Abstract
This research is centered on the design and fabrication of copula 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 aluminum
cans.The furnace was heated to 8700
c and it was observe that the furnace has
36.9% efficiency which is within the acceptable
1.1 Background of Study
Powdermetallurgy 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 ofMetal 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 ofpowders 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 powderproduction process applied depends on the required production
rate, the desired powder properties and the properties desired in the final part.
15
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
aluminum, 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
16
ways depending on the mode in which the energy is supplied. The atomization
process [Mehrotra 1984] can be classified into three main categories:
Pressure atomization.
i. Mechanical
ii. Chemical or centrifugal atomization.
iii.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.
1.2Aim and Objectives of the Study
1.2.1 Aim of Study
The aim of this study is to design and fabrication a mini copula furnace and an
atomizer for the production of powdered metal from waste aluminium cans.
1.2.2Objectives of Study
The objectives of the study include the following
17
i. Determination of the volume of a single aluminum can usinga weighing
balance.
ii. Carrying out a material and energy balance to determine the mass aluminum
to be melted, amount of fuel required and the required capacity of the
furnace.
iii. Carrying out mechanical design of the mini-copula furnace required to melt
the waste aluminum can,
iv. Fabrication of the proposed designed mini-copula furnace plant.
v. Design of the atomizer for metal powder production.
vi. Fabrication of the designed atomizer
vii. Analysis of theobtained aluminumpowdermetal.
1.3Problem Statement
Wide-spread applicationand high demand of powder metal in industrial and
domestic processing activities and the littering- rate of aluminum 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 forthe production of powder metal
from waste aluminum cans which can be used for various domestic and industrial
applications and also servesas a good environmental pollution control for the
aforementioned waste.
18
1.4Scope of the Research Project
This researchproject focuses on the design and fabrication of a mini-copula furnace
and an atomizer for the production of powder metal from waste aluminum cans
through process atomization.
1.5Relevance of the Study
Theimportance of this study includes the following:
i. To reduce the rate ofenvironmental pollution (air, soil and water pollution)
caused by littering waste aluminum cans.
ii. Meet up with the ever-growing demand for powder aluminum metal in the
automobile industry
iii. To save energy and raw materials for the future industries.
iv. To provide raw material for metal matrix composites and wide applications
in paint industries.
v. To encourage researchers think of ways of harnessing other waste materials.
vi. To increase the availability of solid fuels for rockets.
vii. It also serves as a reference material to any researcher on this field.
1.6Limitation of the Study
The factors hindering effective execution of this study are:
i. Inadequate power supply for the operation of the fabricating machines.
19
ii. Inadequate fund
iii. Time limit towards successful completion of the project
iv. Use of readily available air as the atomizing fluid instead of costly pure
nitrogen