DESIGN AND DEVELOP AN EFFICIENT AERATION SYSTEM FOR TASIK UTeM – AERATION DEVICE
SYAZWAN ARIFF BIN MOHD YUNUS B041110140 BMCA Email:
[email protected]
Draft Final Report Projek Sarjana Muda II
Supervisor: PROF. MADYA IR. DR TALIB BIN DIN
Faculty of Mechanical Engineering Universiti Teknikal Malaysia Melaka
MEI 2015
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SUPERVISOR DECLARATION
“I hereby declare that I have read this thesis and in my opinion this report is sufficient in terms of scope and quality for the award of the degree of Bachelor of Mechanical Engineering (Automotive)”
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DECLARATION
“I hereby declare that the work in this report is my own except for summaries and quotations which have been duly acknowledged.”
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ACKNOWLEDGEMENT
First of all, I am grateful to Allah S.W.T for the grace and kindness given the time and space as I to complete my project successfully. Also, I would like to give a round of applause to UTeM (Universiti Teknikal Malaysia Melaka) and FKM (Fakulti Kejuruteraan Mekanikal) specifically for given us the chance to carry out the project and ease us in order to get the reference materials about this topic by providing a lot of facility and convenience like library and cafeteria. Secondly, a lot sincere and thanks to supervisor, Prof. Madya. Ir. Dr. Abdul Talib bin Din for his perfect guidance and good explanation from the beginning of this project until it is completed. Furthermore, I also want to thanks to you for your commitment and trust to us to get this task done. Not to mention my parents who give a ton of supports and encouragements and also pocket money as the money don’t grow on trees this day as to accomplish this project. Lastly in a nutshell, I hope that the project that have been done can enhance our knowledge as a student and hopefully as an engineers in the near future. Besides that, I hope that this project can provide a lot of information and benefit to the society and to the world.
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ABSTRACT
The main objective of the project is to design and develop an efficient aeration system for Tasik UTeM which reduce BOD and COD, and increasing the dissolve oxygen - aeration device. The key factor that should be taken when carrying out this project is to choose the most suitable aeration system while having the efficiency of air distribution based on quality of water, the depth, and the flow of lake. To achieve this task, a relevant research on existing aeration system such as fountain aerator, propeller aerator, paddlewheel and diffuser aerator. To provide the maximum dissolve oxygen to the Tasik UTeM, water quality must be analysed and the pressure in water is determined so that the blower pump can deliver enough air through the piping system. At the same time, mechanical factors and other characteristic should be taken in order to develop and design the aeration such as the loss of air pressure, air flow, types of pipe and so forth. Besides, the design of this system not prevent the flows of streams as well as the cost no too expensive.
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ABSTRAK
Tujuan utama projek ini adalah untuk mereka bentuk dan membangunkan sistem pengudaraan bagi Tasik UTeM – alat pengudaraan air. Faktor utama ketika menjalankan projek ini adalah pemilihan pengudaraan yang paling sesuai disamping mempunyai kadar kecekapan pengagihan udara yang paling maksimum berdasarkan beberapa factor lain seperti kadar kualiti air, faktor kedalaman, dan aliran tasik. Bagi proses pemilihan sistem yang sesuai, kajjian dijalankan berkaitan dengan sistem pengudaraan yang sedia ada seperti pengudaraan jenis pancutan udara (“fountain aerator”), pengudaraan di permukaan dengan kaedah kayuhan (“paddlewheel”) dan kaedah udara terlarut melalui sistem paip (“diffuser aerator”). Dalam usaha untuk membekalkan keperluan oksigen yang maksimum untuk Tasik UTeM, kadar kualiti air harus diketahui terlebih dahulu dan seterusnya tekanan udara di dalam air supaya pam udara dapat menyalurkan udara yang mencukupi melalui sistem paip. Pada masa yang sama, ciri-ciri dan faktor-faktor mekanikal harus diambil kira bagi tujuan mereka sistem pengudaraan seperti kadar kehilangan tekanan udara, kelancaran pengaliran udara di dalam paip, jenis paip dan sebagainya. Selain daripada itu, reka bentuk sistem ini hendaklah tidak menganggu pengaliran arus disamping kos pembangunan yang tidak terlalu mahal.
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TABLE OF CONTENT
CHAPTER
1
CONTENT
PAGE
SUPERVISOR DECLARATION
i
DECLARATION
ii
ACKNOWLEDGEMENTS
iii
ABSTRACT
iv
ABSTRAK
v
TABLE OF CONTENT
vi
LIST OF TABLES
x
LIST OF FIGURES
xi
LIST OF ABBREVIATIONS AND SYMBOLS
xiii
LIST OF APPENDICES
xiv
INTRODUCTION 1.0
Introduction
1
1.1
Background Study
1
1.2
Objectives
2
1.3
Scope
2
1.4
Problem Statement
3
1.5
Idea Concept Design
3
1.6
Research Methodology
4
vii
2
LITERATURE REVIEW 2.0
Background Study
5
2.1
Types of Aeration System
7
2.1.1
Fountain Aerator
2.1.2
Propeller Aerator
2.1.3
Injector Aerator
2.1.4
Paddlewheels
2.1.5
Diffuse Air/Gas Diffuser
2.2
Diffuse Air Aeration
10
2.3
Diffuser
12
2.4
2.3.1
Porous Diffuser
2.3.2
Nonporous Diffuser
Biochemical
Oxygen
Demand
(BOD)
and
15
Chemical Oxygen Demand (COD)
3
2.4.1
Biochemical Oxygen Demand (BOD)
2.4.2
Chemical Oxygen Demand (COD)
2.5
Blower
17
2.6
Air Piping
20
METHODOLOGY 3.0
Introduction
24
3.1
Project Planning
24
3.2
Flowchart
25
3.3
Process Flow Explanation
26
3.3.1
Identify problem Statement
3.3.2
Literature Review
3.3.3
Idea Development
3.3.4
Concept Generation
3.3.5
Analysis
3.3.6
Quality Function Development (QFD)
viii
4
Identify Concept Design
3.3.8
Concept Evaluation
3.3.9
Design Selection
DATA AND CAD DRAWING 4.1
5
3.3.7
Data Calculation 4.1.1
Head Losses in Straight Pipe
4.1.2
Power Require for Blower
4.1.3
Design for Fitting/Joint
35
4.2
Idea Sketching
39
4.3
CAD Drawing
40
4.3.1
Main Pipe Drawing
4.3.2
Sub-line Pipe Drawing
4.3.3
Wye (“Y”) Drawing
4.3.4
Tee Pipe Drawing
4.3.5
Elbow Pipe Drawing
4.3.6
Fine Bubble Diffuser Stone
4.3.7
Coarse Bubble Diffuser Stone
4.3.8
Main Pipe Assembly Drawing
44
RESULT AND DISCUSSION 5.1
Introduction
45
5.2
Ansys-Fluent Software
45
5.3
Main Pipe Analysis
47
5.4
5.3.1
Contour Analysis Result
5.3.2
Velocity Vector Analysis
Sub-Line Pipe Analysis 5.4.1
Contour Analysis Result
5.4.2
Velocity Vector Analysis
52
ix
5.5
Wye (“Y”) Pipe Analysis 5.5.1
5.6 5.7
58
Velocity Magnitude Analysis
Elbow Pipe Analysis 5.7.1
6
Velocity Magnitude Analysis
Tee Pipe Analysis 5.6.1
57
60
Velocity Magnitude Analysis
CONCLUSION AND RECCOMENDATION
62
6.1
Conclusion
62
6.2
Recommendation
62
REFERENCES
63
APPENDICES
65
x
LIST OF TABLES
NO.
TITLE
PAGE
Table 2.1
Table Indicate Types Available at Standard
8
Table 2.2
Classification and Description of Diffused Air
11
Table 2.3
Type of Diffuser
12
Table 2.4
Typical Air Velocities in Aeration Header Pipes
21
Table 2.5
Resistance Factors for Fitting in Aeration Piping Systems
23
Table 2.6
Typical Head Losses through Air Filters, Blower Silencers and Check Valve
23
Table 3.1
House of Quality
32
Table 3.2
Morphological Chart
33
Table 3.3
Possible Combination of Alternative (Aeration Device)
33
Table 3.4
Weight Rating Decision Method
34
Table 4.1
Idea Sketching Concept Designs
39
Table 4.2
Comparison Between Idea Concept Designs
40
xi
LIST OF FIGURES
NO
TITLE
PAGE
Figure 1.1
Map of Tasik UTeM
2
Figure 1.2
Basic Diffused Aeration Concept
3
Figure 1.3
Flow Process for PSM
4
Figure 2.1
Basic Aeration Process
6
Figure 2.2
Fountain Type Aerator
7
Figure 2.3
Propeller Type Aerator
8
Figure 2.4
Injector Type Aerator
9
Figure 2.5
Paddlewheel Type Aerator
9
Figure 2.6
Diffuser Air Type
10
Figure 2.7 Figure 2.8 Figure 2.9
Type of porous air diffuser a) aluminium oxide disk, b) ceramic dome, c) polyethylene disk, d) perforated membrane. Commonly Blowers Used for Diffusion-air Aeration; a) Centrifugal; b) Rotary-lobe Positive Displacement. Characteristic Curve for Centrifugal Blower at Various Inlet Temperatures
13 17 20
Figure 3.1
Methodology Chart
25
Figure 3.2
Simulation Process and Comparison
30
Figure 3.3
Example of Block diagram
31
Figure 4.1
Main Pipe Drawing
40
Figure 4.2
Sub-Line Pipe Drawing
41
Figure 4.3
Wye (“Y”) Pipe Drawing
41
Figure 4.4
Tee Pipe Drawing
42
xii
Figure 4.5
Elbow Pipe Drawing
42
Figure 4.6
Fine Bubble Diffuser Stone
43
Figure 4.7
Coarse Bubble Diffuser Stone
43
Figure 4.8
Main Pipe Assembly Drawing
44
Figure 5.1
Pressure contour in main pipe
47
Figure 5.2
Velocity vector in main pipe
47
Figure 5.3
Contour of dynamic pressure at pipe outlet
48
Figure 5.4
Contour of static pressure at pipe outlet
49
Figure 5.5
Contour of velocity magnitude at pipe outlet
49
Figure 5.6
Velocity vectors coloured by dynamic pressure at pipe outlet
50
Figure 5.7
Velocity vectors coloured by static pressure at pipe outlet
51
Figure 5.8
Velocity vectors coloured by velocity magnitude at pipe outlet
51
Figure 5.9
Pressure contour in sub-line pipe.
52
Figure 5.10
Velocity vector in sub-line pipe.
52
Figure 5.11
Contour of dynamic pressure at pipe outlet
53
Figure 5.12
Contour of static pressure at pipe outlet
54
Figure 5.13
Contour velocity of magnitude at pipe outlet.
54
Figure 5.14
Velocity vectors coloured by dynamic pressure at pipe outlet
55
Figure 5.15
Velocity vectors by static pressure at pipe outlet
56
Figure 5.16
Velocity vectors coloured by velocity magnitude at pipe outlet
56
Figure 5.17
Pressure contour in Y-pipe
57
Figure 5.18
Velocity vector in Y-pipe
57
Figure 5.19
Velocity vectors coloured by velocity magnitude
58
Figure 5.20
Pressure contour in T-pipe
59
Figure 5.21
Velocity vector in T-pipe
59
Figure 5.22
Velocity vectors by dynamic pressure
60
Figure 5.23
Pressure elbow pipe
60
Figure 5.24
Velocity vector in elbow pipe
61
Figure 5.25
Velocity vectors coloured by velocity magnitude
61
xiii
LIST OF ABBREVIATIONS AND SYMBOLS
UTeM
-
Universiti Teknikal Malaysia Melaka
FKM
-
BOD
-
Biochemical Oxygen Demand
COD
-
Chemical Oxygen Demand
Pa
-
Pascal’s
DO
-
Dissolve Oxygen
CAD
-
Computer Aided Design
CFD
-
Computational Fluid Dynamic
MATLAB
-
Matrix laboratory
W
-
Watt
V
-
Volt
N
-
Newton
J
-
Joule
cm
-
centimetre
m
-
metre
mm
-
milimetre
in
-
inch
kg
-
kilogram
mg
-
miligram
L
-
Litre
Fakulti Kejuruteraan Mekanikal (Faculty of Mechanical Engineering)
xiv
mL
-
Mililitre
HP
-
Horse Power
min
-
minute
ºF
-
Degree Fahrenheit
ºC
-
Degree Celsius
K
-
Kelvin
Ø
-
Diameter
ft
-
feet
ppm
-
Parts per million
Hg
-
Mercury
FAS
-
Ferrous ammonium
QFD
-
Quality Function Development
HoQ
-
House of Quality
SOTR
-
Standard Oxygen Transfer Rate
R
-
Rating
WR
-
Weighted Rating
IW
-
Importance Weight
xiv
LIST OF APPENDICES
NO.
TITLE
PAGE
1
Map of Tasik UTeM
66
2
Gantt Chart PSM I
67
3
Gantt Chart PSM II
68
4
Drafting Main Pipe Drawing
69
5
Drafting Sub-Line Pipe Drawing
70
6
Drafting Wye (“Y”) Drawing
71
7
Drafting Tee Drawing
72
8
Drafting Elbow Drawing
73
9
Drafting Fine Bubble Diffuser Stone
74
10
Drafting Coarse Bubble Diffuser Stone
75
1
CHAPTER 1
INTRODUCTION
1.0
INTRODUCTION
There are six titles will be provided in this chapter. First of all is the background study followed by the objective, scope and problem statement provided early of the semester. Then, it will be continued with idea concept design which indicate the basic concept of water aeration and research methodology.
1.1
BACKGROUND STUDY Water is most precious resource in daily life and lake is one the resource to
obtain besides river and mountain. Lake is categorized as an area that surrounded by land apart from any river. It is also vary in shape, depth and exists at different elevations. Some measure only a few square meter and small to fit the backyard referred as ponds. Lakes can be contrasted with rivers or streams, which are usually flowing. However most lakes are fed and drained by rivers and streams. The water in lakes comes from rain, stream and groundwater. Usually most lakes contain freshwater.
Now, in the modern day, lakes are constructed for industrial and agricultural purpose. Besides, it is used for generate power like hydro-electric power generation
2
or domestic water supply. At the same time, lake is also use for recreational activities. In this project, the scope, objective and problem statement according to Tasik UTeM. Figure 1.1 shows the map of Tasik UTeM A and B. The area of Lake A and B is 26148.1m2 and 48076.8m2 respectively.
Figure 1.1: Map of Tasik UTeM 1.2
OBJECTIVE To design and develop an efficient aeration system for Tasik UTeM which reduce BOD and COD, and increasing the dissolve oxygen - aeration device
1.3
SCOPE Literature review on water quality at Tasik UTeM water focus on the parameter of dissolve oxygen (DO).
3
1.4
PROBLEM STATEMENT Throughout this project, there are several aspects and factor that need to be
considered. First of all is to design a suitable aeration system included the blower, automatic switch which suitable on decreasing biological oxygen demand (BOD) and chemical oxygen demand (COD) and increasing the dissolve oxygen. However, some precaution need to be done on the model so that it is durable and not having any pressure loss in order to provide the oxygenation need for Tasik UTeM Next, the level of BOD and COD in Tasik UTeM need to be determined so the correct amount of oxygen can be provided by the aeration system. Besides, a precise pressure level in the water also has to be determined so that the blower can provide enough air through underwater piping. Lastly, the installation process of the aeration system must correctly install.
1.5
Concept Designs Diffused air type will be used for this project where by a tube will be place in
the middle at the bottom of the lake. Apart from that, there are branching structures of the main channel to the overall sides for aeration. A blower house will be located and equipped with two mechanical blowers which operate intermittently to provide air for aeration process. The blower operated automatically controlled by switch depends on BOD and COD of the water. The figure below shows the basic concept diffuse air that will be install at Tasik UTeM.
Figure 1.2: Basic diffused aeration concept.
4
1.6
Research Methodology START
Title Confirmation
Identified the Aeration System
PSM 1
Identified Objective & Scope of the project
Collect Relevant Information & Data
Analyze & Identified the Problems
Experimental on Water quality
NO
Design and Simulation by CAD/CFD YES
Design Detailing
Testing & Validation
Figure 1.3: Flow process for PSM
PSM 2
5
CHAPTER 2
LITERATURE REVIEW
2.0
BACKGROUND STUDY Aeration is the process which area of the contact between water and air is
increased, by natural or mechanical devices for oxygenation process. This process is the most efficient techniques frequently apply in the improvement of the physical and chemical properties and characteristics of water. The function of aeration improves the taste and odor of the water, such as lake and river by supplying the enough oxygen, rescuing the free carbon dioxide and eliminating much of the hydrogen sulfide and other odorous presents. Besides that, removal of iron and manganese from such oxygen deficient waters also usually requires aeration as an initial step. This initial step allows for the lower oxides of these minerals that are dissolved in the water and combined with carbon dioxide to be converted to higher insoluble oxides and in turn removed by subsequent sedimentation, contact or filtration. The benefit from aeration are:
Improve overall water quality.
Increase the population of fish.
Cause circulation currents that might create favorable conditions for more desirable algae to out compete blue green algae.
Reduce the mortality of aquatic life due to low oxygen levels.
Speed up the rate of organic decomposition.
6
The efficiency of the aeration process depends on almost entirely on the amount of surface contact between the air and water. This contact is controlled primarily by the size of the water droplet or air bubbles. The goal of an aerator is to increase the surface area of water coming in contact with air so that more air can react with the water. As air or water is broken up into smaller drops/bubbles or into thin sheets, the same volume of either substance has a larger surface area. Figure 2.1 below shows the basic process of aeration
Figure 2.1: Basic Aeration Process Aeration removes or modifies the constituents of water using two methods which are scrubbing action and oxidation. Scrubbing action is caused by turbulence which results when the water and air mix together. The scrubbing action physically removes gases from solution in the water, allowing them to escape into the surrounding air. Based on the figure above, carbon dioxide and hydrogen sulfide are shown being removed by scrubbing action. Scrubbing action will remove tastes and odors from water if the problem is caused by relatively volatile gases and organic compounds.
7
Oxidation is the other process through which aeration purifies water. Oxidation is the addition of oxygen, the removal of hydrogen, or the removal of electrons from an element or compound. When air is mixed with water, some impurities in the water, such as iron and manganese, become oxidized. Once oxidized, these chemicals fall out of solution and become suspended in the water. The suspended material can then be removed later in the treatment process through filtration.
2.1
TYPES OF AERATION SYSTEM
There are several types of aeration system used for wastewater treatment. The system used depends on the function to be performed, type and geometry of the reactor, and cost to install and operate the system.
2.1.1
Fountains Aerator
For this kind of aerator, it works very well in small pond and relatively shallow. Fountains improve a pond's aesthetic appeal and recirculate the water near the pond's surface. Fountains are generally ineffective because it does not recirculate the water near the bottom of the pond.
Figure 2.2: Fountain type aerator In most cases, water near the pond's surface usually has enough oxygen to support the plants and animals found near the water surface. A fountain should be in the middle of the
8
pond, and the waves creates by the fountain should dissipate before reach the edge. This system is not efficient because energy is used to create the display.
2.1.2
Propeller Aerator
This propeller aerator was specially developed for intensive production of fish in tanks and ponds. This unit employs a float, motor, and prop to splash at the water surface with fairly decent oxygen transfer rate. The maintenance free, heavy duty, motor (230 or 380 Volt) with low power consumption (0.18-1.00 kW) has a mounted propeller which allows a high water circulation of up to 50-180 m3/h (splash height 60-90 cm and splash diameter 160-250 cm). The small float size, compact and lightweight system make it fast and easy to install. This aeration system is not efficient at moving water at deeper level.
Figure 2.3: Propeller Type Aerator The following types are available as standard: Table 2.1: Table indicates types available at standard Power consumption kw/HP
0.18/0.2
0.37/0.5
0.75/1.0
50
100
180
160
180
250
Splash height cm
60
75
90
weight kg
26
28
30
Water circulation m3/h Water splash Ø cm