CHAPTER THREE
MATERIAL AND METHODOLOGY
3.1 Selection of Materials
In the process of selecting materials for this project, some important factors were considered, such as; suitability, availability, within locality, cost and durability.
The engineering properties were considered as well which include the physical, chemical and mechanical properties. Some features of these properties are;
i. Strength; that is, the ability of the material to resist externally applied forces without breaking or yielding.
ii. Stiffness; the ability of the material to resist deformation under stress.
iii. Elasticity; the ability of the material to regain its original shape after certain deformation, when external forces are removed.
iv. Resilience; the ability of a material to absorb energy and to resist shock impact loads e.c.t. Therefore, suitable materials were selected for the fabrication of the battery operated, solar charged boom sprayer.
3.2 Design consideration
In the process of designing the battery operated, solar charged boom sprayer, certain factors were put into consideration. Some of these factors are;
i. The thickness of the frame and the tank weight with other materials.
ii. Ability of the tank to resist chemical reaction
iii. The ratio of water and chemical required for accurate capacity and better volume miseture of the chemical in the boom sprayer.
iv. Labour cost; the specification of improved technology is to reduce labour cost during loading, mixture and unloading of water with chemicals.
v. Motion of the parts or kinematic of the machine
vi. Wheel/tyre pneumatic type inflated to pressure of 28psi for maximum grip with the additional weight of chemicals, to reduce wheel slippage.
vii. Operation techniques
viii. Maintenance cost etc.
Based on the above factors, the following materials were chosen;
i. A quality plastic tank to suit spraying condition, weather condition and more.
ii. A strong mild steel square pipe which supports the whole boom sprayer.
iii. A deep cycle battery of 12v.Dc
iv. A strong solar panel and charge controller
v. Electric pump of 12V.
vi. A pressure pump of 379.2115KPa for adequate pressure.
3.3 Important Description of the Components Parts of the Sprayer.
FRAME; A mild steel hole pipe of 2x4, was used to fabricate the frame.
TANK; A built in tank of approximately 50litres was used. The tank has a cealed space i.e (an exit) underneath with strong cover for the purpose of draining any remaining content from the tank.
It can be made of a well galvanized steel or otherwise treated after fabrication to prevent corrosion. Plastic materials are also used on account of freedom from corrosion and ease of moulding into smooth shapes which avoid difficulty of agitating in recesses and sharp corners.
PUMP; A suitable pump of 379.2115KPa was used for adequate pressure supply.
The pump is a device capable of developing required pressure in the system for many spraying jobs.
There are different types of pump in spraying machine and some of these are; Diaphragm pumps, medium-pressure centrifugal pumps, medium-pressure centrifugal pumps, low-pressure rotary pumps of various types, gear pumps and vane or roller pumps, high pressure and medium pressure piston pump.
