DESIGN, FABRICATION, AND TESTING OF A MOVABLE SOLAR OPERATED SPRAYER FOR FARMING OPERATION

Famers do spray seeds, fertilizers, pesticides, herbicides, etc. to protect crops from different insects, pests, diseases and have good harvests. Hand and fuel operated spray pumps are the most common sprayer used in Nigeria. The sprayer causes user fatigue due to excessive bulky and heavy construction, a user can't use it for more than five (5) hours without getting tired, the fuel sprayer is expensive to maintain, emits carbon dioxide and harmful to our environment. In this study, a movable solar operated sprayer for the farming operation was designed and fabricated to overcome these difficulties


INTRODUCTION
There is fieldwork normally embark on by farmers in the agricultural sector such as weeding, reaping, sowing, spraying, etc. Out of the which, spraying is the most important operation normally performed by the farmer to protect the cultivated crops from pests, insects, funguses, and diseases for which various insecticides, pesticides, fungicides, and nutrients are sprayed on crops for protection (Krishna M.B, 2017).
The recent concern on how to control plant diseases, insects and weeds for the qualitative yield of agricultural products is increasing rapidly in many developing countries like Nigeria. Crop spraying is employed for many varieties of purposes in the traditional farming system by dipping brushes, leaves or brooms into diluted water added to chemicals in an open container and sprinkling on the required area.
A sprayer is a mechanical device used to spray liquid like herbicides, pesticides, fungicides, and fertilizers to the crops to prevent pests or insects from destroying the crops. Sprayer provides optimum utilization of pesticides or any other chemicals with minimum efforts and less cost. Farmers normally use hand or fuel operated sprayers to perform this task. This traditional spraying method causes user fatigue due to excessive bulky and heavy construction (Arunkumar M., 2015).
In Nigeria farms generally, two types of spray pumps are used for spraying; hand-operated spray pump and fuel operated spray pump, out of which hand-operated spray pumps are most common. The setback of the hand-operated spray pump is that the user cannot use it continuously for more than five (5) to six (6) hours since he/she gets tired after such a long time. Similarly, the fuel operated spray pump requires fuel which is expensive and available in the rural areas. At the same time, it emits carbon dioxide as a pollutant that is harmful to our environment. In such a situation, there should be a need to think about how to move towards some non-conventional energy. Considering it, solar energy would be one of the best solutions (Ahalya M., 2017).
The development in pesticides sprayer brings a revolution in the agriculture/horticulture sector which assists farmers to obtain the maximum agricultural output. A sprayer is used for agriculture spraying, garden spraying, weed, and pest control, liquid fertilizing and plant leaf polishing. There are a lot of advantages derived from sprayers such as easy to operate, maintain and handle. It increases the uniform spread of chemicals, capable of throwing the liquid formulation at the desired level, throwing foggy, light and heavy spray depending on the requirement (Pandurang L., 2015).
There are a lot of difficulties normally faced by Nigerian farmers due to harsh weather and thus affect the spray quality and pattern. It also prevents farmers to harness the benefit of the pesticide application even after investing costs and efforts. The available battery operated sprayers have operational constraints such as choking of a nozzle, poor quality of spray, high human effort, low field capacity, the uncertainty of grid power availability and deep discharge of the battery, etc. It was discovered that about 50%-80% of applied pesticide is wasted due to poor spray machinery and improper application methods. During spraying, farmers swing the spray nozzle head that results in uneven application of pesticides making the operation less efficient and uneconomical (Rahul V.K, 2018).
In Nigeria, 73% of the population is directly or indirectly dependent upon the farming produce. Hence Nigeria is now an agricultural producing nation, but still, farmers face numerous problems such as; pest, lack of mechanization, short supply of electricity and existing method (Ergonomically imperfect). To overcome these difficulties, a "movable solar operated sprayer" has been developed. This system can be operated using solar energy, which is converted into electrical energy and stored in a storage battery.

AIM AND OBJECTIVES
This project aims to design, fabricate and test a movable solar operated sprayer for a farming operation.
The objectives of the project are;  To design a solar operated sprayer capable of spraying up to 650litres of pesticides and herbicides daily  To fabricate and test the sprayer on two (2) different crops  To evaluate the performance of the sprayer

LITERATURE REVIEW
There is a lot of researchers works done on different types of sprayer such as a high-pressure sprayer, the engine operated sprayer, tractor mounted sprayer, etc.
 (Joshua R., 2010): Developed a power sprayer with the two-stroke petrol engine. The cost of operating the system is quite high and thus solar operated sprayer is suggested as an alternative. The wheel operated pesticide spray equipment consists of a reciprocating pump to pressurize the liquid and power the reciprocating action of the pump. It is a portable device and does not require fuel for its operation; the main drawback of this equipment is that it cannot move in the land where the crops are already grown to a certain height and it is also difficult to carry on clay land.

Design consideration
 The total weight of the machine should be such that an operator can move it comfortably whenever it is required without any discomfort affecting his performance and health.  It should have DC power backup for not less than 4hours of operation.  The setup should be sturdy with ease of operation and controls along with low repair and maintenance costs.  It should meet the technical, functional, operational, and structural requirements for quality spraying of pesticides and economically viable (Vinay S., 2016).  To avoid clogging, a mesh filter will be placed before the nozzle in the nozzle head to prevent clogging (Vinay S., 2016).

RESULT AND DISCUSSION
The results below where obtain after carrying out a test on the project as follows;  The system was placed in sunlight for 3hrs to charge from 12.4V to 14.4V  Tested on tomatoes, maize, and open field in the farmland  The time required to charge the battery, time required to spray one (1) acre of land, flow rate and application rate was determined by using measuring bowl, stop watch, and grid

Time required operating the sprayer while being charged and discharged simultaneously
The fully charged battery at 14.4V can last for eight (8) hours before dropping to 12.74V when used to spray fluid, charge phone and light up 5W energy bulb concurrently.

Application rate
Application rate (

Discussions
 The system can work for 8 hours with a voltage drop from 14.4V to 12.74V  The fluid discharge is 0.79 L/min  Can spray 162 liters of pesticide or herbicide on 1 acre of land in 2hrs 13mins.  Fine droplets of atomized particles were obtained.

Conclusion
 The result shows that the system is efficient, portable and provides at least 8 hours of operation daily  The system will enhance the working capacity of the farmer by reducing the time and fatigue  The system can spray between 600 -650 liters of chemicals on 3 to 4 acres of land  The system is incorporated with an energy bulb and charging kit to light up the farmyard and for the operator to charge his/her phone  The initial cost of the system is a little higher but does not require running cost

Recommendations
 Incorporating fiber reinforced plastic (FRP) to reduce the weight between 2kg to 3kg  The system can be automated using microcontroller  Incorporating the concentric collector to increase charging efficiency  Energy can be saved using PWM Scheme to drive the pump.