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4.4.3
Low-Volume Sprayers: SPRAYERS "PNEUS"
4.4.3.1 Description FAN of the LOW VOLUME
"PNEUS" The fan group "PNEUS" consists of:
-
CENTRIFUGAL IMPELLER
:
made of polyethylene, it has inside the steel
impeller, that coupled with the gearbox
raises the air volume needed to spray.
-
DIFFUSERS
:
composed by a 3 ways flow divider, it use the
“venture” nozzles system to spray the mixture
-
REGULATORS
:
Taps to adjust the flow rate. Upstream of these taps
are located the interchangeable nozzles.
Introduction to "LOW VOLUME
In the "low Volume" sprayer a strong air flow coming from a horizontal fan run over the
liquid by a specially shaped tubes named VENTURI.
The mixture, that is coming out at low pressure, is pulverized by high speed air; the
obtained droplets sizes are from 50 to 100 microns compared to a 250/300 microns on a
high pressure axial fan sprayer.
This drop size ensures the formation of a "Cloud" of water that settles on the leaf surface
more homogeneous
.
Moreover using the equal volume of water as the axial fan sprayer,
the spraying surface with the low volume is about 3 times higher.
Example:
The amount of the
plant protection
products to use per hectare are noticed
on the
chemical package and are always the same quantity, regardless of the machine model
that is used. Considering that to spray one hectare it needs 3 kg of product melted in
1000 liters of water; in both high pressure axial fan sprayer and low volume sprayer it will
be 300 gr in 100 liters water.
In case of spraying on 2
hectares:
High pressure axial fan sprayer : 6 kg in 2000
liters
low-volume sprayer: 6 kg (2000/3) liters = 700 lt ( against 2000 liters of high pressure
fan sprayer). The result is saving water and a best treatment given by more
uniform distribution of the product on the leaves.
To adjust the spray proceed as described on §. 4.4.1 and §4.4.2 keeping in mind that
the low-volume sprayer requires a lesser quantity of water and the nozzles mounted
are low volume-specific (see tab. 5)
How to determinate the distance between the rows that have to be treated (in meters)
or the width of land which includes the number of rows sprayed at each step taking into
