DESIGN AND FABRICATION OF MINI CUPOLA FURNACE AND AN ATOMIZER FOR THE PRODUCTION OF POWDERED METAL FROM WASTE ALUMINIUM CANS
This research is centered on the design and fabrication of cupola furnace and atomizer for the production aluminium powder metal with the available material.0.4kg of refined coke was chosen as the basis for material and energy balance calculations and the design calculations performed from whose values are used to produce the design drawings. Mild steel was used for the internal linings of the furnace casing while other material were selected based on functionality ,durability ,cost and local availability. The furnace and atomizer were assembled and the furnace inner wall of the casing was lined with refractory bricks made from heated mixture of kaolin, clay, sawdust and water after which the cylindrical shell was positioned .Testing was subsequently performed to evaluate the performance of the furnace and the atomizer by first gathering of the aluminium cans .The furnace was heated to 8700c and it was observe that the furnace has 36.9% efficiency which is within the acceptable value for furnace efficiencies. Atomizer produced various sizes of powder metal depending on the type of mesh used and the shape obtained was irregular in shape.
TABLE OF CONTENTS
Title Page i
Table of Contents vi
List of Tables xi
List of Figures xii
List of Plates xiii
CHAPTER ONE: INTRODUCTION
1.1 Background of Study 1
1.2 Aims and Objectives of the Study 3
1.3 Problem Statement 4
1.4 Scope of Research Project 5
1.5 Relevance of Study 5
1.6 Limitation of Study 5
CHAPTER TWO: LITERATURE REVIEW
2.1 Introduction to Aluminium and Aluminium Recycling 7
2.2 Introduction to Powder Metallurgy 8
2.2.1Historical Development 8
2.2.2 Atomization Process 9
2.2.3 Classification of Atomization process 10
2.2.4 Uses of Powder Metals 10
2.2.5 Some Common Metal Powder 11
2.3 Introduction to Atomizer 12
2.3.1 Classification of Atomizers 13
2.3.2 Atomizer Requirement 14
2.4 Introduction to Furnace 15
2.4.1 Types of Furnaces 15
2.4.2 Classification of Furnaces 16
2.4.3 Introduction to Copula 17
2.4.4 Parts of a Cupola Furnace 17
2.4.5 Zones of Copula 19
2.4.6 Cupola Operations 22
2.4.7 Efficiency of Cupola Furnace 26
2.4.8 Advantages and Limitations 27
2.4.9 Limitations in Cupola Furnace 28
2.5 Introduction to Refractory 28
2.5.1 Refractory Definition 28
2.5.2 Classification of Refractory 29
2.5.3 Properties of Refractory 32
2.5.4 Types of Refractory 36
2.5.5 Selection of Refractory 39
2.5.6 Manufacture of Refractory 39
2.5.7 Functions and uses of Refractory 41
2.5.8 Uses of Refractories 41
2.6 Introduction to Coal 42
2.6.1 Uses of Coal 43
2.6.2 Refined Coal(Coke) 43
2.6.3 Production of Coke 44
2.6.4 Properties of Coke 44
2.6.5 Uses of Coke 45
2.6.6 Advantages of Coal over other Forms of Energy 45
CHAPTER THREE: MATERIALS AND METHODOLOGY
3.1 Introduction 46
3.2 The Design of Cupola Furnace 47
3.2.1 Material Balance 47
3.2.2 Reaction Mechanism 48
3.2.3 Energy Balance 49
3.2.4 Enthalpy Change 50
3.2.5 Standard Heat of Reaction 51
3.3 Energy Balance for the Furnace 52
3.3.1 Combustion Chamber 52
3.3.2 Enthalpy of the Reaction 53
3.3.3 Standard Heat of Reaction 53
3.3.4 Enthalpy of Flue Gases 54
3.3.5 The Design of the Furnace 55
3.3.6 Design of the Combustion Chamber 57
3.3.7 Design of the down Section of the Furnace 58
3.4 Design of an Atomizer 62
3.5 Costing and Safety Measures 67
3.5.1 Costing 67
3.5.2 Safety Measures 69
3.6 Materials of Constructions 70
CHAPTER FOUR: RESULTS, OBSERVATION AND DISCUSSION
4.1 Results 79
4.2 Observations and Discussion 80
4.3 The Size of the Metal Powder produced 81
4.4 The Shape of Aluminum metal powder produced 81
CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS
5.1 Conclusion 83
5.2 Recommendations 83
APPENDIX A 88
APPENDIX B 94
APPENDIX C 97
LIST OF TABLES
Table 2.1 Melting point Chart of pure Compounds 33
Table 2.3 Classes of Fire Clay Brick 38
Table 3.1 Material Balance Table 49
Table 3.2 Specification Sheet for the Designed Atomizer 67
Table 3.3 Cost of Materials 68
Table 3.4 Fabrication cost 68
Table 3.5 Additional Expenses 69
Table 4.1 Results from the Cupola Furnace 79
LIST OF FIGURES
Figure 2.1 Broad Classification of Furnace 19
Figure2.2 Copula Furnace 21
Figure 3.1 The Combustion Chamber (Materials) 48
Figure 3.2 Balance Around the combustion Chamber 52
Figure 3.3 Balance around the Furnace 55
Figure 3.4 Internal and External diameters 58
Figure 3.5 2D And 3D views of the cupola Furnace 59
Figure 3.6 3D View of the Cupola Furnace Sections 60
Figure 3.7 Front View of the Cupola Furnace 61
Figure 3.8 2D Sectioned view of the Lower Section of the Atomizer 63
Figure 3.9 2D Sectioned view of the Middle Section of the Atomizer 64
Figure 3.10 2D View of the Lower Section of the Atomizer 65
Figure 3.11 3-D Section view of the Atomizer 66
LIST OF PLATES
PLATE 1 ALIEN KEY
PLATE 2 VERNIER CALIPER
PLATE 3 HAND FILES
PLATE 4 TAP WRENCH
PLATE 5 TWO WAY GRINDING MACHINE
PLATE 6 LATHE MACHINE
PLATE 7 DRILL BIT
Background of Study
Powder metallurgy is a technique concerned with the production of metal powders and converting them into useful shapes. It is a material processing technique in which particulate materials are consolidated to semi-finished and finished products. Metal powder production techniques are used to manufacture a wide spectrum of Metal powders designed to meet the requirements of a large variety of applications. Various powder production processes allow precise control of the chemical and physical characteristics of powders and permit the development of specific attributes for the desired applications. Powder production processes are constantly being improved to meet the quality, cost and performance requirements of all types of applications. Metal powders are produced by mechanical or chemical methods.
The most commonly used methods include water and gas atomization, milling, mechanical alloying, electrolysis, and chemical reduction of oxides.
The type of powder production process applied depends on the required production rate, the desired powder properties and the properties desired in the final part. Chemical and electrolytic methods are used to produce high purity powders while Mechanical milling is widely used for the production of hard metals and oxides. Atomization is the most versatile method for producing metal powders.
It is the dominant method for producing metal and pre-alloyed powders from aluminium, brass, iron, low alloy steel, stainless steel, tool steel, super alloy, titanium alloy and other alloys.
Atomization [Mehrotra 1984] is a process in which a liquid stream disintegrated into a large number of droplets of various sizes. Basically atomization consists of mechanically disintegrating a stream of molten metal into the fine particles by means of a jet of compressed gases or liquids. It is an important process which finds wide applications such diverse field as spraying for insecticidal use, fuel injection in internal combustion engines, liquid spray drying, and liquid dispersion in numerous liquid–gas contact operations such as distillation, humidification, and spray crystallization.
The technique of atomizing a metal melt, with fluid was connected with the production of metal powders. The basic principle involved in atomization of liquid consists in increasing the surface area of the liquid stream until it becomes unstable disintegrated. The energy required for disintegration can be imparted in several ways depending on the mode in which the energy is supplied. The atomization process [Mehrotra 1984] can be classified into three main categories:
- Chemical or centrifugal atomization.
- Fluid atomization.
The present work concentrated on the third type of atomization. The kinetic energy of a second fluid stream, being ejected from a nozzle is used for disintegrating of the liquid. The stream in a free fall is impacted by a high pressure jet of second fluid which is usually gas or water emerges either tangentially or at angle from nozzle. So that molten which in general, have high surface tension can be atomized by the fluid atomization technique.
1.2 Aim and Objectives of the Study
1.2.1 Aim of Study
The aim of this study is to design and fabrication a mini cupola furnace and an atomizer for the production of powdered metal from waste aluminium cans.
1.2.2 Objectives of Study
The objectives of the study include the following
- Determination of the volume of a single aluminium can using a weighing balance.
- Carrying out a material and energy balance to determine the mass aluminium to be melted, amount of fuel required and the required capacity of the furnace.
- Carrying out mechanical design of the mini-cupola furnace required to melt the waste aluminium can,
- Fabrication of the proposed designed mini-cupola furnace plant.
- Design of the atomizer for metal powder production.
- Fabrication of the designed atomizer
- Analysis of the obtained aluminium powder metal.
1.3 Problem Statement
Wide-spread application and high demand of powder metal in industrial and domestic processing activities and the littering- rate of aluminium cans all over the country which poses a serious adverse environmental condition, have grown at an alarming rate over the years. Therefore, the purpose of this project is to design and fabricate a mini-copula furnace and an atomizer for the production of powder metal from waste aluminium cans which can be used for various domestic and industrial applications and also serves as a good environmental pollution control for the aforementioned waste.
1.4 Scope of the Research Project
This research project focuses on the design and fabrication of a mini-copula furnace and an atomizer for the production of powder metal from waste aluminium cans through process atomization.
1.5 Relevance of the Study
The importance of this study includes the following:
- To reduce the rate of environmental pollution (air, soil and water pollution) caused by littering waste aluminium cans.
- Meet up with the ever-growing demand for powder aluminium metal in the automobile industry
- To save energy and raw materials for the future industries.
- To provide raw material for metal matrix composites and wide applications in paint industries.
- To encourage researchers think of ways of harnessing other waste materials.
- To increase the availability of solid fuels for rockets.
- It also serves as a reference material to any researcher on this field.
1.6 Limitation of the Study
The factors hindering effective execution of this study are:
- Inadequate power supply for the operation of the fabricating machines.
- Inadequate fund
- Time limit towards successful completion of the project
- Use of readily available air as the atomizing fluid instead of costly pure nitrogen.