Equipment II

Nozzles

Nozzles Selection

Low Drift Nozzles

Swath Width

Nozzles• Regulate Flow (GPM)

• Atomize liquid into droplets

• Pattern

Nozzle Materials

Brass Plastic

Stainless Steel

Ceramic

Tungsten carbide

Aluminum

Floodjet

Even Flat Fan

Broadjets/BoombustersBoominators

Tapered Flat Fan

8003

80o fan 0.3 GPM@ 40 psi

0.3 GPM = ? ounces

38.4 ounces

Nozzle selectionpage 86

GPA x MPH x W

5940 GPM =

30 GPA X 5 MPH X 20”

59400.5 GPM =

 

Drift

Why Interest in Drift?

• Spotty Pest Control• Wasted chemicals• Off-target damage• Higher costs - $$$• Environmental impact

– Water and Air Quality

• Public more aware of pesticide concerns! (Negative)

• Spraying in more populated areas? (Suburbs)

2%8%

24%

33%

33% Equipment

Drift

Tank Mix

Wrong Field

Off Label

Source: Farmland Insurance 1996

23%

38%

26%

13%Nozzle

Applicator

Physical

Other

WHAT IS DRIFT?• Movement of ..

• spray particles • vapors off-target

• Less effective control • Possible injury to susceptible

vegetation and wildlife.

Spray Characteristics Affecting Drift• Chemical

Properties

• Formulation

• Evaporation

• Drop size

• Volume

Equipment & Application Factors Affecting Drift

- Nozzle type

– Nozzle size

– Nozzle orientation

– Nozzle pressure

– Height of release

87% reduction in drift prone droplets < 150 microns

Low Drift Nozzles

Low Drift Nozzles

• Larger droplets • At the same flow rate • Same operating pressure than standard flat-

fan (SFF) nozzles.

PRE-ORIFICE

REDUCES LIQUID VELOCITY Reduces small droplets (200 microns) by 50 to 80 percent

Drift Potential is Influenced by:

Droplet Spectrum (Range - big to small)

Comparison of Micron Sizes(approximate)

• 2000 m

• 850 m

• 420 m

• 300 m

• 150 m

• 100 m

#2 Pencil lead

paper clip

staple

toothbrush bristle

sewing thread

human hair

Driftability of Spray Driftability of Spray Droplets of Varying Sizes Droplets of Varying Sizes

10

fee

t 1

0 fe

et

Crosswind @ 3 mphCrosswind @ 3 mph

20 20

50 50

100 100

150 150

400400

8 ft 22 ft. 48 ft. 178 ft. 1065 ft. 8 ft 22 ft. 48 ft. 178 ft. 1065 ft.

\

Nozzle Drop Size ClassesNozzle Drop Size Classes

Very Fine to Fine < 200 um

Medium to Coarse – 200 to 450 um

Very Coarse > 450 um

Tip Spray Selection by Drop Size

Turbo TeeJet Flat-fan

Secondary Break-UpSecondary Break-UpDroplet elongation and fracture produces small Droplet elongation and fracture produces small

dropletsdroplets

\

Sources of Spray Mist or Fines Sources of Spray Mist or Fines Secondary Break-UpSecondary Break-Up

Droplet elongation and fracture Droplet elongation and fracture produces small droplets produces small droplets

\

Sources of Spray Mist or Fines Sources of Spray Mist or Fines Aerodynamic EffectsAerodynamic Effects

Air friction due to speed of the application Air friction due to speed of the application vehicle causes additional production of vehicle causes additional production of

small dropletssmall droplets

Sources of Spray Mist or Fines Sources of Spray Mist or Fines Aerodynamic EffectsAerodynamic Effects

Air friction due to speed of the application Air friction due to speed of the application vehicle is dependent upon the nozzle vehicle is dependent upon the nozzle

orientation angle. 90orientation angle. 90oo produces the greatest produces the greatest number of small dropletsnumber of small droplets

Movement

Hypro Ultra Low Drift

• 15 – 100 psi range

• 120o pattern

• $4.00 - $5.00

• Fits Standard fan tip caps

Spraying Systems DG TeeJet

• Removable Pre-orifice

• $4.50 - $5.00

• Spraying Systems• Flat Fan pattern• wider range of pressures 15

to 90 psi • produce fewer drift-prone

droplets compared to SFF.• Fits standard TeeJet

Nozzle caps

Turbo Tee Jet

Turbo Flood Nozzles

• Spraying Systems

• Clog resistant

• Wide angle

Conventional SSF

Turbo Tee Jet

25 psi at 30” spacings. 20” height

Turbo Drop Nozzle

• Greenleaf Technologies• Air Induction (AI)• Venturi pressure reduction

chamber• Droplets are filled with air

and expand when leaving tip

• Better coverage• $10.00

Tee Jet Air Induction

TeeJet Banding Tip $7 - $8.00

$6.00

• Operates at higher psi to work efficiently

• Needs special caps

CP Nozzle• Dial-an-orifice• Pattern similar to flood jet• Mainly used by aerial

sprayers

Temperature & humidity Air movement (direction and velocity)Air stability/inversionsTopography

Weather and Other Factors Affecting Drift

Evaporation of Droplets

Wind

High Relative HumidityLow Temperature

Low Relative HumidityHigh Temperature

Fal

l Dis

tanc

e

Evaporation and Deceleration of Various Size Droplets*

DropletDiameter(microns)

TerminalVelocity(ft/sec)

Final Dropdiameter(microns)

Time toevaporate

(sec)

Decelerationdistance

(in)

20 .04 7 0.3 <1

50 .25 17 1.8 3

100 .91 33 7 9

150 1.7 50 16 16

200 2.4 67 29 25

*Conditions assumed: 90 F, 36% R.H., 25 psi., 3.75% pesticide solution

Strategies to Reduce Drift

• Avoid adverse weather conditions

• Consider using buffer zones

• Consider using new technologies:– drift reduction nozzles– drift reduction additives– shields, electrostatics, air-assist

• Increase drop size

• Increase flow rates - higher application volumes• Use lower pressures

• Use lower spray (boom) heights

Polymer Drift Supressants produce larger droplets Polymer Drift Supressants produce larger droplets across the spectrum, but will decrease the fan angle. across the spectrum, but will decrease the fan angle. Nozzles on the Left have the polymer supressant.Nozzles on the Left have the polymer supressant.

Adjuvant Influence on Spray PatternAdjuvant Influence on Spray Pattern (Note Fan Angle)(Note Fan Angle)

LI 700LI 700 R-11R-11

Tallow Tallow AmineAmine

WaterWater

Adjuvant Influence on Spray PatternAdjuvant Influence on Spray Pattern (Note Uniformity of Pattern)(Note Uniformity of Pattern)

Source: FRI New ZealandSource: FRI New Zealand

Shielded Sprayers

Shrouded Sprayers