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CHAPTER 1
INTRODUCTION TO INDUSTRIAL TRAINING

The students industrial Work Experience scheme (SIWES) was initiated in 1973 by the
industrial Training fund (ITF)
...
It was aimed at bridging the gap between
the theoretical knowledge acquired in the classes and technical knowledge in the industries by
providing students with the opportunities to apply their educational knowledge in real work
situations
...

Furthermore, the place and relevance of SIWES is underscored by the fact that the scheme
contributes to improving the quality of technical skills generally available in the pool from
which employers source technical manpower
...

Also, it requires students for employment and makes the transition from school to the world of
work easier after graduation
...

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

Prepare student for the industrial work situation they will meet after graduation
...




Make the transition from school to the world of work easier and enhance student’s
contacts for job placement
...

COMPANY’S PROFILE

The Port Harcourt refining company (PHRC) is a Port Harcourt based company that
specializes in the refining of crude oil into petroleum products, its a subsidiary of the
Nigerian National petroleum corporation (NNPC), the company operates two refineries
including an old plant commissioned in 1965 that can process 60,000 barrels of oil per stream
day and the new plant commissioned in 1989, which has a capacity of 150, 000 bpsd
...
(NNPC, 2016)
...
The new refinery is made up of Areas 1-4 while the old refinery is Area 5
...
Straight Run Gasoline (SRG) used for PMS
blend, Liquefied Petroleum Gas (LPG) and Atmospheric residue (AR)
...

Area 2 is made up of Naphtha Hydrotreatung unit (NHU), where naphtha is hydrodesulphurised; the Catalytic Reforming Unit (CRU), responsible for upgrading naphtha to
reformate which has a higher octane value for PMS blend; the kero Hydrotreating Unit (KHU)
where kero is treated to make it acceptable for aviation use: Area 2 also has the Continuous
Catalyst Regeneration Unit (CCR), which constantly reactivates the deactivated catalyst from
the reformer
...


2

Area 3 is made up of a Fluid Catalytic Cracking Unit (FCCU), where Vacuum Gas Oil
(VGO) and heavy diesel oil (HDO) are cracked to obtain more valuable products, like FCC
gasoline used as pms blend and Light Cycle as blend component for LPFO and LPG
...

Area 4 has three process units namely Dimersol, Butane Isomerisation and Alkylation
units
...

Area 5, which is the old refinery, is made up of the Crude Distillation Unit (CDU); the
Platform Unit (CRU), the LPG Unit, as well as utilities section
...
There are four (4) turbo-generators each with a capacity of 14MW of electricity per
hour and four (4) Boilers, capable of generating 120 tons of steam per hour each
...
The refinery has a pool
of maintenance personnel that take care of routine, programmed and emergency repairs of
equipment
...


PRODUCTS:

PHRC produces the following products; Liquefied petroleum gas (LPG), Premium motor spirit
(PMS), Kerosene (aviation and domestic), Automotive Gas oil (AGO –diesel), Low pour fuel
oil (LPFO), and High pour fuel oil (HPFO)
...


QUALITY POLICY AND OBJECTIVES:

PHRC is committed to always offer Petroleum Products and Services that shall fulfil our
customers' requirements and expectations using modern technology at prices that guarantee
customers' value, stakeholders' continued interest and support
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

Deliver all products on specifications
...




·

Strive to achieve nil accident annually
...




Be a responsible corporate citizen by contributing to the social and economic development
of our contiguous communities
...

Compliance with these Policy and Objectives, which shall be communicated to all staff, is
mandatory
...


OPERATIONS AND SERVICES DIRECTORATES, AND KEY DEPARTMENTS

There are two Directorates - the Operations and Services Directorates - with 16 main
Departments in the establishment
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

Maintenance
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

Engineering and Technical Services
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

Health, Safety and Environment
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

Finance and Accounts
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

Administration
...

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

Public Affairs
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

Security
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

Company secretary &Legal Department
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The current Managing director of PHRC is
Dr Bafred Enjugu
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T/SIWES students attached to the various departments

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Figure 1: Organogram of PHRC

PPU

EXPERIENCE GAINED AT PHRC

The experience gained at the completion of my internship were numerous, as a student
of Electrical/Electronics engineering, I have been able to obtain the relevant and effective
practical industrial skills and knowhow needed
...
Also an awareness of the general workplace has been developed in me and I
have acquired important behavior with the opportunity given me get a feel of the work
environment and as a student of Electrical/Electronics to Electrical/Electronics
responsibilities and ethics
...




Teamwork and how to function as part of group
...




How to install gauges
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2 CHAPTER 2

At PHRC, the primary work done there is the refining of crude oil into its various useful
end products
...
Each personnel is issued a color code
according to his section
...


During my stay, I was assigned to the Maintenance Department to be attached to
Instrumentation section
...
I was deployed to the PPU unit
...

The figure below shows the structural organization of Maintenance department
...


These 2 sections are further divided into 12 units;

There are twelve (12) units designed to provide these services as outlined below: -



Waste Water Treatment (Unit 62): Treatment of industrial effluents or
wastewater and sewage from process units and other unit of the refinery
...




Steam Generation (Unit 70): Generation of high pressure, medium pressure and
low pressure steam required for power generation and other refinery operations
...




Raw Water (Unit 72): Treatment of raw water for distribution to the demine
plant, process units common services, fire-fighting and offsite facilities
...


Figure 2-1 : Demin Plant



Cooling Water (Unit 74): Provides cooling water for all cooling

whole-utility plants, process plants, offsite and other cooling medical
...
Plant

Air (Unit 75): Supplies instrument and services air

instrument operations, general plant services and backup to nitrogen unit
...



Fuel Gas (Unit 77): receives gas from process units to feed boilers combustion
system at suitable conditions to different user, mostly boilers operations
...
Significantly, electricity, steam and all these utilities
are very essential to the operations of the

Port Harcourt refinery, which

makes power plant
...


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STRUCTURE OF PPU

Power Plant/Utilities (PPU)

Power Plant (Hot Utilities)

Utilities (Cold Utilities)

Units
Units

Unit 70

Unit 71

Unit 77

WWT (Unit 62)

Unit 68
Bio-Treatment

Boiler

(Turbo-

(Stream

Generator

Generation)

DAF-

Electric

(Fuel Gas)

(Fuel Oil)

Treatment

Power

Unit 72

Unit 73

Unit 74

Unit 75

Unit 76

Unit 80

Unit 81

Service/raw

(De-mine

(Cooling

(Instrument/

(Nitrogen)

(Caustic

(Well

Water

Plant)

Water)

Plant Air

Soda)

Water or
Borehole
Water)

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Figure 2-4 : PPU and its units

POWER PLANT UNIT
Power plant is made up of 4 units; unit 68 (fuel oil), unit 70 (Steam generation), unit
71(turbine generator), and unit 77(fuel gas)
...


UTILITIES UNIT
Utilities is made up of 8 units; unit 62(WWT), unit 72(Raw water), unit 73(demineplant), unit 74(Cooling system), unit 75(Plant and instrument air), unit 76(Nitrogen plant), unit
80(Caustic soda plant), unit 81(Borehole water)
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

Work starts by 8am, The work logbook is consulted to find out if there are any
outstanding jobs
...




In the absence of any outstanding job, I await instructions from the instrumentation
superintendent, or for the Production personnel (Operators) to raise a job permit
informing us of a job to be carried out
...
The
warehouse also stores new equipments
...




On days where there ae no emergent jobs, lunch break is 12pm -12;30pm



At around 4 I go to sign out, this indicates I have closed for the day
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Firing of Boilers and maintenance of its accessories such as iris eye and opacity meter
2
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Installation of pressure gauges
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4
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Zero checking of differential transmitters
6
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There are 4 Boilers, two (2) sets of Deaerators and feed water tanks, four high pressures at a
pressure of 70kg/cm2 -two of these pumps are Electronic Motor driven whereas the other
are Steam Turbine driven and two medium pressure feed water pumps
...
Each Boiler is capable of producing 30
tons of steam per hour
...

The water that’s heated rises into the steam drum
...
In some cases, it can be returned
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to the Furnace via the Superheater to be reheated
...
The boiler comes with a local panel, where relays, switches and all other
electronic devices are connected
...
Hence the Deaerator

removes dissolved oxygen by heating the water with the steam in a deaerating heater
...


Figure 2-7 ; Deaerator

The mineralized Water (water free from ions) is received in the Deaerators from utilities unit
where it is freed of air by flashing with low

pressure steam (3kg/cm2)
...


The upper beadier of each tube well conveys the steam-water mixture to the upper
drum where steam separates and

collects in the vapor space from the vapor space of the

upper drum, the saturated steam flows across the “demisting and drop separating devices”
also called scrubbers, into the superheated section them
...
Flue Gases
leaving the combustion chamber pass across tube bundles where heat transfer takes place,
mainly by Convection
...
When the Boiler pilot is on,
the iris eye senses and sends an output to the signal processor (scanner), which is located in the
Boiler local panel, the scanner processes this signal and sends an output to the Plc indicating
the presence of flame in the Boiler
...
The smoke meter ‘readout’ displays the smoke
density giving a measure of the efficiency of combustion
...
Usually, switches
are used to activate alarms to alert human operators to take special action
...
There are different switches such as pressure
switches, temperature switches,

Electrical switch contacts are typically classified as

either normally-open or normally-closed, referring to the open or closed status of the contacts
under “normal” conditions
...


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Figure 2-11: Contacts

Some of the switches worked on are

•

Pressure switch
...


•

Temperature switch
...

2
...
1 PRESSURE SWITCH

The “PSH” (pressure switch, high) activates when the air pressure inside the vessel
reaches its high control point
...
Both switches feed discrete (on/off)
electrical signals to a logic control device (symbolized by the diamond) which then controls
the starting and stopping of the electric motor-driven air compressor
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2
...
2

HAND SWITCH
As the name implies, the hand switch is an electrical switch actuated by an
operator’s hand motion
...


Figure 2-12 : Action of a hand switch

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2
...
3

LIMIT SWITCH

Limit switches detect the physical motion of an object via direct contact with that object
...
11
...
Good example of a float-type level switch is the
Boiler level switch
...
11
...


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Figure 2-16a : Temperature switch

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Figure 2-15b : Temperature switch showing probe

GAUGES
Gauges are used to measure and display physical variables such as pressure and temperature
...


Figure 2-17 : Gauges

VALVES
A valve is a device that regulates, directs the flow of a fluid by opening, closing or partially
obstructing various pathways, Valves are placed along a process line to limit /control process
variable
...
They can also be classified by how
they are actuated: Hydraulic, pneumatic, manual, solenoid valves

Figure 2-18 : Valves

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SOLENOID VALVE

A solenoid valve is an electromechanically actuated/operated valve
...
A 2-way valve has 2 ports; if the valve is closed then ports are isolated
...

Similarly, if the valve is closed when the solenoid is not energized, then the valve is termed
normally closed
...
Ideally when a solenoid receives
current or when its energized, the solenoid causes the valve stem to move
...
This enables the direct control of flow rate and the
consequential control of process quantities such as pressure, temperature, and liquid level,
according to the process design In automatic control terminology a control valve is termed a
"Final Control Element"
...
16
...
e
...


Figure 2-20b ; A positioner with the cover removed; The flapper is
shown

Figure 2-21a : A positioner

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2
...
2 PNEUMATIC AIR REGULATOR
The Pneumatic air regulator controls the compressed air that comes in or leaves the
actuator or diaphragm
...
16
...
, 2009) etc
...
The differential transmitter measures liquid, gas, or steam flow as
well as liquid level, density and pressure
...


Figure 2-24: A Rosemount differential Transmitter with one impulse line

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Figure 2-25 : A differential transmitter (case removed) with 2 impulse lines shown

Figure 2-26 : A differential transmitter

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2
...
At PHRC junction boxes are used to house the connecting
point between wire from the plant and wire frim the control room
...


Figure 2-27 ; Terminal blocks

2
...
Programmable logic controllers (PLCs) have been an integral part of factory
automation and industrial process control
...
These
systems perform many functions, providing a variety of analog and digital input and output
interfaces; signal processing; data conversion; and various communication protocols
...
In PPU, the Plc controls all the activities of the various equipments installed in
the plant, Each Equipment has a set of instructions programmed into a controller with computer
language, the program is written on a computer and is downloaded to the PLC via cable
...
A visual programming
language known as the Ladder Logic was created to program the PLC also any new major
equipment to be installed at PPU is integrated into the Plc
...
In the case of an Equipment tripping off or
unable to start, The Programmer unit in the Plc is checked to see if the startup requirements are
met
...


Figure 2-28 : Cross section of PLC

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Figure 2-30 : Cross section of PPU control room

Figure 2-29 : Ladder diagram from PLC (Hanon Nigeria, Plc, 2015)
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3 CHAPTER 3
DISCUSSION, ANALYSIS, EVALUATION

At PHRC, before a job is carried out at PPU, a job permit has to be raised by the operators from
PPU
...
A hot permit is raised for jobs involving welding, and a cold permit
for jobs that won’t involve welding
...
A plan for action is always drawn
...


Figure 3-1 : Sample of a job permit

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ANALYSIS OF WORK DONE
3
...
1 STARTING A BOILER
The boiler and auxiliary equipment requires special operator attention during start up
...
The boiler is started/fired by the
instrumentation engineers, requirements for firing the boiler include current, Lpg (liquefied
petroleum gas), Fuel oil, instrument air
...
2
...
Combustion in the boiler starts at the Burner, the burner is made up of 2
parts; the pilot gun which contains the Lpg line, airline, spark plug and power line; The main
burner where the atomizing steam and fuel oil flow into
...
, the water column shutoff
valves and steam pressure gauge valve
...
The solenoid coil is powered and it sends current to the spark plugs which creates
a spark in the Burner
...
The flame from the pilot gun meets up with the fuel oil and atomizing steam in the
main burner and combustion occurs, Once the flame detector detects the flame a signal is sent
to the signal processor(scanner) which in turn processes this signal and outputs it to the PLC
and the boiler is said to have been started
...
5kg/cm2 One (1) Red

Figure 3-2 ; Control room view of the boiler 4

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the

Figure 3-3: Boiler burner showing the main burner, Pilot gun (NNPC, 2016)
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3
...
3 BOILER ACCESSORIES
FLAME DETECTOR

Boiler accessories such as the flame detector is very important in the operation of the boiler,
care is to be taken to ensure that the flame detector is working properly
...
The flame detector/ iris eye is removed from the
Burner and tested (J
...


3
...
4 PROCEDURE



Loosen flame scanner



Remove from burner assembly



Cover flame scanner sensor to stimulate failure
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

Replace flame scanner



Reset the scanner
...
A faulty gauge can cause a
lot of problems because if a process is not properly monitored the safety of that process can be
compromised
...


3
...
1 PROCEDURE FOR INSTALLING GAUGES



The range of the switch to be installed must be known, the range should be
approximately twice the maximum operating pressure
...

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

Gauges should be installed at points where there is little vibration, and moisture, if
it’s to be installed in a place with vibration, glycol is poured into the gauge to
prevent the pointer deflection when vibrating
...




When applicable, Teflon is used in the probe the end to avoid leakage of process
material along the line
...
4
...




Care must also be taken when handling the terminal blocks
...

VALVES

Before carrying out maintenance on a valve, the type of valve should be known
...
The various parts of the valves and their functions should be known
too (Kuphaldt, 2016)
...
5
...




For a valve with a faulty solenoid (in the case of a solenoid valve), Disconnect

the live wire and ensure to avoid it touching the body of the casing so as to avoid short
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circuiting of the solenoid, if a clipping sound is heard this means the solenoid is
powered, also if the solenoid is warm to the touch it indicates that the solenoid is
working
...
But if the solenoid is found to be totally bad, the wires are insulated and the
whole coil is removed and taken to the Maintenance workshop
...




Faulty Relays are removed and cleaned, any blocked outlet on the pneumatic relay
must be cleared out before reinstalling the pneumatic relay
...


CURRENT
4Ma
8Ma
12Ma
16Ma
20Ma

POSITION
0%
25 %
50 %
75 %
100 %

As seen from the table, the amount of current injected will cause the stem to travel the
distance appropriated, For example: 4mA will give 0 % open if the valve is an A
...
O valve
i
...
an air fail open valve (On failure of air pressure to actuator, the valve opens under spring
pressure or by backup power) and 20mA will yield 100% open
...
F
...



In extreme cases where it is found that the Valve seat is bad, the valve will be
brought down with the aid of Mechanical maintenance men and taken to
Maintenance workshop
...
It should be done
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regularly or when one suspects an error in the readout of the said transmitter
(Emerson Electric co
...
6
...




The remaining product stuck inside the transmitter is flushed away, then we
commission the high and low side of the transmitter (open them up for process
material to flow into them)
...
Adjustments will be made
continuously till we arrive at a differential of 0
...


JUNCTION BOXES AND TERMINAL BLOCKS
The major work done on a junction box is changing the terminal blocks, especially
if moisture gets into the Junction box, over time the wires may have become loose,
or the Terminal blocks, rusted (Weidmuller, 2013)
...
7
...




The junction box is then opened with the aid of an adjustable spanner



The Faulty terminal blocks are removed and replaced with new ones, (care should be
taken to ensure that the terminals of the junction box are tightened properly)
...
Assistance was rendered to us when needed
...

Although there were times when we found it difficult to take faulty equipment to the
workshop due to lack of vehicles
...
In addition, another issue I found the working conditions during the rainy
season to be appalling especially emergency jobs, we had to work under intense rain
...
T students and not make proper arrangement for them, the
I
...
I would love this issue to be corrected
in subsequent years so, students can learn while being assured that the management have
their best interest at hand
...
During the 6 Months I was exposed to practical’s on-site situations and activities
...

Finally, I would like to state that the SIWES program is a very relevant and necessary
program for all students and should be taken advantage of by students for professional
development before graduation
...
In that same vein I would love to use this avenue to give a few
recommendations; Firstly, The SIWES program should be integrated into all tertiary
institutions in Nigeria and made compulsory to all students of all Disciplines, so as to
enable them gain ample practical Industrial based skills
...


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BIBLIOGRAPHY
ADEOLA, O
...
A Technical report on student industrial work experience scheme, s
...
: s
...

Anderson, N
...
, 2012
...
s
...
:s
...

DEPARTMENT OF PETROLEUM RESOURCES(DPR), 2016
...

Emerson Electric co
...
Fisher 4200 Electronic positioner Transmitter
...
10
...
Ladder diagram
...
15
...
B Systems, 2007
...
February
...
3
...
, 2016
...
Version 2
...

s
...
:s
...

Kuphaldt, T
...
LESSONS IN INDUSTRIAL INSTRUMENTATION
...

s
...
:Creative commons attribution, p
...

NNPC, 2016
...

ololade, A
...
, 2016
...
n
...


Available

at:

Controls

and

electrical

design
...
rndautomtion
...

Weidmuller, 2013
...
l
...


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APPENDIX

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48



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