DESIGN ANALYSIS OF A MANUALLY OPERATED FOOT (PEDAL) AIR PUMP

DESIGN ANALYSIS OF A MANUALLY OPERATED FOOT (PEDAL) AIR PUMP

ABSTRACT

Pumps are devices that are used whenever fluids (liquid or gases) or sometimes slurries are to be moved by mechanical mechanism or action. This project centers on the design of an air pump which is operated by using a foot, through the aid of a pedal, to force air through a discharge tube into a vacuum. The principle of operation of this pump is similar to that of the popular hand air pump with the physical structure being the most significant difference hence the name, “MANUALLY OPERATED FOOT AIR PUMP”. In the course of this project, parameters such as mass flow rate of air through the nozzle of the discharge tube and pressure of air at the nozzle of the discharge tube were considered for the design. After the design analysis, the result was used to evaluate the performance of this pump. It shows that the efficiency of the pump was greatly depends on the properties of spring used and the pump was relatively inexpensive if it will be fabricated.

CHAPTER ONE

1.0       INTRODUCTION

1.1        BACKGROUND

Pumps are devices that are used whenever fluids (liquid or gases) or sometimes slurries are to be moved by mechanical mechanism or action. The study of pump is a very large scope on its own however, we will be dealing particularly with air pumps.(fao.org, 2011)

A reciprocating air pump is a positive displacement pump which is used to inflate tires, ballots, balls etc. Hence reciprocating air pumps are generally useful whenever the transfer of a gas, usually air is desired. Air pumps vary in shapes, sizes and tasks. Even though they generally commonly pump air, some may have a very little similarity or more as the case may be. However, they are essential tools used in everyday life. Perhaps, without them, a little portion of life’s simplicity would have been lost.(Black, 2003).

The first air pump known as the spool vacuum air pump was invented in the year 1649 by Otto Von Guericke which was later called air pump in the 19^th century. Robert Hooke made the first effective air pump for scientific purposes for Robert Boyle in England in 1658 (George Wilson, 1849).

Air pumps can be placed into different categories depending on:

• Method of operation and
• Principle of operation

The classification base on the method of operation includes:

1. Manually operated air pumps (as will be referred to simply as manual air pump) and
2. Automatic (motor) powered air pumps (or simply automatic air pump).

Those which are manual often require pumping by hand, arm or foot (as in this project). They use human power and mechanical advantage to move fluid from one place to another while the automatic pumps run off some sort of other power sources, mostly electricity. The latter are always easy to operate and offer more efficiency but the formal have the advantage of portability, least cost of production to name a few.

We can see the applications of these pumps firstly, the automatic air pumps in aquarium and in ponds to diffuse oxygen into the water to make it more inviting and for animal life and in the area of septic systems which employs an aerobic process to use bacteria to accomplish the goals of removing and/or reducing the amount of solids in the system. And secondly the manual air pumps which find various applications in inflating vehicles and motorcycles in rare occasions and mostly bicycles tires and footballs.

Classification of pumps based on the principle of operation includes:

• Positive displacement pumps
• Rotodynamic pumps

In positive displacement pumps, fluid is drawn or forced into a finite space bounded by a mechanical parts and is then sealed by some mechanical means. The fluid is then allowed to flow out from the space and the cycle is repeated. Thus, in a positive displacement pump, the fluid is intermediate or fluctuating. The flow rate of the fluid is governed by the dimensions of the space in the machine and by the frequency with which it is filled or emptied.(Amadu, meen 512, 2016)

In the rotodynamic type, there have a rotating element through which the fluid passes (such element is called an impeller)

Hence, from the classifications above, the present project- manually operated foot air pump can be classified as a “manually operated positive displacement foot air pump”.

1.2        STATEMENT OF THE PROBLEM

Man’s continuous search for better ways to make life simpler seems to be an unending mission. It is in this light that the decision to improve the manually operated foot air pump arose. Also, in the same quest for an easier life, man strives to substitute for the barely unavailable sources of power, expensive materials related with automatic air pumps.

The correct tire pressure is crucial to the safe operation of a vehicle (a car, motorcycle and bicycle) but many owners do not check the air pressure of their tires before hitting the road. This may be partly perhaps because of the stress it takes to check the pressure and fill the tire; is never very fun no matter how you look at it: kneeling down on the rough ground against your bare kneels, fumbling around trying to attach the tire air pump to the valve stem are all parts of the routine. Moreover, the difficulty in reaching the valve stem of some vehicles can be a discouraging factor in carrying out the necessary and frequent check.

Having a less complicated and a work-easing device (air pump) i.e. one which fits into our above mentioned goals could be the solution to the tedious and undesirable routine.

Electrically operated air pump would have been the best option for such a device but its general bulkiness, heavy weight and added complication of the electrical connection make it unsuitable for use.

1.3              AIM AND OBJECTIVES OF THE PROJECT

This project aims at analysing, the design and evaluating the performance of a manually operated foot air pump for footballs, bicycles and motorcycles with improved efficiency. The specific objectives include

1. To carry out the design analysis of the pump.
2. To carry out the performance evaluation of the pump.
3. To estimate the cost of the pump.

 1.4      SIGNIFICANCE OF THE PROJECT

The project of discussion relates to a manually operated air pump, in particularly, a manually operated foot air pump. This project provides a manually operated foot air pump, as it will be subsequently referred to as simply “foot pump,” that uses a foot to transfer almost the same volume of air to a pneumatic tire as its hand operated pump counterpart with an additional balance and comfort as bonuses. There are just very few modifications of the hand operated pump which are mostly structural. Almost every working principle is common to both pumps.

1.5       SCOPE AND LIMITATION

This project requires only the use of mechanical operations. The use of electrical supply or any other source of energy such as solar or fuel is not necessary hence, maintenance and capacity costs are very low and affordable.