COOLING TOWER GROUP 7

FACULTY OF ENGINEERING DEPARTMENT OF CHEMICAL AND ENVIRONMENTAL ENGINEERING UNIVERSITI PUTRA MALAYSIA ECH3118 PHYSICAL SEPARATION DESIGN PROJECT: COOLING TOWER LECTURERS : PROF DR ZURINA BINTI ZAINAL ABIDIN : DR FAIZAH BINTI MD YASIN GROUP 7: MATRIC NO. NO. NAME 198554 1. MOHAMAD HAZMAN BIN MOHAMAD HUSNIN 198253 2. SUBASHINY NADARAJAH 198900 3. DIVYASHINI MOHAN 198742 4. NAZEERA BINTI ZUKERNAIN 198681 5. NURAZLIYANI BINTI JAMALUDDIN DUE DATE: 27 JANUARY 2021 2|Page

TABLE OF CONTENT 4 5 1. LIST OF TABLES AND FIGURES 8 2. INTRODUCTION 10 3. PROCESS DESCRIPTION 17 4. MASS AND ENERGY BALANCES 20 5. DETAILED MECHANICAL DESIGN OF COOLING TOWER 21 6. MECHANICAL DRAWING OF COOLING TOWER 23 7. DISCUSSION 24 8. CONCLUSION 25 9. ACKNOWLEDGEMENT 27 10. REFERENCES 11. APPENDICES 3|Page

LIST OF TABLES AND FIGURES LIST OF TABLES Table 3.1 Reference Data………………………………………………………....10 Table 3.2 Equilibrium Line Data.…………………………………………..…..... 12 Table 3.3 Comparison between Excel and Aspen Simulation…………………....16 LIST OF FIGURES Figure 1.1 Schematic Diagram of Cooling Tower……………………………….. 6 Figure 3.1 The Enthalpy against Liquid Temperature Graph………………….… 12 4|Page

1. INTRODUCTION In the light of the environmental renaissance of the last 20 years, thermal pollution is now receiving serious attention. It is environmentally unethical to directly discharge hot water back to its source after it has been used to cool chemical process equipment, electrical generating turbines or refrigeration and air conditioning equipment. These hot processed waters must either be cooled before discharge, or cooled and recycled. Purchasing and then discarding large quantities of water into sewage systems is cost prohibitive in many parts of the country, and even if favourable economics were to exist, environmental concerns would forbid such practices. 1.1 HISTORY OF COOLING TOWER Due to abundance of water resources in the past, it was possible to use cold water on a once through basis. In ancient times rivers, seas, lakes, ponds, and other water resources were utilized as a medium of water supply. With limited industrial activities of the past ages and plentiful water resources, cold water could be used \"once through,” and then discharged without the need of being recycled. This method requires large land areas. To overcome this problem sprays systems were installed to aerate water in holding pond and to promote faster cooling. This lead to the development of cooling tower technology as it was discovered that by spraying downwards instead of upwards, cooling could be down faster. After mechanics and hydrodynamics of water-cooling was well studied, cooling tower technology was converted into first prototype as hyperbolic cooling tower. In today's economic framework and limited water resources, however, energy conservation matches the importance of our ecology. Consequently, utilizing cooling water efficiently become a vital engineering consideration. 1.2 COOLING TOWER OPERATION Cooling towers are used to remove the heat from industrial cooling waters used in heat exchanger units. This equipment has recently developed into an important part of many chemical plants. They represent a relatively inexpensive and dependable means of removing low-grade heat from cooling water. The air flows from bottom of the tower or perpendicular to the direction of water flow and then exhausts to the atmosphere after effective cooling. To 5|Page

prevent the escape of water particles with air, draft eliminators are provided at the top of the tower. Figure 1.1: Schematic Diagram of Cooling Tower Cooling towers can be classified into several types based on the air draft and flow pattern. Each type of cooling tower has its own advantages and disadvantages; thus, the proper selection is needed based on the system operation. Beside type selection, the material selection of cooling tower is also important. Cooling towers tends to be corrosive since it always has direct contact with the water. Proper material selection or additional water treatment is needed to keep the cooling tower in good working condition. 1.3 TYPES OF COOLING TOWER Cooling towers are generally classified by either build, heat transfer methods or airflow generation methods. Each type of cooling towers serves for different purposes and has its own advantages and disadvantages; thus, the system operation and condition are the key elements for proper selection of cooling tower. 1. Cooling towers by build:  Package type cooling towers: Package type cooling towers are pre-fabricated. The shell is usually made of corrosion-free, heat resistant and durable material like fiberglass-reinforced polyester. Since they are pre-assembled, they can be easily transported to a facility of choice. Since they are compact, they are preferred in facilities with low heat rejection requirements like hospitals, malls, and office buildings. 6|Page

 Field erection type: These large units are generally used in power plants and huge manufacturing facilities such as steel processing plants or oil refineries. They are large structures compared to the package type. They can be manufactured according to custom specifications. 2. Heat Transfer Method :  Dry cooling towers: Dry cooling towers operate by transferring heat through a surface that separates the working fluid from ambient air. This operates on the principle of heat transfer by a heat exchanger with extended fins. The fan is driven by an electric motor. Hence, dry cooling towers do not consume any water.  Wet cooling towers or Open Circuit cooling towers: These are the most popular cooling towers because they are cost-effective and renewable. They use water to cool the facility and the heat transfer is measured by the decrease in the process temperature and a corresponding increase in both the moisture content and the wet bulb temperature of the air passing through the cooling tower. 3. Air Flow Method :  Counter flow cooling tower: In this tower, hot water that enters at the top, while the air is introduced at the bottom and exits at the top. Both forced and induced draft fans are used. The distribution is done through channel with lateral pipes, fitted with splash spray nozzles. Growth of algae is highly restricted, as the lateral pipes are a closed unit and not located in direct sunlight. Their power consumption is lower than cross flow units and offers the advantage of easy maintenance.  Cross Flow cooling towers: These cooling towers are structured to allow air to flow horizontally while the water flows down vertically. This is done through open trough systems in the fan deck, fitted with nozzles. Since the airflow contact time is lesser, more air is required for heat transfer to occur. This type of cooling tower has many disadvantages such as higher power consumption due to the airflow required; maintenance is time consuming and is susceptible to scaling and clogging of opening. 7|Page

2. PROCESS DESCRIPTION Cooling tower operation is based on evaporative condensation and exchange of sensible heat. The mixing of two fluid streams at different temperature (in this case air and water) releases latent heat of vaporization, causing a cooling effect to the warmer fluid (water). This cooling effect is accomplished by transforming a portion of the liquid into a vapour state, thereby releasing the latent heat of vaporisation. In a cooling tower's operation, sensible heat also plays a role. When warm water contacts cooler air, the air cools the water and its temperature rises as it gains the sensible heat of the water. Roughly, 25% of the sensible heat transfer takes place within the tower, with the balance of the cooling phenomenon achieved from the evaporative effect of the latent heat of vaporization. In simple terms, a cooling tower is a device that transfers quantities of heat from one mass to another. In short, a cooling tower is simply an air-mass heat exchanger. In our design project, we are required to design a cooling tower that is used to reduce the warm inlet water with 45˚C to 30˚C using air. The total mass flowrate of water into the tower is about 6000 kg.m3h into a packed bed-cooling tower. Cooling towers cool the warm water by contacting it with ambient air. The warm water is pumped to the top of the IPCT and is distributed across the distribution deck where it flows through a series of nozzles onto the top of the tower's fill material. Fill material is used in cooling towers to create as much water surface as possible to enhance evaporation and heat transfer. As the water flows down the fill material, it contacts air that is drawn or forced across the fill material by one or more fans at the top of the tower. A small percentage of the water evaporates, cooling the circulating water and heating the air. A smaller portion of the water is entrained in the air stream as droplets of water, which are called \"drift\" if they leave the tower. Two principles of heat transfer are involved: evaporation and convection. The rate of heat transfer by both convection and evaporation increases with an increase in air-to-water interfacial surface, relative velocity, contact time and temperature differential. Packing and fill in a tower serve to increase the interfacial surface area; the tower chimney or fans create the relative air-to-water velocity; and contact time is a function of tower size. These three factors all may be influenced by the tower design. The ability of a tower to function is measured by how close it brings the cold-water temperature to the wet-bulb temperature of the surrounding air. The lower the wet-bulb temperature (which indicates either cool air, low humidity or a 8|Page

combination), the colder the tower can make the water. The water temperature will never go below the temperature of the incoming air. In practice, the final water temperature will be several degrees above the wet-bulb temperature. When a stream of unsaturated gas is passed over the surface of a liquid, the humidity of the gas is increased due to evaporation of the liquid. The temperature of the liquid falls below that of the gas, and heat is transferred from the gas to the liquid. At equilibrium, the rate of heat transfer from the gas just balances that required to vaporise the liquid, and the liquid is said to be at the wet-bulb temperature. The rate at which this temperature is reached depends on the initial temperatures and the rate of flow of gas past the liquid surface. With a small area of contact between the gas and the liquid and a high gas flow rate, the temperature and the humidity of the gas stream remain virtually unchanged. The rate of transfer of heat from the gas to the liquid can be written as ������ = ℎ������(������ − ������������) where Q is the heat flow, h the coefficient of heat transfer, A the area for transfer, and θ and θw are the temperatures of the gas and liquid phases. In our designed cooling tower, the wet bulb temperature used was 25.6˚C. In short, we designed a cooling tower with mass flowrate of 6000 kg/hr where it cools down the warm water with an initial temperature of 45˚C to 30˚C.This cooling tower operated under counter flow where the water flows into the tower from top whereas the air enters from the bottom of the tower. This is to increase the efficiency of heat exchanging between the air and water. 9|Page

3. MASS AND ENERGY BALANCES Given data: Assumptions: Warm inlet Water temperature: 45°C 1. L, the water flowrate is assumed to be Outlet Water temperature: 30°C constant since the rate of water vaporize is much less than the rate of Mass flowrate of Water: 6000 ������������.������2 water input to the cooling tower ℎ whereby the loss of feed water is just about 1%.  To find out air flowrate, G: 2. This process is assumed to be occur in Wet bulb temperature= 24℃ ≈ 74.4℉ (assumption box (5)) steady state. Therefore, no generation Dry bulb temperature = 30.87℃ ≈ 87.56℉ (calculated using and accumulation. table provided below) (������������������ = ������������������������) Table 3.1: Reference data 3. The cooling process is also assumed to be adiabatic resulting in no heat loss or Dry bulb T Relative Resultant Wet heat absorption throughout the process, (℉) Humidity bulb T (℉) although, there is internal circulation of 50 40 heat since the process involving two 60 40 50 different phases. 70 50 55 85 35 73 4. Considering how the air flowrate, G is 90 55 78 not given, it needs to be calculated 60 using this formula took from journal: ������ = 1.5������������������������ Having two parametric (dry bulb temperature and wet bulb temperature), relative humidity, humid ratio, and ������������ can be Based on journal, it appears that for calculated. actual tower, a value of G is greater than ������������������������ and the range is always from 1.3 – 1.5 times greater. As for this calculation, 1.5 has been used to calculate the air flowrate. 5. Evaporating cooling tower will typically provide cooling water 5 -7℃ higher for the current ambient wet bulb condition. Thus, with the outlet temperature given, the wet bulb temperature can be calculated by 30℃ − 6℃ = 23℃ 10 | P a g e

From psychometric chart, Relative Humidity: 57.29% (According to the table, this is correct) Humid ratio: 0.01617 ������������ ������20 ������������ ������������������ ������������������ ������������ = ������������ (������ − ������������) ������������ = (1.005 + 1.88������)103(������ − 0) + (2.501106������) ������������ = (1.005 + 1.88(0.01617))103(30 − 0) + (2.501106(0.01617)) ������������ = 71503.158 ������ ≈ 71.503 ������������ ������������ ������������ For saturation curve (equilibrium line) Vapor Pressure @ 45℃ = 0.09350 bar Humidity = ������������ ( 18.02 ) ������−������������ 28.97 H = 0.09350 (18.02) = 0.064 1.013−0.09350 28.97 H, Enthalpy of saturated air at 45°C [ref. temp = 0°C] H = ((1.005+1.88(0.064)103)(45-0)) + (2.5014  106(0.064)))/10^3 H = 209 kJ/kg The calculations were repeated by replacing temperature with 25°C, 30°C,35°C, and 40°C and the results obtained are shown in Table 2. 11 | P a g e

Table 3.2: Equilibrium line data T (°C) T (K) Vapor Humidity (kg H20/kg Enthalpy (kJ/kg) 25 298 Pressure D.A) 75.93 30 303 0.03147 0.020 98.70 35 308 0.04186 0.027 127.20 40 313 0.05522 0.036 163.02 45 318 0.07213 0.048 208.72 0.0935 0.063 Enthalpy against Liquid Temperature Graph 250.0 200.0 y = 9.1479x - 202.93 Enthalpy Hy (kJ/kg) 150.0 100.0 50.0 30 35 40 45 25 Liquid Temperature (°C) Equilibrium Line Tangent line Linear (Tangent line) Figure 3.1: The Enthalpy against Liquid Temperature Graph slope/gradient 9.1479 kg/m².hr L 6000 kJ/m².K CL (constant) 4.187 12 | P a g e

Slope = ������(������������) ������������������������ ������������������������ = ������(������������) ������������������������������ ������������������������ = 6000(4.187) 9.1479 = 2746.20407 kg/m^2.hr G = 1.5 ������������������������ G = 1.5 (2746.20407) = 4119.31 kg/������2.hr  Air flowrate, G: 4119.31 kg/������2.hr MASS BALANCE: Assumption: 1. Steady state operation. For cooling tower, since there is reactive reaction takes place, ������������������������������������ = ������������������������������������������ (Air) ������������������������������ = ������������������������������������ (Water) (ṁ������)������������ = (ṁ������)������������������ ������������������������������������������ = ������������������������������������������������ (ṁ������)������������ + (ṁ������) = (ṁ������)������������������ ṁ������ is the flowrate of water coming from makeup tank which in this case is negligible. Hence for water, (ṁ������)������������= (ṁ������)������������������ 13 | P a g e

ENERGY BALANCE: Q̇ + Ṗ = Ḣ������������������ − Ḣ������������ Q̇ + Ṗ = Work done on system Ḣ������������ = Energy loss due to enthalpy change From literature, Ṗ = 100 W = 100 J/s From previous calculation: ṁ������ = 4119.31 kg/������2.hr ṁ������ = 6000 kg/������2.hr Element Temperature (°C) Specific Enthalpy Mass flowrate (kg/������2.hr) Air (kJ/kg) Water ������������������ ������������������������ ℎ������������ ℎ������������������ ṁ������������ ṁ������������������ 30.87 X = 40.09 72.385 Y= 4119.31 4119.31 163.86 45 30 188.45 125.79 6000 6000 To find out x, L (������������)(������������2 − ������������1) = G (������’2 – ������’1) 6000 (4.187) (45-30) = 4119.31 (������’2 − 72.385) ������’2 = 163.86 ������������/������������ = Y 14 | P a g e

From the table and calculated value, ������ – 40 45 − 40 163.86 − 163.02 = 208.72 − 163.02 X = 40.09°C Q̇ + Ṗ = (ṁ������ℎ������������������,������������������ + ṁ������ℎ������������������,������������������������������) − (ṁ������ℎ������������,������������������ + ṁ������ℎ������������,������������������������������) Q̇ + 100 ������ = [(4119.31 ������������ × 163.86 ������������������������) + (6000 ������������ 125.79 ������������ )] - ������ ������2.hr ������2.hr ������������ [(4119.31 ������������ × 72.385 ������������������������) + (6000 ������������ × 188.45 ������������������������)] ������2.hr ������2.hr Q̇ + 100 ������ = 853.88225���������2������.���hr 1000������ 1 ℎ������ ������ 1������������ 3600 ������ Q̇ = (237.1895���������2��� .s  17.5������2) – 100������������ Q̇ = 4050.82 ������ s Q̇ = 4.051 kJ/s ≈ 4.051 ������������  Assumptions made are considered valid since the value calculated for Q̇ is positive and justified or indicating that heat is absorbed in cooling tower, which is correct 15 | P a g e

COMPARISON OF ASPEN PLUS SIMULATION AND MANUAL CALCULATION Table 3.3: Comparison between Excel Calculation and ASPEN Simulation Stream Excel Calculation ASPEN Simulation Inlet Outlet Inlet Outlet AIR WATER AIR WATER AIR WATER AIR WATER Pressure 1 1 1 11 1 11 (bar) Temperature 30.87 45 40.09 30 30.87 45 39.15 28.42 (°C) Mass 4119.31 6000 4119.31 6000 4119.31 6000 4273.61 5845.70 Flowrate (kg/hr) Mass 72.385 188.45 163.86 125.79 5.7257 -15770.8889 -470.2083 -15839.391 Enthalpy (kJ/kg) 4.051 -0.09997 Δ Q̇ (kW) The table shows the values of mass flowrate inlet and outlet between excel manual calculation and ASPEN simulation in cooling tower unit mass balance, wherein the error percentage is 2.57%. This small amount of error below 5 % verifies the manual calculation via excel whereby the information used such as assumptions (steady state) and ������������������������. The error could be possibly due to few other assumptions like neglecting presence of makeup tank. However, a huge gap amongst the energy balance of 4.051 kW and -0.099 kW in excel calculation and ASPEN PLUS simulation, respectively. Variation in outlet temperature for both ASPEN and excel calculation affected the enthalpy change. For simulating the cooling tower in ASPEN PLUS, an approach based on equilibrium stages is applied. ASPEN PLUS offers a built-in RADFRAC block to be able to calculate the liquid and vapor/gas equilibrium for each equilibrium stage, considering neither reboilers, nor condensers. Considering, how the steps of simulation carried out based on a video uploaded in YouTube, which does not, has proper credits and references could be another reason for the huge gap. Additionally, according to a journal on cooling tower simulation, there is no standard procedure for setting up a cooling tower block when simulating a cooling water network with process simulators such as ASPEN PLUS. 16 | P a g e

4. MECHANICAL DESIGN PARAMETERS OF COOLING TOWER (REFER APPENDIX B FOR DETAILED CALCULATIONS) Unit Operation: Specification: Cooling Tower Overall Height: 9.3 m Component of Cooling Tower: Packed Height, z = 4.05 m Filled Height, dz = 1.2 m *(from journal) Diameter, D = 4.5 m Material: Galvanized steel, various grades of stainless steel, fiberglass, and concrete Specification: Packed Bed Film Fill Height = 1.2 m Fan Blade Diameter = 4.5 m Nozzle Material: PVC Louvers Fan Diameter = 2.44 m *(from journal) Tip speed: 14000 FPM Cold Water Basin Number of Blade: 4 Blades Type of fan: Axial Material: Cast aluminum alloy Nozzle Diameter = 0.08 m *(from journal) Distance between two nozzles = 0.2 m Type of nozzle: NS 5&6 Material: PP materials Height = 0.24 m Diameter = 0.5 m Sheet Spacing = 0.19 m *(from journal) Thick = 0.003 m Type of Louver: MC 120 Material: Plastic Height: 1.15 m *(from journal) Diameter: 4.5 m Material: fiberglass, galvanized steel or stainless steel 17 | P a g e

JUSTIFICATION FOR DESIGN PARAMETERS OF COOLING TOWER Cooling Tower Unit operation that have been calculated is cooling tower. Cooling tower is a specialized heat exchanger in which air and water are brought into direct contact with each other in order to reduce the water’s temperature. The hot water enters at the top, while the air is introduced at the bottom and exits at the top. In this cooling tower, the counter flow design is chosen due to increase the efficiency of heat exchanger between the air and the water. This can result to the less of water and air required thus lead to the less cost. The tower material are being structured by galvanized steel, fiberglass and concreate. This structure can reduce the corrosion and long service life. Packed Bed Film Fill For the packed bed, film fill is chosen in this cooling tower. Film fill is made using thin sheets of PVC material which are placed very close together. This creates a very large surface area which allows hot air to circulate and come into contact with the film of material. This cools the water by increasing the rate of heat transfer. Film fill produces a more efficient heat transfer as it generates a bigger surface area. The diameter is 4.5 m which is same as the diameter of cooling tower. The PVC material is chosen because PVC is abrasion resistance, lightweight and good mechanical strength. Fan Blade For the fan blade in cooling tower, the axial fan is used in the design. Axial fan is a type of fan that causes gas to flow through it in an axial direction, parallel to the shaft about which the blades rotate. The flow is axial at entry and exit. The fan is designed to produce a pressure difference and force hence cause a flow through the fan. Axial fan model meet the high efficiency and low noise requirements. The axial fan diameter is 2.44 m which is found from the journal. The tip speed 14000 FPM which required 4 blades. The material that used is cast aluminium alloys which are high strength, high quality, low cost and possess outstanding of corrosion resistance. 18 | P a g e

Nozzle The spray nozzles are used in cooling tower, which is to distribute water in wet cooling towers. Cooling towers are evaporative heat rejection devices, which take out the waste heat to the atmosphere through the cooling of water by the air. The type of nozzle is NS 5&6, which is counter flow nozzles. This type have “full cone” distribution pattern, which will assures uniform water distribution for all film fills. Minimal spray overlap is required, providing uniform water distribution even near spray boundaries. The nozzle diameter is 0.08 m, which is found from journal and made from PP (polypropylene) materials. This type of nozzle have a good characteristic, which will increase efficiency of cooling tower. Louvers The type of louvers that is used in this cooling tower is MC 120. The primary function of the air intake louvers in a cooling tower is to act as a barrier for sunlight, noise, water splash-out and debris while also improving the airflow of the cooling tower and improving it’s appearance. It is a component that will increase the efficiency of cooling tower and help to ensure that water is in good quality and quantity. The height for this louvers is 0.24 m and the diameter is 0.5 m. Basically louvers are made from plastic which will prevent cooling tower from UV resistance, corrosion resistance and give smooth and glossy surface. Cold Water Basin The cold water basin is used in cooling tower to act as storage and collect cold water from the tower. The other function is to provide the main structure and foundation for the cooling tower itself. Cold water basins usually lye below ground level or on top of the soil. The height that we found from journal is 1.15 m. The diameter is same as diameter of cooling tower, which is 4.5 m. The material that is used in water cold basin are fiberglass, galvanized steel or stainless steel. This material gives the best performance in terms of corrosion resistance and long life service. 19 | P a g e

5. MECHANICAL DRAWING OF COOLING TOWER TITLE : COOLING TOWER NAME : COUNTER FLOW TOWER GROUP : GROUP 7 SUPERVISOR : PROF DR ZURINA BINTI ZAINAL ABIDIN SUPPORTING CALCULATION : APPENDIX B SPECIFICATIONS No. Descriptions Specification Qty 1 1 Fan Cast aluminum 1 alloy 1 1 2 Filling PVC 4.50 3 Nozzle PP Materials 2.44 4 Louver Plastic 1 3 4.05 2 1.20 4.05 4 1.16 20 | P a g e

6. DISCUSSION Usually cooling towers are used to remove heat from the building and are used widely in industries like power plants, petroleum refineries and many manufacturing industries. The cooling tower design project is intended to reduce the warmer inlet water, 45°C to 30°C before releasing it to the environment. The size of the designed building of cooling tower and relative humidity of the air determine the cooling load. In terms of technical feasibility, this cooling tower is technically feasible because its overall height 9.3m with diameter of 4.5m. Cooling tower is an important unit in plant because it will produce an optimum effluent temperature before it is discharge to the environment. The feasibility of using cooling tower is studied from the design of this unit. The cooling tower design unit should be equipped with a drift eliminator that can mitigate pollution from evaporative cooling droplets. The drift eliminator is designed to capture water droplets that pertain in the air steamer of the cooling water; thus, it can prevent the damage of environment and save water by recycling it. By implementing this preventive measure towards less pollutants produced, it suits the 12th Sustainable Development Goal. In this goal, it targets to substantially reduce waste generation through prevention, reduction and recycling the waste. Besides, the importance of treating the circulating cooling water is to reduce scaling and fouling. This is because, the water should be filtered to remove particulates, dosed with biocides and algaecides to avoid growths that can disturb the flow of water. So, when there is fouling in the flow, it will reduce the cooling tower efficiency. The unfiltered particulates can bring harm to the environment and cooling tower itself since microorganisms such as bacteria and algae can grow rapidly in cooling water. Soon, it will reduce the heat transfer efficiency of the cooling tower. Hence, a feasibility design of cooling tower should include biocides such as oxidizing and non-oxidizing agents to ensure the microorganisms are killed in the flow of cooling water. Furthermore, by developing methods to increase cooling tower efficiency, it can significantly contribute in conservation of environmental resources like water. This can be achieved by implementing some alternative methods for sustainability development that suitable for large scales and integral approaches. To apply the concept of sustainable development in this cooling tower design, it is prudent to implement an innovation in the design to be more environment friendly and can benefit the society. Besides, raising awareness to the 21 | P a g e

society on cooling tower and its impact on the environment can maximize benefits while minimize risks over long periods since the chemical plant should be built with buffer zone surround it. Sustainability is interconnected with the concepts of safety, health, and environmental issues related to workers and the society. In terms of society, the cooling tower can play a role in improving the livelihood of the society by providing new job opportunities. Operators, managers, engineers, analyst, cleaner, switchman, technicians and many more work force will be needed to operate the cooling tower. This directly improves the quality of life of the society by helping them to generate a fixed monthly income. Moreover, the sustainability in the aspect of environmental can be seen as there is no GHG gaseous emitting from our designed cooling tower, thus the unit is considered a green building, which aims to implement green technology. To conclude, feasibility design in cooling tower can be achieved by treating the circulating cooling water, equipped cooling tower with a technology that can mitigate pollution and develop methods that can increase its efficiency. Therefore, the impact of the unit operation design towards society, environment and sustainable development must be seriously took into consideration so that it can benefit others. 22 | P a g e

7. CONCLUSION In conclusion, the cooling tower design for 6000 kg.m2h to cool down warm water, 45°C to 30°C require a total height of 9.3m with diameter of 4.5m. Galvanized steel was chosen as the material of the tower structure. For packed bed film fill, PVC is chosen as the film fill with the height 1.2m. Besides, the spray nozzle has been designed to have NS 5&6 with counter-flow nozzle. As for cold water basin, the material that is used in the design are fiberglass, galvanized steel or stainless steel. In short, to have a best performance of cooling tower, only the most suitable material is chosen. The cooling tower is designed to comply the feasibility that give impact to society, environment and sustainable development. Our cooling tower serves the purpose by contributing to the sustainable development of humankind by playing a significant role in two major aspects, the societal and environmental. The proposed cooling tower design work within the feasible parameters with more sustainable, economical, energy efficient and environmental friendly than existing design. 23 | P a g e

8. ACKNOWLEDGEMENT First, we would like to thank God for giving our team the strength and support to complete our design project just in time even though we faced with some difficulties during the completion of this project. Regarding to the design project that has been assigned to us entitled Cooling Tower Design; we would express our deepest appreciation to our lecturer, Professor Dr Zurina Zainal Abidin for giving us the opportunity to carry out this project that helps broaden our knowledge on cooling tower and its operation. Thank you for always giving us the motivation that uplifts our spirits to finish this project successfully. Without your guidance and persistent help, this design project would not have been possible. We would also like to express our heartfelt gratitude towards our teammates and classmates for their invaluable advice and their helps throughout this design project. Their patience and willingness to share and teach us on how to fully utilize Microsoft Excel, AspenPlus and AutoCad to complete the whole cooling tower design is much obliged. Finally, we would like to take this opportunity to express our sincere thanks to those who helped us direct and indirectly to complete this project. 24 | P a g e

9. REFERENCES Bedekar, S. V., Nithiarasu, P., & Seetharamu, K. N. (1998). Experimental investigation of the performance of a counter-flow, packed-bed mechanical cooling tower. Energy, 23(11), 943- 947. Bernier, M. A. (1994). Cooling tower performance: theory and experiments (No. CONF- 9406105-). American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (United States). Chowdhury, B. A., Islam, M. S., Begum, F., Parvez, A. M. (2010). Design and Performance Analysis of a Cooling Tower in Sulfuric Acid Plant. Journal of Chemical Engineering, 23(5), 5-6. https://doi.org/10.3329/jce.v23i0.5568 Delta Cooling Towers (2017). Wet Bulb Temperatures and Cooling Tower Performance. Retrieved from https://deltacooling.com/resources/news/understanding-wet-bulb- temperatures-and-how-it-affects-cooling-tower-performance Hensley, J. C. (Ed.). (1985). Cooling tower fundamentals. Marley Cooling Tower Company. Jafar, S. A., Kamal, S. K. (2016). Analysis Studying For Improving Cooling Tower. Journal of Scientific Studies (KUJSS), 11(3), 186-202. https://doi.org/10.32894/kujss.2016.124656 Kim, J. K., & Smith, R. (2001). Cooling water system design. Chemical Engineering Science, 56(12), 3641-3658. Lee, Y. (n.d.). The Basics of AXIAL FLOW FANS Hudson Products Corporation. Retrieved from https://www.academia.edu/37153357/The_Basics_of_AXIAL_FLOW_FANS_HUDSON_Pr oducts_Corporation M. (2020, November 21). Simulate of Cooling Tower by Aspen Plus ‫محاكاة برج التبريد بإستخدام أسبن‬ ‫بلص‬. YouTube. https://www.youtube.com/watch?v=K0xR4zyIAIw&feature=youtu.be Marley MS Cooling Tower. (2019). Cooling Tower Parts Reference Guide. Retrieved from https://spxcooling.com/library/marley-ms-cooling-tower/ 25 | P a g e

Mashood, E. (2019, February 8). Cooling Tower Design Calculations - Height of Packing & Air Flow Rate. Blogger. https://chempds.blogspot.com/2019/02/cooling-tower-design- calculations.html?m=1 Milosavljevic, N., & Heikkilä, P. (2001). A comprehensive approach to cooling tower design. Applied thermal engineering, 21(9), 899-915. Papaefthimiou, V. D., Zannis, T. C., & Rogdakis, E. D. (2006). Thermodynamic study of wet cooling tower performance. International journal of energy research, 30(6), 411-426. Queiroz, J. A., Rodrigues, V. M., Matos, H. A., & Martins, F. G. (2012). Modeling of existing cooling towers in ASPEN PLUS using an equilibrium stage method. Energy conversion and management, 64, 473-481. Sara Cooling Tower. (n.d.). Cooling Tower Louver. Retrieved from https://www.saracoolingtower.com/cooling-tower-louvers/#:~:text=or%20needed%20size.- ,Material,of%20galvanized%20or%20stainless%20material. 26 | P a g e

APPENDIX A: ASPEN SIMULATION 27 | P a g e

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APPENDIX B: MECHANICAL DESIGN MANUAL CALCULATION 29 | P a g e

Psychometric Chart 30 | P a g e

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-Plot (TL1,Hy1), (30, 76.5) at the graph. Draw a line until it reached the end of the equilibrium line to produce a tangent line. Graphical Solution using Excel 32 | P a g e

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