Nozzle Selection and Their Optimised Use - PowerPoint PPT Presentation


Title: Nozzle Selection and Their Optimised Use


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Nozzle Selection and Their Optimised Use
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Nozzles Summary
  • Nozzles have three main functions
  • Nozzles regulate spray liquid emission rates
  • Nozzles break the liquid into droplets.
  • Nozzles ensure the spray is distributed as
    intended.

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Nozzles Summary
  • These three nozzle functions are each critical to
    the safe, effective use
  • of products
  • Regulating spray liquid emission at the nozzle -
    helps control the volume and dose applied.
  • Droplets carry the product to the target surface
    - the size of these droplets and their numbers
    will affect product performance as well risks of
    drift or run-off.
  • Effective distribution of droplets by the nozzle
    over the intended area and/or target surface
    avoids product waste through less point to
    point variability.

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Nozzles Summary
  • Best product performance can only be gained if
  • The choice of nozzle, their condition and correct
    use is suitable for the intended spray
    application.
  • Nozzles must be in perfect working order. A
    defective nozzle may cause higher costs - through
    non optimal product use - than that spent for its
    replacement.
  • Note Although each nozzle design has some
    flexibility in use and is designed to work at a
    range of pressures, the required flow rates and
    pressures must be safely achieved and used with
    the intended spraying equipment.

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Nozzles Introducing the ranges
Air inducing (sometimes called bubble
jets) Flat fan Low drift Air inducing smaller
version Hollow cone Flood jets (sometimes
called anvil or reflex)
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Nozzles Introducing the colours
Nozzles of the same colour will have the same
flow rate whilst at the same pressure, irrespectiv
e of nozzle design. These colours are defined by
an IS and have been agreed by all major nozzle
manufacturers.
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Nozzles The colours used for each flow rate
Note Each flow rate category has a defined rate
of emission
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Understanding nozzle codes
Example of the code used on a Spraying System
TeeJet nozzle Codes can be used in catalogues
and on the nozzle itself to identify the nozzle
type, spray angle and size. Note These codes
may vary between manufacturers.
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Understanding nozzle codes
The BCPC introduced a generic system to be used
as a nozzle code to encourage greater use on
product labels. The code uses letters and numbers
such as FF/110/03 to indicate that this specific
design is a flat fan nozzle, with a 110 spray
angle and an 03 capacity.
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Nozzle manufacturing material and wear
Nozzles that are readily eroded and/or corroded
in use may not emit the intended rate of spray
liquid, may produce non optimal spray patterns
and drop sizes. Nozzle manufacturers minimise
these effects but the range of materials used in
their manufacture still have a differing wear
resistance. Relative wear resistance of nozzles
is dependant on the products sprayed, the purity
of water used such as lack of sand and the
material of which the nozzle is made. Wear scales
used are typically multiples of that measured
with brass the most readily worn material in
common use.
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Nozzle selection spray volume rates
  • Water volume rates are usually stated on product
    labels to ensure adequate coverage of target
    surfaces.
  • Too low volume rate ?
  • - Poor coverage
  • - Poor penetration
  • Too high volume rate ?
  • - Product run off from the target
  • - Over dilution of product and
    surfactants
  • - More time taken to spray the crop

Note Label stated volumes may be a range to
consider the need to ensure adequate drop
movement/placement through the canopies of
developing crops.
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Nozzle selection spray volume rates cont.
Nozzle height distance to target surface may
influence the applied volume rate, quality of
distribution and swath width
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Nozzle selection
Different nozzle designs, as well as nozzle size,
produce different drop sizes and therefore
different drop dispersion patterns.
The effect of these different dispersion patterns
on product performance is dependent on that
products mode of action - how it works. Product
labels may state a required drop size spray
quality and/or the preferred nozzle type and/or
pressure. Water Sensitive Paper is a most useful
tool to check on a nozzles spray pattern.
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Nozzle selection Water Sensitive Paper (WSP)
shows size and numbers of drops likely to impact
on target sites
Monitor the spray deposit
Before using product, optimise the application -
with water only - by placing WSP at points
important to that treatment
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Nozzle selection optimum coverage can be checked
in the field with water sensitive papers
Good
Excessive run off
Not uniform
www.stewardshipcommunity.com
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Nozzle selection and spray quality drop size
  • Nozzle selection and maintenance can have a major
    impact on the quality of your application and the
    efficacy of the products applied.
  • Nozzle selection and spray pressure will have an
    impact on potential environmental and personal
    contamination through either run off and/or
    drift.

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Nozzle selection and spray quality drop size
More droplets from the same volume of water are
produced if drop size is decreased.
Better drift-control
Better biological activity for some products
Which drop size is best may be dependent on the
product used, the drift risk or be a compromise.
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Nozzle selection and spray quality drop
sizeDrop size and some rules of thumb
Ideally, the droplets produced by nozzles should
be in the range from 150 to 700 µm. Drops smaller
than this range are likely to drift and effect
operator safety whilst, droplets too large,
reduces their available number - and may not be
retained - by the target surface due to the
higher energy of large droplets on impaction.
More droplets available more coverage on the
target.Rule of thumbSystemic acting
products 20 30 drops/cm2
Contact acting insecticides/fungicides 50 70
drops/cm2 Contact herbicides 30
40 drops/cm2General rule in the field for any
product Aim for an average 20 drops/cm2
Notes to slide 18 All important for the success
of an application is the amount of droplets
reaching the target and forming a deposit there.
Droplet sizes below 150 µm are likely to be lost
as drift while large drops may bounce off the
target. The proportion of droplets below 150 µm
should therefore be small e.g. 5 of the spray
volume.
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Nozzle selection and spray quality drop size
general rules may be stated
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Nozzle Type and spray volumes general advice
given for boom sprayer use in temperate arable
crops
xxx Preferred xx Useful alternative x
Acceptable when used at higher volumes and
pressures (e.g. ID 5 bar)
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Nozzle selection and use nozzle guidance
supported with clear pictograms vital to knapsack
users
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Application volumes and plant growth
  • Application volumes may need to be increased when
    target plant surfaces get more extensive or dense
    because there is more foliage to cover.
  • Volumes applied by knaspack sprayers can be
    increased by-
  • Walking slower Not easy to keep constant
    forward speed.
  • Increasing sprayer pressure May cause excessive
    drift.
  • Changing the sprayer nozzle size Prefered
    option.

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Nozzles on knapsack sprayers main types in use
In very common use to apply herbicides. Low
drift, wide swaths, non blocking nozzle holes are
benefits offered.
Insecticides and fungicides are usually applied
using hollow cone nozzles
Uniform, overall spraying of bare ground or low
vegetation best achieved with flat fan nozzles
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Flat fan nozzles Standard and even spray types
These standard types can be used on small
multi-nozzle booms whilst even spray designs
produce uniform deposits from a single nozzle
Standard
Even spray
Spray distribution
Colour-coded nozzle
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Hollow Cone Nozzles are typically made from two
components
Higher volumes of spray liquid can be atomised
into smaller drops very appropriate for many
insecticides and fungicides
Colour-coded nozzle
Spray distribution
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Solid Cone Nozzles not commonly used on knapsack
sprayers
Colour-coded nozzle
Spray distribution
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Deflector Nozzles most commonly used on knapsack
sprayers especially for herbicides
Note that pressurised spray liquid strikes an
angled surface in the nozzle to form the spray
sheet that produces the drops and the pattern.
Used to apply wider swaths and can be used at low
nozzle heights such as under tree/bush canopies.
Colour-coded nozzle
Spray distribution
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Nozzles Low drift types not yet in much knapsack
use but could be in the future
Pre-orifice Flat fan
Air induction Flat fan
TT-type Deflector
Large to very large drops produced with
deflector/flood jet design commonly used on large
boom sprayers
These low drift nozzles are often not available
in areas where knapsack sprayers are used, this
might change in the future offering a range of
different nozzles that would work well with
knapsacks.
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Drift reducing nozzles cross sectional drawings
Pictures from Spraying Systems
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Air inclusion nozzle detailed cross sectional
drawing
These designs have become extensively used on
boom sprayers in many countries especially
those where legislation demands that products
must not drift onto surface water
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Nozzle selection adjustable hollow cones
Many knapsacks are supplied with adjustable
hollow cone nozzles. This type of nozzle is not
recommended as they are impossible to accurately
calibrate, a calibration would be required before
each use to ensure the nozzle setting have not
been changed. The nozzle setting can change
during an application. These adjustable hollow
cone nozzles are often made of brass which is the
softest of nozzle materials, meaning that they
should be regularly replaced. If your sprayer
comes equipped with one of these nozzles you
should change the nozzle.
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Knapsack filters
Filters minimise the risk of partially or totally
blocked nozzles and other malfunction of a
knapsack sprayer. Filters should be positioned
at key sites in tank openings, lance and before
the nozzle itself. Filters will protect your
nozzles from dirt and grit and give the nozzles a
longer life span.
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Sprayer pressure
  • On certain types of sprayer, output pressure can
    be adjusted to meet the needs of different nozzle
    designs and sizes.
  • Nozzles are designed to work within specific
    pressure ranges. Ensure that the nozzles chosen
    are appropriate for the sprayer output pressure.
    Refer to the manufacturers guidelines.
  • If you can change sprayer pressure then the
    sprayer should be equipped with a pressure gauge
    to enable reliable calibration. Or fit a constant
    flow valve.
  • Note Increasing or decreasing sprayer pressure
    will have an effect on sprayer output and also
    the size of droplets leaving the nozzle.
  • The higher the pressure - the smaller the
    droplets.

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Pressure may vary when using a standard lever
knapsack
Sprayer output may vary as you pump, reducing the
ability to apply an even application rate
Notes to slide Pump strokes, intensity and
frequency result in fluctuating pressure,
flow-rate and less uniform spray pattern.
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Nozzle selection and use of constant flow valves
  • Sprayer pressure can be stabilised and controlled
    using constant flow
  • CF valves.
  • CF valves are available to operate at 1, 1.5, 2
    and 3 bar pressures.
  • Benefits -
  • Uniform application
  • Less pumping effort whilst spraying
  • Can save product
  • Increases reliability of product performance
  • Reduces spray drift

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Constant Flow Valve placement
Located between the pump or pressurised tank of
spray solution and nozzle. For the most accurate
pressure fit CF valve close to the
nozzle. Caution when removing the trigger
assembly as the CF valve will retain pressure in
the spray lance.
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Spray drift risks influenced by many factors
  • Spray drift should be minimized for your safety,
    the safety of those near you and to lessen damage
    to adjacent crops, water, the environment
  • Many factors influence the risk of spray drift
  • Nozzle type, size, pressure and drop size spray
    quality produced
  • Application Equipment sprayer pressure, type of
    sprayer
  • Application Skills calibration, settings,
    operator accuracy, nozzle height above target
  • Meteorological Conditions wind, temperature,
    relative humidity
  • Structure of the target distance, especially
    height, to project spray.
  • Nozzles are now available that will reduce drift
    risks by increasing droplet size at the same
    application volume.

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Nozzle selection and spray quality
  • DO NOT -
  • Clean a nozzle with an abrasive implement
  • Clean a nozzle by blowing through it with your
    mouth
  • Use damaged or worn nozzles
  • Use fine spray drop sizes on a windy day
  • DO -
  • Wear gloves when handling nozzles
  • Clean a nozzle with water and a light brush
  • Protect nozzles from blockages with use of
    recomended filters
  • Frequently clean nozzles
  • Calibrate nozzles and sprayer every season
  • Replace the nozzle if damaged
  • Follow any product label recommendations
  • Change nozzles as necessary depending on the
    crop, growth stage and product mode of action

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Questions
  • What are the best type of nozzle for applying
    a) herbicides b) insecticides and fungicides?
  • What are the benefits of using constant flow
    valves?
  • How should you clean a blocked nozzle?
  • What is the purpose of the nozzle?
  • How can you protect a nozzle from blockage?
  • What type of nozzle should not be used and why?
  • How frequently do you change nozzles?
  • Are different nozzles readily available in your
    region?

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Trainer notes
  • Have arrange of different nozzles available to
    hand around
  • Use water sensitive paper to demonstrate
    different nozzle spray paterns, this can be done
    by connecting a nozzle to a small killer spray
    type bottle fitted with a CF valve.

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Equipment suppliers
Nozzle Manufacturers
http//www.lechler-agri.de/englisch/company.html
http//www.spray.com/products/default.asp
http//www.agratech.co.uk/products/spray-tips-nozz
les/lurmark-nozzles-products.html
http//www.teejet.com/english/home.aspx http//www
.hardi-nozzles.com/Hand20Operated.aspx
Constant flow valves
http//gate-llc.com/cfvalve001.htm
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Notes to slides 8 and 9
  • Nozzles should be labelled providing useful and
    important information to the user. Different
    nozzle producers use their own system, but
    labelling should indicate
  • Producer
  • Flow rate (at standardised pressure)
  • Spray angle (at standardised pressure)
  • Additionally information may include the nozzle
    type, material etc.
  • Flow rate data are of great use for checking on
    the nozzles condition. A worn out nozzle would
    deliver higher flow rates than indicated when
    operated at the standardised pressure. Also a
    mounted pressure gauges can be checked using
    brand new nozzles of a producer of repute.
  • Concerning the spray volume it is recommended to
    carry out a proper calibration. Of course, the
    flow rate figure allows to calculate the spray
    volume as well.
  • Unfortunately not all nozzles are labelled. In
    this case calibration and a check on the spray
    pattern is highly indicated.

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Notes to slide 10
  • Nozzle materials
  • Materials most often used for nozzle manufacture
    are brass, stainless steel, various plastics and
    ceramics.
  • Brass - fairly cheap to produce and resistant to
    many chemicals. However, particulate materials
    such as wettable powders easily abrade brass.
  • Stainless steel - excellent resistance to both
    abrasion and corrosion, but more expensive to
    produce than brass.
  • Ceramics - very resistant to abrasion and
    corrosion but expensive, and prone to damage
    (chipping) when dropped.
  • Plastics - nylon resists corrosion and abrasion
    but may swell when exposed to certain solvents.
    Nylon has the advantage that it is cheap to
    produce. Some of the newer plastics such as
    Kematal offer excellent resistance to abrasion
    and corrosion, are unaffected by most chemical
    solvents and are relatively cheap to produce.
    Plastic nozzles also allow for colour coding for
    easy identification. (Lurmark Ltd., Longstanton,
    Cambridgeshire.)
  • Most manufacturers now produce nozzles with the
    outer part made from a plastic which is cheap and
    can be colour coded, and a small insert including
    the orifice, made from a more resistant but more
    expensive material such as stainless steel or
    ceramic.

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Notes to slide 24
  • The flat fan nozzle has a lens-shaped or
    elliptical orifice. This produces a narrow
    lens-shaped pattern, with the highest spray
    deposit occurring immediately under the nozzle
    and the amounts of spray lessening towards the
    edges of the fan. This means the swaths must be
    overlapped to achieve an even deposit on the
    target, and hence are usually used in overlapping
    fashion on a spray boom.
  • These nozzles are produced in a range of sizes
    and possible spray angles although the most
    commonly used spray angles are either 80 or
    110. The larger spray angle (110) gives a wider
    swath but generally produces smaller droplets.
  • Fan nozzles are most suitable for spraying flat
    surfaces such as soil when applying pre-emergence
    herbicides, to walls of buildings, for example,
    when spraying against insect disease vectors or
    stored product pests.
  • A special type of flat fan nozzle is known as the
    'even spray' nozzle. This is designed to give an
    even deposit across the swath to eliminate the
    need for overlapping swaths, and is best suited
    for a single nozzle on a knapsack lance when band
    or strip spraying. They are most commonly
    available only with an 80 spray angle.
  • Most flat fans are designed to produce a
    specified throughput and spray angle at a spray
    pressure of 40 psi or 3 bar. However, also
    available are low pressure (LP) flat fan nozzles,
    which give the same flow rates and spray angles
    but at 15 psi (1 bar). These tend to produce
    larger droplets and so are better for herbicide
    spraying to minimise drift.

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Notes to slide 25
  • Cone nozzles are typically made up of two
    components
  • nozzle tip or orifice disc
  • core or swirl plate.
  • The core has one or more angled holes or slots
    around it. The angle of these holes causes the
    liquid to move around the space between the core
    and the nozzle tip (the swirl chambers) in a
    swirling or circular motion. This results in a
    hollow cone-shaped spray pattern.
  • A wide range of flow rates, spray angles and
    droplet sizes can be obtained by various
    combinations of orifice size, number and size of
    slots or holes in the core, size of swirl chamber
    and liquid pressure. In general, higher
    pressures, smaller core slots and larger nozzle
    tip orifice sizes lead to wider spray angles. A
    narrow cone and larger droplet sizes are produced
    by increasing the depth of the swirl chamber,
    which can be achieved by inserting a washer
    between the core and orifice disc.
  • Nozzles consisting of separate components are
    found commonly, more recent constructions
    incorporate them into one unit. This nozzles are
    often colour-coded giving clear information
    concerning the flow-rate / pressure relation.
  • Hollow cone nozzles are best suited to spraying
    crop foliage, because droplets approach the
    leaves from more directions than in the single
    plane produced by the flat fan, giving good
    coverage over the many different target surfaces
    in a crop. This means they are most commonly used
    for insecticide and fungicide spraying in crops.

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Notes to slide 26
  • If the core or swirl plate also has a central
    hole in addition to the angled slots, the centre
    of the cone will be filled with droplets, and
    therefore they type of nozzle is referred to as a
    solid cone nozzle. It typically produces smaller
    spray angles and larger droplets and so is used
    for spot treatments of herbicides or situations
    where greater downward penetration of spray is
    required, but tends to be used mainly for tractor
    boom spraying.
  • Without picture
  • Another type of cone nozzle is occasionally
    encountered - known as the variable-cone nozzle.
    With this nozzle, turning the nozzle body adjusts
    the depth of the swirl chamber and alters the
    spray angle and droplet size from a narrow jet
    with large droplets to a wide cone with smaller
    droplets. This is the nozzle type frequently
    encountered on sprayers designed for the amateur
    gardener, but is not recommended for most serious
    spraying as intermediate nozzle positions are not
    easily repeated consistently.

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Notes to slide 27
  • Deflector nozzles are also known as impact,
    flooding or anvil nozzles. They produce droplets
    by the impaction of a straight jet of water onto
    a deflector surface, which produces a wide-angled
    flat spray pattern. Larger droplets land at the
    outer edges of the fan, so the pattern is
    somewhat uneven
  • Deflector nozzles used at low pressure are
    ideally suited for herbicide applications. They
    are, however, available in a range of flow rates,
    often colour coded, and the smallest orifice
    sizes giving flow rates less than 0.6
    litres/minute at 15 psi (1 bar) should be avoided
    since they will produce smaller droplets liable
    to drift and so are better suited to insecticide
    or fungicide spraying.
  • The deflector nozzle sizes which give flow rates
    in excess of 1.6 litres/minute at a pressure of
    15 psi (1 bar) are less suitable for use in
    knapsack sprayers, since it becomes difficult to
    maintain an adequate pressure with the higher
    flow rate nozzles.

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Notes to slide 29
  • Drift-reducing nozzles generate larger droplets
    than nozzles of comparable size.
  • Generally drift control nozzles fall into three
    main types
  • Examples from Spraying Systems (ss), Lechler
    (le), Lurmark (lu) and Hardi (ha) to be used
    instead of standard nozzle types of the same
    spray pattern.
  • Orifice-design specially made to reduce the
    portion of drift-prone droplets
  • Flat fan nozzles XR (ss), LU (le), VP (lu)
  • 2) Pre-orifice types
  • Flat fan nozzles DG (ss), AD (le), Lo-drift
    (lu), LD (ha)
  • 3) Air inclusion or venturi types.
  • Flat fan nozzles AI (ss), ID and IDK (ss),
    Drift-BETA (lu), Injet (ha)
  • Flat fan off-centre nozzles AIUB (ss), IS
    (le),
  • Hollow cone nozzles ITR (le)
  • Further nozzles designed to reduce drift are
  • TF (ss) replaces a conventional deflector nozzle
    but has a pre-orifice and a turbulence chamber at
    the exit point to increase droplet size and to
    give a better spray pattern.
  • TT (ss) is like a hybrid between an flat fan and
    an deflector nozzle and can be used to replace a
    flat fan nozzle but at a wider range of pressures
    than the pre-orifice nozzles for examples.

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Notes to slide 30
  • There are now a wide range of air inclusion types
    available which is a more radical change as the
    resulting large droplets contain small air
    bubbles which make them less prone to drift than
    the pre-orifice types but also gives better
    coverage than similar large droplets as they
    shatter on impact.
  • But while e.g. the pre-orifice types are designed
    to be used at conventional flow rates and
    pressures, some of the air inclusion/venturi
    types require higher operational pressures to
    operate and it is important to check that the
    sprayer can cope with these higher pressures
    (typically 60-75 psi). However the higher
    pressure nozzles do reduce drift to a greater
    degree than the lower pressure ones. Also the
    larger droplets of the air inclusion types may be
    inappropriate for situations where good coverage
    is needed.

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Notes to slide 32
  • A tuned cascade of filters helps best.
  • The basket filter should not be wider than 0.5 mm
  • The lance filter should not be wider than 0.3 mm
  • The nozzle filter depends on the size and type of
    nozzle mounted
  • Example
  • - Flat fan nozzles use mesh filter of size
  • sizes 01 to 015 100 mesh (0.14 mm)
  • sizes 02 to 08 50 mesh (0.28 mm)
  • sizes 09 and bigger no filter
  • - Hollow cone nozzles use slotted strainer
  • Important
  • The last filter before the nozzle must be
    somewhat smaller
  • than the orifice.
  • It should be possible to handle filters with
    gloved hands.

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Notes to slide 36
  • Pressure regulating valves allow spraying at
    constant flow and serve as well as anti-drip
    devices.
  • Example CFValves from G.A.T.E. (USA)
  • Material Delrin (Plastic), weight 19 grams, ISO
    9002 certified
  • They come in four sizes
  • Colour-code Pre-set pressure
  • YELLOW 1.0 bar (14.5 psi)
  • RED 1.5 bar (21.0 psi)
  • BLUE 2.0 bar (29.0 psi)
  • GREEN 3.0 bar (43.5 psi)
  • Assembly Spray lance - Nozzle body Filter
    CFValve Nozzle
  • Result More uniform spray pattern, reduce of
    waste, reduce of drift potential

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Notes to slide 37
  • Drift control nozzles are becoming increasingly
    important. They where developed in Europe and the
    USA based on environmental concerns. In
    countries where regulations governing spraying in
    relation to drift risk exist, they offer farmers
    a cheaper drift control option than low drift
    sprayers, and can allow spraying in higher wind
    conditions than might normally be possible,
    thereby increasing flexibility. Where there are
    guidelines covering the spraying of pesticides
    adjacent to water courses with minimum buffer
    zones required, low drift nozzles allow the user
    to spray closer to the water bodies than is
    otherwise permitted, and there is an officially
    approved star rating system for different
    manufacturers low drift nozzles the higher the
    number of stars, the greater is the flexibility
    to reduce the buffer zone.

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Nozzle Selection and Their Optimised Use

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Title: Nozzle Selection and Their Optimised Use


1
Nozzle Selection and Their Optimised Use
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Nozzles Summary
  • Nozzles have three main functions
  • Nozzles regulate spray liquid emission rates
  • Nozzles break the liquid into droplets.
  • Nozzles ensure the spray is distributed as
    intended.

2 of 52
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Nozzles Summary
  • These three nozzle functions are each critical to
    the safe, effective use
  • of products
  • Regulating spray liquid emission at the nozzle -
    helps control the volume and dose applied.
  • Droplets carry the product to the target surface
    - the size of these droplets and their numbers
    will affect product performance as well risks of
    drift or run-off.
  • Effective distribution of droplets by the nozzle
    over the intended area and/or target surface
    avoids product waste through less point to
    point variability.

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4
Nozzles Summary
  • Best product performance can only be gained if
  • The choice of nozzle, their condition and correct
    use is suitable for the intended spray
    application.
  • Nozzles must be in perfect working order. A
    defective nozzle may cause higher costs - through
    non optimal product use - than that spent for its
    replacement.
  • Note Although each nozzle design has some
    flexibility in use and is designed to work at a
    range of pressures, the required flow rates and
    pressures must be safely achieved and used with
    the intended spraying equipment.

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Nozzles Introducing the ranges
Air inducing (sometimes called bubble
jets) Flat fan Low drift Air inducing smaller
version Hollow cone Flood jets (sometimes
called anvil or reflex)
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Nozzles Introducing the colours
Nozzles of the same colour will have the same
flow rate whilst at the same pressure, irrespectiv
e of nozzle design. These colours are defined by
an IS and have been agreed by all major nozzle
manufacturers.
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Nozzles The colours used for each flow rate
Note Each flow rate category has a defined rate
of emission
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Understanding nozzle codes
Example of the code used on a Spraying System
TeeJet nozzle Codes can be used in catalogues
and on the nozzle itself to identify the nozzle
type, spray angle and size. Note These codes
may vary between manufacturers.
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Understanding nozzle codes
The BCPC introduced a generic system to be used
as a nozzle code to encourage greater use on
product labels. The code uses letters and numbers
such as FF/110/03 to indicate that this specific
design is a flat fan nozzle, with a 110 spray
angle and an 03 capacity.
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10
Nozzle manufacturing material and wear
Nozzles that are readily eroded and/or corroded
in use may not emit the intended rate of spray
liquid, may produce non optimal spray patterns
and drop sizes. Nozzle manufacturers minimise
these effects but the range of materials used in
their manufacture still have a differing wear
resistance. Relative wear resistance of nozzles
is dependant on the products sprayed, the purity
of water used such as lack of sand and the
material of which the nozzle is made. Wear scales
used are typically multiples of that measured
with brass the most readily worn material in
common use.
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11
Nozzle selection spray volume rates
  • Water volume rates are usually stated on product
    labels to ensure adequate coverage of target
    surfaces.
  • Too low volume rate ?
  • - Poor coverage
  • - Poor penetration
  • Too high volume rate ?
  • - Product run off from the target
  • - Over dilution of product and
    surfactants
  • - More time taken to spray the crop

Note Label stated volumes may be a range to
consider the need to ensure adequate drop
movement/placement through the canopies of
developing crops.
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Nozzle selection spray volume rates cont.
Nozzle height distance to target surface may
influence the applied volume rate, quality of
distribution and swath width
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Nozzle selection
Different nozzle designs, as well as nozzle size,
produce different drop sizes and therefore
different drop dispersion patterns.
The effect of these different dispersion patterns
on product performance is dependent on that
products mode of action - how it works. Product
labels may state a required drop size spray
quality and/or the preferred nozzle type and/or
pressure. Water Sensitive Paper is a most useful
tool to check on a nozzles spray pattern.
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Nozzle selection Water Sensitive Paper (WSP)
shows size and numbers of drops likely to impact
on target sites
Monitor the spray deposit
Before using product, optimise the application -
with water only - by placing WSP at points
important to that treatment
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15
Nozzle selection optimum coverage can be checked
in the field with water sensitive papers
Good
Excessive run off
Not uniform
www.stewardshipcommunity.com
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16
Nozzle selection and spray quality drop size
  • Nozzle selection and maintenance can have a major
    impact on the quality of your application and the
    efficacy of the products applied.
  • Nozzle selection and spray pressure will have an
    impact on potential environmental and personal
    contamination through either run off and/or
    drift.

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17
Nozzle selection and spray quality drop size
More droplets from the same volume of water are
produced if drop size is decreased.
Better drift-control
Better biological activity for some products
Which drop size is best may be dependent on the
product used, the drift risk or be a compromise.
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18
Nozzle selection and spray quality drop
sizeDrop size and some rules of thumb
Ideally, the droplets produced by nozzles should
be in the range from 150 to 700 µm. Drops smaller
than this range are likely to drift and effect
operator safety whilst, droplets too large,
reduces their available number - and may not be
retained - by the target surface due to the
higher energy of large droplets on impaction.
More droplets available more coverage on the
target.Rule of thumbSystemic acting
products 20 30 drops/cm2
Contact acting insecticides/fungicides 50 70
drops/cm2 Contact herbicides 30
40 drops/cm2General rule in the field for any
product Aim for an average 20 drops/cm2
Notes to slide 18 All important for the success
of an application is the amount of droplets
reaching the target and forming a deposit there.
Droplet sizes below 150 µm are likely to be lost
as drift while large drops may bounce off the
target. The proportion of droplets below 150 µm
should therefore be small e.g. 5 of the spray
volume.
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19
Nozzle selection and spray quality drop size
general rules may be stated
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20
Nozzle Type and spray volumes general advice
given for boom sprayer use in temperate arable
crops
xxx Preferred xx Useful alternative x
Acceptable when used at higher volumes and
pressures (e.g. ID 5 bar)
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Nozzle selection and use nozzle guidance
supported with clear pictograms vital to knapsack
users
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22
Application volumes and plant growth
  • Application volumes may need to be increased when
    target plant surfaces get more extensive or dense
    because there is more foliage to cover.
  • Volumes applied by knaspack sprayers can be
    increased by-
  • Walking slower Not easy to keep constant
    forward speed.
  • Increasing sprayer pressure May cause excessive
    drift.
  • Changing the sprayer nozzle size Prefered
    option.

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23
Nozzles on knapsack sprayers main types in use
In very common use to apply herbicides. Low
drift, wide swaths, non blocking nozzle holes are
benefits offered.
Insecticides and fungicides are usually applied
using hollow cone nozzles
Uniform, overall spraying of bare ground or low
vegetation best achieved with flat fan nozzles
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24
Flat fan nozzles Standard and even spray types
These standard types can be used on small
multi-nozzle booms whilst even spray designs
produce uniform deposits from a single nozzle
Standard
Even spray
Spray distribution
Colour-coded nozzle
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25
Hollow Cone Nozzles are typically made from two
components
Higher volumes of spray liquid can be atomised
into smaller drops very appropriate for many
insecticides and fungicides
Colour-coded nozzle
Spray distribution
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26
Solid Cone Nozzles not commonly used on knapsack
sprayers
Colour-coded nozzle
Spray distribution
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27
Deflector Nozzles most commonly used on knapsack
sprayers especially for herbicides
Note that pressurised spray liquid strikes an
angled surface in the nozzle to form the spray
sheet that produces the drops and the pattern.
Used to apply wider swaths and can be used at low
nozzle heights such as under tree/bush canopies.
Colour-coded nozzle
Spray distribution
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Nozzles Low drift types not yet in much knapsack
use but could be in the future
Pre-orifice Flat fan
Air induction Flat fan
TT-type Deflector
Large to very large drops produced with
deflector/flood jet design commonly used on large
boom sprayers
These low drift nozzles are often not available
in areas where knapsack sprayers are used, this
might change in the future offering a range of
different nozzles that would work well with
knapsacks.
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29
Drift reducing nozzles cross sectional drawings
Pictures from Spraying Systems
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30
Air inclusion nozzle detailed cross sectional
drawing
These designs have become extensively used on
boom sprayers in many countries especially
those where legislation demands that products
must not drift onto surface water
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31
Nozzle selection adjustable hollow cones
Many knapsacks are supplied with adjustable
hollow cone nozzles. This type of nozzle is not
recommended as they are impossible to accurately
calibrate, a calibration would be required before
each use to ensure the nozzle setting have not
been changed. The nozzle setting can change
during an application. These adjustable hollow
cone nozzles are often made of brass which is the
softest of nozzle materials, meaning that they
should be regularly replaced. If your sprayer
comes equipped with one of these nozzles you
should change the nozzle.
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32
Knapsack filters
Filters minimise the risk of partially or totally
blocked nozzles and other malfunction of a
knapsack sprayer. Filters should be positioned
at key sites in tank openings, lance and before
the nozzle itself. Filters will protect your
nozzles from dirt and grit and give the nozzles a
longer life span.
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33
Sprayer pressure
  • On certain types of sprayer, output pressure can
    be adjusted to meet the needs of different nozzle
    designs and sizes.
  • Nozzles are designed to work within specific
    pressure ranges. Ensure that the nozzles chosen
    are appropriate for the sprayer output pressure.
    Refer to the manufacturers guidelines.
  • If you can change sprayer pressure then the
    sprayer should be equipped with a pressure gauge
    to enable reliable calibration. Or fit a constant
    flow valve.
  • Note Increasing or decreasing sprayer pressure
    will have an effect on sprayer output and also
    the size of droplets leaving the nozzle.
  • The higher the pressure - the smaller the
    droplets.

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34
Pressure may vary when using a standard lever
knapsack
Sprayer output may vary as you pump, reducing the
ability to apply an even application rate
Notes to slide Pump strokes, intensity and
frequency result in fluctuating pressure,
flow-rate and less uniform spray pattern.
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35
Nozzle selection and use of constant flow valves
  • Sprayer pressure can be stabilised and controlled
    using constant flow
  • CF valves.
  • CF valves are available to operate at 1, 1.5, 2
    and 3 bar pressures.
  • Benefits -
  • Uniform application
  • Less pumping effort whilst spraying
  • Can save product
  • Increases reliability of product performance
  • Reduces spray drift

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36
Constant Flow Valve placement
Located between the pump or pressurised tank of
spray solution and nozzle. For the most accurate
pressure fit CF valve close to the
nozzle. Caution when removing the trigger
assembly as the CF valve will retain pressure in
the spray lance.
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37
Spray drift risks influenced by many factors
  • Spray drift should be minimized for your safety,
    the safety of those near you and to lessen damage
    to adjacent crops, water, the environment
  • Many factors influence the risk of spray drift
  • Nozzle type, size, pressure and drop size spray
    quality produced
  • Application Equipment sprayer pressure, type of
    sprayer
  • Application Skills calibration, settings,
    operator accuracy, nozzle height above target
  • Meteorological Conditions wind, temperature,
    relative humidity
  • Structure of the target distance, especially
    height, to project spray.
  • Nozzles are now available that will reduce drift
    risks by increasing droplet size at the same
    application volume.

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38
Nozzle selection and spray quality
  • DO NOT -
  • Clean a nozzle with an abrasive implement
  • Clean a nozzle by blowing through it with your
    mouth
  • Use damaged or worn nozzles
  • Use fine spray drop sizes on a windy day
  • DO -
  • Wear gloves when handling nozzles
  • Clean a nozzle with water and a light brush
  • Protect nozzles from blockages with use of
    recomended filters
  • Frequently clean nozzles
  • Calibrate nozzles and sprayer every season
  • Replace the nozzle if damaged
  • Follow any product label recommendations
  • Change nozzles as necessary depending on the
    crop, growth stage and product mode of action

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39
Questions
  • What are the best type of nozzle for applying
    a) herbicides b) insecticides and fungicides?
  • What are the benefits of using constant flow
    valves?
  • How should you clean a blocked nozzle?
  • What is the purpose of the nozzle?
  • How can you protect a nozzle from blockage?
  • What type of nozzle should not be used and why?
  • How frequently do you change nozzles?
  • Are different nozzles readily available in your
    region?

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40
Trainer notes
  • Have arrange of different nozzles available to
    hand around
  • Use water sensitive paper to demonstrate
    different nozzle spray paterns, this can be done
    by connecting a nozzle to a small killer spray
    type bottle fitted with a CF valve.

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41
Equipment suppliers
Nozzle Manufacturers
http//www.lechler-agri.de/englisch/company.html
http//www.spray.com/products/default.asp
http//www.agratech.co.uk/products/spray-tips-nozz
les/lurmark-nozzles-products.html
http//www.teejet.com/english/home.aspx http//www
.hardi-nozzles.com/Hand20Operated.aspx
Constant flow valves
http//gate-llc.com/cfvalve001.htm
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42
Notes to slides 8 and 9
  • Nozzles should be labelled providing useful and
    important information to the user. Different
    nozzle producers use their own system, but
    labelling should indicate
  • Producer
  • Flow rate (at standardised pressure)
  • Spray angle (at standardised pressure)
  • Additionally information may include the nozzle
    type, material etc.
  • Flow rate data are of great use for checking on
    the nozzles condition. A worn out nozzle would
    deliver higher flow rates than indicated when
    operated at the standardised pressure. Also a
    mounted pressure gauges can be checked using
    brand new nozzles of a producer of repute.
  • Concerning the spray volume it is recommended to
    carry out a proper calibration. Of course, the
    flow rate figure allows to calculate the spray
    volume as well.
  • Unfortunately not all nozzles are labelled. In
    this case calibration and a check on the spray
    pattern is highly indicated.

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43
Notes to slide 10
  • Nozzle materials
  • Materials most often used for nozzle manufacture
    are brass, stainless steel, various plastics and
    ceramics.
  • Brass - fairly cheap to produce and resistant to
    many chemicals. However, particulate materials
    such as wettable powders easily abrade brass.
  • Stainless steel - excellent resistance to both
    abrasion and corrosion, but more expensive to
    produce than brass.
  • Ceramics - very resistant to abrasion and
    corrosion but expensive, and prone to damage
    (chipping) when dropped.
  • Plastics - nylon resists corrosion and abrasion
    but may swell when exposed to certain solvents.
    Nylon has the advantage that it is cheap to
    produce. Some of the newer plastics such as
    Kematal offer excellent resistance to abrasion
    and corrosion, are unaffected by most chemical
    solvents and are relatively cheap to produce.
    Plastic nozzles also allow for colour coding for
    easy identification. (Lurmark Ltd., Longstanton,
    Cambridgeshire.)
  • Most manufacturers now produce nozzles with the
    outer part made from a plastic which is cheap and
    can be colour coded, and a small insert including
    the orifice, made from a more resistant but more
    expensive material such as stainless steel or
    ceramic.

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44
Notes to slide 24
  • The flat fan nozzle has a lens-shaped or
    elliptical orifice. This produces a narrow
    lens-shaped pattern, with the highest spray
    deposit occurring immediately under the nozzle
    and the amounts of spray lessening towards the
    edges of the fan. This means the swaths must be
    overlapped to achieve an even deposit on the
    target, and hence are usually used in overlapping
    fashion on a spray boom.
  • These nozzles are produced in a range of sizes
    and possible spray angles although the most
    commonly used spray angles are either 80 or
    110. The larger spray angle (110) gives a wider
    swath but generally produces smaller droplets.
  • Fan nozzles are most suitable for spraying flat
    surfaces such as soil when applying pre-emergence
    herbicides, to walls of buildings, for example,
    when spraying against insect disease vectors or
    stored product pests.
  • A special type of flat fan nozzle is known as the
    'even spray' nozzle. This is designed to give an
    even deposit across the swath to eliminate the
    need for overlapping swaths, and is best suited
    for a single nozzle on a knapsack lance when band
    or strip spraying. They are most commonly
    available only with an 80 spray angle.
  • Most flat fans are designed to produce a
    specified throughput and spray angle at a spray
    pressure of 40 psi or 3 bar. However, also
    available are low pressure (LP) flat fan nozzles,
    which give the same flow rates and spray angles
    but at 15 psi (1 bar). These tend to produce
    larger droplets and so are better for herbicide
    spraying to minimise drift.

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45
Notes to slide 25
  • Cone nozzles are typically made up of two
    components
  • nozzle tip or orifice disc
  • core or swirl plate.
  • The core has one or more angled holes or slots
    around it. The angle of these holes causes the
    liquid to move around the space between the core
    and the nozzle tip (the swirl chambers) in a
    swirling or circular motion. This results in a
    hollow cone-shaped spray pattern.
  • A wide range of flow rates, spray angles and
    droplet sizes can be obtained by various
    combinations of orifice size, number and size of
    slots or holes in the core, size of swirl chamber
    and liquid pressure. In general, higher
    pressures, smaller core slots and larger nozzle
    tip orifice sizes lead to wider spray angles. A
    narrow cone and larger droplet sizes are produced
    by increasing the depth of the swirl chamber,
    which can be achieved by inserting a washer
    between the core and orifice disc.
  • Nozzles consisting of separate components are
    found commonly, more recent constructions
    incorporate them into one unit. This nozzles are
    often colour-coded giving clear information
    concerning the flow-rate / pressure relation.
  • Hollow cone nozzles are best suited to spraying
    crop foliage, because droplets approach the
    leaves from more directions than in the single
    plane produced by the flat fan, giving good
    coverage over the many different target surfaces
    in a crop. This means they are most commonly used
    for insecticide and fungicide spraying in crops.

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46
Notes to slide 26
  • If the core or swirl plate also has a central
    hole in addition to the angled slots, the centre
    of the cone will be filled with droplets, and
    therefore they type of nozzle is referred to as a
    solid cone nozzle. It typically produces smaller
    spray angles and larger droplets and so is used
    for spot treatments of herbicides or situations
    where greater downward penetration of spray is
    required, but tends to be used mainly for tractor
    boom spraying.
  • Without picture
  • Another type of cone nozzle is occasionally
    encountered - known as the variable-cone nozzle.
    With this nozzle, turning the nozzle body adjusts
    the depth of the swirl chamber and alters the
    spray angle and droplet size from a narrow jet
    with large droplets to a wide cone with smaller
    droplets. This is the nozzle type frequently
    encountered on sprayers designed for the amateur
    gardener, but is not recommended for most serious
    spraying as intermediate nozzle positions are not
    easily repeated consistently.

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47
Notes to slide 27
  • Deflector nozzles are also known as impact,
    flooding or anvil nozzles. They produce droplets
    by the impaction of a straight jet of water onto
    a deflector surface, which produces a wide-angled
    flat spray pattern. Larger droplets land at the
    outer edges of the fan, so the pattern is
    somewhat uneven
  • Deflector nozzles used at low pressure are
    ideally suited for herbicide applications. They
    are, however, available in a range of flow rates,
    often colour coded, and the smallest orifice
    sizes giving flow rates less than 0.6
    litres/minute at 15 psi (1 bar) should be avoided
    since they will produce smaller droplets liable
    to drift and so are better suited to insecticide
    or fungicide spraying.
  • The deflector nozzle sizes which give flow rates
    in excess of 1.6 litres/minute at a pressure of
    15 psi (1 bar) are less suitable for use in
    knapsack sprayers, since it becomes difficult to
    maintain an adequate pressure with the higher
    flow rate nozzles.

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48
Notes to slide 29
  • Drift-reducing nozzles generate larger droplets
    than nozzles of comparable size.
  • Generally drift control nozzles fall into three
    main types
  • Examples from Spraying Systems (ss), Lechler
    (le), Lurmark (lu) and Hardi (ha) to be used
    instead of standard nozzle types of the same
    spray pattern.
  • Orifice-design specially made to reduce the
    portion of drift-prone droplets
  • Flat fan nozzles XR (ss), LU (le), VP (lu)
  • 2) Pre-orifice types
  • Flat fan nozzles DG (ss), AD (le), Lo-drift
    (lu), LD (ha)
  • 3) Air inclusion or venturi types.
  • Flat fan nozzles AI (ss), ID and IDK (ss),
    Drift-BETA (lu), Injet (ha)
  • Flat fan off-centre nozzles AIUB (ss), IS
    (le),
  • Hollow cone nozzles ITR (le)
  • Further nozzles designed to reduce drift are
  • TF (ss) replaces a conventional deflector nozzle
    but has a pre-orifice and a turbulence chamber at
    the exit point to increase droplet size and to
    give a better spray pattern.
  • TT (ss) is like a hybrid between an flat fan and
    an deflector nozzle and can be used to replace a
    flat fan nozzle but at a wider range of pressures
    than the pre-orifice nozzles for examples.

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49
Notes to slide 30
  • There are now a wide range of air inclusion types
    available which is a more radical change as the
    resulting large droplets contain small air
    bubbles which make them less prone to drift than
    the pre-orifice types but also gives better
    coverage than similar large droplets as they
    shatter on impact.
  • But while e.g. the pre-orifice types are designed
    to be used at conventional flow rates and
    pressures, some of the air inclusion/venturi
    types require higher operational pressures to
    operate and it is important to check that the
    sprayer can cope with these higher pressures
    (typically 60-75 psi). However the higher
    pressure nozzles do reduce drift to a greater
    degree than the lower pressure ones. Also the
    larger droplets of the air inclusion types may be
    inappropriate for situations where good coverage
    is needed.

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50
Notes to slide 32
  • A tuned cascade of filters helps best.
  • The basket filter should not be wider than 0.5 mm
  • The lance filter should not be wider than 0.3 mm
  • The nozzle filter depends on the size and type of
    nozzle mounted
  • Example
  • - Flat fan nozzles use mesh filter of size
  • sizes 01 to 015 100 mesh (0.14 mm)
  • sizes 02 to 08 50 mesh (0.28 mm)
  • sizes 09 and bigger no filter
  • - Hollow cone nozzles use slotted strainer
  • Important
  • The last filter before the nozzle must be
    somewhat smaller
  • than the orifice.
  • It should be possible to handle filters with
    gloved hands.

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Notes to slide 36
  • Pressure regulating valves allow spraying at
    constant flow and serve as well as anti-drip
    devices.
  • Example CFValves from G.A.T.E. (USA)
  • Material Delrin (Plastic), weight 19 grams, ISO
    9002 certified
  • They come in four sizes
  • Colour-code Pre-set pressure
  • YELLOW 1.0 bar (14.5 psi)
  • RED 1.5 bar (21.0 psi)
  • BLUE 2.0 bar (29.0 psi)
  • GREEN 3.0 bar (43.5 psi)
  • Assembly Spray lance - Nozzle body Filter
    CFValve Nozzle
  • Result More uniform spray pattern, reduce of
    waste, reduce of drift potential

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52
Notes to slide 37
  • Drift control nozzles are becoming increasingly
    important. They where developed in Europe and the
    USA based on environmental concerns. In
    countries where regulations governing spraying in
    relation to drift risk exist, they offer farmers
    a cheaper drift control option than low drift
    sprayers, and can allow spraying in higher wind
    conditions than might normally be possible,
    thereby increasing flexibility. Where there are
    guidelines covering the spraying of pesticides
    adjacent to water courses with minimum buffer
    zones required, low drift nozzles allow the user
    to spray closer to the water bodies than is
    otherwise permitted, and there is an officially
    approved star rating system for different
    manufacturers low drift nozzles the higher the
    number of stars, the greater is the flexibility
    to reduce the buffer zone.

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