ABSTRACT

Nowadays, the destruction and pollution of humane environment has produced an ever growing awareness worldwide of the need for more effective sedimentation processes. The main aim of this project was to design and fabricate an experimental sedimentation rig with the objective to determine the rate of settling against time using calcium carbonate as a test sample.The rig consists mainly of the cylindrical tank, valves, motor, stirrer, and the sight glass. For the test run, 82 litres of water and500g of calcium carbonate was introduced into the tank,stirred andwas let tosettle under gravity. The settled height was observed with time at time intervals of 60 seconds,it could be observed that the calcium carbonate settles at different height of 115, 110.5, 104.6, 99.3, 92.5, 85.7, 77.5, 68.3, 60.1, 52.5, 42.3, 33.4, 20.6 and 10.8cm considering the settling behavior. The settling velocity and Reynolds number of flow gotten was 15.42cm/min and 84.5respectively. It could be concluded from the experiment conducted with the rig thatthe higher the concentration is the quicker the sedimentation process is done quickly and the rig could be recommended for waste water industries to study rate of settings of sediments of different particulate distribution from fluids.

TABLE OF CONTENTS

CONTENTS PAGE

Cover page i

Title Page ii

Declaration iii

Certification iv

Dedication v

Acknowledgement vi

Abstract vii

Table of Contents viii

List of Figures 

CHAPTER ONE: INTRODUCTION

1.1 Background of Study 1

1.2 Statement of Problem 2

1.3 Aims and Objectives 2

1.4 Significance of Study 2

1.5 Scope and Limitations of Study 3

1.6 Definition of Terms 3

CHAPTER TWO: LITERATURE REVIEW

2.1 Theory of sedimentation 5

2.2 Application Of sedimentation Process 6

2.3 Factors Affecting Sedimentation 6

2.3.1 Particle Size 6

2.3.2 Temperature 7

2.3.3 Currents 7

2.4 Sedimentation Basin Zones 7

2.4.1 Inlet Zone 8

2.4.2 Settling Zones 8

2.4.3 Sludge zone 8

2.4.4 Outlet Zone 8

2.5 Settling Velocity Theory 9

2.5.1 Stokes Law 9

2.5.2 Newton’s Law of Sedimentation/Settling 10

2.6 Context 11

CHAPTER THREE: METHODOLOGY

3.1 Selection of Materials 13

3.2 Basic Design Requirements 13

3.3 Design Details 14

3.4 Sediment Introduction and Outlet System 14

3.5 Materials and Equipment Used 14

3.5.1 Materials Used 14

3.5.2 Equipment Used 19

3.6 Fabrication of Apparatus 24

3.7 Cost Estimation 27

3.8 Project plan 28

CHAPTER FOUR: RESULTS AND DISCUSSION

4.1 Results 29

4.2 Discussion 32

CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS

5.1 Conclusion 34

5.2 Recommendations 34

REFERENCES 36

LIST OF FIGURES

Figure 2.1: Free Body Diagram of a discrete particle 5

Figure 2.2: Current flow in feed 7

Figure 2.3: Settling Zones 8

Figure 3.1: Mild steel 15

Figure 3.2: Stirrer 16

Figure 3.3: Electric Motor 17

Figure 3.4: Rollers or casters 17

Figure 3.5: Valve 18

Figure 3.6: Tape rule 19

Figure 3.7: Drilling Machine 20

Figure 3.8: Hammer 20

Figure 3.9: Cutting Machine 21

Figure 3.10: File 21

Figure 3.11: Plate rolling machine 22

Figure 3.12: Welding machine 22

Figure 3.13: Spray paint machine 23

Figure 3.14: AutoCAD diagram of apparatus 24

Figure 3.15: Picture of fabricated apparatus 25

Figure 3.16: Labeled diagram of apparatus and P&ID diagram 26

Figure 4.1: Graph of Clear Height against Time 31