DIRE DAWA UNIVERSITY

INSTITUTE OF TECHNOLOGY

School of mechanical and industrial engineering

Department of mechanical engineering

Host Company: Shemu PLC

Final Internship Report and project

Prepared by:

Name ID Numb.

1. Eskinder derebe …….………………………….....1206007

2. Nebil wehib ……………………………………….1204194

Advisor: Getasew Guade

Date of submission :
 DECLARATION
We hereby declare that this work entitled Internship Report at Shemu PLC was prepared by us
according to the standards set by Dire dawa university Institute of Technology, about our internship
experience in Shemu PLC. It has been approved by our advisor Mr Getasew Guade We solemnly
vow to have used our own ways for writing and composing this report rather than copying previous
works from other students. As the student academic advisor, I clarify that the internship prepared by
the student is original work and compiled according to the guide line provided by the institute office
as far as our knowledge is concerned.

Name of students Date Signature

1. ……………………… ……………………. …………………...

2. ……………………… ………………………. ……………………
3. ……………………… ………………………. ……………………

Approved by:

Authenticate

……………………… …………… ………………..

Name of the academic Advisor Date Signature
 ACKNOWLEDGEMENT

First of all, we would like to thanks our GOD that help as by everything we did in our duration in the
internship that made all things possible.Then our university, especially for school of mechanical
engineering department staff and also we would like to thank for our advisor Mr. Getasew G. , who
inform us to do our report using the guide line a great thanks for university industrial linkage that
makes a great opportunity situation to get this internship period for us and the company that we stay
in it for the support that they do for us to finish this internship period successful with practical skill
and knowledge, as well as they make us to walk one step in engineering knowledge and in practical
skill. we want to address our deep thank to our company supervisor Mr.Bereket, of SHEMU SOAP
AND DETEGENT COMPANY for his friendly treatment and motivate us to do our job correctly and
help us to finish this internship period. Also we need to give our thanks to whole workers of SHEMU
SOAP AND DETERGENT COMPANY plc. For their positive attitude towards us and helping us in
showing everything that we don’t know happily and in their parental treating.
EXECUTIVE SUMMARY

The major objective of internship course is to reinforce and enhance the theoretical knowledge gained
in the class room with practical job experiences so students have an opportunity to both theoretical
and practical knowledge applied and gather knowledge about the tools, principles and practices. A
real world is suitable place to see everything in practice. Generally, internship is the best opportunity
to know who I am in order to test my own patience and skill because we have already found out how
the life looks like in the future. From this internship we have seen the work ethics and related things
like how to communicate with others and the interaction between leaders and workers, also team
work. In other word it’s the best place to improve practical skill, theoretical skill, interpersonal
communication skill and others. In this report we have done a lot of things, like departmental
information, detailed information about bar shop plants, over all structure of the company, the work
flow in the company, the tool used, the machines found in the factory.
Table of Contents page

ACKNOWLEDGEMENT.........................................................................................................................................ii
EXECUTIVE SUMMARY.......................................................................................................................................iii
CHAPTER ONE........................................................................................................................................................ 1
INTERNSHIP REPORT...........................................................................................................................................1
1.1 Background of Shemu PLC.............................................................................................................................1
1.1.1 History........................................................................................................................................................1
1.1.2 Products and Services of the company....................................................................................................4
1.1.3 Main Users Of End Products....................................................................................................................6
1.1.4 Overall Organization and Work Flow.....................................................................................................6
1.2 Overall Internship Experience........................................................................................................................9
1.2.1 objective ....................................................................................................................................................9
1.2.2 Activities of the company we have been working....................................................................................9
1.3. Bar Soap Production plant Machine...........................................................................................................24
1.4 Liquid Detergent Soap Plant ......................................................................................................................27
1.5 Bottle Production .........................................................................................................................................29
1.6 Overall benefits of the internship..................................................................................................................32
1.6.1 What we gained in terms of improving our practical skill...................................................................32
1.6.2 What we gained in terms of up grading our theoretical knowledge....................................................33
1.6.3 What we gained in terms of improving our interpersonal communication skill................................33
1.6.4 What we gained in terms of improving our team playing skills...........................................................33
1.6.5 What we gained in terms of improving our leadership skill.................................................................34
1.6.6 What we gained in terms of understanding about work ethics issues.................................................34
1.6.7 What we gained in terms of entrepreneurship skill..............................................................................35
CHAPTER TWO.....................................................................................................................................................36
PROJECT.................................................................................................................................................................36
2.1 Design Of Bucket Elevator............................................................................................................................36
2.1.1 bucket elevator.......................................................................................................................................36
2.1.2 how does bucket elevator work.............................................................................................................36
2.1.3 Types of bucket elevator ........................................................................................................................37
2.2 Problem statement and justification.............................................................................................................39
2.3 Objective of the project..................................................................................................................................39
2.3.1 General objective.....................................................................................................................................39
 2.3.2 specific objective ………………………………………………………………………………………………………………………………….39
2.4 Literature review............................................................................................................................................39
2.5 Methodology...................................................................................................................................................40
2.5.1 Methods....................................................................................................................................................40
2.5.2 Data Collection........................................................................................................................................40
2.5.3 Material selection....................................................................................................................................41
2.6 Design consideration and calculation...........................................................................................................41
2.6.1 Selection of size of elevator....................................................................................................................41
2.6.2 Selection of type of bucket elevator........................................................................................................41
2.6.3 Selection of Bucket..................................................................................................................................41
2.6.4 The selection of casing.............................................................................................................................43
2.6.5 SELECTION OF CHAIN AND BELT..................................................................................................45
2.7 Component Description.................................................................................................................................50
2.8 Conclusion......................................................................................................................................................52
2.9 Recommendation............................................................................................................................................53
Reference.................................................................................................................................................................. 54
 List of figures

Figure 1 : Some of Shemu PLC’s Brands........................................................................................5

Figure 2: Work Flow Inside Shemu PLC.......................................................................................8
Figure 3 : Caustic Dissolution Tank.............................................................................................12
Figure 4 : Saponification Tanks...................................................................................................15
Figure 5 : Cyclone....................................................................................................................... 16
Figure 6 : Block Diagram for Saponification Process Flow.........................................................17
Figure 7 : Saponification Process Flow Diagram.........................................................................18
Figure 8 : Cooling Tower.............................................................................................................19
Figure 9 : Water Pool...................................................................................................................20
Figure 10 : Oil and Caustic Solution Heat Exchangers................................................................21
Figure 11 :Inside Look of Water Softener...................................................................................22
Figure 12 : Boiler.........................................................................................................................23
Figure 13 : Simplified Saponification Flow Diagram..................................................................24
Figure 14 : Mixer Machine.......................................................................................................... 24
Figure 15 : Miller.........................................................................................................................25
Figure 16 : Conveyor................................................................................................................... 25
Figure 17 : Chiller machine ........................................................................................................ 26
Figure 18 : Plodder machine........................................................................................................26
Figure 19 : Mixer machine...........................................................................................................27
Figure 20 : Filling machine..........................................................................................................28
Figure 21 : Flow chart of liquid detergent ...................................................................................28
Figure 22 : Hot perform method machine………………………………………………………..29
Figure 23: cold performed method fully automated machine…………………………………...30
Figure 24 : Bottle production plant ………………………………………………………………30
Figure 25 : flow chart of blowing proccess……………………………………………………….30
Figure 26 : Extrusion blow molding………………………………………………………………31
Figure 27 : Proximity sensor ……………………………………………………………………...32
Figure 28 : diagram of bucket elevator…………………………………………………………….37
Figure 29 : Types of bucket elevator……………………………………………………………….38
Figure 30: bucket……………………………………………………………………………….50
Figure 31: Pulley………………………………………………………………………………..51
Figure 32: Ball bearing………………………………………………………………………….51
Figure 33: Belt…………………………………………………………………………………..52
Figure 34: Electric Motor………………………………………………………………………..52

List of table

Page

Table 1: Products of Shemu PLC....................................................................................................5

Table 2: recommendation to select size of bucket (IS:6833-1973)...............................................42

Table 3: recommended spacing and sprocket diameter for continuous type of bucket elevator...43

Table 4: recommended percentage bucket filling factor................................................................45

Table 5: Minimum number of plies based on projection of bucket...............................................48

Table 6: Allowances for pulley width...........................................................................................48

CHAPTER ONE
1. Introduction

1.1 Background of Shemu PLC

1.1.1 History
Every big company starts with a mastermind and a small idea which soon blooms to fruition with the
help of strong leaders and diligent employees. When it comes to Shemu PLC, the mastermind is Mr.
Kahssey Wolday and hundreds of his workmates. For over a decade Shemu PLC has dominated sales
around Dire Dawa with its products shelved at each shop and market around town. The company was
also successful in being one of the competitive soap and detergent company in Ethiopia, and it is no
surprise to walk into a shop in Addis Ababa or Adama and see the brand.

The foundation for this whole success was laid in 2009 (2000 EC). It was difficult to think at that
time to build a company that manufactures soap from its raw materials, because caustic soda and fatty
oils, the two raw materials for saponification were not available in Ethiopia. Most investors imported
the soap noodles from abroad and only molded soaps. But Mr. Kahsay thought it was cost effective if
someone imported the raw materials separately and install the plant for making soap noodles.

This idea soon became to be very profitable. The soap noodles were sold for other companies in
Ethiopia. The company then expanded and started to mold its own soap. Some years after that liquid
detergent plant, edible oil plant and others opened. Now this company holds an area of around 13000
m2 with almost 9 manufacturing and functioning plants.

The company is estimated to start with a 4.5 million capitals and 75 employees working on one plant.
It has come a long way from its origins. Today, hundreds of workers are hired; opening job
opportunities for many young job applicants.

At this time, Shemu PLC is one of the members of SHEMU GROUP, a conglomerate which includes
many companies including Asveza PLC. Current location is around Dire Dawa Industry Zone.

Company’s core values are:

1. Innovative
2. Leadership
3. Moral Responsibility
4. Quality

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 5. Excellence
6. Partnership
VISION: to serve and provide quality products, innovative solutions to our society.

Mission: to be a leading soap producer and exporter that quickly responds to customer demand with
the capacity to meet and exceed their expectation with growing market share by investing on peoples,
machineries, technologies, system and Procedures that will increase productivity and improve quality.

As of the year 2020, the company has opened work opportunities for over 450 employees. New
technologies including Database technology and fingerprint are adopted by the company.

There are 9 plants inside the company. Some plants service is to provide raw materials, packages,
plastic bottles for consecutive plants. Others provide an end product which is sold directly under its
brand. The plants and brief explanation of their purpose is discussed below:

1. Saponification Plant
Main Product: Soap Noodles

Capacity: 60,000 tons/year (200 ton/day)

This plant is one of the oldest operating plants in the company. Raw materials are imported from
Malaysia, Indonesia and China. Then they are all reacted in a process called Saponification and the
product is cooled and made into noodles. These noodles are used as a raw material for Bar Soap Plant
nearby and also sold for other bar soap manufacturers.

2. Bar Soap Plant 1

Main Product: Bar Soap

Capacity: 24 ton/day

The soap noodles from the saponification plant are further blended with many other chemicals. These
are colors, perfumes, binders, water and essential oils. Then the blended chemical is molded in
different size and shape. The product from Bar Soap plants is readily usable soap.

3. Bar Soap Plant 2

Main Product: Bar Soap

Capacity: 120 ton/day

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This is the same plant with advanced capacity from the former. Due to increasing demand in the
market and increasing types of products, a second plant with better capacity was bought.

4. Liquid Detergent Production Plant

Main Product: Liquid Detergent

Capacity: 48 ton/day

The business of soaps is usually followed by a detergent. These two products are basically used for
cleaning purposes, although their production is completely different. The raw materials for liquid
detergent include STTP, SLES, salt and water. All of the raw materials are imported abroad except
water.

5. Plastic Bottle Production Plant

Main Product: HDPE Plastic Bottle

Capacity: 60,000 bottle/ day

The company also imports High Density Polyethylene (HDPE) which is melted and molded into
different shape and color. These bottles are needed in Liquid Detergents and Oil products.

6. Palm Oil Refinery Plant

Main Product: Edible Palm Food Oil

Capacity: 100 ton/day

Same as other plants raw materials imported abroad are refined and the product is edible food oil.
This oil is only refined in the company, an already extracted and purified oil is imported.

7. Cosmetics Production Plant

Main Product: Shampoo, Conditioner, Hair Gel, Lotion, Lip Gel, Fabric Softener, Hand Sterilizer

Capacity: 5 ton/day

This production plant produces hair and skin care product. This is a field which the company is trying
to expand into. After a while working at Dire Dawa, this plant was moved to Addis Ababa.

8. Printing and Labeling Plant :This is one of the plants which only work alongside with other
production units. The digital printing of the labels which are plastered on the plastic bottles
and also the labels in which the bar soaps are sold are all manufactured inside the company.

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 9. Green & Low Energy Consumption Plant
This includes a collection of solar panels, cooling towers, 1000 KW electrical generator &
transformer. Steam boiler fuel consumption before the solar panels was 33,000,000/year and after it
was 6,600,000/y.

1.1.2 Products and Services of the company

When it comes to products, Shemu PLC has numerous brands. From soap noodles to laundry soaps,
from hand wash to liquid detergent, and few other new products on their way into the market, the
company provides different products.

According to the data from Ethiopian Conformity Assessment Enterprise (ECAE), an enterprise
which provides conformity assessment service according to international practices and gives a
certificate for quality products, there are 13 products which have been tested and given a certificate
for conformation. These products are tabulated with their brand name, certificate number and date
issue below:

Apart from below mentioned products, the company also provides Packed Soap Noodles and Packed
Edible Oil. Recently, the company has also agreed with UNHCR to make a 250 gm soap for people
leaving under immigration camps and temporary location for displacement. This soap is not for sale.

No. Item Certificate No. Date Issued

Type Brand
1 Laundry Soap Peacock 310014 09/05/06
2 Penal 310015 09/05/06
3 Medy 310016 09/05/06
4 Polar 310017 09/05/06
5 Bear 310018 09/05/06
6 Shemu White 310019 09/05/06
7 Shemu Pink 310097 20/03/08
8 Lula 310116 15/10/08
9 So White 310115 15/10/08
10 Liquid Detergent Liquid Dish Wash
11 Shemu 110106 12/08/08
Liquid detergent

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 12 Hand Wash 310102 15/12/07
13 Toilet Soap Avena 310098 20/03/08

TABLE 1: PRODUCTS OF SHEMU PLC

FIGURE 1 : S OME OF SHEMU PLC’S BRANDS

The business objective of the SHEMU Soap and detergent industry as stated in the memorandum of
association includes:

 To be leading producer of quality liquid detergent

 Production of laundry and bar soap detergent
 Manufacturing of packing material for liquid detergent and laundry, to keep the quality and
moisture.
 Production of basic raw material for the production of soap and detergent.
 To be the best manufacturer and exporter of detergent and soap.
 Engaging in other import and export activity wholesale and retail service and other.

Engineering service

 Processing and delivering the same information to users

 Prepare and disseminate project profile
 Preparation of feasibility study
 Follows up and facilitate projects, implementation and address associated
 Provides support on selection manufacturing technologies

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  Provides support on design development and plan
 Provides support on plant election
 Provision of support on manufacturing commissioning
Marketing service
 Identified important products and ensure their sustainability by manufacturing locally
 Establishment of modern management and marketing system
 To provide product promotion and market linkage supports
 Searching international markets for products of sub sector
 Establishment of marketing system which encourages the local production

1.1.3 Main Users Of End Products

Shemu’s main products as stated before are soaps, detergents and edible oil. These products are
known to be day to day household necessities. Hence, the customers are mostly individuals and some
organizations like hotels, hospitals et cetera. These individuals usually purchase the product from a
nearby shop or supermarket. To reach a wider number of customers all around Ethiopia, Shemu
works with agents that distribute products. From a 2020 data from the company, Mr. Mesfin Tesfaye
looks for sales in East Hararge region, Mr. Taye Tefera looks for sales in Addis Ababa region and
Mr. Biruk serves as an agent in Jijiga region. The company also exports goods to Djibouti and
Somalia. Moreover, working alongside UNHCR, it produces soaps for different displaced people and
people in exodus.

1.1.4 Overall Organization and Work Flow

Organizational chart is visual media of communication. As a matter of fact organizational structure
is a main function of the management planning. The chart represents the various departments
and their intern-relationship between them. The objective of preparing an organization Chart is to
ensure that all the signification positions and departments have been covered in the organization
structure. It is a visual representation of the activities. It facilitates to understand at different positions,
function, lines of authorizes and responsibility. A master organization chart reflects the pattern of
network of the entire organization showing the primary fundamental details. It is also possible to
prepare separate auxiliary charts for each department.

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1.1.5 Task of Each Division

a) General Manager:-Control, follow up and lead all over the company. Apply yearly plan and
occupational program, check if the plan is applied or not and follow up all over working
process of the company.
b) Legal Services:-Give advice and legal suggestion on legal issue and question; give description
and explanation about legal proclamation.
c) Production Manager:- Controls all production process, supplies raw material, identifies
product type and formulate plans to increase products.
d) Distribution & Sales Manager: - gather marketing information, searches market places,
purchase raw materials and inputs applies customer attracting activities and product advertising
activities.
e) Technical Manager: - follow up the activities of processing machine, solve the problems
which are occurred in the work machines, maintains damaged machines and gives technical
training for workers etc.
f) Quality Control: - coordinates, follow up and control the quality of products.

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 Legal Advisor Executive Secretary GM Assistant

General Manager

Manufacturing
Senior Finance Senior Distribution & Senior HR & GS
Manager
Manager Sales Manager Manager

Assistant Finance Assistant HR & GS

Manager Manager

Production
Manager

Technical
Manager
AA Logistics Officer Sales Supervisor
Officer

QA/QC Logistics & Officer Logistics &

Manager Transport Officer

Senior Warehouse Special Accounts

Officer Sales Coordinator

FIGURE 2: WORK FLOW INSIDE SHEMU PLC

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1.2 Overall Internship Experience

1.2.1 Objectives
1.2.1.1 General Objective
The objective of the internship course is to facilitate reflection on experiences obtained in the
internship and to enhance understanding of academic materials by application in the internship
setting. Internships will provide students the opportunity to test their interest in a particular career
before permanent commitments are made.
1.2.1.2 Specific objective
Internship students will develop skills and techniques directly applicable theoretical to their practical
work. Internships will provide students the opportunity to develop attitudes conducive to effective
Interpersonal relationships. Internships will provide students with an in-depth knowledge of the
formal functional activities of a participating organization. Internship programs will enhance
advancement possibilities of graduates. In general, an Internship is thought of as a program which
"bridges the gap" between the academic environment and a future work environment. Many
employers prefer students who have previous work experience and the Internship provides that.
Students that participate in an Internship are generally more confident and more qualified when
seeking future employment.
1.2.2 Activities of the company we have been working
Shemu PLC has 4 main sections:

1. Saponification Plant Section

2. Bar Soap Plant Section
3. Detergent Plant Section
4. Oil Plant Section
Previously it was mentioned that there are 9 specialized plants in the company. These plants are
grouped into sections and each section holds at least 1 functioning plant. For example, the Oil Plant
section only has the Palm Oil Refinery Plant. The Detergent Plant section on the other hand combines
Printing and Labeling Plant as well as Liquid Detergent Production Plant.

After we started Our internship, we were assigned to the SAPONIFICATION PLANT.

This plant is one of functioning plants the oldest in the company. It started working a little while after
the company opened. It is also the backbone of the company and the most profitable of all the other
sections.

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Saponification Plant

Saponification process can be simplified as neutralizing the acid on triglycerides with a proper basic
solution which is most likely alkaline hydroxide. Triglycerides themselves are derived from reaction
between glycerol and fatty acids. The following formula summarizes a saponification reaction:

A saponification plant is therefore an integrated system of reactors, coolers, boilers, melting

chambers, tubes, pumps and many more parts working together to perform the basic task of
saponification reaction.

Raw Materials

 METALLIC ALKALI - Caustic soda or sodium hydroxide flakes are used. These are imported
from China because they are not produced in Ethiopia. The use of caustic soda is advised since
they are cheaper and widely manufactured worldwide. The flakes are white solid pellet-like
substances that are transported in a 25KG sack. They are dissolved in water before they are
used in the process. Caution is needed when transporting the Caustic Soda as they are 99%
concentrated.
 TRIGLYCERIDES – commonly known as fats and oils. They are esters of glycerol and long
chain fatty acids. When a triglyceride reacts with a caustic soda, the product is soap and
glycerol. The only useful product is soap. Hence, the fats used must be distilled so that glycerol
will not be produced.
There is some choice of raw materials when it comes to Fats; the company usually uses RBD
(Refined Bleached Deodorized) Palm Stearin and DPFA (Distilled Palm Fatty Acid) imported

10
 from Indonesia and respectively. On some occasions the company also purchases PFAD
(Palm Fatty Acid Distillate), RBD Palm Oil and animal tallow.
 WATER – reactions work faster when reactants are in liquid form, this is because there is
more collision of particles in solutions. The caustic soda flakes which are in solid form are
dissolved in water and the concentrated solution is stored in tanks.
Process Flow and Working Theories

There are mainly 3 groups of system in the Saponification plant.

1. Saponification Process Flow: this includes the caustic dissolution tank, oil melting chambers,
soap preparation, soap storage tanks, the atomizer, vacuum dryer, cyclones, plodders and all
the tubes, pumps, gauges connected to the main process line.
2. Cooling System: the hot soap needs to be cooled in a vacuum dryer before it is scrubbed off
its walls. Heat is generated inside gears and other machine parts, therefore cooling water is
passed over to reduce the heat, saving these machines from developing extreme heat and
stop functioning or damage completely. Cooling system includes water pool, heat
exchangers, condensate collector and cooling tower.
3. Heating System: this system does the opposite of cooling. Processes like oil melting and
saponification need heat to function. Steam is used to provide this heat. Working alongside
this process are water softener and pre heaters. But the heart of heating system lies in the
boiler. It is the place where the water is boiled and the steam is extracted and pumped all
around the company where it is needed.
These 3 processes work side by side and none of them are fully functional on their own. Further
breakdown of each system is presented below in order of process flow with brief explanation and
flow diagrams.

Saponification Process Flow

As mentioned above, Saponification is the name of the special chemical reaction between metallic
hydroxides and fats. In a nutshell the process includes preparing the raw materials for reaction then
passing them in a homogenizer. Then the crude soap is dried with impurities removed from it. At the
end of the process the soap is shaped into noodles, packed and ready for sale.

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  Raw Material Transportation

Most of the raw materials and imported from different parts of the world. After arrival, it takes a great
deal of manpower to transport them into the plant. Manual labor workers are hired in many numbers
for this purpose. Caustic Soda comes with a 25KG sack. A batch of saponification uses 18 to 30 sacks
based on the fat used. These sacks are first loaded on forklifts which move them to the dissolution
tank. Due to the height of the tanks feed area, the forklift can’t reach the required position. Therefore,
other group of workers unloads the sack. The package is torn open and the flakes are charged into the
tank.

The fats also go through the same process. The only difference is that it takes more effort and care
when the fats package is torn. I strongly recommended using a conveyer which can reduce the use of
manpower and waste when the same job is done.

 Caustic Soda Dissolution

This is where the caustic soda flakes are diluted into solution with proper amount of water. The
concentration of solution which is needed differs according to the fats used. Recipes and proportions
for the compounds used will be given later on. The place where this process takes place is called
Caustic Soda Dissolution Tank. Here an operator first checks the amount of caustic soda flakes in the
tank. An easy way of doing that is by counting the number of torn packages. If the amount of flakes is
in a correct proportion, the operator then opens water pipeline. Since the gauges are manual, a person
should carefully monitor the amount of water flowing to the tank. As to how much water is used, it
differs from 1090 litters to 1500 litters again based on the recipe. When the amount of water required
is obtained, the operator closes the water flow. Once correct batch of water and caustic soda are
inside the tank, the dissolution is started. This process does not require heat. An average of 30
minutes time is taken until the flakes are completely dissolved in water. The stirrer is stopped and the
solution is moved to the next stage.

FIGURE 3 : CAUSTIC DISSOLUTION TANK

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  Caustic Soda Storage

Right below the dissolution tank lies another tank whose purpose is storing the dissolved solution.
Until the fats are melted and a batch of production starts, the,, solution is stored safe and sound.

 Fatty Acid Melting Chamber

Raw materials which are used by the company usually RBD Palm and DPFA are white chunk of fats.
In order to melt the fats, 2 big tanks with added steam are used. These are called the melting
chambers.

The process starts by introducing the required amount of fats into one of the tanks. The process takes
time as it takes 8-10 people. The packed fats are first unloaded then the package is torn open then
they are thrown into the tank. Due to the slippery nature of the fats, it is extremely dangerous to work
on those areas. Moreover, the fats usually get stuck on the opening of the tank, a common problem
and source of waste.

When finished the door of the tank is closed and the stirrer and steam inlet are opened. There are 2
steam inlets in the melting chamber. One is connected at the bottom, which form bubbles that rise to
the top and fasten the melting process. Other is connected to the top and provides additional heat. It
takes a total of 30-45 minutes for the oil to melt. An inspector checks the progress through the
inspection door and before the oil starts to change it color to dark brown, the stirrer and steam lines
are closed. The oil is ready for the saponification process.The use of the second tank is for conserving
time. Until the oil inside the 1 st melting chamber is used up, the 2 nd melting chamber is filled with fat
and melting process is begun. This reduces the time between productions. In other words maximizes
profit.

 Homogenizer

Once the fats are melted and the caustic soda is dissolved, the saponification process is ready to
begin. The raw materials are pumped by a Dosing Pump. After that they pass through a heat
exchanger which heats the mixture to a certain temperature.

Then 3 pipelines, containing dissolved caustic solution, melted fat and steam are joined into one. For
better controlling of what goes on at the pipe junction, there is an inspection glass. If only oil is
flowing through the glass, the process is stopped and the caustic line is examined. The same thing

13
happens if only the caustic soda line is working. If both compounds are flowing, the inspection glass
shows an immediate formation of liquid soap upon contact. The place right after the inspection glass
where the two solutions mix thoroughly is called homogenizer.

There are 2 pathways the process flows from here on, and it all depends whether the production is
continuous or batch.

A continuous process flow skips the saponification and soap storage tank. The soap that is produced
in the homogenizer goes directly to the atomizer. From then it follows the subsequent drying, milling
and plodding processes.

A batch on the other hand stays in the saponification tank for further processing. Currently the
company uses the batch process most often. The process flow diagram for both batch process is
discussed later on.

 Saponification Tank

After the NAOH and the fatty acid oils are pumped, they are mixed in the homogenizer and directly
sent to a big tank where they can be mixed to finish or yield more soap.

The mixture is stirred continuously, hence the tank is CSTR. Steam is provided on the pipes
connected at the bottom and top of the tank. The heat provided coupled with the stirring process
maximizes the soap yield. This saponification process could take 45 minutes up to 1 hour duration.
The product from this process is a melted crude soap.

There are 2 CSTR saponification tanks in the plant. Both are labeled as soap preparation tankers. The
only difference is that the second one serves as storage for the already prepared soap and as a feed
tank for the consecutive processes. Hence, the thick crude soap is pumped via a gear pump to its
neighboring tanker.

In the second tank, the mixture is steadily stirred with lower speed. Heat is added the same way with
the previous chambers. The heat keeps the soap in liquid state. When the soap is transferred from the
first tank to the second completely, another batch is filled in the first CSTR and the soap from the
second tank is pumped via another gear pump to the atomizer.

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 FIGURE 4 : S APONIFICATION TANKS

 Atomizer or Spray dryer

The soap that is pumped from the storage feed tank is a slurry hot liquid. It also contains the steam
water that has been added on previous processes. Therefore, the next task should be removing this
water and cool the hot liquid into more manageable solid dust.

For this purpose, the company uses a spray dryer with an atomizer and cyclones.

Inside the spray dryer, an atomizer sprinkles the liquid until its surface area becomes so large and
loses its property along the way. Then the sprayed liquid forms a solid surface on the walls of the
dryer. Here the dryer’s walls are coupled with a water jacket. Cold water runs across this water jacket
that further cools the soap inside the walls. A rotating scrubber is then used to scrub the cooled solid
soaps off the walls of the dryers. These solid particles fall down into the machine parts called
plodders. The spray dryer also does another important job. Upon drying, water inside soap evaporates
from the soap. This is very essential as the moisture content of the soap reduces; it is termed to be
more qualitative. The result of this process is the escaping of evaporated water particles out of the
soap. The next unit operation deals with ways of collecting this water.

 Cyclones

Inside spray dryer, the evaporated water and other dust particles along with a small amount of
impurities collect. This build up is very fatal for the process as it clogs the atomizers nozzle. It also
mingles with the disintegration process, greatly affecting the efficiency of drying. In order to get rid

15
of the unwanted particles, a vacuum dryer is installed to suck off any dust and water vapors out of the
dryer.

The removed impurities are then fed into the cyclones arranged side by side. The overflow from the
first cyclone goes as a feed for the second cyclone, and then the overflow from the second cyclone
which consist mainly vapor is sent to the condensate collector.

Inside the cyclone the feed is made to swirl in a vortex. This is possible because the feed is made to
attain high tangential speed before it enters the cyclones. As the feed rotates, the water vapors rise to
the top and are removed as an overflow. The other impurities flow downward to the bottom of the
cyclone. They are collected in the underflow section. The impurities consist mainly of un-saponified
oils and caustic soda, water vapors and small amount of Glycerine.

FIGURE 5 : CYCLONES

 Plodder

Just below the dryer is located a combination of different mechanical parts whose task is shaping the
soap in a chips or noodle shape. The collective name of these machines is plodder. The plodder
basically takes in the solid soap particles that just came out of the dryer. After the soap is cooled and
milled the soap is ready for shaping. Different mechanical parts are used for the mentioned processes.

16
As a result heat is produced in huge amounts inside the plodding compartment. To this effect, most
parts are aided with water jackets as a cooler. At this stage the soap has higher density which makes it
better for packing and gives it strength. At last soap passes through the plodder, it is cut into noodle
shape. Then the noodle is packed with the help of labor workers. The soap noodle is ready for sale.

Inside the plant Outside the plant

Caustic
flakes
Caustic Dissolution Boiler
OIL MELTER Steam header
Tank
Water

Oil Feed tank

Caustic Storage
Tank

Homogenizer

Saponification
Tank

Cyclones 1 & 2 Condensate

VACUUM DRYER Collector

PLODDER
Sludge

Soap Noodles

FIGURE 5 : BLOCK DIAGRAM FOR SAPONIFICATION PROCESS FLOW

17
 FIGURE 6 : S APONIFICATION PROCESS FLOW DIAGRAM

 Cooling System

Cooling system refers to all the systems invested in the purpose of reducing the heat produced inside
machines or cooling of different unit operation.

It is no surprise that water is used as a coolant fluid in the company. It is cheaper and easy to move
also water has good qualities when it comes to cooling. It has high specific heat and latent heat of
vaporization. In fact the only problem when using water is the corrosion of metal pipes. Although
galvanizing gives a good protection, it cannot guarantee a complete protection.

The other good thing when it comes to cooling is that water can be recycled without any further
reduction in volume. This is a big difference compared to companies which use water one-way. In
such companies water that has done a cooling purpose is discharged with effluents. But in Shemu the
water from the cooling system is recycled back into the plant. This method saves large volume of
water from waste, saving a paralleled amount of money.

Here are some of the cooling system parts inside the company:

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  Cooling Tower
This is the heart of cooling process. Cooling Tower is place that resembles a small room. Its roof is
installed with a very big fan. The rotation of the fan generates cold air that cools the water inside the
chamber. The cooled water is then pumped to the place where it is needed.

With the use of cooling tower comes a problem. The main problem is water retention. Water is stored
for a long time inside the tower which can bring growth of some algae inside it. To overcome these
problems a water pool is constructed just near the cooling tower.

FIGURE 7 : COOLING TOWER

 Water pool

Water pool refers to the place of small area where recycling water is temporarily stored. The water
pool has some important function: one is that by cycling the water from the tower to the pool and
from the pool to the parts to be cooled, the water is set in motion rather than being stagnant. This
reduces the formation of different microorganisms like algae in the water.

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 FIGURE 9 : WATER POOL

 Condensate collector

The moisture that is overflowed from the cyclones is a hot steam that is discharged through a tube to
a condenser located just outside the plant. Cold water is pumped to the stream of the feed hot gas.
Upon contact the steam condenses rapidly and drops downward to the hotwell chamber. The cold
water which has already been in contact with the hot steam gas also flows down and joins the
chamber. From here the water is taken to a heat exchanger. The outlet of the heat exchanger is cold
water that is sent up higher to the condensate cooling process.

 Heat exchangers

The water from the hotwell chamber is cooled by the water from the water flowing from the tower in
this part. The hot water is then sent to the cooling tower to finish the cycle.

There are 2 routes of water that goes to the parts inside the plant.

The first one is water that goes straight up to the condensate collector then fall into the hotwell tower
which then goes to the heat exchanger and recycles this process.

The other route leads straight to the machine parts and dryer jacket. This route cools these different
machine parts and is taken back through a tube that joins the hot water from the heat exchanger. The
two pipes join into one and go straight to the tower. The same way the tube that carries cold water to
the heat exchanger is separated to a line that takes some part of it to the machine parts. In this way the
cooling water from different machine parts does not go through the heat exchanger, hence it is cooled
by directly joining the main water line.

The other heat exchanger is used inside the plant to heat up the caustic solution coming from the
storage tank and also heat the melted oil, before they are homogenized and sent to the saponification
tank

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 FIGURE 8 : O IL AND CAUSTIC SOLUTION HEAT EXCHANGERS
 Heating System

Heat generation is another system that is crucial to the functioning of oil melting chambers and
saponification tanks. Once again water is used for heating system. The system of heating resembles
that of cooling because both of them use recycling water. Heating system is basically generation of
heat and distribution of heat. The steam is used all around the company, with some part of it used by
Oil Plant and Plastic Bottle Plant.

Here are the important parts of heating system:

 Water Softener

Tap water is usually hard. Water Hardness is the total concentration of Di Valent metallic ions
present in water. These ions are mainly Calcium and Magnesium. There are many reasons why the
hardness of water should be reduced. One of the reasons is that hard water causes scale build up in
pipes and clogs pipes. Hard water therefore reduces efficiency of boilers and heat exchangers. It also
might cause corrosion, which is the most dangerous effect of the hardness.

The use of water softener is the reduction of this hardness and giving a soft water. This is done with
an ion exchanger. Calcium and magnesium are positively charged molecules. As hard water is
pumped through the softening system, it also passes through a negatively charged resin bed. These
negative charges attract the positively charged positive charged hard matters. This leaves the water
which is free from those positive charges. Sample of water is taken to insure that the softener is

21
working properly. For regeneration, the resin is washed with brine solution and the calcium and
magnesium are repelled with sodium in the brine. Then they are washed off with the salty water.

FIGURE 9 :INSIDE LOOK OF WATER SOFTENER

 Pre heaters

In order to maximize the efficiency of boilers, the water is pre-heated before it enters the boiler. Pre-
heated water also takes less time to boil. Moreover, fuel consumption is reduced. The pre-heaters are
cylindrical tanks with 4 sections of resistance electrical heaters than can heat up the water to a
maximum of 85oC.

 Boiler

The water that has been softened and pre-heated is then brought to the boiler. Boilers are widely used
in several kinds of industries. Produced Steam is utilized in different processes. Steam is used to A
fire-tube boiler is a type of boiler in which hot gases pass from a fire through one or more tubes
running through a sealed container of water. The heat of the gases is transferred through the
walls of the tubes by thermal conduction, heating the water and ultimately creating steam. Fire
tube boilers are those boilers that use high temperature flame generated in the tube side to
heat the water at the shell side of the boiler.

The boiler which is in use for Shemu PlC is also a firetube, shell and tube type boiler which is
generating steam by combusting heavy fuel oil in the tube side of the boiler. Fire tube boiler consists

22
of a series of straight tube that are housed in a water filled outer shell. The tubes are arranged so that
not combustion gases flow through the tubes. As the hot gases flow through the tubes these gases
heating the water surrounding the tubes. The water is confined by the outer shell of the boiler.

FIGURE 10 : BOILER
 Steam header

Once the steam has been generated it is pumped to the steam header. This is the part that divides the
steam into different parts. The lines from the steam header lead to Plastic Bottle Production Plant,
Saponification Plant, and Palm Oil Refinery Plant. The steam also have additional bypassing pipe to
prevent the overflow of steam inside the header.

Material Balance & Efficiency of Plant

Saponification plant is the plant that uses fats and caustic solution to produce soap with some amount
of sludge and water as an output. Based on plant specification and data, material balance and
efficiency can be calculated.

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 Sludge
Caustic flakes Cyclone
Caustic Water
Water Dissolution
Saponification Spray Dryer
Tank
Plodder Soap
Oil Melting
Fats
Chamber

FIGURE 11 : S IMPLIFIED SAPONIFICATION FLOW DIAGRAM

1.3. Bar Soap Production plant Machine

In production one there are different types of machines, these are

Mixer Machine
Soap mixer machine are important soap manufacturing equipment that are used to mix the different
raw materials used in soap making. The machine can be used to mix a variety of activities with raw
soap and produce home paste form. Available in variety of sizes dimensions. The technology mixing
machines are easily to use and operate and require minimum maintenance. It has two motor with
7.5kw, this means it has 15kw power and 30A current the one motor connect in delta (to produce
larger torque) and the other is on star (in which it multiply the speed it needs to mix the raw
materials) .The shaft rotated by two motors, which controlled by direct on line one control circuit and
two power circuit. It is used normal push button and when one motor is ON by time delay the second
motor is ON. After the mixer finish its function it uses a pneumatic mechanism to open it get to the
refinery.

FIGURE 14 MIXER MACHINE

Miller Machine
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Miller machine widely used in soap and detergent industry specially chilled casting rolls are
employed which rotate in roller bearing. it is an electrical machine having two motor with 75kw and
150A.The miller machine has a roller motor shaft done by forward-reverse, used to star- delta control
circuit system. It is used to soften the output of the mixer, which is transported by the conveyor. Since
the shaft are rotating there is a friction between the components in order the make suitable working
condition some amount of heat needs to be removed to do so the chiller machine supply cooled water
to flow inside of the shafts tube so the miller maintain its temperature.

FIGURE 15 : MILLER

2.3 Conveyor

Widely, used for automatic shifting of the soap mixer from the triple roll mill to the plodder. The
soap conveyor plants use the screw mechanism to make the soap making process totally smooth. It
uses the star-delta connection. The speed of this machine controlled by frequency adjuster, if
frequency increases the speed of the motor also increase and it is manual system.

FIGURE 16 : CONVEYOR

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Chiller machine
It is used to control the temperature of the machine, In addition to this the temperature of the machine
need heater which controlled by temperature sensor this temperature sensor used to sense the chiller.
If the chiller is not works properly the soap become melt.

FIGURE 17 : CHILLER MACHINE

Plodder Machine
Plodder machine is a soap making that is used to extrude the final soap and is suitable for stamping
the on the soap. Machine comprises of two separate stages in which the First stage is refiner and
second stage is extrude is used to produce the final bar shape along continuous belt.
The vacuum chamber that functions to delicate the soap connects these two stages. An extruder is
commonly called plodder in the soap bar at this point it is completely finished. At this stage the soap
bar is actually finished and anything left it to change for bar by cutting the billers into smaller pieces
are stamping a shape it needed. It is type of electrical machine, which has two motor with one 15kw
connected by belt and used star-delta as well as other 18.5kw motor having gear box controlled by
potentiometer (variable resistance control). The output of the miller is transported to the plodder by
the conveyor, after transported the system used to make the shape of the soap and transported to the
cutter machine.

FIGURE 18 : PLODDER MACHINE

Cutter Machine

26
Cutter is the equipment used in soap manufacturing process to cut soap into desired length, sizes and
forms, in this machine, soap cutters are usually placed downstream from a plodding machine and the
soap bars that come from the plodder enter the cutter and come into contact with on incremental
encoder; which sends a signal the cutting system. The cutting system provides a horizontal and
vertical blade shift to cut bars into specified length and sizes. It is an electrical machine having
position sensor and servo-motor depending on adjusting of the machine encoder, encoder is speed
controller cutter used to cutting the soap and transported to packing machine, then the packing
machine pack the soap and transport to the end product machine.

1.4 Liquid Detergent Soap Plant

The liquid detergentsoap plant, have some types of machine or equipment involves in the production.
These are: 
 Mixer (reactor) machine
 Filling machine
 Shrink packaging machine
 Container (Deposit)

Mixer Machine: used to mix raw material on it, the equipment used to mix the different raw
material.

FIGURE 19 : MIXER MACHINE

Filling Machine: is available with variable speed drive to control the operating speed of the machine
liquid filler machine can be combined with the conversed bottle filling for automatically by using
proximity.

27
 FIGURE 20 : FILLING MACHINE
Shrink Packing Machine
The hot air is kept in a small having room which save power consumption clearly in the shrinking
process, packing product one wrapped perfectly with strong hot circulating air flow shrinking process
can be observed through transparent cover. Shrinking T=2000C and speed almost 4 min and max
1m/s.

FIGURE 21 Flow Chart of Liquid Detergent

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 1.5 Bottle Production
Plastic Bottle Production
In SHEMU Company we have been seen how to produce the bottle, first adding the raw material to
the first tanker, then due to the automatic loader the added raw material transferred to the second
tanker. This transmission controlled by proximity sensor, if the amount of raw material is low the
sensor gives the sound, and used to control the proper amount of the raw material, after the second
tanker the raw material heated and that material changed to liquid form.
This system also controlled by temperature sensor and transferred to molding, then we get output.
8 Steps in production of plastic bottles
Step one “hot perform” method
Step two “cold perform” method
Step one “hot perform” method
This method is just first step to produce plastic bottles, all the processors are done in one integrated
machine. that is from injection mold of the preform to the removal of the preform from the injection
cavity, and to stretch blow the preform to a bottle all in one machine, while the temperature remain
constantly high for the whole process as injection molding and blow molding the material should in
an elastic form. This method saves a lot of energy as the material has to be heated only once, that is
when injected into cavity to produce preform

FIGURE 22: Hot perform method machine

Step two “cold perform” method

This method has 2 distinct machine to perform the injected and blow moldings. the preform is
injected into shape on the first machine, and then the preform is reheated as the it isn’t brought
directly to the blow molding machine and blown on the second machine.

29
FIGURE 23: Cold performed method fully automated machine

FIGURE 24: Bottle production process

Blowing Process
Blow molding is a manufacturing process for forming and joining together hollow plastic parts. It is
also used for forming glass bottles or other hollow shapes.

Preform is preheated

Open the mold and insert

the preform

Blowing of air into preform

Allow the bottle to cool for

Solidification as desired shape

Open the mold and eject

the component

FIGURE 25: Flow Chart of Blowing Process

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Then after complete all the necessary process to packing the products before product deliver to the
customer. In the production line separated the packing based on the product that produced.
Generally the company used the bottle on the amount of container fill the soap, especially in the
production of liquid soap.

FIGURE 26 : Extrusion blow molding

The equipment that used for complete extrusion blow molding system are:-
 Extrusion blow molding machine
 Blowing mold
 Mold chiller system
 Air compressor
 Hopper dryer
 Mixer
 Crusher
 Cooling tower system
 Auto loader

Proximity sensor
A proximity sensor is a sensor able to detect the presence of nearby objects without any physical
contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic
radiation (infrared, for instance), and looks for changes in the field or return signal. The object being
sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand
different sensors. For example, a capacitive proximity sensor or photoelectric sensor might be
suitable for a plastic target; an inductive proximity sensor always requires a metal target.

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 FIGURE 27: Proximity sensor

1.6 Overall benefits gained

1.6.1 Overall benefits gained
There exists a big difference between learning in class and working in an industrial plant. It’s not
uncommon to see newly employed graduates finding it hard to cope with the working environment of
a company. This is the main issue of internship program. It is believed that if a student is introduced
to the environment before graduation, then those problems can be solved.
In my 4 month stay, I have observed what the real work place looks like. I believe that the internship
has helped me in a lot of ways. It has shaped my mind in a form of an employed chemical engineer. I
have tested my theoretical knowledge into practical ground. I learned to work alongside fellow
workmates, engineers and administrators. Most importantly, I learned to take on responsibilities upon
my shoulder. Finding problems that needed fixing and finding the best suitable and available solution
is also an experience that extended to help me both as an engineer and as a person.

1.6.2 On improving Practical Skills

Practical Skills refer to ability find solution in a work domain. As a student, I spent much of my time
solving problems on paper. Although that gave me a big engineering background, it was not enough
when it comes to applying it on the real world. To tackle this problem, I worked hard to expand my
practical experience in the internship program.
Here are some of the methods I followed:
 After being introduced to the working principles of unit operation or any machines, I tried to
gain more knowledge on the topic by reading books or browsing the internet. This helped me
to compare the technologies available around the globe to the one the company was using.
 Some words like efficiency or balances on energy and matter were only a figment in my
minds. But while working on the plant, it was possible to measure out inputs, outputs, losses,

32
 accumulations and the like. Therefore, most of the terms that I knew in class became more
familiar.
 From the practical process flow, I was also able to develop my own flow diagrams and block
diagrams.
 In laboratory sessions, I was required to do simple calculations based on instructions. this
included titration, drying then finally use formulas to calculate values.

1.6.3 On Upgrading Theoretical knowledge

Theoretical knowledge is a pre-requisite for practical knowledge. Only students who have grasped
and swallowed the theory can proceed into applying it practically.
During internship duration I am not only develop the practical skill but also I recall and relate the
theoretical knowledge with practical. While you do something you force to refer about the subject this
make you to remember and upgrade yourself for integrate theoretical with practical.

1.6.4 On improving interpersonal communicative skills

Individual ability to appeal pleasant with fellow workmates was very crucial. Communication was
also a skill I developed in my stay. A person should show respect, explain his thoughts clearly, talk in
a mild voice and wait for his turn if he wanted to be heard. When asking for help for our seniors or
talk with, I followed the mentioned skills. The result of that is a peaceful and respectful working
environment. Moreover due to the pleasant communication environment, I got more help and
encouragement from my leaders. My questions were answered accordingly, my ideas were
thoroughly examined, and my requests were fulfilled on time. Generally, development of a good
communication skill creates an environment that is suitable and appealing to work.

1.6.5 On improving team playing skills

Teams need strong team players to perform well. Teams need people who speak up and express their
thoughts and ideas clearly, directly, honestly, and with respect for others and for the work of the
team. Team work has a dramatic effect on the organizational performance. An effective team can help
an organization achieve incredible results. a team that is not working can cause unnecessary
disruption, failed delivery and strategic failure.
From the above mentioned points that a good team player should have:

33
  Ability to take others ideas into consideration
 Willingness to help fellow partners
 Respectful and pleasant towards others
 Being able to rise up from failures
 Look for better methods and modern solutions for modern problem

1.6.6 On improving leadership skills

Leadership is by far one of the most difficult task one can take. A leader should always be calm,
motivating, responsible for his actions and active. Leader should set path and set goals which are to
be executed along with his people. He also should keep employees happy and satisfied rather than
making them feel guilty and unwanted. When failure occurs, a good leader admits it and looks for
ways to make things work. Generally leader is someone who serves a higher purpose than himself.
In my internship stay, I have seen many types of leadership approach. Some leaders impose their
ideas on fellow employees without consulting anyone. This method fails sooner or later as it is
unstable because it has got no support from others. Some leaders on the other hand were very
successful. They always helped those in need. They kept a happy face and a victorious spirit while
working. They showed themselves as a model to what a leader should look like. I have learned that
success is a team effort and leaders play an important role making this success real.

1.6.7 On understanding about work ethic related issues

While working in Shemu, there were some work ethics. These work ethics were rules and regulations
followed by all employees. As an internship student, I was also subjected to the work ethics. Hence,
employees are expected to be:
 Punctual
 Accountable
 Honest
 Reliable
 Responsible for their duty
 Respect each other
 Have a respect for the rules of the company

34
The other important point is safety. Working around a big company requires people who are
responsible for their safety and safety of others. Here are the company’s safety rules:
 You are responsible for your own safety and safety of others
 Wear personal protective equipment necessary for the job
 Always use equipment (tools) machinery safely and properly
 Keep your work area clean
 Wear appropriate and safe work clothing and footwear
 Report any unsafe conditions
 Report all injuries
 No alcohols or drugs to be used or allowed on company property.

1.6.8 On improving entrepreneurship skills

Shemu PLC is a good example for successful enterprise. The business venture they tend to are
carefully examined. The success of the company is mostly based on adjusting to changing needs. This
has taught me some qualities to what a good entrepreneur should have:
 Dedicated to bring success
 Being aware of current situations and taking decisions on their best interest
 Taking chances to make a swift move
 Knowing limitations and resources that are in hand
 Finally, not giving up when thing don’t work out and willingness to try again

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 CHAPTER TWO

PROJECT
2.1 Design Of Bucket Elevator

2.1.1 Bucket elevator

Bucket elevator is a kind of conveying machine, bucket elevator usually uses a series of buckets
which are uniformly fixed to the endless traction chain or belt to continuously lift bulk or broken
materials in or near the vertical direction.

Bucket elevator is suitable for lifting convey from low to high, the conveying speed can be adjusted
according to the transmission volume, and the lifting height can be selected as needed.

2.1.2 How does bucket elevator work

The bucket elevator working principle is relatively simple, mainly relying on the bucket hoppers
fixed on the chain (belt) to lift the materials flowing evenly into the tail feed port from the tail of the
bucket elevator to the head of the bucket elevator uninterruptedly, and then unload the materials from
the head outlet to complete the whole lifting process of the materials.

Bucket elevator is suitable for lifting from low to high, the lifting height can reach 40 meters; bucket
elevator is generally equipped with casing to prevent dust flying.

 Bucket elevator structure

The bucket elevator is mainly composed of traction parts, buckets, driving device, head, barrel, base
and so on

 Traction Parts: there are 2 kinds of traction parts: belt and chain. Belt is generally divided
into cotton rubber belt, nylon belt, steel belt. The chain mainly includes HL, forged ring chain,
forged square chain as well as plate chain.
 Buckets: carbon steel, stainless steel and polypropylene materials can be selected according to
material characteristics.
 Driving Device: the driving device consists of drive drum (or sprocket), motor, reducer,
coupling,backstop and driving platform.
 Head: it is composed of head wheel, head shell, discharge port and transmission device. The
bucket elevator will install an anti-reverse device on the head wheel shaft toprevent material
blockage caused by equipment failure in the process of operation.
 Base: it is composed of machine base shell, bottom wheel, tensioning device, feed hopper and
induction devices.

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 Figure 28 : Diagram Of Bucket Elevator

2.1.3 Types of bucket elevator

There are 3 types of bucket elevators. Bucket elevators are classified based on bucket spacing
and mode of discharge of materials. As per IS:7167-1974, ‘‘Code for Selection and Use of
Bucket Elevators,’’ they are classified into following three basic types:
1. Centrifugal discharge elevators

2. Positive discharge elevators

3. Continuous discharge elevators
1. Centrifugal bucket elevator

The centrifugal style elevator has the ability to move large amounts of material quickly, and works
well for durable and abrasive materials like sand, gravel, and other free flowing bulk materials.

The centrifugal style elevator starts by scooping material from the boot or inlet section; this action
requires a durable bucket. Due to the high speed of operation; this elevator generates centrifugal force
at the head pulley. This force throws the material out of the bucket and into the discharge chute as
shown in the next figure. The launching and digging actions of this design run the risk of damaging
fragile material, so this style is not recommended when handling more delicate materials. Centrifugal
style elevators are available in either belt or chain drive.

37
2. Positive bucket elevator

This is similar to centrifugal discharge elevator except that spaced buckets are end-mounted between
two strands of chain and are snubbed back under the head sprockets to invert buckets and gain
complete discharge. Bucket speed is slower and this type is specially suited to handle light, aerated,
dusty, and sticky materials that will not discharge without difficulty in centrifugal discharge elevator.
The slight impact of chains skating on snubbed sprockets also helps to free materials, such as wet coal
with tendency to stick to buckets.

3.Continious bucket elevator

This is the elevator, often used for handling larger lumps and material that may be difficult to handle
by centrifugal discharge elevators. Buckets are so shaped and mounted on chain or belt that, as they
pass over the head wheel, the flanged end of the preceding bucket acts as a chute to lower material to
the elevated discharge spout. The slow speed and gentle method of loading and discharging minimize
breakage of fragile materials and also makes this a satisfactory type for fluffy materials, such as lime,
cement, or certain dry chemicals. Continuous buckets are not recommended to be filled in by digging
and must be filled in by a loading leg. This type of elevator can be operated vertically or inclined;
when inclined, special guides are furnished for carrying rim and wider casing provided to allow for
sag in return run.

FIGURE 29 : TYPES OF BUCKET ELEVATOR

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 2.2 Problem statement and justification

As we observed it is very difficult to bring caustic soda from the bottom to the top of tanker using
forklift due to the lack of space and it takes a lot of time to hang it up. Not only this, but the person
who flips and adds he caustic is on the cliff and may fall. After stick up the caustic soda to the top it
will take up a lot of space.

2.3 Objective of the project

2.3.1 General objective
General objective of the project is to design bucket elevator that covey/lift powder of caustic soda
(NaOH) from ground to upstairs tanker.

2.3.2 Specific objective

 To provide safety to labors.

 To reduce plant space
 Reduce forklifts work therefore; the forklift focus on transporting end products.

2.4 Litrature review

Snehal Patel, Sumant Patel,Jigar Patel,et.al.

This paper deals with the design and analysis of differentparts of elevator for conveying different
types of materials.The modeling of bucket elevator done using solid modelingsoftware and analyzed
using conventional finite element software (Ansys) and stresses and deflections are obtained.

This study also shows that the negative influences of supportof the shaft reflected through theincrease
in the stress concentration and occurrence of the initial crack are the main International Journal of
Engineering Science and Computing, July 2016 8350.

N. Yashaswini, Raju. B and A. Purushottham,et.al.

“Authors have designed a bucket elevator and analyzed it for conveying granular materials to the
height of 15m at the rate of 10 tones/hour output. This paper gives basic design calculations for the
development of the bucket elevator, in 3D environment of NX software. Static and vibration analysis
carried out on the bucket elevator in order to need the required output from 10 tonnes/hr-20 tonnes/hr.

39
This paper also gives the dynamic behavior of the bucket and gear shaft assembly. The results
obtained from the analysis study critically examine the modification of design parameters.

Snehal Patel, Sumant Patel, Jigar Patel,et.al.

This work deals with the design and analysis of elevator for conveying granular materials at 2
tonnes/hr output and lifting height 12m. Modeling of different components of bucket elevator has
been done using 3d Solid Modeling software based upon the dimensions obtained from analytical
design. The new modified design of the bucket elevator is proposed and validated using CAE tools
which are well within the safe limit. Bucket elevator mainly fails due to breaking occurs at the inner
edge of the pulley, it consider as fretting corrosion. So new material EN24 has been suggested for the
shaft. From the analysis, it can be seen that for modified design has higher FOS than existing design.

Hemlata H.Mulik, Bhaskar D.Gaikwad, “Design of Sugar Bucket Elevator and Roller
Conveyor Chain for 20 Tonnes per Hour Capacity”, International Journal of Engineering Trends and
Technology. In this paper the different components of roller conveyor chains are designed for sugar
bucket elevator used in sugar industries for 20 tonnes per hour capacity and the loading conditions are
described. the advantages of chain drive as compared with other drives are discussed. The chain wear
mechanisms found in literature are listed. Abrasive and adhesive wear between pin, bushing, and
roller are also discussed.

2.5 Methodology

2.5.1 Methods
The design starts with the set of all possible solutions bounded by the external constraints, and by a
process of progressive evaluation and selection narrows down the range of candidates to find the best
design for the purpose.

There are so many stages are there in the design process

 Select a proper material that used to design.

 After selecting a proper material start the design of components
2.5.2 Data Collection
The methods which collected data to achieve the objectives of this project are the following:

 Primary data collection

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  By observation the related works
 Secondary data collection
 By reading related books
 From internet access
 Using different software (solid work)
2.5.3 Material selection
Materials used for Design

Engineering materials are materials whose properties are technologically useful. Selecting the right
materials for a specific design is probably the single most important decision facing designers.
Materials are chosen for a variety of reasons such as cost effectiveness, availability and workability
and affordability

2.6 Design consideration and calculation

2.6.1 Selection of size of elevator
The size of the elevator will depend upon the maximum capacity (in t/h) that will ever be handled at
any time which in turn will depend upon:

a) the bucket size,

b) the spacing of the buckets,

c) the speed of the bucket,

d) the bulk density of the material handled, and

e) the percentage filling of the bucket.

2.6.2 Selection of type of bucket elevator

Continuous bucket elevators are preferred choice for safely conveying hazardous chemical powders.
Fully enclosed elevators that safely contain caustic or acidic powders. fully interlocking buckets
eliminate spillage.

2.6.3 Selection of Bucket

The selection of the type of bucket shall be done on the basis of type of elevator that is centrifugal or
continuous type according to recommendation (IS: 6833-1973).

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Bucket Capacity - The maximum amount of material (in volume or weight) that bucket can contain
when filled completely.

NOTE - The actual capacity depends on the material handled, its angle of repose, loading and
inclination the elevator.

Material selection for bucket

fabricated buckets shall be manufactured from suitable steel, aluminium or stainless’ steel sheets
conforming to relevant Indian Standards.

Selection of the proper bucket material is depend on the material that we convey. Since we have to
convey caustic soda we have to know its property. Chemical powders which are caustic or acidic in
nature are corrosive. Corrosive substances destroy other substances and materials with which they
come into contact. When these substances are conveyed, corrosion of the conveying equipment can
occur due to direct contact with the material or the position of fines. the resulting corrosion can
degrade or destroy the equipment, necessitating repair or replacement of failed parts and components.
In the worst cases, outright replacement of the equipment may be required for handling caustic or
acidic powders, corrosion resistant rubber belt and running components, as well as stainless steel
frames or corrosion resistant paint finishers are available.

TABLE 2: RECOMMENDATION TO SELECT SIZE OF BUCKET (IS:6833-1973)

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 From the table 2.1 (IS:6833-1973)
Length= 250mm
Projection= 150mm
Depth=150mm
Thickness =2mm
Mass of bucket= 1.8 kg

Recommended for spacing

TABLE 3:RECOMMENDED SPACING AND SPROCKET DIAMETER FOR CONTINUOUS TYPE OF

BUCKET ELEVATOR

From the above table

Spacing (S)=200mm
2.6.4 The selection of casing
The selection of casing shall generally be done on the basis of type of elevator and bucket size as per
IS: 7054-1973* but the selection of take up at the boot shaft or head shaft shall be done according to
the following recommendations.

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Take Up at Head Shaft

The take up at head shaft is recommended to be used in case:

a) material handled is likely to take up after some time of storage, as in case of chemical
fertilizer, cement, etc;
b) where accumulation of material in boots results in deterioration of quality as in food
products;
c) when elevator is required to handle different products which should not be mixed;
d) where material handled is coarse, hard and lumpy but approximately round or cubical
only. In case of sharp cornered pieces, fixed bearing boot is not recommended;
e) where confinement of material to bucket path is not necessary, for example, hot clinker
elevator in cement mills; and
f) where from layout point the loading pit is so placed that approach is difficult, take up at
head shaft is preferred.
Take Up at Boot Shaft

Except for cases mentioned.in take up of head shaft take up should always be provided at the boot
shaft due to following advantages:

a) Easy approach for adjustment of tension,

b) Direct drive to head sprocket, and

c) Possibility of provision of an automatic take up.

RECOMMENDED PERCENTAGE BUCKET FILLING FACTOR, F

NOTE- While selecting value of F, effect of inclination of the elevator should be taken into account.

 Amount of take up shall vary up to 500 mm but shall never be less than 200 mm in any
case.

MATERIAL TYPES OF BUCKET F

CHARACTERISTICS ELEVATOR

Powdered (ground) example: Positive discharge 0.85

coal dust, cement, chalk,
centrifugal discharge 0.75
phosphate fertilizer, etc

44
Granular and small lumped (60 Centrifugal discharge
mm) mildly abrasive example: 0.7 to 0.8
saw dust, dry clay in lumps,
coal, peat, grain, etc

Granular and small lumped (60 Continuous discharge 0.7 to 0.85

mm) highly abrasive example:
Centrifugal discharge 0.7 to 0.8
gravel,,sand,ash,earth, rock, etc

Medium and large lumped (60 Continuous discharge 0.6 to 0.8

mm) mildly abrasive example:
Centrifugal discharge 0.5 to 0.7
coal, peat in lumps, etc

Medium and large lumped (60 Continuous discharge 0.6 to 0.8

mm) highly abrasive e.g.
crushed ore, stone, slag

Lumped, fragile, downgraded Continuous discharge 0.6

by, Continu crushing e.g. char
coal, coke, etc

Sluggish, powdered and Positive discharge 0.4 to 0.6

granular, moist e.g. moist
chemicals, fluffed peat, earth, Centrifugal discharge 0.4 to 0.6
wet sand, wet powdered chalk

Table 4 recommended percentage bucket filling factor

From the above table F=0.7

2.6.5 SELECTION OF CHAIN AND BELT

General recommendations for using chain or belt for different materials is listed in IS:7167-1974
Table 1. However, guidelines for selection of chains or belts shall be as follows.

 Chains are normally used when the required duties are heavier or when the
material to be handled is hot, hard and lumpy, abrasive or corrosive, that
excessively limit the life of the belt or which pack between the bucket and the

45
 belt. For positive discharge elevators and for long bucket elevators requiring
extra strength, chain should be used.
 Belts are used on elevators handling grains, cereals and many other free
flowing or abrasive materials, for example, coke breeze, glass batch, etc. Belts
are also used for handling corrosive materials such as caustic soda, salts,
chemical fertilizer. With belts it is possible to run elevator at higher speeds
thus resulting in higher capacity with smaller buckets, giving smoother and
quicker operation. However, belts are not recommended for wet material, hard
and splintery lumps and hot materials or those materials which tend to pack
between bucket and belt.
 Belt -The selection of belt should be done on the basis of the following:
a) Belt width-should be 10 to 12 percent wider than the length of the
bucket but not less than 40 mm on narrow belts.
b) Number of plies - minimum number of plies should be chosen from
Table 3.
c) Fabric grade and cover thickness -The fabric and grade of cover to be
chosen according to recommendation given in IS:1891-1968* and the
cover thickness shall be as given in Table 4.
d) Belt tension -In most of the cases (a), (b) and (c) above determine the
complete design of the belt,, however, it is always necessary to check
whether the above belt is suitable for maximum tension, which is
computed as follows:
1. Tension due to mass of belt = B × H in N
H ×b
2. Tension due to mass of bucket = in N
spacing of bucket ( S )
H ×W
3. Tension due to mass of load in bucket = in N
Spacing of bucket (S)
4. Tension due to mass of pick up load and over coarse pully friction =
H 0× W
in N
Spacing of bucket (S)

Max tension = (1) + (2) + (3) + (4)

46
 H × b HW H 0 ×W
= B× H + + + in N ….. ( A )
S S S
where ratio of material load in buckets to the weight of the belt and buckets is high, it may
become necessary to apply additional tension at the boot pulley in order that the head pulley will
drive the elevator properly. In such case the maximum tension is calculated as:

W
Max tension= (1+K) ( H+ H 0) in N …………( B )
S
The larger of the two values obtained from ( A ) and ( B ) is used for selection of the belt in above
equation.

Where

B = belt mass in kg/m run,

H= vertical height of elevator in m,

S = bucket spacing in m,

W=mass of material in each bucket in kg,

b = bucket mass in kg,

H 0 = height factor to allow for pick up force and boot pulley friction

K = 0.97 for bare pulley drive with screw take up,

= 0.80 for lagged pulley drive and screw take up,

= 0.64 for bare pulley drive with gravity take up,

= 0.5 for lagged pulley drive with gravity take up.

Therefore

maximum tension∈ N
Number of plies=
(Width of belt ∈ cm)× ¿ ¿

47
CLASS OF MATERIAL PROJECTION OF BUCKET IN mm

100 125 150 180 200 230 250

Light powdery or free flowing materials 4 4 5 5 5 6 6

free from lumps
Cement, dry coal, dry sand, pea- coal, 4 5 5 6 6 7 7
fertilizers heavy but free from lumps
Gravel, coarse sand, crushed stone, coal, 5 6 6 7 7 8 8
light ores, etc
Lumpy or sticky materials heavy ores of - 7 7 8 8 9 10
other similar materials

TABLE 5: M INIMUM NUMBER OF PLIES BASED ON PROJECTION OF BUCKET

PULLEY/SPROCKET DIAMETER VS SPEED

Pulley Diameters for Elevators Using Belt

Pulley face width, B is nominally the same as the width of the belts they are to carry.
However, allowances should be made to ensure that the belt stays in the pulley. Allowances
for pulley width for different belt width are given in Table

Belt width, mm Allowance, mm

Under 350 25
305 to 610 51
Over 610 76
TABLE 6: ALLOWANCES FOR PULLEY WIDTH

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 Belt width= bucket length+50mm
=250mm+50mm
=300mm
Allowance for pulley width is 25
Pulley width=325mm
But,
pulley width =pulley diameter=325mm
πD
belt length=2H +2( )
2
π × 325 mm
=2(3500mm) +2( )
2
=8021mm = 8.02m
where

D= pulley diameter

H=Height of elevator from center of top pulley to center of bottom pulley

Area of belt = length × width

=8.02m×0.3m
=2.406m2

PROJECTION OF BUCKET DIAMETER OF PULLEY

R= + +THICKNESS OF BELT
2 2
0.150 0.325
R= + +0.03
2 2
R=0.2675m
29.9
N O=
√R
29.9
¿
√0.2675
¿ 57.81 rpm

where

N O =optimum speed

49
 V=2πR N O /60

V=2× π ×0.2675 × 57.81/60

V=1.619 m/s

Capacity Calculation

General formula for calculation of the capacity of all types of elevator shall be follows:

T=C×V ×W × F ×Y

=0.00306m3×1.619 m/ s ×2100 kg /m3 × 0.7 ×3

=21.85kg/s

where

T = capacity of bucket elevator in kg/s;

F = constant, representing percentage filling of the buckets;

C = capacity of individual bucket in m3;

W= material bulk density in kg/m3;

V = belt speed in m/s; and

Y= Number of buckets per meter

 The values for F and S shall be taken from above Tables

Power calculation
P=T× g × H × f
m
=21.85kg/s × 9.81 ×8.02 m ×1.2
s2
=2063 watt

2.7 Component Description

The project has main components and other additional components.

1. Buckets
2. Head pulley and tail pulley
3. Ball bearing

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 4. Motor
5. Belt

Buckets

buckets are a component which are attached to belt to convey bulk material in vertical path. They are
attached to belt by means of bolt and nut. we are selected stainless steel bucket because it is
recommended to carry caustic powder.

Figure 30 : bucket
Head pulley
A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction
of a taut cable or belt, or transfer of power between the shaft and cable or belt. In the case of a pulley
supported by a frame or shell that does not transfer power to a shaft, but is used to guide the cable or
exert a force, the supporting shell is called a block, and the pulley may be called a sheave. Normally
the discharge end of the conveyor where the material is transferred to another conveyor is called as
Head end and the pulley in this end is called the head pulley. Most of the cases the drive is attached to
the head end of the pulley and so head pulley will designed stronger and bigger when compared to
others.

The pulley which is situated in the receiving end of the conveyor is called as tail pulley. Sometimes
screw take-up will be situated in the pulley. This pulley is movable when take up is kept in this.
When belts take a turn for take-up arrangement or for any other drive arrangement this term comes.
This acts as a support when belt takes a turn. External screw take-ups are provided on each side of the
shaft in the boot section for adjustable tension. Internal gravity take-up is also available.

51
 FIGURE 31 : PULLEY

Ball bearings

Ball bearings are extremely common because they can handle both radial and thrust loads, but can
only handle a small amount of weight. They are found in a wide array of applications, such as roller
blades and even hard drives, but are prone to deforming if they are overloaded. In ball bearing, the
load is transmitted from the outer race to the ball and from the ball to the inner race.

FIGURE 32 : BALL BEARING

Belt
Belt is also a basic component used to carry buckets and it rotate with pulley. We are selected
corrosion resistant rubber belt.

FIGURE 33 : BELT

Motor

An electric motor is an electrical machine that converts electrical energy in to mechanical energy.
Most electric motors operte through the interaction between the motors magnetic field and electric
current in a wire winding to generate force in the form of torque applied on the motors shaft.
Typically, the shaft at the top of the elevator, “hood section” is driven but if this is not accessible for
maintenance the bottom, “boot section” shaft is driven. The lowest cost drive is the shaft mount type.

52
Shaft mount motor/gear drives are standard but an alternate: motor, gearbox, and chain drive may be
used to power the elevator.

Figure 34 : electric motor

2.8 Conclusion

Internships are a perfect medium to see how the real world functions and what is expected from a job.
It is an opportunity for engineering students to learn to use their education for more practical
purposes. Internships are the perfect learning steps that allow the students to experiment, understand
their strengths and weaknesses and go all out to achieve more. They are also introduced to the latest
technologies in the field and taught how to use them effectively. Our experience in the company
working upon a different machine's made our knowledge better as a mechanical engineering students
in Dire Dawa University and to see the gaps and problems that face the company and give solutions
for the problems and gaps. In the company from our first day visitation to the last day of our staying
in the company we took a lot of experience and develop our practical skills that our reports explain
the advantage of internships program in general. Our report explains briefly that how Shemu PLC
works in the working area with an organized and skilled way works for the production system. We
did have the chance to participate in the production system of Shemu PLC and to work as the member
the company in the working area how they maintain their machines, the way they clean their
machines, the way that they collaborate with all kinds’ man power for the better production system
and also we did have the chance see and to know what is their vision, their mission, their values and
other incentive works.

2.9 Recommendation

It is said that ‘’Nothing is perfect’’ and ‘’There is always room for improvement’’. Although Shemu
PLC is one of the successful companies around Ethiopia, it still has some problems that need fixing.

53
According to the mission of the company to fulfilling the customer’s needs. It is necessary to satisfy
the customer need by increasing the capacity of man power and employing the experienced worker or
engineer. Generally control system used to produce good quality product with in sufficient profit.
During our stay, we have observed some problems. These were:

 Safety Issue: although the safety rules are stated briefly in the company, there seems to be
not enough attention when it comes to following them.
 Hygienic condition of equipment also should be given great attention. Processing area and
people around the production area, because the more hygiene a working place is the
product will be safe and high quality.
 If the company produced the shampoo and powder detergent the company will gain more
income and also more profitable.
Quality is never an accident. It is always the result of intelligent effort. we believe that with
modification of the problems that we have mentioned, the company can go a step ahead from its
current position. Finally, we recommend the company to create a team that can investigate the
problems from each plant and give immediate response and repair. It is my strong opinion that
although perfection is never attained, Shemu PLC can get closer and closer.

Reference
[1] https://www.shemu p.l.c.com

[2] https://en.wikipedia.org/wiki/shemuplc/

[3] https://en.wikipedia.org/wiki/pulley/

[4] Groover, Mikell P. Fundamentals of modern manufacturing: materials, processes and systems, 4 th
Ed.s

[5] https://www.mechengg.net

[6] Snehal Patel, Sumant Patel,Jigar Patel, A Review on Design and Analysis of Bucket Elevator,
International Journal of Engineering Research and Applications, Volume 2, Issue 5, Sep- Oct 2012,
pp.018-022

54
[7] Hemlata H.Mulik, Bhaskar D.Gaikwad, Design of Sugar Bucket Elevator and Roller Conveyor
Chain for 20 Tonnes per Hour Capacity, International Journal of Engineering Trends and
Technology, Volume 20 Issue 1, Feb 2015

[8] F. J. C. Rademacher, Non-Spill Discharge Characteristics of Bucket Elevators, Powder

Technology, Volume 22, pp 215-241

[9] J.L. Perez-Aparicio, R. Bravo, J.J. Gomez-Hernandez, Optimal numerical design of bucket
elevators using discontinuous deformation analysis, Department of Continuum Mechanics and
Theory of Structures, Universitat Politecnica de Valencia, Valencia, Spain

55