Power Sprayer

A) Motorized knapsack sprayer:

• The spray liquid is flown out by means of an air current generated in the machine.
• They deliver 6.8 to 42.5 m3 (240 to 1500 ft3) of air per minute at a velocity of 200-420 km (125-260 miles) per hour at the nozzle.
• small tank of 10-15 lit capacity is provided for the fuel.
• powered by 1.2 – 3.0 hp petrol engines and the frame is provided with shock-proof cushion which comfortably fix on the back of the operator to eliminate vibrations of the engine.
• The delivery hoses are very small.
• Advisable not to load the tank to its full capacity. About half a litre space should be left to provide for air cushion.
• Liquid from the tank passed through a tube to the nozzle on the spray lance by gravity, partly helped by the air pressure exerted over the liquid within the tank.
• The machine, when fitted with a rotary pump and high tree lance can spray trees about 8 m high.
• Takes 0.4 to 3.0 minutes to discharge one litre.
• A power sprayer essentially consists of :

(i) Prime mover: needed to supply power (1 to 5 Hp) to the power sprayer.

(ii) Tank: Steel tank is widely used to prevent corrosion. A covered opening, fitted with a removable strainer is provided for easy filling, inspection and cleaning. A drain plug is there at the bottom of the tank for draining the liquid.

(iii) Agitator: needed to agitate the liquid of the tank. Propeller or paddle type mechanical agitators are provided for agitating the liquid.

(iv) Air-chamber: provided on the discharge line of the pump to level out the pulsations of the pump thereby providing a constant nozzle pressure.

 (v)Pressure gauge: provided on the discharge line to guide the operator regarding spray pressure.

 (vi) Pressure regulator: meant for adjusting the pressure of the sprayer according to the requirement of the crops in the field.

 (vii) Strainer: included in the suction line between the tank and the pump to remove dust, dirt and other foreign materials.  

(vii) Boom: has a long boom in a horizontal place on which nozzles are fixed at specified spacing

(ix) Nozzles: used to break the liquid into the desired spray and deliver it to plants. A nozzle consists of: (a) body (b) screw cap (c) disc (d) washer (e) vortex plate (f) strainer

B) Hand Rotary Duster:

• consists basically of a blower completely with a gearbox and a hopper.
• It is operated by rotating the crank.
• The cranking motion is transmitted through the gearbox to the blower.
• A drive is taken from the dust agitator located in the hopper.
• The feeder is controlled by a feed control lever, which operate a slide to control the aperture at the bottom of the hopper.

C) Motorized knapsack duster:

• Capacity: 9 liters.
• The discharge of the dust can be controlled by rotating the plated hose on the blower elbow, which carries the discharge hose.
• Agitation is provided by directing a part of air from the discharge.
• In some cases, there is a separate unit for replacing the spray lance.

D) Battery operated sprayer:

• Capacity: 10 liters.
• Consists 6 Volt rechargeable battery both fixed in a frame which is carried on the back of the operator.
• A plastic spinning disc along with a micro motor is fitted at the end of an aluminum handle.
• Chemical is taken from the tank to the spinning disc through a plastic hose.
• A cut off valve is provided in the hose line to stop of flow of spray fluid when desired.