Internship report of MBMP 2008

ACKNOWLEDGEMENT
First of all, i would like to give my special thanks to our dedicated industrial adviser, Engineer
Tesfahun; crusher and raw mill (CRM) Manager for guiding us at every stage with clarity,
spending much time to discuss and help in our report & project. Second we would also like to
thank to all workers of CRM Department, Special thanks to Engineer teklay, m/r saol, w/ro
abeba, and m/r yared who helped us directly or indirectly in completing of this internship
practice. Thirdly, my heart felt respect and thanks to my academic adviser m/r Dawit G/amlak.
Finally we would like to thank to our friends from Bahir Dar University & Mizan Teppi
University.

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EXECUTIVE SUMMARY
MBMP is one of the huge cement factories in Ethiopia. The factory was established with the aim
of producing cement for domestic use. Due to demand increase, the company expanded
gradually from time to time to solve problem. IN the production of cement, production process
and quality parameters are the main process put in to consideration. This report describes about
MBMP cement factory which has a great role by producing cement for infrastructures with a
high quality. The advantage of this internship report of this project is also discussed briefly. This
internship program has many advantages in its different aspects in relating the thing we know
with theoretically and practically. Moreover, we acquire different types of skill like: technical
skill, interpersonal skill, team playing skill, entrepreneurship skills and leadership skills.

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Table of Contents
ACKNOWLEDGEMENT............................................................................................................................i

EXECUTIVE SUMMARY.........................................................................................................................ii

CHAPTER ONE..........................................................................................................................................1

1 INTRODUCTION....................................................................................................................................1

1.1 Brief history of MBMP P.L.C............................................................................................................2

1.2 Vision of the factory..........................................................................................................................3

1.3 Mission of the factory........................................................................................................................3

1.4 Objective of the factory.....................................................................................................................3

1.5 Values of the company......................................................................................................................3

1.6 Main Products of the company and their services..............................................................................4

1.6.1 OPC (ordinary Portland cement).................................................................................................4

1.6.2 PPC (Portland pozzolana cement)...............................................................................................5

1.6.4 LHHSR (low heat high sulfur resistant) cement.........................................................................5

1.7 Customers or users of MBMP P.L.C.................................................................................................6

1.8 Organizational Structure of the Company..........................................................................................6

1.9 The overall work flow of Messebo building material production......................................................7

CHAPTER TWO.........................................................................................................................................8

2 PROCESS FLOW OF MESSEBO BUILGINGMATERIAL PRODUCTION.........................................8

2.1 The Main and Auxiliary of Raw Materials cement............................................................................8

2.2 Energy Sources of MBMP P.L.C.......................................................................................................8

2.2.1 Energy flows:..............................................................................................................................9

2.3 Raw Material Quarry.........................................................................................................................9

2.3.1Loading & transport:..................................................................................................................10

2.4 Raw Material Crushing....................................................................................................................10

2.4.1Dumping of raw material in to hopper:......................................................................................11

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2.4.2 Crushing of raw material with hammer crusher:.......................................................................11

2.4.3 Transfer of crushed raw material to stock pile:.........................................................................12

2.5 Raw material storage hall................................................................................................................12

2.5.1Stacker& Reclaimer Systems.....................................................................................................13

2.6 Proportioning unit............................................................................................................................15

2.7 Raw mill..........................................................................................................................................16

2.8 Sepax separator................................................................................................................................17

2.9 Coal plant........................................................................................................................................17

2.10 CFS (controlled flow storage silo).................................................................................................17

2.11PYRO PROCESSING....................................................................................................................18

2.11.1 Preheater.................................................................................................................................19

2.11.2 Kiln.........................................................................................................................................20

2.12 Cooler............................................................................................................................................21

ELECTRO STATIC PERCIPATER......................................................................................................21

2.13 Clinker silo....................................................................................................................................22

2.14 Cement mill...................................................................................................................................22

2.15 Cement storage..............................................................................................................................23

2.16 Packing..........................................................................................................................................24

Chapter three.............................................................................................................................................26

3 OVERALL INTERNSHIP EXPERIENCES..........................................................................................26

3.1 The section we have been working on.............................................................................................26

3.2 The work task we have been executing............................................................................................26

3.3 Procedures and methods..................................................................................................................26

3.4 The Challenges and problems we have been facing.........................................................................26

3.5 Solutions’ in order to overcome these challenge..............................................................................27

3.6 THE OVERALL BENEFITS FROM THE INTERNSHIP PROGRAM.........................................27

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3.6.1 Practical skills...........................................................................................................................28

3.6.2 Theoretical knowledge..............................................................................................................28

3.6.3 Team playing skills...................................................................................................................28

3.6.4 Leadership skills.......................................................................................................................28

3.6.5 Work ethics...............................................................................................................................29

3.6.6 Entrepreneurship.......................................................................................................................29

3.6.7 Interpersonal skills....................................................................................................................29

Conclusion.............................................................................................................................................30

Recommendation...................................................................................................................................30

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List of figure
Figure 1: organization of MBMP P.L.C....................................................................7
Figure 2: drilled machine & drilled hole.................................................................10
Figure 3 loading the raw material & transporting raw material..............................10
Figure 4: dumping into the hopper & crusher hopper.............................................11
Figure 5: primary crusher........................................................................................12
Figure 6: stacker......................................................................................................13
Figure 7: reclaimer..................................................................................................14
Figure 8: Proportioning unit....................................................................................16
Figure 9: raw mill....................................................................................................16
Figure 10: raw meal silo..........................................................................................18
Figure 11: pyro processing......................................................................................19
Figure 12: kiln.........................................................................................................20
Figure 13: cooler......................................................................................................22
Figure 14: packing & transportation........................................................................25
Figure 15: process flow diagram of messebo cement factory.................................25

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CHAPTER ONE

1 INTRODUCTION
Cement is manufactured by intimately mixing together limestone, shale, silica sand and iron ore
bearing materials, burning them at clinkering temperature and grinding the resultant
clinker so as to produce cement. The production process of cement has three major stages. The
first stage is Raw Mix Preparation stage which is responsible to mix certain proportion
of clay and limestone and to crush them to powder form. The second and the most
important stage is pyro processing which consumes more than 90% of total energy. This stage
includes pre-heater, calciner, kiln and cooler. In the pyro processing a gray and hard clinker is
formed. Then, clinker is transported to the finish mill, which is the third stage, by a conveyor belt
to be ground into fine powder cement. A small amount of gypsum is added during grinding to
control the set properties of the produced cement. The Raw Mix Preparation and Cement
grinding stages are concerned in size reduction which is a physical process. Raw mix
preparation includes the process; quarrying, crushing and transportation, proportioning of the
ingredients and grinding of raw mix. The finishing grinding of cement includes the process of
grinding of clinker and gypsum and Packing of cement. Messebo Building Materials Production
plc is found in northern Ethiopian in the Tigray province 9.5km far from Mekelle city in the
northern direction. This factory or plants have got many economic benefits to the country and
especially to the Tigray region. Before the construction of this plant there have been scarcity of
cement in the country especially in the region but after the construction of this factory the
scarcity have been decreased. This factory have many environmental hazards due to the dust
which is released to the environment and just to decrease this impact the surrounding people a
job priority have been given to them and is still given to them. The raw materials used are mostly
found around the plant & its surrounding.

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1.1 Brief history of MBMP P.L.C.

Messebo cement factory is located in Mekelle town in the Tigray regional administrative 790km
Far from A.A (capital city) of Ethiopia.The factory is located 11 km far from Mekelle town near
to Messebo hills with the number of employees about 1000 and established in 1991E.C with 1.2
billion Ethiopian birr. The factors taken in the consideration to build the factory are the
fulfillment raw materials availability, cement market, energy supply, and infrastructure
requirement and investment incentives.The feasibility study of Messebo cement factory was
commissioned to be conducted by Austro plan, Austrian Engineering Company Ltd and was
sponsored by Tigray development association (TDA). The company was established around
Mekelle with high raw material potentials. The factories technology is the leading technology of
the 21st century by the best manufacturer of cement machineries in the world, F.L.Smidth CO. of
Denmark. It has a production capacity of 600,000 tons of Ordinary Portland Cement (OPC) per
year. After the installation was completed commissioning of its product was started in year of
1992 E.C with best quality and at highest standard. But as the construction is developed fastly in
Ethiopian from time to time the cement was not enough and still created a large black market in
cement then the government of Ethiopia decided to expand the Messebo cement factory. This
expansion project is started by china’s contractor with 2.2 billion birr in 2009. Its product was
started in 2011 with a capacity of 4000 tons/day and this Messebo cement Expansion
project is inaugurated by his Excellency prime minster Meles Zenawi on 25th June 2011.
Currently the production capacity of Messebo cement factory is 7000 tons/day which is
the summation of the production capacity of the two lines.

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1.2 Vision of the factory

 To enhance the assets of its welfare in such a way that assets are invested in profitable
and lucrative business so as to continue its welfare activities on a sustainable base.
 MCF is highly committed and has social responsibility to support and be involved in the
development activities of the Tigray region in particular and the whole national in
general.
 To contribute to the social and economic development by investing in those business
areas which are neither covered by the neither government nor private businessman

1.3 Mission of the factory

 Being competent in global market
 Entering in a progressive development path
 Being an exemplary company in a country.
 To assure its existence & become a profitable company a sustainable basis &
support the Continuously growing for construction industry with the supply of
construction materials of Acceptable quality & reasonable price.

1.4 Objective of the factory

 To create bound sustainable market by supplying competitive product that fulfill
customer Requirement
 Enhance proper ownership & ensure sustainable profit
 To continuous development, modern & scientific methodology work culture system
 To create conductive work environment
 Develop human resources create job opportunities
 To substitute the important of cement so that to reduce the cash out flows of hard
currency.

1.5 Values of the company

 commitment and hard working
 innovation and learning culture

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 teamwork
 integrity
 trust and empowerment
 Accountability /socially sensitive

1.6 Main Products of the company and their services

As Messebo cement factory is a cement factory it produces cement. But in the world there are
different Types of cement. From these different types of cement Messebo cement factory is
produced four types of cement. These cements are different by their raw material composition.
Also their composition is varying from day to day with in specific interval of percentage. These
cements are:-

1) OPC (ordinary Portland cement)

2) PPC (Portland pozzolana cement)

3) PLC (Portland limestone cement)

4) LHHSR (Low heat high sulfur resistant)

These are all types of cement available in the market at present. These Special cement products
are quality assured and proved in Ethiopia and abroad.

1.6.1 OPC (ordinary Portland cement)

It is the first product of Messebo cement factory
It is the most energy consumable cement due to high percentage of clinker
It is the most expensive cement due to high energy consumption.
Its percentage composition is
 clinker = 90-95%
 Additives=5%
 Gypsum =5%

It is more applicable for high building in fast constriction because

it is high heat release cement and has early strength

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it attains its strength fastly

1.6.2 PPC (Portland pozzolana cement)

It is called low heat release cement. This type of cement contains pozzolana which is
aluminum silicate burned by volcanic eruption in its composition.
It is more expensive than PLC due to long distance transporting of pozzolana
Messebo cement factory produces PPC in high amount than the other
The percentage composition of PPC is
 Clinker= 70-75%
 Gypsum= 5%
 Pozzolana=20-25%

It is mainly applicable for massive construction because it recesses relatively low heat

1.6.3 PLC (port land limestone cement)

This types of cement contains raw material limestone in its composition

This types of cement is the cheapest next to LHHSR type of cement than the other products
The percentage composition of PLC is
 Clinker =70-75%
 Gypsum=5%
 High grade Limestone= 20-25%
 Pumice=5%

The PLC cement is more applicable for –masonry and plastering

Note: - Strength of OPC greater than PPC and PLC due to high clinker content

1.6.4 LHHSR (low heat high sulfur resistant) cement

This types of cement called special cement
This types of cement contains raw material limestone in its composition
This types of cement is the cheapest type of cement than the other products

is the most energy consumable cement due to high percentage of clinker than the other types

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The percentage composition of LHHS is

 95% clinker &
 5% gypsum

Can be used huge buildings, Bridges and dam constructions, to produce concretes, for house

buildings and small constructions etc.

1.7 Customers or users of MBMP P.L.C

MBMP P.L.C is one of the biggest suppliers of cement next to Durban Midroc cement
factory and Mugher cement factory. Currently sells OPC &PPC at around 270 birr & 190 birr
per quintal respectively. In order to satisfy consumers of MBMP P.L.C distributes this type of
cement within Reasonable values sends to branch stores of cement in Addis Ababa, Bahir Dar &
Dessie. Besides it has a direct distribution channel to Gonder, Ghambella, Weldia, Kanissia,
Semera and etc. Obviously every Building & construction of northern Ethiopia is consumer of
MBMP P.L.C. MBMP P.L.C’s cement builds governmental & nongovernmental institutions in
Ethiopia. For instance governmental institutions are; about 33 newly constructed universities,
Tekeze river hydroelectric Power station, roads, Gil gel gibe river hydroelectric power station
currently Abay dam renaissance Project and etc. Non-governmental institutions are; institutions
built by contractors, concrete product Manufacturers and retail shop builder. The most widely
used type of cement in Ethiopia is Ordinary Portland Cement (OPC), and in addition Pozzolana
Portland Cement (PPC) is being manufactured. Messebo Building Materials Production plc.
(MBMP) was planned to produce only OPC but at this time it is Manufacturing OPC, PPC, PLC
and LHHS as its products. These products are mostly used for Local consumption but at this time
an expansion project is being done in order to be able to compute in the global market fulfilling
the local consumption. The consumers of this plant’s Production are generally the whole
Ethiopian people for the purpose of huge buildings, Bridges, Dams, house buildings and small
constructions.

1.8 Organizational Structure of the Company

The company has different functional departments, divisions, sections and units under the
umbrella of the general manager. The company has permanent, contract and trainer employs

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with different Educational level and various experiences. The overall organization of the
company is as follows.

Figure 1: organization of MBMP P.L.C

1.9 The overall work flow of Messebo building material production

In the cement factory there are many workers and the work flow is as follows. Daily workers are
under the control of the senior workers and trainees are also under the control of senior Workers.
These senior workers are under the control of formals. Formal is the controllers of the Shift
engineers and for the normal workers Formal can control unless the one which have to Control is
the supervisor. Formals are under the control of supervisors and supervisors are under the control
of division heads. The one who have to control the division head is the department head. Every
Formal in every shift has to write the things which have done on the logbook every time at the
end of his work time. Then every worker have to read that logbook before doing anything that is
to know the progress of the whole process or to continue or finish maintenance works if there are
any. Then after the division head and the department head read that log book and report to the

chief operating officer and ask for decisions sometimes when difficult conditions occur. The
chief operating officer is under the chief executive officer and the chief executive officer is
controlled by the board of directors. When we see this all the board of directors is the final
controller of the company.

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CHAPTER TWO

2 PROCESS FLOW OF MESSEBO BUILGINGMATERIAL PRODUCTION

2.1 The Main and Auxiliary of Raw Materials cement
Table 2.1 the main raw materials of cement production in MBMP

2.2 Energy Sources of MBMP P.L.C

In cement plant energy is the basic input in the process & it consumes a huge amount of energy.
This energy is coming from basic energy sources. These are:-

 thermal energy ,
 Oil &
 Coal.

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2.2.1 Energy flows:

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Electrical Energy: The energy flows in a typical cement plant is given in the figure below. The
major electrical energy consumption areas are mill drives, fans and conveying systems.

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2.3 Raw Material Quarry

Raw materials are extracted from earth through mining and quarrying. The raw materials are;
limestone, shale, silica sand and iron ore. The raw material is crushed to less than 25mm in its
size. Quarrying operation consists of the process of drilling, blasting, excavating, handling,
loading, hauling, crushing, screening, stack piling and storing.

Figure 2: drilled machine & drilled hole

2.3.1Loading & transport:

The blasted material is loaded in to dumpers with the help of excavators to transport lime stone
to the crusher.

Figure 3 loading the raw material & transporting raw material

2.4 Raw Material Crushing

Lime stone crushing & stacking Crusher is a new stone crusher machine that absorbs advanced
technologies at home and abroad. Dealing with the material with the side length 500mm, not
more than 350Mpa anti-pressure strength, hammer Crusher can be widely used in the primary
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and secondary crushing process. This impact pressure is also used in lime stone crushing.
Process of crushing the raw material and transferring the crushed raw material to stock pile.

2.4.1Dumping of raw material in to hopper:

This stage continues after transportation of raw materials from mining .The material loaded in
dumper at mining is dumped in the crusher hopper.

Figure 4: dumping into the hopper & crusher hopper

The dumped raw material in the hopper moves in to crusher. Contains apron feeder, hammer
crusher, belt conveyors. Apron feeder is used for horizontal, inclined transportation of bulk
materials those comes from quarry in to crusher roller inlet. Transportation of bulk materials
those come from quarry in to crusher roller inlet. The apron feeder is driven through drive shaft
by two frequency controlled geared motors which are mounted directly on the shaft.

2.4.2 Crushing of raw material with hammer crusher:

Crushing: - is a process in which of breaking down of materials into very small pieces that are
coming from quarry.

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Figure 5: primary crusher

2.4.3 Transfer of crushed raw material to stock pile:

After the raw material is crushed to required size (25mm) in a crusher. The small size raw
material is transferred to stock pile with the help of belt conveyors.

2.5 Raw material storage hall

Material storage is a big material storing house which is used to store raw material which
comes from quarry. Storage is used to store the raw materials by the helping of stacker and
reclaimed systems. After crushing the raw material for homogenization of the composition and
for store it goes to the storage. The storage also very important for protected the raw material
from the rain fall and high wind.

The raw material storage contains six raw materials. These are:

 Limestone

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 Shale
 Silica sand
 Iron ore
 Gypsum
 Pozollana

Here within the raw material storage there are huge instruments that are used to perform the
activities within the store. These are:

 One stacker
 Two reclaimers
 Limestone reclaimer and
 Shale reclaimer

2.5.1Stacker& Reclaimer Systems

2.5.1.1 Stacker
Stacker machine is used for filling the piles with the respective raw material by moving from
pile one to pile seven. The stacker machine operates automatically while filling the piles &
works with the chain (cable) drum and the sensor which senses how much proximate that sensor
is called ultrasonic sensor.

The main application of stacker is:

 Filling the raw material storage

 Homogenizing the raw materials between the low & high quality

Figure 6: stacker

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2.5.1.2 Reclaimer
A very huge machine called reclaimer which are two in number are used to fide the belt
conveyor which is heading to the proportioning unit. Thus one reclaimer is used for
two piles consisting of limestone each and the other reclaimer for two piles consisting of
shale each. From the material storage only limestone and shale are transported belt
conveyor to the proportioning unit while sandstone and iron ore are transported in other
way to the proportioning unit.

The main applications of reclaimer are:

 Homogenizing the raw materials
 Transporting
 Filling the belt conveyor

Figure 7: reclaimer
Two types of arrangement of the cement raw material in the raw material hall

A, Chevron method lime stone and shall are arranged in this method because this two raw
materials needs to homogenized by reclaimer the raw materials contains two or more than
two minerals.

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Figure 2:6 Chevron methods

B, Cone method iron ore, silica sand, additives are arranged in this method by stacker. The
Cone Shape method is often used in cases where homogenization is not necessary.

Fig
ure 2:7Cone method

2.6 Proportioning unit

Here in the proportioning unite there are four bins. These bins are named as:

 Limestone bin
 Shale bin
 Silica sand bin
 Iron ore bin

In proportioning unit there are four variable speed motors one for each raw material. The
variable speed motor helps to adjust the speed of the motor to the required level.
Adjusting the required speed level means controlling the amount raw material flowing
through the conveyor which rotates by the variable speed motor. Thus limestone is
required in very large amount so the variable speed motor is set to a very fast speed. The
shale is also required in some amount so the variable speed motor has to be set to
required speed corresponding to required amount .The same is true for the iron ore and
sandstone. The proportioning percentage can be changed from time to time as required.

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Figure 8: Proportioning unit

2.7 Raw mill

In this portion the four type of raw materials will mixed together and grind here. The mill for
dry grinding of raw materials is of the semi-air swept type equipped with a drying chamber
and one grinding component. The material to be ground passes through the drying chamber
before entering the grinding component. The lifters fitted in the drying chamber ensure that
the raw material is cascaded through the flow of hot air during mill rotation. Raw mill is one
of the huge machineries and the largest power consuming machine next to cement mill. The
purpose of raw mill is to produce homogeneous raw meal which can give good burning
condition in kiln by drying and grinding the raw material.

Figure 9: raw mill

The milling system is a ball type with a different ball size in which the ball size
decreases with increasing the fineness of the raw material.

The ball type raw mill decrease size from the entrance thought to the out let of raw material or
the end position. The balls are:

 90 mm ball - in the inlet of the raw mill.

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 60 mm ball - inside the mill.

 30 mm ball- inside the mill.
 20 mm ball – at the out let.

The grinding process in the ball mill is performed by means of impact and
attrition. The balls which fall down hit material particle and the impact force will
divide it in two more pieces. Another grinding force is attrition, i.e friction forces
material particle are sheared between lifted up by the turning of the mill and balls
moving down wards( not falling). The fineness of the raw material should be fine
enough to allow better burn ability in the kiln. The row meal fineness is normally
measured as micro sieve.

2.8 Sepax separator

Sepax separator is used in a closed circuit grinding plant for separation of the fines from the
coarse material which is received from the mill. Subsequently, the fine fraction is separated in a
filter as a finished product and the coarse fraction is recycled to the mill inlet for further grinding
.the prime function of the separator is to improve the grinding efficiency of the grinding plan, but
also to widen the scope for adjustment and control of the fineness of the finished product.

2.9 Coal plant

This is another ordinarily organized plant. The raw material coal comes from west Ethiopia
jimaa and South Africa. The coal plant has its own instruments starting from crusher up to the
last coal mill. Like raw material storage it has a coal storage we do have: Stacker and Reclaimer.
The raw mill for coal plant is vertical not horizontal like that of cement plant. After we get the
last stage of this plant the powder fill in to the pre heater and rotary kiln for the purpose of firing
raw material.

2.10 CFS (controlled flow storage silo)

The CF-silo is a continuous operation homogenizing and storage silo for feeding and extraction
of raw meal for cement production. The silo proper is built as a cylindrical structure which has
an elevated bottom is made of concrete and is provided with a plan roof for large diameter
smaller than 22.4m and with conical roof for large diameter. The material is continuously

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supplied to the silo through an inlet located in the centre of the silo top. The equipment
comprises the man hole, over and under pressure valve and vivo pilot as safe guard against over
loading. When the raw mill is suddenly stop CF-silo helps to work the kiln by sacking from CF-
silo.

Figure 10: raw meal silo

The Main Important OF CF-Silo Are The Following.

 High reliable extraction.

 Low air and specific power consumption.

 It is used as storage of raw mix and for homogenization and raw mix. It helps to
work the kiln when the raw mill is stopped suddenly.

2.11PYRO PROCESSING
IS the main part of kiln system and that includes:

 preheater,
 kiln shell and
 Clinker cooler.

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Figure 11: pyro processing

2.11.1 Preheater
Pre heater is the arrangement of five cyclones on line 1 and 6 cyclone on line 2 in messebo
cement plant used to heat the material before it enters the calciner burner. The proper function of
the pre heater cyclone is to the reduced energy consumption by pre heater raw material. The heat
source for pre heater is the hot gas that comes from the calciner and kiln burners. In A pre heater
cyclone is a stationary entity and apart from the material flag-gates involves no moving of
mechanical parts. As compared to the other parts of the plant, there are only limited points to be
considered in terms of mechanical maintenance. And also compare to two lines line 1 more heat
release to the surrounding and more dust material release by chimney to the surrounding than
line 2.No of pre heater cyclone stage determine the heat efficiency .it also depend on the
intended use of heat of exit gas leaving the system. Increase cyclone stage.

 Decrease fuel consumption of the system

 Decrease specific gas consumption
 Increase specific power of pre heater fun
 Decrease exhausted heat leaving to the system
 Decrease the dust of raw material out the system
For this reason increase no of pre heater cyclone more effective as a result line2 more effective
than line 1.

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In the cyclone pre heater gases and materials flow in opposite direction. That means hot gases
from kiln flows from bottom to top and material flow down ward in to kiln. Then the material
meets the gases a heat exchanger takes place. Due to that the material is heated and entering the
kiln.

2.11.2 Kiln
Kiln is a long horizontal rotating cylinder used for the production of clinker. The kiln burning
system is composed of a∅ 3.75×57m with inline calciner and a single five stage preheater. In
MBMP P.L.C the kiln is used to burn the raw materials by a coal to produce clinker. The kiln
feed enters the system at the top of the pre-heater and fall until the lower end of kiln. The heat
exchange occurs during this process when the hot gases from the kiln end rises up to the top of
the pre-heater. The rotary kiln is normally provided with bricks in the burning zone. Raw
material comes from calciner enter to kiln inlet and burn by 1400 degree Celsius with the
energy source of coal. Kiln is the most expensive than the other components of cement plant
cause 60% of energy consume at this and the kiln does not stop without maintenance problem if
shut down the kiln to start up more energy consume.

Figure 12: kiln

The main components of kiln like live-ring, supporting rollers, journal bearing are more
expensive than the shell. The kiln capacity of Messebo cement factory for line-1 is 2000t/d and
3000 t/d produce line 2.

The Main Components of Kiln Are:

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 Base plat: is a welded steel structure partly grouted in the concrete foundation.
 Journal bearing: it is important to the alignment and axial balance of the kiln. Its
position is on the base plate. And that is oil lubricated and water cooled.
 Supporting rollers: This roller consists of a roller with a through going shaft and placed
on the base plate. The general degrees of contact between live ring and supporting rollers
have been turned through 300 from the kiln center line.
 Live Ring: is used to support and stiffen the kiln tube and to guide the kiln tube in the
axial direction. The live ring is mounted loosely on the kiln tube on supporting blocks
bolted to the kiln tube. The supporting blocks are provided with located rings which limit
the axial moment of the living ring.

2.12 Cooler
It cools the material that comes from kiln which is highly heated. The cooling system is takes
place by air. Cooler is used to cool the high temperature clinker formed from kiln. the cooler
operates with a cross current principle, in which clinker falls from the kiln through the kiln
hood in the cooler inlet and forms a clinker bed on the grate. A high concentration of air blasts
across the clinker, and this spreads the clinker across the grates width. The clinker is quenched
and the possibility of the clinker forming in to an adhesive mass is avoided. The clinker is in
fact almost in a liquid state and could easily bind to gather in to unworkable lump. After the
clinker is cool the clinker is crushed.

ELECTRO STATIC PERCIPATER.

Use electrostatic forces to separate the dust from the exhaust gas. By means of discharge
electrodes, the dust particles are negatively charged and can be separated on corresponding
collecting electrodes. The particles are then discharged from the collecting electrodes to dust
hoppers by electrode rapping. In contrast to bag filters, the design of electrostatic precipitators
allows the separate collection of coarse and fine particles. ESPs are susceptible to process
changes such as CO Peks.The dedusting efficiency can be increased by making use of more
than one electric “field” operating in series. Not all the kiln dust can be returned to the system.
Whereas an electrostatic precipitator allows the high alkali part of the dust to be separated and
rejected, such a separation cannot be achieved with a bag filter and all the dust would have to
be rejected.in mosobo cement factory line 1 use this type of filter.

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Figure 13: cooler

2.13 Clinker silo

The clinker silo receives a raw material from a coal lax cooler through a pan conveyor system.
The clinker-silo is a continuous operation homogenizing and storage silo for feeding and
extraction of clinker for cement production. The silo is built properly as a cylindrical structure
which is made of concrete and is provided with a plan roof for large diameter. The material is
continuously supplied to the clinker silo though an inlet located in the center of the clinker silo
top. A clinker storage silo with capacity of 15000tons and an open yard with a capacity of 20000
tons are built in the plant. Under the clinker silo, the rod gate and the motorized discharging gate
are installed. The clinker discharged by the equipment is fed to different belt conveyor
correspondingly, then carried to the clinker feed bin in cement grinding plant by means of belt
conveyer.

2.14 Cement mill

The final manufacture stage at the cement plant is the grinding of cement from kiln, mixed
with approximate 4-5%gepsum and other possible additives, in to the final product cement. A
closed circuit grinding is applied. The main equipment consists of a 4.6 ×12m double
compartment tube mill and sepax separator. This mill at this time produces four types of
cement namely ordinary Portland cement (opc), pozzolana Portland cement (ppc), Portland
Limestone cement (plc) and low heat Portland cement (lhpc).

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The quality of final cement is dependent on the operational mode and parameters of the cement
grinding plant. Then the cement grinding plant is adequately designed and properly operated. It
is a two compartment mill separated by a double diaphragm .These two cement grinding
compartments are coarse grinding compartment and fine grinding compartment. Cement
grinding compartment with 90-60mm balls is coarse grinding compartment and a fine-grinding
compartment with 25-10mm balls or clypeus. The fine-grinding compartment can have a
classifying lining with dam rings, or dragged linins with doula rings. The difference between
raw mill and cement mill are;

Raw Mill Cement Mill

Drive system Pinion girth gear Symmetric gear

Compartments Drying and grinding Coarse and fine grinding

compartment
Table2.3: difference between raw mill and cement mill

From the cement grinding section the cement will be transported to the storage silo by means of
bucket elevators & air slides.

2.15 Cement storage

 Two ∅ 16m concrete silos are setup as cement storage facilities; each of them has
a storage capacity of 10,000ton.
 Air ducts are erected on the bottom of the silo for aeration of the cement
fluidization. The air is supplied to these ducts by root blowers.
 On the bottom of each cement silo a discharging unit of manual gate and a
pneumatic flow control gate is installed. The discharge from these gates is
transported to the cement packing system via air slides and bucket elevator.
Connecting with the discharging units, there is bulk loader for both silos installed
for loading the bulk cement to the Lorries.
 The cement flow rate to the loader can be controlled by a flow control gate,
which is mounted beside the discharging unit,

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2.16 Packing
Packing is the final stage of manufacturing cement. The produced cement will be packed into a
bag container of 50 KG capacity which comes from flexible packaging company P.L.C. The
packing line of products in powder form is equipped with different elements/machines.

The principal elements of the packing line are;

 Vibrating screen
 Feed hopper
 Rotary feeder
 Packing machine
 Discharge belt

The flow of material rises from the bucket elevator to reach the vibrating screen, where is
screened, to be settled in the storage hopper. The former is equipped with control systems
(called sensors) placed inside the hopper. These sensors control the extraction system and keep
the level as the steady as possible.

Then the flow of materials passes through the rotary vane feeder equipped with alternate gear
to adjust the level of materials in the packet hopper. The sensor, by which the bag packer is
equipped, serves the purpose of the checking the rotary vane feeder in order to keep the level as
steady as possible. The flow of materials is in then directed to the spouts; most part of it is
packed in the bag, whereas a very small of scraps, in the form of dust, over flows.

The dust is sucked up and collected, by means of a sucking chute, in the lower hopper. The
reject is then separated: the dust is gathered by screw conveyors and led back into the
conveying cycle.

The packing bag cement is sent out and guided to the bag cleaner and bag cutter (for those less
than50kg) by means of belt conveyor. The cleaned bags are carried by a roller conveyor and a
belt conveyor to truck loaders conveyor, and then loader or trucks. The weight tolerance of
bagged cement is guaranteed by the automatic control system. In cement manufacturing from
its raw material there are a lot of processes starting from quarry up to packing.

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Figure 14: packing & transportation

Figure 15: process flow diagram of messebo cement factory

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Chapter three

3 OVERALL INTERNSHIP EXPERIENCES

3.1 The section we have been working on
We have been working in the maintenance section called CRM. In a different advisors
assigned by the student training department. In this section the main function is to
maintain the whole process of the company if some damage occurs or preventing
damages from occurring since they have preventive maintenance schedule. Then after
some time our company advisor told us to work under design section since our project is
start.

3.2 The work task we have been executing

The work task we have been executing is maintaining damaged parts and learning the
different processes in the company in terms of their installation, mechanism and
adjustment of the machines. But especially in the ESP part in line-1 since our project is
based on reducing the emission of dust to the environment. Emission of dust and other
gases cause different problems in the community around the factory, in the city, in our
country and also in the whole world.so the strategy is to reduce the emission to create
better living environment for this generation and for future.

3.3 Procedures and methods

The engineering methods we have been considered to perform our task are;
Direct observation and attending in the whole processes.
Finding the problems faced in the line.
Selecting the main problems to be researched.
Showing the title of the project to my advisor and deal about with him.
Collect data to solve the problem.
Finding the problem and Discussing with my adviser to come up with the best solution.

3.4 The Challenges and problems we have been facing.

 In our four month internship we have facing the following problems:

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 The Company’s environment is disturbed by dust, noise and high temperature. Due to
those reasons we couldn't adjust our selves to the environment noise and high
temperature because it makes us feel tired so soon every day.

 We had only safety clothes no safety shoes, helmet or glasses and noise protectors so it
was hard to work on different machines because safety comes first.

 When our advisors are busy there is no one who could show us what to do so we return
without working anything.

 During the time of collecting data's we asked the same question for different workers
under the same occupation and we get different answers .In this case we couldn't select
and trust the right information.

 The Company have no any computer lab or Wi-Fi. Due to this reason we couldn’t get
information from internet unless we go out and use internet service to analyze our project
soon.

3.5 Solutions’ in order to overcome these challenge

 In order to solve these challenges we took the following measurements:

 In order to protect ourselves from dust we used the safety clothes. As of shoes, helmet
and eye glass we tried to fulfill them ourselves as much as we can to overcome the
dangers.

 When our advisors are busy instead of going to our home we try to study on the
documentation room.

 When we collect data we took the most repeated answer by different persons of the
same occupation and also we took assumption based on the answers we got.

3.6 THE OVERALL BENEFITS FROM THE INTERNSHIP PROGRAM

The four months internship practice was very good in terms of developing strength of real time
engineering problem solving and gaining working knowledge. It also guides us to decide our
future job in which ways and companies. The benefits which we got from the internship work are
listed as follows:-

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3.6.1 Practical skills

The benefits we gain from the internship in terms of practical skills in this company by the senior
engineers are not only theoretical knowledge but also we should adapt practical skills. Like how
to use engineering tools to the required function and how to increase their life time in order to be
useful for the next function. Also how to follow work instructions and to execute them
accordingly. The practical skills are not exactly like professionals but we have gained a better
experienced practical skill.

3.6.2 Theoretical knowledge

The benefits we gain from the internship in terms of theoretical skills takes a great roll In terms
of upgrading our theoretical knowledge. It helps us gain more theoretical knowledge related to
the real world work life that we didn’t get it from school. And also helps us to know how
theoretical knowledge is cooperated with other many professions and made us to think and
process in multi-dimensional ways.

3.6.3 Team playing skills

The benefits we gain from the internship in terms of team playing skills can be seen as a core
point in our brains “team spirit”. In the practical world cooperating, sharing what you know and
asking what you don’t know and helping to each other with your work mate leads to better
result.so this is what it taught us to do. Now we are in the best perception of law of association
and team work.

3.6.4 Leadership skills

The leadership skill which we developed from observing the senior engineers, foremen’s,
supervisors, site Engineers and each section of employers could be seen as:

 Ability to inspire and motivate team members to do their best.

 Listening the ideas and problems of operators and solving their problem.
 The ability to solve problems by focusing 100% on the solution.
 Respecting team member’s differences and needs.
 As a leader to have clear and defined goals, missions and visions.
 As a leader to be a model at all times.

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3.6.5 Work ethics

 The benefit of the internship program was interesting in the development of strong ethical
work since work ethics is vital to a company achieving its goals.so every employee must
have a good work ethic to keep the company functioning at its peak. We gain a lot of
benefits from the factory regarding of work ethics like:
 To perform service only in our area of competence.

 To be punctual means to be on time at work and leave work by the right time.

 To be responsible in analyzing and interpreting gathering of data.

 To be disciplined means to stay focused on our goals and to be determined to complete

our assignment.

 To work as a team or group to meet a company’s objectives.

 In addition to this I practiced skill of being loyal and honest when doing professional
judgments on issues of Cost vs. benefit and analysis Safety.

3.6.6 Entrepreneurship
The benefits we gain from the internship in terms of entrepreneurship is the willingness to take
risks and develop, organize and manage a business venture in a competitive global marketplace
that is constantly evolving. And also the internship program contributes for us a lot on the
entrepreneurial way of thinking and skills. To mention some:

 It helps us to understand the business concept.

3.6.7 Interpersonal skills

our interpersonal skill also developed with those of site engineers as well as technicians specially
on the CRM area through communication based on scientific idea and also we have developed
how to control the feeling that emerge in difficult situations and respond appropriately; instead of
being over whelmed by emotion.

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Conclusion
Actually, this internship program is provided to introduce and to give knowledge on how
the professional life looks like, and to make a bridge that links the student life with the
professional life, in addition to observe and fill the gap between the theoretical and practical
knowledge. I got practical work experiences and benefits at messebo cement factory. In
Generally my theoretical knowledge got strengthen by those practical techniques participated on
factory It supports me in moving toward my career goals by combining what I had learned from
school, practical and internship work experience; it thus explained the necessity of every student
to undergo this process. I can say that the internship practice was so interesting and effective
linkages to meet the student’s theoretical knowledge with practical knowledge and with real
world working principle.

Recommendation
During my internship program I observe so many problems in the company. If these problems
are solved or minimized, the company can get many additional profits like increasing of cement
quality, decreasing human power, decreasing of number of trucks and preventing of
environmental pollution. Beside this makes a comfortable situation for the company employs to
do their work tasks with responsibility. Then the company should solve or minimize the
following problems.

Therefore the company should work on

 construct big store to protect materials from dust, rain and sun
 Give full maintenance for the machine before it stop working
 Provide full cooperation to the internship students when they are in practice
So the responsible body shall give attention for all of the above listed recommendations.

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