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Pesticide sprayer
Abstract: India is a land of agriculture which comprises of small, marginal, medium and
rich farmers. Small scale farmers are very interested in manually lever operated knapsack
sprayer because of its versatility, cost and design. But this sprayer has certain limitations like
it cannot maintain required pressure; it lead to problem of back pain. However this
equipment can also lead to misapplication of chemicals and ineffective control of target pest
which leads to loss of pesticides due to dribbling or drift during application. This
phenomenon not only adds to cost of production but also cause environmental pollution
and imbalance in natural echo system. This paper suggests a model of manually operated
multi nozzle pesticides sprayer pump which will perform spraying at maximum rate in
minimum time. Length and height of the nozzle could be varied with respect to the
application.
Uneconomical Existing High cost Pumps for Indian Marginal and Small Farmers :Presently
farmers are using knap-sack sprayer for spraying pesticides on crops in their farms which
costs for Rs 1800-4500/-.Pesticides are diverse and omnipresent[5].This sprayer has a wide
limitations and thus farmers can use the other sprayer also like bullock driven sprayer pump
and tractor mounted sprayer. Cost of bullock driven is about Rs 28000/-[7]. But though this
these sprayer has high advantages but are not affordable by farmers of developing nation
.So, it’s a need to find out a golden mean among these. The height factor also play a key role
in spraying .For cotton, about 5 to 6 times spraying of pesticides is done. Cotton is one of
the important commercial crops grown extensively in India. Over 4 million farmers in India
grow cotton as their main source and income & livelihood. The textile sector, which is
primarily based on cotton fibre, is the largest employer & income provider in India, second
only to agriculture. It employs close to 82 million people – 35 million in textile & 47 million
in allied sector Table III flashes the light on No. of crops on which spraying is done and their
horizontal, vertical distances and maximum height
Existing high features high cost sprayer
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OBJECTIVE OF PESTICIDE APPLICATION
The objective of the application of pesticide is to keep the pest under check. The pest
population has to be kept suppressed to minimum biological activities to avoid economic
loss of crop yields. Thorough killing of pest or eradication of pest is neither practical nor
necessary. The objective of pesticide application besides keeping the pest population under
check should also be to avoid pollution and damage to the non targets.
The success of pest control operations by pesticide application greatly depends on the
following factors:1. Quality of pesticide
2. Timing of application
3. Quality of application and coverage
Different types of pesticides are used for controlling various pests. For example Insecticides
are applied against insect pests, Fungicides against crop diseases, Herbicides against weeds
etc. in order to protect the crop losses. But it is essential that besides choosing an
appropriate pesticide for application it has to be a quality product i.e., proper quantity of
pesticide active ingredient (a.i) must be ensure that the quantity is maintained in production
and marketing of pesticide formulations.
SPRAYING TECHNIQUES
Most of the pesticides are applied as sprays. The liquid formulations of pesticide either
diluted (with water, oil) or directly are applied in small drops to the crop by different types
of sprayers. Usually the EC formulations, wettable powder formulations are diluted suitably
with water which is a common carrier of pesticides.
The important factors for spray volume consideration are: The volume of spray liquid
required for certain area depends upon the spray type and coverage, total target area, size
of spray droplet and number of spray droplets. It is obvious that if the spray droplets are
coarse-size then the spray volume required will be larger than the small size spray droplets.
Also if the thorough coverage (eg. both the sides of leaves) is necessary then the spray
volume requirement has to be more.
On the basis of volume of spray-mix the technique of spraying is classified as:
1. High volume spraying
(300-500 L/ha)
2. Low volume spraying
(50-150 L/ha)
3. Ultra low volume spraying
(<5 L/ha)
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WIDELY USED SPRAY TECHNIQUE:
COMPRESSION SPRAYER
It comprises of a cylindrical metal tank for holding the spray liquid, a hand operated piston
type air pump, a filler hole in the tank out let with delivery pipe, cut-off.
FOOT OPERATED SPRAYER
LEVER OPERATED KNAPSACK SPRAYER
HIGH PRESSURE POWER SPRAYER
AERO PESTICIDE SPRAYER:
DRAWBACKS IN PRESENT PESTICIDE SPRAYER:
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Use of systems like automated or aero systems leads to higher productivity along
with high cost
Use of conventional hand operated sprayer leads to unwanted human stress and less
productivity.
Use of motorised systems leads to high power consumption and lack of mobility.
Use of leg operated system leads to use of two labours along with lack of mobility.
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CONCEPT DEVOLEPMENT:
In concept development we need to consider the problems in the existing systems,
followings are the procedures :
3D Model of our developed concept of
UPS (Universal Pesticide Sprayer)
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In the beginning only conventional type of hand operated pesticide sprayer was used, it was
completely human operated and that has good mobility and low weight. But it can be used
by carrying on the human shoulder. That makes the man too stress along with it, the
operator also need to operate the handle of actuator in one hand and handle which carries
the nozzle to various heights.
Due to the problems mentioned above in the conventional system, it was developed that
the pesticide tank was put in the bicycle and operation can move that bicycle to actuate the
handle of actuator rather than direct hand intervention. But here also the operator can’t
operate the another handle of nozzle comfortably on his other hand. This were leads to
uncomfortable and in-efficient in ergonomic design.
Along with that on the other side these systems are characterized by electronic syste ms like
microprocessor and microcontroller etc., this were leads to automating the system that
means reduces the human work. But this is very expensive and difficult to understand by
the operator if he is a uneducated. Even now completely automated systems are invented
but they are not in a position to get acceptability by the customers.
Then on the basis of customer reviews and their feedback the concept was devoleped that
the complete assembly is to put in a wheel base system so that can be easily carried through
the land. But it was designed ergonomically bad such that, it should requires more force and
low response from the mechanical systems.
And this wheel base system cannot be used for different applications i.e., for different
heights of crops.
Then the concept was developed such that the same wheel base system should
accommodate for different heights and for different widths. So that it were be like universal
and having more flexibility than the previous systems and this was named as “UNIVERSAL
PESTICIDE SPRAYER”.
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OVER VIEW OF UNIVERSAL PESTICIDE SPRAYER:
Fig shows the physical features of the UNIVERSAL PESTICIDE SPRAYER.
HOW IT WORKS:
This machine make use of mechanisms such as cam with oscillating follower, here we make
use of cam to operate the arm of the actuator to pressurise the pesticide to spray through
the nozzle, and it is featured with spring to bring back the arm to its original position.
It can spray the pesticide to different heights of the crop, this plays significant role in naming
this as the UNIVERSAL and this has slotted bar which can be oscillating at its hinged point
and carries the nozzle at its other end. Here the crank which operates the slotted bar has a
slot through its radius, so that the slotted bar can be adjusted to any of its length.
Here the power needed to drive both cam mechanism and crank mechanism is derived from
the rear wheel so that the rear wheel is made so bigger than the front wheel to have more
torque, this leads to put minimum effort to push the machine forward.
From the design consideration we know that the pushing is more efficient than pulling, so
that this machine was designed in such a way that it handle is put rear of the machine .
Gear drive mechanism is used to drive all these mechanisms, because of its efficient power
transmission capabilities with reduced losses.
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MAJOR MECHANISMS IN UNIVERSAL PESTICIDE SPRAYER:
Cam makes a higher kinematic pair with follower. Cam mechanisms are widely used because
with them different types of motion can be possible. Cams can provide unusual and
irregular motions that may be impossible with the other types of mechanisms. However,
the manufacturing of cams is expensive and the wear effect due to the contact stresses is a
disadvantage. On the other hand, cams are not proper for the systems with high speeds and
heavy loads
We are adopting translating or oscillating cam.
The figure shows the detailed drawing of the cam which
is used in this machine.
This is directly coupled with the shaft of gear which is
driven by the gear from rear wheel shaft.
CRANK AND SLOTTED LEVER MECHANISM:
The slider-crank mechanism is one of the most useful mechanisms in modern technology
since it appears in most of the internal combustion engines. The slider-crank kinematic chain
consists of four bodies linked with three cylindrical joints and one sliding or prismatic joint.
It is used to change circular into reciprocating motion, or reciprocating into circular motion.
This linkage also converts rotary motion of the crank into oscillatory angular motion of the
slider guide link. This mechanism is used in shaper machine tools for cutting metals.
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MATERIAL USED:
Selection of materials for particular application will decides the cost of machine along with its
capabilities. Similarly certain parameter also needs to consider for this particular application because
it works under the worst environmental condition, they are
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Working in cultivated land leads to chemical erosion, which inturn leads to undesirable part
maintains.
Moisture content is high during pesticide spray.
Sudden loads may happen during spray operation.
It should non-corrosable in case of tank material etc.
For tank:
Tank is made to hold the pesticide and is placed on the frame. Here the material requirement is to
be
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Non reactable with pesticide.
Should withstand uneven sudden loads.
Should be less weight i.e. it should have high strength to weight ratio.
Should have high wear resistant capacity i.e. must harder etc.
For the above condition HDPE(High Density Poly Ethelene) polymer will suits this particular
application.
This is the polymer having high strength and low density i.e., high strength to weight ratio.
This is used for pesticide tank and front wheels.
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For base or frame:
The main function of the frame here is to carry the pesticide tank and which supports the auxiliary
mechanism.
Followings are factors need to consider,
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The base should be in a position to withstand the weight of whole machine and it should
withstand fluctuating loads.
It should not expensive to buy and to maintain.
It should have corrosion resistant capability.
Considering the above we can choose steel as material for for base and it should be painted to avoid
corrosion.
For mechanisms:
For the selection of material for mechanisms i.e. for crank and cam mechanism followings are the
factors need to consider,
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That should have high wear resistant capability.
It should have high strength to weight ratio.
It should not expensive to buy and maintain.
By considering the above parameters aluminium and aluminium alloy can be selected as material for
mechanisms.
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UNIVERSAL PESTICIDE SPRAYER
BILL OF MATERIAL:
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DESIGN CALCULATION:
Through the data collected a human being can only can handle a wheel base systems of
twice of his own weight, along with that the machine works under the agricultural land so
that the resistance to move the machine is very large therefore the whole weight of
machine should be almost 80-85kg according to which only the design is carried on:
For the best mobility and for best economic size the capacity of pesticide tank is considered
as 50 litres.
For that a tank size of 600*200*500 (length*breadth*height).
We use HDPE(High Density Polyethylene) for that density =800-1042 kg/m3
1. It contains 90% of water and 10% of pesticide.
Design for higher density, allowance of 5 litres,
Weight=density*volume
W=1042*0.050
Weight of pesticide (w)=52.1 kgs
2.
For HDPE density=970 kg/m3
Assuming thickness of tank (t)=5mm
Area=(0.5*0.6)+(0.2*0.6)+(0.2*0.6)=0.54m2
Volume=0.54*0.005=0.0027 m3
Total weight of tank=2.619 kg
Here HDPE is suggested to reduce erosion due to toxic acids and to reduce the
weight of machine.
3. Deign of cam:
Assumed that cam has base circle dia of 50 mm.
On calculation and according to our requirement it should be
made of chromium steel and should have a lift of 50mm.
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Design of crank:
Assumed to made by aluminium sheet of thickness 5mm
Dia(D)=100mm
Slot length in crank=45mm
Slotted bar of length=1000mm =1m
For the slotted bar length of 1000mm and is hinged 250mm behind the crank it has almost
oscillating length od 480mm at its other end carries nozzle.
DRIVING MECHANISM:
Both gears are connected between two shafts where the distance need to transmit is 86mm
It is requirement of machine that it should oscillate 3 or more times for 1.5m length
For that adopt velocity ratio (i) =3
d1+d2=86mm
i=d1/d2 , d1=3d2
therefore d1=64.5mm and d2=21.5 mm
aopted 20 degree full depth spur gear from economic point of view and power
requirements.
From calculation whole weight of machine:
W=78.65kg
Force needed to operate one side mechanism is
Ft=659.83 N
,
Fr=240.11 N
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Ft=(P*1000)/v
V=pi*D*N/60
V=4.17159*400*(4/60)/60 =0.067 m/s
Therefore,
P=Ft*V/1000
P=44.55watt = 45 watts.
Power need to drive the machine is 89.4 watts.
PHYSICAL FEATURES OF UNIVERSAL PESTICIDE SPRAYER:
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Total width of machine-450 mm
Total height of machine-1100mm
Total length of machine-1300mm
Total weight of machine-71.36 KG (with 55 litre of pesticide)
Weight of machine-18.01 KG (without pesticide)
Minimum height of nozzle spray-160mm
Maximum height of nozzle spray-720mm
Nozzle operating range-460mm
Maximum capacity of machine-50 -55 litre of pesticide
Power need to operate the machine-880 watts
COST ESTIMATION:
SL
NO.
Component
NO.
Cost of one
component in RS
Total cost of component
in RS
1
Hydraulic actuator
2
600
600*2=1200
2
3
4
5
6
7
8
9
Pesticide tank
Crank and slotted bar
Cam and spring
Wheel supports
Shaft(15mm diameter)
Shaft(20mm diameter)
Nozzle
Flexible pipe
1
2
2
4
2
2
2
-
500
650
700
70
120
150
200
40 RS/M
500*1=500
650*2=1300
700*2=1400
70*4=280
120*2=240
150*2=300
200*2=400
40*2.4=96
10
Frame or base
-
Approximated on
the basis of its
volume
900