0 mtr

48. Construction Of Clinker Silo(Contd.)
8. Dismantling of self climbing
hydraulic rigs
9. Casting of 1st lift of tunnel with
starter
10. PCC of tunnels including sand
filling upto 536.00 lvl
11. Casting of wall of tunnels
12. Casting of top slab of tunnels
13. Back-filing in foundation of
tunnels
14. Laying of floor PCC
15. Laying of grade slab over PCC

49. Jump formwork used in Clinker Silo Clinker Silo Construction

50. Quality Control
• Quality control is error prevention rather than error detection.
• Online reaction to special cause of variation will lead to progressive
improvement in the process, performance and cost.
• Fundamental improvement in quality results from testing rational
prediction about special process using statistical method. The effective
pursuit of quality permanent commitment through out an organization.
• Pitfall of the successful implantation of the permanent quality
improvement culture are:
 Lack of top management support.
 Lack of middle management support.
 Commitment to only department.
 Haphazard approach a little of this and that with no meaning change in
the system.
 Measurement of success and guidance program on the basis of short-
term profile.

51. Inference
• The Indian cement industry has been on a high growth
trajectory for more than a decade, led by buoyancy in
sectors such as real estate and construction. The
industry has witnessed continuous modernisation and
adoption of new technologies in recent years.
• The modern Indian cement plants are state-of-the-art
plants and amongst the best in the world. In order to
meet the expanding demand, cement companies are
fast developing new plants.
• Cement plant construction is quite a specific
construction and it requires high quality and precision
with adequate safety.