PRESENTATION ON THE CONSTRUCTION OF

ABSTRACTThe construction of the five (5) litre Electric Kettle was carried out in mechanical workshop of the Institute of Management and Technology Enugu. (I.M.T). The fabrication process, included measuring and marking out operations of which the following dimensions was taken; the cylindrical body was taken as 170mm by 700mm in height and length respectively, the base diameter was 223mm, the lid diameter 140mm, length of nozzle 75min, water outlet and inlet were 20mm and 35mm, respectively and the drill position of the nozzle and heating element were 40mm and 25mm respectively. The marked parts were cut out, filed for smooth edges, welded to form a drum like shape, insulating handle, cover and heating element were installed.  At the end of the exercises, the electric kettle was fabricated. The parent material used for the construction is the stainless steel, which was preferable for its easy workability, corrosion resistance and heat conductivity that is high.  The stainless steel cannot contaminate food and drink.

The construction of electric kettle is recommended serve as heating equipment in our laboratory home, hospital etc.  it also serves as a device which requires electricity conduction to generate heat to perfect its function.  As well as in laboratories, industries foe heating and boiling of fluids.  The mechanism of heat transfer in the electric kettle equipment is transferred into the liquid by firstly the metal conducting heat probably from electric source in contact by conduction and transfer the heat in the liquid causing the molecules of the liquid to expand colliding with one another exerting pressure and at equal prevailing atmospheric pressure which the under boils.

CHAPTER ONE

1.0   INTRODUCTION

Heat is said to be energy in transient by virtue of temperature difference.  It is a known fact that heat generated an through various means such as conduction, convection and radiation as in radioactive ensure.

Heat energy occurs chemically when a chemical reactions of a strong acid reacts with a strong base.  Heat is either liberated external (Exothermic reaction) or absorbed internally (Exothermic reaction).  Heat also occur mechanically when an automobile engine is working.  Heat generated results to hotness of the engine surface and environment as a result of fumes from the exhaust pipe.  Heat is an effect generated in connection with complete continuous flow of elections in a circuit.

The electric kettle as a heating device requires electricity conduction to generate heat to perfect its friction.  Electric kettle as a very important equipment used in our homes, hospitals, laboratories and industries for heating and boiling of fluids.

It is a device in which the mechanism of heat transfer is studied and highly felt.  The heat transfers into the liquid by firstly; the metal conducting heat probably from electric source in contact by conduction and transfer the heat in the liquid causing the molecules of the liquid to expand colliding with one another exerting pressure and at equal prevailing atmospheric kettle pressure the water boils.  Heat transfer mechanism in an electric kettle is a combined process of conduction and convection.

In progression, the mass of the liquid before boiling remains constant and the liquid become, less dense that the cold liquid surrounding it.  Both layers of the liquid exerting pressures moves up and down till the whole liquid acquire a vapour pressure which when equal with the atmospheric pressure boiling occurs and the liquid is said to reach its boiling point.

DEFINITION OF TERMSBoiling Point:  This is the temperature reached by a liquid when its vapour pressure is same with the atmospheric pressure at room temperature.  In other words, it is the temperature at which water boils and it normally 100o for pure substance such as water.

At this point, when the temperature is reached the electric kettle can be seen scientifically as a control instrument that will regulate any system or a system if too high by stripping off.

VAPOUR PRESSURE:       This is the pressure exerted by liquid molecules at its boiling point it is the force per unit area of the liquid layer in contact.  Its unit is Newton Rir meter square (N/M2).  In the process as it attains its vapour pressure there is a transfer of chemical specie (solute) from its initial liquid phase to gaseous phase with a small change in concentration.

This agrees with the analogous theory of heat transfer and mass transfer mechanism in the functioning of electric kettle.

1.1       AIM OF THE PROJECT

The object of all construction project is to test students ability to construct with given specifications.

This project is specifically for the construction “S” litre electric kettle which will boil at 100oc (373k) and capable of using 220 – 240 voltage and voltage and 13 – 15 amperes.

Moreover to construct a vessel that low the under listed advantage which is for superior to other methods of heating e.g using gas, cool and fire etc.

(i)                 Cleanliness:  Since neither dust nor ash is produced in electric heating.  It is a clean system of heating requiring minimum cost of cleaning.  More also, to be heated does not get contaminated .

(ii)               ND Pollution:  Since no flue gases ate produced in electric heating, no provision has to be made for their exit.

(iii)             Economically:  The lost of maintenance is not much and it doesn’t occupy much position.

(iv)             Easy Control:        It is easy to control and regulate the temperature of an electric furnaces with the help of manna or automatic devices.

(v)               Special heating requirement:         Such as uniform heating of a material or heating one particular portion of the job without affecting its other parts or heating with no oxidation can be met only by electric heating.

HIGHER EFFICIENCY:

Heat produced electrically does not go away waste through the chimney or man hole and other by products.  Consequently most of the heat produced is utilized for heating the material itself.  Hence, electric heating has higher efficiency as compared to other types of heating.

BETTER WORKING CONDITIONS:

Since electric heat produce no irritating Norse and also the radiation losses are low, it results in low ambient temperature.

Safely:            Electric heating is quite safe because it responds quickly to the controlled signals.

Lower attention and maintenance costs:

Electric heating equipment generally will not require much attention and supervision and their maintenance cost is almost negligible.  Hence, labour charges is negligibly small as compare to other forms of heating.