The application of pesticides and fertilizers in agricultural areas is of prime importance for crop yields. The use of aircrafts is becoming increasingly common in carrying out this task mainly because of reduction in cultivated land, labour shortage, unscientific and out-dated method. Manual spraying of pesticides and fertilizers are mainly responsible for the increase in the number of chronic diseases. The potential health effects of pesticides are asthma, allergies, and hypersensitivity. In addition, pesticide exposure causes cancer, hormone disruption, and problems with reproduction and foetal development. However, some factors may reduce the yield, or even cause damage (e.g. crop areas not covered in the spraying process, overlapping spraying of crop areas, applying pesticides on the outer edge of the crop).
Climatic condition, such as the intensity and direction of the wind while spraying add further complexity to the control problem. an architecture based on unmanned aerial vehicles (UAVs) which can be employed to implement a control loop for agricultural applications where UAVs are responsible for spraying chemicals on crops. The aim of the SPRAYONE is to minimize the burden of the farmer in spraying the fertilizers and pesticides. The most important goal in the application of agricultural pesticides is to get uniform distribution of the chemicals throughout the crop foliage. Under dosing may not give the desired coverage and control needed. However, Overdosing is expensive as it wastes pesticide and increases the potential for groundwater contamination.
Generally, two types of sprayers are available for application of pesticides: hydraulic and low-volume. There are many variations of these that fit particular crops or growing methods. In the hydraulic sprayer, a pump supplies energy that carries spray material to the target (plant foliage). Water is the carrier and the pump create the pressure at 40-1000 psi. Nozzles on the boom or handheld gun break the spray into small droplets and direct it to the foliage. The speed of the air stream may be as high as 200 mph. However, As the droplet size is much smaller, good coverage can be achieved with less chemical.
Compressed air sprayer
The hand carried compressed air sprayers are the smallest sprayers. They contain a 1- to 5-gallon tank with an air pump in the top and a wand with a nozzle for directing the spray. However, Their best use is for spot treatment of small areas.
The tank in this sprayer holds about four gallons of material. However, A hand-operated pump pressurizes the spray material as the operator walks along, and the wand with nozzle directs the spray to the target.
With a tank size up to 200 gallons, these sprayers will fit onto an ATV or electric cart. A small electric or gas engine powers the pump. The unit may contain a hose reel and gun or a boom with nozzles.
Irrigation boom sprayer
As increasing production in plug and cell trays, the use of the boom sprayer has become an important tool for getting uniform watering. In addition, By installing three-way turrets with nozzles for irrigation, misting and pesticide application, one piece of equipment serves multi-purposes. An alternate method is to add a pesticide application boom to the same transport cart. So, It needs an independent mixing tank, pump, filter and valves.
Central pesticide application system
In gutter-connected ranges, it is possible to install a piping system that will deliver pesticides to any part of the greenhouse. In addition, A single pump and piping that will handle the pressure developed are required.
Backpack Mist Blower
A small gas engine and integral fan creates an air stream with a velocity of 100-200 mph. Concentrate spray injected into the air stream by a special nozzle is carried to the foliage by the air. The spraying technique is more complicated than with a hydraulic sprayer.
Compressed air, given a negative electric charge as it travels through the nozzle, forms spray droplets and carries them to the plants. This helps to create more uniformly sized particles that disperse well because they repel each other. Charged particles are attracted to leaves, metal and some plastics; when they strike a surface, these particles create a momentary overcharge that repels other particles. These other particles land elsewhere on the leaf, so there is more uniform coverage. The simplest electrostatic sprayer is backpack-carried and contains a tank and spray gun. It requires an independent air supply to charge the tank. In addition, Other units are cart-mounted with an integral compressor powered by a gas engine or electric motor. So, Electrostatic sprayers work best if the spray distance is less than 15 feet.
Rotary Disk sprayer
The spinning disk is used to impact and break a stream of water into droplets that are 60-80 microns in diameter. Moreover, A variety of sizes are available for greenhouse use.
This machine requires a specially formulated carrier that is mixed with the pesticide to improve uniformity of droplet size and distribution of the spray material. The carrier also decreases molecular weight, allowing the particles to float in the air for up to six hours, a disadvantage if you have to get into the greenhouse to care for the plants. In the operation of a thermal Fogger, the pesticide is injected into an extremely hot, fast-moving air stream that vaporizes it into fog particles. Moving from one end of a greenhouse to the other, a thermal Fogger can cover in as little as 15 minutes. Above all, Air circulation from an HAF system will give more uniform coverage and better foliage penetration. Temperature and humidity also affect the spray droplets. Because of the noise associated with the jet engine, hearing protection is recommended.
Also called a cold Fogger, this device uses a high-pressure pump (1,000-3,000 psi) and atomizing nozzles to produce fog-size particles. Distribution of the spray material is through a hand-held gun or external fan unit. With the fan unit, the distance and amount of area that can be covered depends on the capacity of the fan. So, Multiple units or settings may be needed to cover large areas. As with other forgers, penetration and coverage may not be as good as with a mist or hydraulic sprayer. Droplets in the 30-micron size drop out of the air fairly quickly but droplets in the 5-micron size may evaporate or float in the air currents for hours. Small particles don’t have the mass or velocity to move into heavy foliate; however, in most studies, good insect control has been achieved.
SPRAYING TECHNIQUE OF SPRYONES
These sprayers produce a spray with most droplets in the 200-400-micron diameter range (thickness of the human hair is about 100 microns) And under Low-volume it develops a mist (50-100 microns) or fog (0.05-50 microns). In addition, Small droplets from a mist or fog applicator can result in more uniform coverage and greater likelihood of contact with the insect or disease. One disadvantage of smaller droplets is that they evaporate quicker when the humidity is low and may not reach the target. Another is that the tiny droplets tend to bounce or skip on the leaf surface.
When making a tank mix, both the dosage and water requirement need to be considered. The dosage, the amount of chemical that should be applied to a given area. With most pesticides, a range such as 4-12 oz per 100 gal. The amount of water needed to cover the growing area depends on the topography of farmland. In addition, With this sprayer, a rate of 25-50 gal. per 10,000 sq. ft. is possible. Under Low-volume spray this use only 1/4-2 gal per 10,000 sq. ft.
COMPONENTS OF SPRAYER
- pump with agitator
- pressure gauge
- regulating valve
- relief valve
- control valves
- piping and nozzles
- power source and
- support frame
For 1400kv motor
RPM max.power= (Kv * 0.5 * Battery volts)/2
= (1400 * 0.5 * 12)/2
W =power factor
Alpha =power coefficient
D = diameter
P =Air density
M = mass
G = gravity
Ideal Motor rpm from Momentum