Cavitation in Centrifugal Pumps and Fouling in Heat Exchangers in The Mechanical Side of KEMYA Plants .pdf

King Fahd University of Petroleum & Minerals
College of Engineering Sciences
Mechanical Engineering Department
Coop Training Program
“Al-Jubail Petrochemical Co”
Company logo
If available
Cavitation in Centrifugal Pumps and Fouling in Heat
Exchangers in The Mechanical Side of KEMYA Plants
Prepared by: Alwaleed Alharthy

SEMESTERS (213) - (221)
2/32
ME 350-351 COOP TRAINING REPORT
Summary
This technical report focuses on the oil byproduct company, KEMYA, located in Jubail
industrial city. The report begins by providing an introduction to the parent company,
SABIC, and then gives a brief overview of the plants and processes at KEMYA, as well
as the safety systems in place. The report then delves into a comprehensive theoretical
background on centrifugal pumps and includes two case studies that are designed to
identify and resolve specific issues. The first case study examines the centrifugal pump
with the tag number MP-01 in the KOP plant, specifically focusing on the cavitation
problem and potential solutions. The second case study looks at the heat exchanger with
the tag number XE-01, discussing the design of the shell and tube heat exchanger and
addressing the issue of fouling and ways to reduce it. a proposed design of a cleaning
equipment tailored to address an issue in the quench tower is also given. The report then
reaches a conclusion and gives recommendations and references for further research and
implementation.
Acknowledgement
I would like to extend my deepest appreciation to all those who have contributed to the
success of this report. A special thanks to Mr. Khalid Alzahrani for his invaluable help in
making the training process as smooth as possible and for always being accommodating
to questions and enquiries. I am also grateful to Sr. Manager Mr. Feras Alshubaili for
providing assistance in the workplace and workflow, as well as his valuable insight in the
mechanical field. My thanks also go to Engineers Abdullah Alqarni and Salman
Alshammari for sharing their experience and knowledge in the field, and for being open
to questions. My gratitude also goes to Dr. Mohamed Habib for his guidance and notes
throughout the writing of this report. I am truly grateful for the opportunity to work with
such a dedicated and supportive group of individuals.

SEMESTERS (213) - (221)
3/32
Table of Contents
List of Figures......................................................................................................................................... 5
List of Abbreviations and Symbols......................................................................................................... 6
Chapter 1................................................................................................................................................. 7
Introduction to coop Activities ............................................................................................................... 7
1.1 Introduction .............................................................................................................................. 7
1.2 Company Profile ...................................................................................................................... 7
1.2.1 Company Plants.................................................................................................................... 7
1.2.2 Integration Between Plants Within the Company ................................................................ 8
1.3 Company Organization ............................................................................................................ 8
1.4 Safety Issues in The Workplace............................................................................................... 8
1.4.1 General Safety Rules in KEMYA ........................................................................................ 8
1.4.2 LSR: Life Saving Rules........................................................................................................ 9
1.5 Coop Plan (In the Appendix) ................................................................................................ 10
1.6 Discrepancy From the Coop Plan Activities.......................................................................... 10
Chapter 2............................................................................................................................................... 11
Theoretical Background........................................................................................................................ 11
2.1. Introduction ............................................................................................................................ 11
2.2 Theoretical Background ......................................................................................................... 11
Chapter 3............................................................................................................................................... 14
Work Activities and case studies .......................................................................................................... 14
3.1 Introduction ............................................................................................................................ 14
3.2 Main Activities ...................................................................................................................... 14
3.3 Case Study 1: Cavitation........................................................................................................ 15
3.3.1 Locations ............................................................................................................................ 15
3.3.2 General Description............................................................................................................ 15
3.3.3 Critical Factors ................................................................................................................... 15
3.3.3.1 NPSHA and NPSHR....................................................................................................... 16
3.3.4 Specifications of Pump MP-01 In KEMYA....................................................................... 18
3.3.5 Cavitation Region............................................................................................................... 18
3.3.6 Cavitation Damage ............................................................................................................. 19
3.3.7 Solutions To Cavitation...................................................................................................... 19
3.4 Case Study 2: Fouling ............................................................................................................ 20
3.4.1 Locations ............................................................................................................................ 20
3.4.2 General Description............................................................................................................ 20

SEMESTERS (213) - (221)
4/32
3.4.3 Critical Factors ................................................................................................................... 21
3.4.4 Fouling: Definition and Causes .......................................................................................... 21
3.4.5 Fouling Factor..................................................................................................................... 21
3.4.6 Specifications of Heat Exchanger XE-01 In KEMYA....................................................... 22
3.4.7 Effects of Fouling on Heat Transfer................................................................................... 23
3.4.7.1 Using LMTD To Show the Effect of Fouling On XE-01 ............................................... 23
3.4.8 How To Reduce Fouling..................................................................................................... 24
Chapter 4............................................................................................................................................... 26
Design Component................................................................................................................................ 26
4.1 Introduction ............................................................................................................................ 26
4.2 Quench Tower Cleaning Tool................................................................................................ 26
4.2.1 The Process of The Quench Tower .................................................................................... 26
4.2.2 Quench Tower Incident ...................................................................................................... 26
4.2.3 Suggested Design for The Quench Tower Cleaning Tool.................................................. 27
4.2.4 The Working Concept of The Quench Tower Cleaning Tool............................................ 28
Chapter 5............................................................................................................................................... 29
Conclusion and Recommendation ........................................................................................................ 29
5.1 Conclusions............................................................................................................................ 29
5.2 Recommendation.................................................................................................................... 29
References............................................................................................................................................. 30

SEMESTERS (213) - (221)
5/32
List of Figures
Figure1 a map of the KEMYA plants 7
Figure2 the LOTTO system used in KEMYA 8
Figure3 the PPE used in KEMYA 8
Figure4 the weather category system used in KEMYA 9
Figure5 a cross sectional side view of a centrifugal pump 11
Figure6 the parts of a centrifugal pump 11
Figure7 cross sectional top view of a centrifugal pump 11
Figure8 the efficiency vs volumetric flow rate curve 11
Figure9 the head vs volumetric flow rate curve 11
Figure10 the work vs volumetric flow rate curve 12
Figure 11 the pump performance curves 12
Figure 12 cooling towers 14
Figure 13 a pump overhauling 14
Figure 14 a turbine overhauling 14
Figure 15 a visual representation of cavitation 15
Figure16 NPSH vs Q vs head 16
Figure 17 the vapor pressure of varies liquids vs temperature 16
Figure 18 a cross sectional view of a centrifugal pump 17
Figure 19 the dip in pressure drop in different locations inside the pump 17
Figure 20 the MP-01 pump design 18
Figure 21 a linear plot of the NPSH curves 18
Figure 22 the cavitation region 18
Figure23 the damage done by cavitation on different parts of the pump 19
Figure24 a shell and tube heat exchanger 20
Figure25 the passes inside the heat exchanger 20
Figure 26 external fouling of tubes 21
Figure27 the internal fouling of shell and tubes 21
Figure 28 the fouling resistance of different fluids 21
Figure29 the BEU shell and tube heat exchanger 22
Figure30 the efficiency VS Rf curve 23
Figure 31 the temperature vs position curves for cold and hot fluids inside the heat exchanger 23
Figure 32 temperature sensors 24
Figure33 a pressure gauge 25
Figure34 antifouling paint 25
Figure35 PFPE and PTFE spray 25
Figure36 quench tower 26
Figure 37 the process of the quench tower 26
Figure38 sketch of the design for the cleaning tool 27
Figure39 final design for the cleaning tool 28
Figure40 a steam pressure washer 28
Figure41 nozzle head 28

SEMESTERS (213) - (221)
6/32
List of Abbreviations and Symbols
KEMYA: Al-Jubail Petrochemical Company
SABIC: Saudi Basic Industries Corporation.
CEO: Chief Executive Officer
KOP: KEMYA Olefins Plant
LDPE: Low Density Polyethylene
LLDPE: Linear Low-Density Polyethylene
PBR: Poly Butadiene Rubber
SBR: Styrene-Butadiene Rubber
EPDM: Ethylene Propylene Diene Monomer
HB: Halo Butyl
MTBE: Methyl Tert-Butyl Ethe:
CGC: Charged Gas Compressor
EHSS: Environment, Health, Safety and Security
PPE: Personal Protection Equipment
LOTO: Log Out/Tag Out
LSR: Lifesaving Rules
NPSHA: Net Positive Suction Head Available
NPSHR: Net Positive Suction Head Required
PM: Periodic/Preventive Maintenance
ABB: ASEA Brown Boveri
LMTD: Log Mean Temperature Difference
PTFE: Polytetrafluoroethylene
PFPE: Perfluoropolyether

SEMESTERS (213) - (221)
7/32
Chapter 1
Introduction to coop Activities
1.1 Introduction
Founded in 1980 with initial production starting in 1984, the Al-Jubail Petrochemical Company
(KEMYA) is a joint venture between SABIC and ExxonMobil. To supply the domestic, regional, and
international markets, the company has the capacity to produce ethylene at a rate of around 900,000
tons annually and low density and linear low-density polyethylene at a rate of over 1.3 million tons
annually. KEMYA was founded with the primary objective of producing ethylene and polyethylene
from the excess ethane and propane that were previously burned off. Since then, it has proven that it is
committed to fostering a local rubber industry in Saudi Arabia that supports job creation, develops
downstream industries, and aids in economic diversification.
Saudi Basic Industries Corporation (SABIC) was established in 1976 by royal decree. Ghazi Abdul
Rahman Al Gosaibi served as the organization's first chairman, and Abdul Aziz Bin Abdullah Al Zamil
served as its first CEO. Its primary objective is to transform oil waste into beneficial chemicals,
polymers, and fertilizers. Over 40,000 people are now employed by SABIC worldwide across 60
manufacturing and compounding facilities in 40 different nations. The production network of SABIC
in Saudi Arabia comprises of 18 affiliates, the majority of which are situated in Jubail Industrial City.
The $3.4 billion investment in the new elastomers facility at the KEMYA site, which marks a
considerable expansion of KEMYA's product line, demonstrates SABIC and ExxonMobil's
commitment to promoting a local rubber sector in Saudi Arabia. The strategic partnership between
SABIC and ExxonMobil provides the strength of industry-leading competitive assets, introduces new
specialty products to the Kingdom and offers global marketing and supply capability of exceptional
quality. [1]
1.2 Company Profile
1.2.1 Company Plants
KEMYA consists of 8 plants as of
2022 as shown in figure1. These plants
are: KOP, LDPE, LLDPE, PBR /SBR,
EPDM, HB, MTBE and utilities. KOP
also known as KEMYA Olefins Plant
produces olefins which are
hydrocarbons containing a carbon –
carbon double bond. This is achieved
by braking one of the bonds in the
ethane to create the double bond. The
LDPE plant is a plant that produces
Low Density Polyethylene by
pressurizing the ethylene up to 3000
bar using a series of compressors and
activating it chemically to make the
polymers. The LLDPE uses a different
process to produce Linear Low-Density Polyethylene. The HB plant produces Halo Butyl. The
MTBE plant produces Methyl Tert-butyl ether. The PBR plant produces Poly Butadiene Rubber.
The EPDM plant produces Ethylene Propylene Diene Monomer and the utilities plants provides the
other plants with the utilities they need for production like steam or sea water.
Figure1 a map of the KEMYA plants

SEMESTERS (213) - (221)
8/32
1.2.2 Integration Between Plants Within the Company
Each of these plants has its own line of production, but all of the plants are connected to ensure full
efficiency in the production. As an example, ethane comes into the olefins plant through a feedstock
that comes from Aramco. The gases undergo steam cracking, then they enter furnaces with steam
dilution to reduce the cock formation in the tubes. After that they enter a shell and tube secondary
exchanger after that they enter the convection section. After the convection section they enter the
radiant section. After the radiant section, the gas enters the two tube-in-tube heat exchanger, which
are the primary exchangers. Which marks the end of cracking. After cracking the gasses are then
quenched in the quench tower and they are then sent to the CGC (charge gas compressor) which
has 5 stages. After being compressed, hydrogen separates leaving the rest of mixed gasses. The
mixed gasses are then sent to Demethanizer, separating the C1, then the Dethenizer, separating C2
then the Depropnizer separating C3, until nothing is left other than heavies and C4 which are also
utilized. Any acetylene that was created during the process goes to the hydrogenation reactor to be
turned into ethylene. Some of the ethylene from that process will also be used in the LDPE plant.
The process starts with ethylene coming from KOP and through a series of compressors, its pressure
is taken from 30 to 300 Bar. After that it’s cooled to be compressed even further. After its pressure
reaches 3000 Bar, it’s then taken to the reactor where 6 initiator points add additives to start the
formation of polyethylene. After that the polyethylene is taken to an extruder and fed through a
screw and cut into desired shape, then it gets water cooled. After being water cooled it’s then taken
to a dryer that removes all moisture and after that it’s taken to blenders and packaged and shipped.
Along the process, excess gas is recycled and cooled or compressed to be sent back into the
production pipeline. Whatever wax that was developed during the process is trashed since it has no
valid use.
1.3 Company Organization
SABIC operates through three Strategic Business Units – Petrochemicals, Agri-Nutrients and
Specialties – and one standalone organization, Metals (Hadeed). They support customers by identifying
and developing opportunities in key end markets such as construction, medical devices, packaging, agri-
nutrients, electrical and electronics, transportation and clean energy.
1.4 Safety Issues in The Workplace
1.4.1 General Safety Rules in KEMYA
KEMYA is by far the safest SABIC
affiliate. Since it is a joint venture with
Exxonmobil, both of the corporations
combined their safety expertise together
to create a more robust EHSS foundation
to ensure the safety of the people and the
environment. The EHSS department in
KEMYA is concerned with all health and
safety rules and problems that can happen
inside the bounds of the company, from
buckling the seatbelt while driving to
ensuring the safety of worker from any
life-threatening violations or hazards. Inside the company, smoking is
prohibited due to the chemical nature of the company atmosphere. No
horseplay or running is allowed to avoid any injuries. It is highly enforced that any driver must wear
their seatbelt and adhere to the signs and drive under the speed limit of 25 Km/hr. Inside the plant,
any worker or visitor must wear the proper PPE as shown in figure3 consisting of fire-resistant
Figure2 the LOTTO system used in KEMYA
Figure3 the PPE used
in KEMYA

SEMESTERS (213) - (221)
9/32
clothes, a helmet, gloves, glasses, earplugs and
safety shoes. This is done to avoid any injuries
inside the plants. Some places might require
special PPE depending on the level and kind of
hazard in that place such as goggles, earmuffs and
harnesses. Some of the safety precautions set to
eliminate hazards from occurring is the LOTO
system (figure2), in which a lockout device a tag
is placed on an energy isolation device. Another
system that has been implemnetned to ensure the
sfatey of the workers is the weather category.
Harmful effects can occur when the body
becomes overheated and large amount of water
and salts are lost through profuse sweating while
at or after work or exercise in a hot environment.
and that’s why the EHSS depratment made sure
to catogrize the working conidtions for the
benefit of the workers which are shown in detail
in figure4.
1.4.2 LSR: Life Saving Rules
LSR is a list of 10 rules that are set to prevent the occurrence of any fatal incidents. The first rule is
related to safe systems of work. This rule states that workers should not work without a valid work
permit issued for that specific job, stating the hazards that could occur and the location and time of
the procedure. The second rule is related to confined space entry, which states that a worker should
not enter a confined space without a valid entry permit. This rule has been set to avoid endangering
the lives of workers by exposing them to hazardous atmosphere inside that confined space. The
third rule is related to working at height. The rule states that any worker working at a height more
than 1.8 meters must wear a harness. This is done to avoid endangering the workers by putting them
at risk of falling from height. The fourth rule is related to lifting operation using cranes. The rule
states that no one should ever walk under suspended loads. This is meant to prevent any person
from being under the load if it happened to drop. The fifth rule is related to line breaks. This rule
states that no one should open process equipment without verifying the correct location. This rule
is set to prevent the release of any hazardous material or trapped pressure which might result in an
injury. The sixth rule is related to energy isolation. The rule states that no work can be done before
confirming isolation and applying LOTO. This is done to prevent the exposure of workers to
mechanical, electrical, radiation or any form of energy. The seventh rule is related to openings
created whether by removing a part of the scaffolding or removing the lid of a pipe or any other
way. This rule states that openings created by any worker needs to be barricaded using hard
barricade. This is done to eliminate the chance of any person falling in that opening. The eighth rule
is related to disabling safety systems. This rule states that SHE critical devices such as relief valves,
extinguishers, sprinklers must not be disabled without the proper approval. This rule is meant to
make sure that all safety systems are always running and any disabled safety system is properly
noted because if they were to fail suddenly, they wouldn’t be able to protect against the hazards for
which they were assigned. The ninth rule is related to vehicle safety. This rule states that every
driver inside the company must not ride a vehicle without wearing seat belt and needs to respect
speed limit of 25 km/hr. this is done to prevent the vehicles from coming into contact with
pedestrians. Other vehicles, plants, installation or the presence of an ignition source. Lastly, the
tenth rule is related to Management of change, and it states that none can modify or change
Figure4 the weather category system used in KEMYA

SEMESTERS (213) - (221)
10/32
equipment without proper approval. This is done to eliminate the danger due to changes or
modifications to equipment, processes installations or staffing.
1.5 Coop Plan (In the Appendix)
Please refer to Appendix A for the coop plan
1.6 Discrepancy From the Coop Plan Activities
Due to lack of opportunity, a formal training was not given and therefore the participating in overhauling
of a centrifugal pump and steam turbine were not possible. As for engaging with the Instrument team
and getting an overview of instrument devices, this was not possible due to the fact that the instrument
team were engaged in a project that required them to be in field during the week in which the meeting
was meant to be held. Similarly, the electrical team were participating in the same project. As for DCR
activities, the opportunity didn’t arise to work on an activity since none were being worked on during
the 7 months coop period. As for participating in the KOP furnace retubing and the cooling optimization
in LDPE, this couldn’t be arranged since these activities were held during the night shift.

SEMESTERS (213) - (221)
11/32
Figure9 the head vs volumetric flow rate curve Figure8 the efficiency vs volumetric flow rate curve
Chapter 2
Theoretical Background
2.1. Introduction
As stated in the introduction section of this paper, KEMYA has many plants. Each plant has a production
line that requires specific machinery. As an example, In the KOP plant, the process is heavily focused
on heating and compressing gas. Those processed require special furnaces and an array of compressors.
However, across all plants, a specific piece of machinery proves important, and that is the pump.
2.2 Theoretical Background
A pump is a device that moves fluids (liquids or
gases), by mechanical means. They can be
classified into two basic categories based on the
procedure of which the fluid is moved. The
categories are: dynamic and positive
displacement. Positive displacement pumps move
the fluid by enclosing a fixed volume repeatedly
in a cyclic action. Positive displacement pumps
could be driven by pistons, screws, gears,
diaphragms, vanes or rollers. However, in
dynamic pumps, the energy is transferred
continuously by means of delivering kinetic energy to the
fluid, increasing its velocity as it passes through the impeller. This
increased velocity is then transformed into pressure. The most
commonly used pump in KEMYA plants is a dynamic pump called
the centrifugal pump (figure5&7). Centrifugal pump is a type of
dynamic pump that uses centrifugal force to convert mechanical
energy into hydraulic energy through two major components of the
pump: volute casing (F in figure6) and impeller (J in figure6). The
volute casing is there to gather the liquid while it’s exiting, and the
impellers job is to transform the velocity into pressure. Centrifugal
pumps are most commonly used to pump liquids from low head to
high head. If the discharge of a centrifugal pump is pointed upwards (as in the figure6) the fluid will
pumped to a certain height, which is called the shut off head. This maximum head is mainly determined
by the outside diameter of the pump's impeller and the speed of the rotating shaft. The head can change
if the capacity of the pump is changed. [2] [3] [4]
The characteristic curve of a pump is the interaction of two variables which are the head (H) which can
be defined as the energy by unit of mass that the pump can supply to the fluid and the flow rate (Q)
which is the quantity of fluid that goes through a section in a certain period of time. In the left-hand
side, the curve has the head plotted on the Y axis and the flow rate on the X axis. The performance
curve on the right shows the relation between the rated power of the pump and the absorbed power also
known as the efficiency, in relation to the volumetric flow rate. [5]
Figure5 a cross sectional side view
of a centrifugal pump
Figure7 cross sectional top view
of a centrifugal pump
Figure6 the parts of a centrifugal pump

SEMESTERS (213) - (221)
12/32
The absorbed power curve shown in figure10
shows the electric power used in relation to
the flow rate. In fluids the term head is used to
measure the kinetic energy which a pump
creates. Head is a measurement of the height
of the liquid column the pump could create
from the kinetic energy the pump gives to the
liquid. [5]
The head of a pump H can be expressed in metric units as:
𝑯 =
𝒑𝟐 − 𝒑𝟏
⍴𝒈
+
𝒗𝟐
𝟐
𝟐𝒈
Where
H = total head developed (m)
𝑝2 = pressure at outlet (N/𝑚2
)
𝑝1= pressure at inlet (N/𝑚2
)
ρ = density (kg/𝑚3
)
g = acceleration of earth’s gravity (m/𝑠2
)
𝑣2 = velocity at the outlet (m/s)
Pump efficiency, η (%) is a measure of the efficiency with which the pump transfers work to the
fluid.
η = 𝑷𝐨𝐮𝐭 / 𝑷𝐢𝐧
Where
η = efficiency (%)
𝑃in = power input
𝑃out = power output
The shaft power 𝑃in is the power required from the motor to drive the shaft
The ideal hydraulic power to drive a pump 𝑃out depends on
• the mass flow rate the
• liquid density
• the differential height
Figure10 the work vs volumetric flow rate curve
Figure 11 the pump performance curves

SEMESTERS (213) - (221)
13/32
It can be calculated like
𝑷𝐨𝐮𝐭 =
𝑸 𝝆 𝒈 𝒉
𝟑.𝟔𝐱 𝟏𝟎𝟔
Where
Q = flow (𝑚3
/h)
ρ = density of fluid (kg/𝑚3
)
)
h = differential head (m)
p = differential pressure (N/𝑚2
, Pa)
since 𝑯 =
𝒑𝟐−𝒑𝟏
⍴𝒈
+
𝒗𝟐
𝟐
𝟐𝒈
and hv =
𝑝𝑣
𝛾𝑣𝑎𝑝𝑜𝑟
then NPSH𝐴= h – hv – hs – hf , can also be expressed as:
NPSH𝐴 =
𝑝2−𝑝1
𝛾𝑙𝑖𝑞𝑢𝑖𝑑
+
𝑣2
2
2𝑔
−
𝑝𝑣
𝛾𝑣𝑎𝑝𝑜𝑟
− ℎ𝑓 − ℎ𝑠
Where,
𝑝2 = pressure at outlet (N/𝑚2
)
𝑝1= pressure at inlet (N/𝑚2
)
γliquid = specific weight of the liquid (N/𝑚3
)
vs = velocity of fluid (m/s)
)
pv = vapor pressure (N/𝑚2
, Pa)
γvapor = specific weight of the vapor (N/𝑚3
)
hs = static head (m)
hf = friction head (m)

SEMESTERS (213) - (221)
14/32
Chapter 3
Work Activities and case studies
3.1 Introduction
In KEMYA, there are two teams of workers working together to ensure a smooth production. The two
teams are the operation and the maintenance. The operation team is there to operate the equipment. It’s
also their job to isolate the equipment, pipe or valve and make sure to adhere to the LSR rule number 6,
before the maintenance team can start their job. The maintenance teams’ job is to maintain the equipment
through regular PMs, some of which are weakly, some are monthly and some are yearly. It is also their
job to fix any issue with the equipment, to run troubleshooting and to take apart any equipment that
would need to be overhauled. The maintenance teams can be electrical, mechanical or instrument
depending on what expertise the job needs.
3.2 Main Activities
In the utility, KOP and LDPE departments, work was carried
out by a machinery maintenance team in each department. The
teams’ job was mainly to run PMs, take apart damaged parts
and take them to the workshop, to fix any damage that can be
fixed on the spot. The utility plant consists of two joined plants,
utility 1 and utility 2. Some of the main activities that were
done during this coop period were the installation of a
centrifugal pump, the overhauling of a pump and the
maintenance of a turbine. However, the activity that took the
longest time was the troubleshooting process of a cooling fan
in the cooling tower (figure12) which falls under the utility
plant. The utility plants main job is to provide utilities to other
plants. This includes sea water, steam, electric power,
compressed air, and every other utility needed in the other
plants. However, since the KOP plant is run at a much higher
pressure than can get up to 3000 bar, the main focus of the
machinery team was to ensure the health of the heavy-duty
pumps and turbines and compressors. Another very important
focus for the machinery team in the KOP department was the
quench tower. Since the gasses from the KOP production line
need to be cooled before being compressed, the quench tower
needs to stay running constantly, which calls for very extensive
maintenance around the clock. Since the product produced in
the LDPE plant is polymers, the biggest concern for the
maintenance team is to make sure the product doesn’t clog the
machine. This calls for onsite and offsite overhauling of
compressors. The main purpose of the overhauling
(figure13&14) is to take apart the compressor that is suspected
to have a leak in the product and clean it from the inside. The
parts to be cleaned include mechanical seals, O rings, and the impeller of the compressor itself. The
reason behind that is to ensure the product leak doesn’t solidify and cause permanent damage to the
machine, causing a need for a replacement.
Figure 12 cooling towers
Figure 13 a pump overhauling
Figure 14 a turbine overhauling

SEMESTERS (213) - (221)
15/32
3.3 Case Study 1: Cavitation
3.3.1 Locations
Several areas of a pump are susceptible to cavitation, including the suction side, the impeller,
and the discharge side. If the liquid being pumped is being drawn from a source that is at a lower
pressure than the pump's suction pressure, cavitation may happen on the suction side. This may
lead to the vapor bubbles in the liquid forming before they burst as it enters the pump. If the
liquid is driven too quickly in the impeller, cavitation can happen. This results in a drop in
pressure and the creation of vapor bubbles. As the liquid leaves the impeller, these bubbles
eventually explode. If the liquid is being discharged into a pipe or other channel at a pressure
greater than the pump's discharge pressure, cavitation may happen on the discharge side. As a
result, vapor bubbles may form in the liquid, which will eventually explode as the liquid enters
the pipe or channel. Overall, cavitation can harm a pump's components and decrease its
efficiency, therefore it's critical to design and run pumps in a way that minimizes cavitation.
3.3.2 General Description
One of the most dangerous failures in centrifugal
pumps is a phenomenon called cavitation.
Cavitation occurs when the absolute pressure at the
eye of the impeller is less than the vapor pressure
of the pumped liquid. Cavities -aka vapor bubbles-
would form in the liquid. As the bubbles move from
the low-pressure area near the impeller toward the
high-pressure area near the discharge, they implode
in a violent manner going back to their liquid form.
As long as NPSHA > NPSHR, cavitation will not
occur. NPSHR is a characteristic of the pump and
should always be provided by the pumps
manufacturer. NPSHA is a function of the system
and it includes:
• The temperature and vapor pressure of the liquid
• The absolute pressure on the liquids free surface
• The dimensions of the piping on the suction side along with all the pipes fittings
• he height of the liquids in the supply tank weather above or below the centerline of the pump.
3.3.3 Critical Factors
Cavitation in centrifugal pumps is brought on by a number of crucial variables, such as a drop
in suction pressure, an increase in suction temperature, and an increase in flow rate above the
pump's design capability. The primary cause of cavitation is liquid vaporization within the
pump. The liquid starts to boil and produce vapor when the pressure within the pump drops
below the vapor pressure. Another important consideration is the Net Positive Suction Head
Available (NPSHA), which determines whether cavitation will develop when it is lower than
the Net Positive Suction Head Required (NPSHR). In order to prevent cavitation, the suction
pressure must to be greater than the liquid's vapor pressure. The pressure drop in the eye of a
centrifugal pump also plays a role in the occurrence of cavitation, when it is great enough to
cause the liquid to flash to steam when the local pressure falls below the saturation pressure for
the fluid being pumped.
Figure 15 a visual representation of cavitation

SEMESTERS (213) - (221)
16/32
3.3.3.1 NPSHA and NPSHR
To adequately define cavitation, the relationship between the
pump performance and the pump inlet or the net positive suction
head available need to be described. Figure16 shows a three-
dimensional surface and NPSHA. The part denoted with a 1, in
which the pump performance does not depend on the NPSH. In
that part, any decrease in NPSH doesn’t change the flow/head
relationship in the pump. In the part denoted with a 2, the pump
flow/head relationship greatly depends on the NPSH. Any
decrease in the NPSH will result in a decrease in the pump output
and performance. These parts can be dubbed the “cavitation” and
“no cavitation” zones for part 2 and 1 respectively. The transition
between these two zones is shown through a definite
discontinuity on the three-dimensional surface which helps
describing the onset of the cavitation. [6]
Before going in detail about NPSHA and
NPSHR, some other variables need to be
defined. In a paper published by Xylem
Applied Water Systems, the vapor
pressure is defined as the pressure at which
the molecules are vaporized (2015).
Temperature and vapor pressure linked.
Vapor pressure for liquids in general tend
to vary with temperature. Using water as
an example, at 5 Celsius, the vapor
pressure is 872 rounded to the nearest
figure. At 100 Celsius however, it
increases until it reaches 101,000 which is
a very significant change in pressure. The
graph in figure17 shows the plot of the
vapor pressure of varies liquids vs the temperature. If a specific pressure is selected, the
corresponding temperature will be the temperature at which the liquid will turn into vapor
under the selected pressure. The same can be done for any liquid to find the combination of
pressure and temperature that will result in the vaporization of liquids. Another variable that
needs to be defined is the pressure available at the inlet of the pump. It can be simply defined
as what remains after tsking the losses into conciliation, such as the friction loss and velocity
head loss and outlet/inlet losses. Which is why It is essential to calculate them during the
design process and subtracting them from the NPSHA [7].
As stated before, cavitation occurs when the liquid in the pump is vaporized at a low pressure
because there is not enough pressure at the suction of the pump. And it also occurs when
there is an insufficient net positive head suction available. NPSHA doesn’t necessarily have
anything to do with the pump itself. It’s a system value which means its specific to the
system design. NPSHA is completely independent from the pump itself because it is defined
as the actual difference between the pressure at the inlet of the pump and the pressure of the
liquid in its vapor form which is also known as the vapor pressure which is determined by
the design. NPSHA cannot be mentioned without mentioning NPSHR which is the net
positive suction head required. As stated before, NPSHR is a pump characteristic and needs
to be provided by the pump manufacturer which makes it unrelated to the system. NPSHR
Figure16 NPSH vs Q vs head
Figure 17 the vapor pressure of varies liquids vs temperature

SEMESTERS (213) - (221)
17/32
is the difference between the inlet pressure and the required vapor pressure. However, that
value should not be used as it is. A margin should be in place so that cavitation doesn’t
occur. A margin of 1.5 meters is sufficient enough in most cases if not specified by the
manufacturer. Since NPSHR is a fixed value for every pump, NPSHA needs to be adjusted
during the system design process to ensure that NPSHA ≥ NPSHR + margin [7].
A cross section of a suction pipe and the impeller is shown
in figure18. Taking into consideration that the liquid flows
from 1 to 5, the flow rate must be constant through the
positions denoted by the numbers 1 through 5. Since the cross
section at 1 is much bigger than that of 5, the velocity at the
eye of the impeller is much higher than it is at 1 due to the
change in the cross-sectional area. Velocity here is inversely
proportional to the pressure, meaning if the velocity decreases
the pressure increases and vice versa. This is due to the fact
that velocity causes a waste in energy by creating head. A
way of grounding this concept to reality is imagining
squeezing the end of a garden hose. The flow rate of the water
is constant but the velocity can be adjusted by squeezing the
end decreasing the cross section. In this case the water exits the hoes at a high velocity but
at atmospheric pressure. [7]
Using figure18 as a reference, figure19
shows the pressure at different positions
inside the pump. The plot shows that there
is a drop in the pressure as the liquid enters
the impellers but it recovers towards the
exit. This is caused by the diameter of the
eye of the impeller being smaller than that
of the suction. Another reason is that the
impeller itself is also adding energy which
increases its pressure as its exiting and
therefore aiding its recovery. [7]
Figure 18 a cross sectional view of a
centrifugal pump
Figure 19 the dip in pressure drop in different locations
inside the pump

SEMESTERS (213) - (221)
18/32
Figure 21 the cavitation region
3.3.4 Specifications of Pump MP-01 In KEMYA
The pump which this case study is based on is a pump with the
tag name MP01, also known as the Demethanezier bottom
pump. It is a centrifugal pump located at the bottom of the
Demethanizer. Its purpose is to push the bottoms feed (C2 and
above) towards the Deethanizer. According to the data sheet
provided by ABB Lummus global B.V., the pump’s listed model
is JVCR-D which is a special design provided for KEMYA by
SULZAR. According to SULZAR’s official website, there is a
model called JVCR high pressure canned LNG loading pump,
which can be taken as the base model of the JVCR-D pump in
KEMYA. SULTAR state in their site that The JVCR high
pressure canned LNG loading pump is an ISO13709 / API610
Type VS6 vertical multistage can pump that is used in situations
where Net Positive Suction Head Available (NPSHa) is limited.
ISO 13709 specifies requirements for centrifugal pumps,
including pumps running in reverse as hydraulic power recovery
turbines, for use in petroleum, petrochemical and gas industry
process services. It is applicable to overhung pumps, between-
bearings pumps and vertically-suspended pumps. API 610 is
the API standard relating specifically to centrifugal pumps and
centrifugal pumping systems, it covers centrifugal pumps, and
includes end suction, double suction and other types. Figure20
shows the JVCR pump. however, the design used in KOP,
KEMYA is different since it was made especially for the intended purpose requested by the
company. [8] [9] [10] [11]
3.3.5 Cavitation Region
This centrifugal pump, much like every other pump
has its own NPSHA and NPSHR. According to the
data sheet provided by ABB Lummus global B.V.,
the NPSHA is listed as 7.04m. The NPSHR is listed
as well and its value is 5.7m, which a value that was
provided by the manufacturing company, SULZER
ROTEQ LTD. As stated before, in order to avoid
cavitation, the equation NPSHA ≥ NPSHR + margin
needs to be satisfied. since no margin is specified in
the sheet, the equation can be written in its
alternative form which is NPSHA > NPSHR. by
plugging the values listed in the equation, it is
evident that the values do indeed satisfy the equation
which means that the pump is safe and will not
experience cavitation. Figure21 show the graph
obtained by plotting both the NPSHA and NPSHR
along with the Q. since the information needed to
calculate the NPSHA at different values of Q are
classified, the best approximation of the NPSH
curves that can be obtained is a linear plot of both
NPSHR and NPSHA and Q. this is not accurate since
the NPSH doesn’t change in a linear way but it’s the
Figure 20 the MP-01 pump design
Figure 22 a linear plot of the NPSH curves

SEMESTERS (213) - (221)
19/32
best that can be done with the data sheet provided for this pump. By comparing the plot to
figure22, 6.48m is the cavitation point and the region denoted by C is the cavitation region. [12]
3.3.6 Cavitation Damage
Maintaining the NPSHA and Q required to keep the pump
working in the safe zone, denoted by A in figure22 is very
important. If the NPSHA were to fall in the cavitation zone
denoted by C in the graph, the cavitation occurs. Cavitation
can result in the damage of equipment or in extreme cases,
it can render the pump useless and unfixable. If left without
resolution, cavitation can destroy impellers and pump
casing. It can also cause failure in the seal and bearings. It
can heavily impact the flow and pressure making it
consume significantly more power. Figure23 show
examples of the damage left by the cavitation. The first
picture shows an eroded pump interior. The second and last
pictures show a completely damaged set of pump impellers.
Cavitation has large effects on the pump. The surface of the
passage will be damages due to collapsing bubbles resulting
in the shock waves creating cavities in the metal. The
material will be subject to cyclic stress on the surface
causing fatigue. The pump will have large amounts of
vibrations and loud noises due to the collapsing of the
bubbles. And last but not least, the efficiency will be
negatively affected due to the flow being restricted. Some
of the most common indications that cavitations has
occurred are; loud noises, vibrations, erosion in the
impellers, seal/bearing failure and higher power consumption that usual. [13]
3.3.7 Solutions To Cavitation
The main concern of large companies like SABIC when it comes to cavitation is the efficiency.
When the efficiency of the pump is lower, the production will be slower and will need more
power to keep running. Another big concern is the health of the pump itself. If the pump
continues to run after cavities have formed in the impellers of the pump, they will end up
breaking and therefore ceasing all production depending on the pump. In this case, pump MP01
is a very important pump in the process which means it is essential to ensure cavitation does not
occur.
In order to prevent the occurrence of cavitation, there are some measures that can be taken. One
of them is by decreasing the pressure drop by removing all as many bends and valves as possible
since each one of them will make the pressure drop further. Making sure to remove all blockage
in the suction is also helpful. The most effective way of preventing cavitation is the selection of
the correct pump since cavitation heavily depends on the NPSHR. However, the pump is this
case study has already been selected and cannot be replaced since that will be very costly.
Nevertheless, there are ways to increase the NPSHA of the pump:
• Pump maintenance
o Check the filters and strainers regularly since dirty or clogged filters and strainers create
a buildup in pressure inside the pump.
o Assess the overall design of the pump system.
Figure23 the damage done by cavitation on
different parts of the pump

SEMESTERS (213) - (221)
20/32
Figure24 the passes inside the heat exchanger
o Evaluate the characteristic curves. including the pressure demands and the pump data
and checking it fits the intended purpose., determining whether the pump is suitable for
the needed flow rate or not.
o Check pressure measuring equipment.
o Look for cracks or damages to the pipes and other parts
• Elevating and maintaining the level of the tank fluid
• Raising the supply tank
• Reducing the piping losses caused by too many joints or very small diameters
• Replacing the damaged components frequently
• Removing solids from inside of pipes before they creating a blockage
• Clearing the suction strainer
• Replacing the corroded pipe as soon as possible
By implementing every applicable one of these solutions and maintaining the pump as much as
possible, the pump is more likely to last longer and the occurrence of cavitation will remain
unlikely. [13]
3.4 Case Study 2: Fouling
3.4.1 Locations
Fouling occurs only occur on either the inside and outside the tubes inside the shell and tube
heat exchanger or the inner surface of the shell itself. this is due to the fact that fouling can only
occur when the object is in contact with water. These types are called external and internal
fouling and each of them has its own nature and affects the efficiency of the heat exchanger
differently.
3.4.2 General Description
In companies that deal with large amounts
of production, especially in the oil
byproducts industry, the use of heat
exchangers is essential. sometimes the
liquid product needs to be cooled down.
Before going to the next stage of
production and some others need to be
heated. This is the reason why heat
exchangers are always used in large plants.
Figure24 shows a shell and tube heat exchanger
is a piece of equipment that are used to transfer
heat from one medium to the other. The mediums
could be a liquid, gas or a combination of the two.
They are in some cases separated by a solid wall
to prevent the two mediums from being in direct
contact or mixing. Heat exchangers either
provide heat or take away heat/cool for certain
processes. This exchanger is the most common
heat exchanger in large production facilities such
as KEMYA. The shell and tube exchangers are
made of a bundle of tubes fixed inside a cylinder
shell. Two fluids exchange heat, one fluid inside
the tubes while another flows over them inside
the shell itself. In this way, the heat is taken from
Figure25 a shell and tube heat exchanger

SEMESTERS (213) - (221)
21/32
the hot fluid to the cooler fluid and the two liquids will continue their way through the piping
system. Heat exchangers consist of the shell, shell cover, tubes, channel, channel cover, tube
sheets baffles and nozzles. The shell and tube exchanger can have one or two or four or six or
eight passes. A single pass is shown in figure25. As the number of passes increase, the heat
transfer coefficient also increases. The number of passes is the number of times the liquid or gas
moves through the shell. [14][15][16][17]
3.4.3 Critical Factors
The kind of fluid being handled, its temperature and velocity, the surface material of the heat
exchanger, and the existence of impurities and pollutants are among the significant fouling
factors. Other crucial elements are the heat exchanger's design and configuration, the operating
environment, and the maintenance and cleaning procedures used. To accurately forecast and
reduce fouling in shell and tube heat exchangers, it is crucial to comprehend these crucial
aspects. The efficiency and durability of the equipment can be increased by regulating and
optimizing these elements, which will also maintain heat exchanger performance.
3.4.4 Fouling: Definition and Causes
the biggest limitation of using shell and tube exchangers is
the fact that they are prone to fouling. It is a phenomenon
that occurs from the accumulation of unwanted material in
the exchanger. It can be divided into external (figure26) and
internal (figure27) fouling. The fouling material can be
either living organisms or nonliving substances. Biofouling
is the accumulation of plants and small animals and
microorganisms on the surface of the exchanger. Fouling
can also occur due to the liquids and or gasses being
handled under certain conditions such as temperature and
velocity. The most known foulant in the industry include
airborne dust, waterborne mud, salts, oils, greases and
heavy-duty organic deposits such as polymers and tars. In
most cases, fouling is found to be less at higher fluid
velocities due to the increase in the fluid shear stress which
removes any stuck material. This means that lower
velocities in the fluid can lead to the accumulation of the
material. Similarly, in research from J. Pugh, fouling shows
a peak at higher temperatures (2009). [18][19][20][21]
3.4.5 Fouling Factor
Fouling has to accounted for when the heat
transfer is being calculated, that is why the
fouling factor is needed. The fouling factor is
the reciprocal of the heat transfer coefficient
of the layer that is affected by fouling. It is
represented by the symbol R”f. the fouling
factor is the measure of the thermal
resistance introduced by fouling. One of the
formulas used to calculate heat inside a heat
exchanger is the LMTD method, the formula
for the LMTD method is 𝑞 = 𝑈𝐴 △ 𝑇𝑙𝑚. △
𝑇𝑙𝑚 is the log-mean value of the temperature
Figure 26 external fouling of tubes
Figure27 the internal fouling of shell and
tubes
Figure 28 the fouling resistance of different fluids

SEMESTERS (213) - (221)
22/32
difference (between two fluids inside the heat exchanger) and U is the total heat coefficient
which includes all the resistances. This means that the fouling resistance is taken into
consideration within the UA term thusly:
The figure28 is showing the fouling resistance of the most commonly used fluids in the industry
which include fluids like river water with a fouling resistance of 0.0002 to 0.001. by using this
table, UA can be calculated by substituting the value for the fouling resistance in the formula
shown prior. [22]
3.4.6 Specifications of Heat Exchanger XE-01 In KEMYA
according to the ABB Lummus
global B.V data sheet for heat
exchanger XE-01, it is a
horizontal BEU shell and tube
heat exchanger located in the
KOP plant used to cool down
ethylene from 131 Celsius down
to 50 Celsius using cooling water
in the shell side. The BEU heat
exchangers are shell and tube
exchangers that have U shaped
tube bundles as opposed to
straight tubes. Figure29 shows an
example of a typical BEU shell
and tube heat exchanger. The U tube bundle is fixed toa singular sheet, which allows the tubes
to expand and contract under varying temperature freely. The tube bundle is made to be easily
removable. This allows the tubes to be easily cleaned or replaced easily if a failure were to occur.
According to SOUTHWEST THERMAL TECHNOLOGY INC, the BEU heat exchanger is the
best choice for low fouling fluids including water (2022). This is idea since the fluid used in the
cooling process inside the XE-01 heat exchanger is water. The BEU heat exchangers are
preferred when handling a high temperature difference between the fluids in the shell and tube
sides. As stated before, the fluid in the tube side, which is ethylene, enters at a temperature of
131 Celsius and exit at a temperature of 50 Celsius while water enters the shell side at 43 Celsius
and leaves at 48 Celsius. The XE-01 heat exchanger has a bundle of 18 U-tubes. Each has an
outer diameter of 19.05 mm and a thickness of 2.11 mm. each U- tube has a length of 2.39
meters. The bundle is stated to have a mass of 250 Kg. [23]
Figure29 the BEU shell and tube heat exchanger

SEMESTERS (213) - (221)
23/32
3.4.7 Effects of Fouling on Heat Transfer
Fouling is a big concern for
production companies such as
KEMYA. The most major
affect fouling has on the heat
exchanger is that it decreases
the heat transfer significantly.
The thermal conductivity of
fouling layers is in most cases a
lot lower than that of the fluid
or the tubes inside the heat
exchanger. Due to this fact, the
overall thermal resistance is
increased therefore decreasing
the thermal efficiency as shown
in figure30. This is very crucial since a lower efficiency means a slower production or an
unnecessary increase in the power needed in order to match the production level of the heat
exchanger before the fouling layers started accumulating. [24][25]
3.4.7.1 Using LMTD To Show the Effect of Fouling On XE-01
𝑞 = 𝑈𝐴 △ 𝑇𝑙𝑚 in the LMTD method. in order to calculate the q, the inlet and outlet
temperatures of both cold and hot fluids need to be plugged into the LMTD formula which
states that △ 𝑇𝑙𝑚 =
△𝑇1−△𝑇2
ln (
△𝑇1
△𝑇2
)
. Water is the cold fluid in this case with an inlet temperature of
43C and an outlet temperature of 48C.
Ethylene is the hot fluid with an inlet
temperature of 131C and an outlet
temperature of 50C. by comparing the
temperature values to the graph shown in
figure31, it is apparent that the flow in this
case is a parallel flow. This is significant
because as it is show in the graph, △ 𝑇1 is
the difference between the inlet
temperature of the hot fluid and the cold
fluid. The same is shown for △ 𝑇2.
Therefore, the LMTD can be written as:
△ 𝑇𝑙𝑚 =
△ 𝑇1 −△ 𝑇2
ln (
△ 𝑇1
△ 𝑇2
)
=
(131 − 43) − (50 − 48)
ln (
(131 − 43)
(50 − 48)
)
= 22.72613 𝐶
Since the overall heat transfer coefficient is given in the data sheet as 571
𝑊
𝑚2.𝐶
, the only
other variable left to calculate in order to find the exchanged heat is the area. This can easily
be solved for using the equation for the surface area of a hollow cylinder. The O.D of the U-
tubes is given as 19.05 mm. the inner diameter can be found by subtracting the thickness of
2.11 mm from the outer diameter, which gives an inner diameter of 16.94 mm. lastly, the
length of the tubes is 2.39 m. therefore, the area is:
Figure30 the efficiency VS Rf curve
Figure 31 the temperature vs position curves for cold and hot
fluids inside the heat exchanger

SEMESTERS (213) - (221)
24/32
𝐴𝑜𝑢𝑡𝑒𝑟 = 𝜋𝐷𝑜𝑢𝑡𝑒𝑟𝐿 = 𝜋(0.01905)(2.39) = 0.143035 𝑚2
𝐴𝑖𝑛𝑛𝑒𝑟 = 𝜋𝐷𝑖𝑛𝑛𝑒𝑟𝐿 = 𝜋(0.01694)(2.39) = 0.127192 𝑚2
𝐴𝑡𝑜𝑡𝑎𝑙 = 𝐴𝑜𝑢𝑡𝑒𝑟 + 𝐴𝑖𝑛𝑛𝑒𝑟 = 0.143035 + 0.127192 = 0.270228 𝑚2
since the area and the overall heat transfer coefficient and the LMTD are now found, the
heat exchanged can be found by plugging them into the equation thusly:
𝑞 = 𝑈𝐴 △ 𝑇𝑙𝑚 = 571(0.270228)(22.72613)(18) = 63.11954 𝑘𝑊
The multiplication by 18 is due to the fact that there is 18 U-tubes.
The fouling resistance is already accounted for in the UA term. The fouling resistance is
listed as 0.00009
𝑚2.𝐶
𝑊
. A way of showing the effect of fouling on the heat transfer is to
calculate the heat exchanged without the fouling resistance:
1
𝑈𝐴𝑓
= (
𝑅𝑓
𝐴𝑖𝑛
+
𝑅𝑓
𝐴𝑜𝑢𝑡
) = (
0.00009
0.127192
+
0.00009
0.143035
) = 0.001337
1
𝑈𝐴
=
1
571(0.270228)
= 0.006481
1
𝑈𝐴
−
1
𝑈𝐴𝑓
= 0.006481 − 0.001337 = 0.005144
𝑈𝐴 =
1
0.005144
= 194.3983
𝑊
𝑚2. 𝐶
By substituting the new value of UA in the formula for q,
𝑞 = 𝑈𝐴 △ 𝑇𝑙𝑚 = 194.3983(0.270228)(22.72613)(18) = 79.52258 𝑘𝑊
The increase in the heat transferred after excluding the resistance caused by fouling
shows that the fouling does indeed affect the performance of the heat exchanger
significantly.
3.4.8 How To Reduce Fouling
For a large production company like KEMYA,
fouling needs to be dealt with before it can affect
the production flow and therefore cause the
company unnecessary losses and potentially the
loss of customers. But the complete elimination of
fouling like what was shown in the calculations
previously is only feasible on paper and is
impossible to implement in real life. This is why all
heat exchangers need to be monitored to make sure
any accumulation of material that might result in Figure 32 temperature sensors

SEMESTERS (213) - (221)
25/32
fouling is dealt with before the fact. Since a drop in
both temperature and increase in pressure drop are
indications of heat transfer loss caused by fouling, an
efficient way of monitoring fouling in heat
exchangers is by monitoring their temperature and
pressure. This can be done using temperature and
pressure transmitters at the inlet and outlet of the heat
exchanger. By monitoring these variables, if there
was an indication that fouling has in fact occurred,
cleaning will be needed in order to remove the
accumulated material. And since the heat exchanger
used in KOP plant in KEMYA is BEU kind, cleaning
it is easier due to the fact that the U-tubes can be taken apart and cleaned then put back inside.
[26][27]
Another way of reducing fouling is by using durable material. For
example, carbon steel is easier to work with and is cheaper, which might
make it a very tempting option when building a heat exchanger. But it
is also brittle and prone to corrosion. Which makes it a poor choice
when it comes to reducing fouling. However, since the material for this
specific heat exchanger has already been selected, the best option is to
apply coating. Applying protective coating to the surface of the heat
exchanger can help reduce the foulant from adhering to the surface and
therefore decrease the fouling. It is also useful since the coating will act
as a barrier between the water and the metals inside the heat exchanger
which helps prevent the substances that could be in the water.
Synthetic fluoropolymers are usually used in coating of heat exchanger
due to the fact that they’re hydrophobic and have nonstick properties
and high thermal stability. Examples of fluoropolymers that are used
are polytetrafluoroethylene (PTFE) and perfluoropolyether (PFPE)
which are both shown in figure35. Another type of coating is
antifouling paint (figure34). Antifouling paint is a special kind of
coating that is typically applied to ships and boats since they also tend
to experience fouling due to the fact that they spend long amounts of
time submerged in water. Accordinng to an experament conducted by
Bremen university, antifouling coatings were applied to heat
exchangers and the performance of the coated heat exchangers were
much higher than those of the uncoated ones (Scharnbeck & Hartmann, 2009). Which shows
that the antifouling paint is not only useful to shield boats from corrosion, but also to reduce
fouling is large production heat exchangers and therefore increasing its efficiency. [27][28]
Figure33 a pressure gauge
Figure35 PFPE and PTFE spray
Figure34 antifouling paint

SEMESTERS (213) - (221)
26/32
Chapter 4
Design Component
4.1 Introduction
In large production company such as KEMYA, there are many processes that
include a number of intricate equipment. with the level of complexity the
equipment have, problems tend to arise. In the KOP plant, the quench tower
(figure36) is a very important piece of equipment. the entire process of breaking
the bond of the ethane to create ethylene depends on the heating up of the gasses
using the 8 furnaces the KOP plant is equipped with. The superheated gasses
are then expected to be cooled down to a certain degree before it continues
through the system. This is the job of the quench tower. Less than a year ago,
an incident occurred in KEMYA where the power was shut down momentarily.
This sudden shut down in power resulted in the ceasing of all motion in all of
the turbines that push the water into the quench tower which resulted in a big
issue inside the tower that is still being dealt with almost a full year later, and is
still influencing the productivity of the plant negatively. This is why a design
for a specific tool was made so that it can try and resolve this issue.
4.2 Quench Tower Cleaning Tool
4.2.1 The Process of The Quench Tower
as stated in the introduction, the quench tower is
one of the most essential parts of the KOP
production line. The quench tower’s purpose is to
cool down the mixture of gasses that was heated
through a specifically designed heating cycle that
involves 8 furnaces and two heat exchangers. The
way it works is as shown in figure37. The cracked
up superheated gas entered the cooling tower
from the bottom, naturally going up due to the
fact that it’s a gas. When the gas is going up, it
passes through a metal mesh designed to direct
the flow of the gas to maximize the cooling
efficiency of the cooling tower. While its being guided by the metal mesh, the cooling water
that enters the quench tower from the upper pipes starts showering the gas and therefor
quenching it. This is important because the gas is meant to be compressed afterwards and the
colder the gas is the less energy it needs to be compressed. [30]
4.2.2 Quench Tower Incident
In November of 2021, a power shut down occurred in the area of which the KEMYA plant was
located. This shut down in power was catastrophic to the KOP plant due to the fact that the
motors that push the gas through to the quench tower operate on electricity. The process for the
quench tower is designed in a way so that the hot gas coming from the bottom to be cooled is
also constantly heating the heavy materials in the quench tower in such a way that the water that
is quenching the gas is also rinsing those heavies. When the power failure happened the tower
went cold, which caused the heavy materials to solidify plugging the mesh inside the quench
tower. The plugging of the guide mesh resulted in a lower cooling rate for the gas mixture. The
lower cooling rate meant that the CGC was limited since the gas had a significantly higher
Figure36 quench tower
Figure 37 the process of the quench tower

SEMESTERS (213) - (221)
27/32
temperature than it should have which resulted in a lower production rate. This caused a huge
decrease in the efficiency of the heat exchange inside the cooling tower when it stated running
again.
4.2.3 Suggested Design for The Quench Tower Cleaning Tool
The clogged quench tower was a very significant problem that needed an innovative solution.
Since the quench tower is an essential part of the KOP process, it cannot be shut down in order
to be cleaned from the inside since shutting down the quench tower would mean terminating the
entire olefins production which will cost the company millions. Another constraint is that no
one can enter the quench tower while its running due to the large amounts of toxic gas and the
high degrees of temperature. Moreover, the quench tower cannot be meddled with since it was
specifically designed for its intended purpose and any change in the design will affect the
efficiency greatly.
With these constraints and limitations and requirements taken into consideration, the idea for a
mobile cooling tool was suggested.
The tool was designed in a way so that it be inserted through the already existing nozzles in the
quench tower, this eliminated the problem of not being able to shut down the tower for cleaning
the tower. As demonstrated in the sketch, the cleaning tool is extendable and is operated through
a switch, which means the workers will not be exposed to the harmful gasses while operating
this cleaning tool. The design is also meant to have wheels attached to the bottom of the tool in
order to move it easily whenever cleaning is needed in case this problem were to occur again.
Figure38 sketch of the design for the cleaning tool

SEMESTERS (213) - (221)
28/32
4.2.4 The Working Concept of The Quench Tower Cleaning Tool
The concept of the cleaning tool for the quench tower is to act
like a high-powered pressure washer. The head of the cleaning
tool is meant to be a radial nozzle with holes along the
circumference and its sides. This head is also meant to rotate
to make sure that it covers all sides of the mesh and the inside
of the quench tower. An example of the head is meant to be is
shown in figure41. With the nozzle rotating 360 degrees inside
the tower and the tool itself being extendable and retractile,
giving it a full range of motion inside the tower, the tool will
be an efficient cleaning tool. As stated prior, the
tool would work with the same principle as a
pressure washer using water (figure40). Using a
motor powering a pump alongside the tool, the
pump causes the water to accelerate pushing it out
of the holes on the nozzle. This specific cleaning
tool is meant to operate at a pressure of 20kPSI and
more, in order to ensure the cleaning of the mesh
inside of the quench tower and therefore increasing
its production back to how it was before the
incident occurred.[31]
Figure39 final design for the cleaning tool
Figure41 nozzle head
Figure40 a steam pressure washer

SEMESTERS (213) - (221)
29/32
Chapter 5
Conclusion and Recommendation
5.1 Conclusions
KEMYA being a large production company means it hosts many plants that have numerous amounts
of processes running at all times. There processes are designed to be integrated in a way that maximizes
production and minimizes the cost and power needed. This level of integration is also meant to reduce
the need for outside recourses by recycling material from certain processes in others and producing the
material needed inside the company rather than import it from others. Considering that all these plants
are running on heavy machinery that is costly to replace and might cause a dip in production if it were
to stop, every plant has a number of maintenance teams. These teams have a main job of ensuring the
welfare and wellbeing of machinery and to preform periodic maintenance and cleanups. These teams
work in tandem with the mechanical engineers that were assigned to each department. However, the
engineers are more concerned with the numbers and the data rather than the physical machine. They
check the data and preform a number of calculations using known formulas in the mechanical
engineering courses such as heat transfer, fluid mechanics and machine design to make sure the process
is running smoothly and will not fail. With the mechanical engineers analyzing the data and the
maintenance team repairing any issues in the machinery, the production is set to run smoothly with
minimal problems. For a pump, this is done by monitoring the performance curves and the heads to
make sure the pump is running at maximum efficiency. For a heat exchanger this is done by monitoring
the heat exchanger to make sure fouling doesn’t occur which can be done using numerous ways such
as temperature and pressure sensors.
5.2 Recommendation
Implementing routine maintenance schedules for all equipment is essential in guaranteeing ongoing
production at KEMYA, in addition to the advantages already discussed in chapter 3. This entails
scheduling standard cleaning and repairs in addition to regular inspections and examinations. Potential
problems can be found and fixed by keeping up with maintenance before they develop into significant
issues that would halt production. Additionally, using the cleaning tool created in the design section
helps lengthen the quench tower's total lifespan, minimizing downtime and boosting efficiency. The
training of the maintenance staff in the proper use and maintenance of the equipment, as well as
providing them with the resources and tools they need to efficiently carry out their jobs, are additional
key factors to take into account.
The heat exchanger XE-01 needs special attention as well because fouling can significantly affect its
effectiveness and performance. Any deviations from typical operating conditions can be rapidly
detected and dealt with, preventing fouling from forming, by using heat sensors and pressure gauges.
Additionally, the materials can dissolve more quickly and wash away with the water via the bottom of
the tower when cleaning chemicals are added to the water in the heat exchanger, preventing the
accumulation of fouling.
Similar to this, it is essential to constantly monitor the MP-01 pump to ensure that any issues may be
fixed before they escalate. The maintenance team can rapidly identify any faults with the pump, such
as vibration, temperature, pressure, and flow rate, and take steps to prevent downtime and keep the
production going smoothly by employing sensors, data loggers, and remote monitoring.

SEMESTERS (213) - (221)
30/32
References
1. Kemya - ExxonMobil and SABIC joint venture. (n.d.). ExxonMobil.
https://corporate.exxonmobil.com/locations/saudi-arabia/kemya-exxonmobil-and-sabic-joint-
venture
2. Wikipedia contributors. (2023, January 26). Pump.
Wikipedia. https://en.wikipedia.org/wiki/Pump
3. Useful information on positive displacement pumps. (n.d.). https://www.michael-smith-
engineers.co.uk/resources/useful-info/positive-displacement-pumps
4. Team, L. (2022, August 29). 6 Main Types of Dynamic Pumps: Examples + PDF | Linquip.
Industrial Manufacturing Blog | Linquip. https://www.linquip.com/blog/types-of-dynamic-
pumps/
5. DEBEM Srl (2018, December, 4) CHARACTERISTIC CURVE OF A CENTRIFUGAL PUMP
https://www.debem.com/en/characteristic-curve-of-centrifugal-pump/
6. Polgrave, R. P. (n.d.). VISUAL STUDIES OF CAVITATION IN PUMPING MACHINERY.
Retrieved January 26, 2023, from https://6. https://www.911metallurgist.com/blog/wp-
content/uploads/2016/01/Visual-Studies-of-Cavitation-in-Pumping-Machinery.pdf
7. Xylem Applied Water Systems. (2015). Pump cavitation and how to avoid it best practices in
pump system design. Xylem Lets Solve Water. https://www.xylem.com/siteassets/support/case-
studies/case-studies-pdf/cavitation-white-paper_final-2.pdf
8. JVCR high pressure canned LNG loading pump | Sulzer.
(n.d.). https://www.sulzer.com/en/shared/products/jvcr-high-pressure-canned-lng-loading-pump
9. Rahman, M. (2020, October 9). API 610 CENTRIFUGAL PUMP STANDARD. Pump Projects.
https://pumpprojects.com/about-us/library/centrifugal-pumps/api-610-centrifugal-pump-
standard/.
10. ISO 13709:2009. (n.d.). ISO. https://www.iso.org/standard/41612.html
11. SULZAR. (n.d.). JVCRv High Pressure Canned LNG Loading Pumps. Retrieved January 26,
2023, from https://www.sulzer.com/spain/-/media/files/products/pumps/vertical-
pumps/brochures/jvcrvhighpressurecannedlngloadingpumps_e00625.pdf?la=en
12. Pump Net Positive Suction Head Test. (n.d.). https://www.inspection-for-industry.com/pump-
net-positive-suction-head-test.html
13. Team, L. (2022a, June 19). How to Avoid Pump Cavitation? 6 Main Steps | Linquip. Industrial
Manufacturing Blog | Linquip. https://www.linquip.com/blog/what-is-pump-cavitation/

SEMESTERS (213) - (221)
31/32
14. Heat exchangers (2022). (n.d.). Ipieca. https://www.ipieca.org/resources/energy-efficiency-
solutions/efficient-use-of-heat/heat-exchangers-2022/
15. Control Engineering. (2016, January 4). Applying heat exchanger control strategies.
https://www.controleng.com/articles/applying-heat-exchanger-control-strategies/
16. Sciencedirect. (n.d.). shell and tube exchangers
https://www.sciencedirect.com/topics/engineering/shell-and-tube-exchangers
17. Shell and Tube Heat Exchangers. (n.d.). https://www.iqsdirectory.com/articles/heat-
exchanger/shell-and-tube-heat-exchangers.html.
18. Klaren International. (2022, March 18). Fouling. Klaren International - Just Another WordPress
Site. https://klarenbv.com/what-is-fouling-and-scaling-in-heat-exchanger/
19. HRS explains exchanger fouling. (2020, December 2). Filtration and Separation.
https://www.filtsep.com/content/features/hrs-explains-exchanger-fouling/
20. Zambelli, M. (2017, April 28). Fouling in heat recovery heat exchangers. Tempco Blog.
https://www.tempco.it/blog/en/5909/fouling-in-heat-recovery-heat-exchangers/
21. Pugh , S. J. (2009, September 9). Fouling During the Use of "Fresh" Water as Coolant - The
Development of a "User Guide". Researchgate. Retrieved January 26, 2023, from
https://www.researchgate.net/publication/225003558_Fouling_During_the_Use_of_Fresh_Wat
er_as_Coolant_-_The_Development_of_a_User_Guide
22. Patrik P. (n.d.) Fouling factor in heat exchanger: Definition, Formula, Units [with Pdf]. (2021,
October 30). Mech Content. https://mechcontent.com/fouling-factor/
23. BEU Shell & Tube. (n.d.). https://www.shell-tube.com/Stainless-Steel/BEU_exchanger.html
24. Al-Haj Ibrahim, H. (2012, September 26). Fouling in Heat Exchangers. IntechOpen.
https://www.intechopen.com/chapters/39353
25. AL-Mubaddel, F. (2021, April 13). Effect of fouling resistance on the condenser performance.
Researchgate. https://www.researchgate.net/figure/Effect-of-fouling-resistance-on-the-
condenser-performance_fig3_350744933
26. Welsh, M. (2021, August 13). How To Reduce Fouling In Heat Exchangers. Chardon Labs.
https://www.chardonlabs.com/resources/reduce-fouling-in-heat-exchangers/
27. Central States Industrial Equipment & Supply. (2022, September 7). Fouling in Heat
Exchangers: Learn Causes, Detection, and Prevention. Central States Industrial.
https://www.csidesigns.com/blog/articles/fouling-in-heat-exchangers
28. Kananeh, B. A. (2009, June 14). APPLICATION OF ANTIFOULING SURFACES IN PLATE
HEAT EXCHANGER FOR FOOD PRODUCTION. Wordpress. https://heatexchanger-
fouling.com/wp-content/uploads/2021/09/21_Bani-Kananeh_F.pdf

SEMESTERS (213) - (221)
32/32
29. Karl Kolmetz. (2013, December 1). ETHYLENE QUENCH WATER TOWER SELECTION,
SIZING AND TROUBLESHOOTING. KLM. https://www.klmtechgroup.com/PDF/EDG-
ETH/ENGINEERING-DESIGN-GUIDELINES-ethylene-quench-water-tower-Rev2.2web.pdf
30. Instrumentation Solutions for Quench Tower and Settler Level Measurement | Magnetrol. (n.d.).
https://www.magnetrol.com/fr/blog/instrumentation-solutions-quench-tower-and-settler-level-
measurement
31. Berendsohn, R. (2022, March 29). The Best Pressure Washers for a Deeper Clean. Popular
Mechanics. https://www.popularmechanics.com/home/tools/reviews/g120/we-test-the-top-
small-pressure-washers/

Cavitation in Centrifugal Pumps and Fouling in Heat Exchangers in The Mechanical Side of KEMYA Plants .pdf

Recommended

Recommended

More Related Content

Similar to Cavitation in Centrifugal Pumps and Fouling in Heat Exchangers in The Mechanical Side of KEMYA Plants .pdf

Similar to Cavitation in Centrifugal Pumps and Fouling in Heat Exchangers in The Mechanical Side of KEMYA Plants .pdf (20)

Recently uploaded

Recently uploaded (20)

Cavitation in Centrifugal Pumps and Fouling in Heat Exchangers in The Mechanical Side of KEMYA Plants .pdf