ENVIRONMENTAL ENGINEER Health, Engineering and Sciences (HES) - PowerPoint PPT Presentation

Ian P. Craig BSc MSc PhD Cranfield ENVIRONMENTAL ENGINEER Health, Engineering and Sciences (HES) Centre for Pesticide Application and Safety (C-PAS) University of Southern Queensland (USQ) Gatton Campus, University of Queensland (UQG) craigi@usq.edu.au mob 0419 636691

Rotary Nozzle Development and Testing

Edward Bals Ligament formation Sheet Breakup Controlled Droplet Application (CDA) Direct Droplet Formation Graham Matthews possible at very low flowrates

Malvern 2600 laser diffraction analyser Stacked discs have fine ‘v’ grooves which are prone to blockage • A row of teeth is only possible about every 5mm (with each cupped disc) • Rather than a groove leading to a tooth arrangement, the SP nozzle has • individual pins every ~1mm …. so ~5x flowrate should be available

IN 2003, IN 2003, I PATENTED A I PATENTED A NEW NEW “SPINNING PINS” NOZZLE “SPINNING PINS” NOZZLE FOR AERIAL FOR AERIAL APPLICATION OF PESTICIDES, (WHICH I APPLICATION OF PESTICIDES, (WHICH I HOPE HOPE WILL HELP WILL HELP WORLD FOOD SECURITY). WORLD FOOD SECURITY). so you see - I’m not actually all that green ! 22

Schematic diagram (based on stroboscopic light observation) of near-monosized droplet formation, via controlled fluid ligament breakup Craig, I. 2003. THE SPINNING PINS (SP) Nozzle; A New Controlled Droplet Applicator for Aircraft. IP Australia Application Number AU200163597B2 Patent Number 779967. Published 2003.02.27 Craig, I.P. Hewitt, A, and Terry, H. 2014. Rotary atomiser design requirements for optimum pesticide application efficiency. 23 Crop Protection 66 34-39

About 3 million tonnes pesticides (ai) produced globally every year ~ application efficiency (AE) is thought to be substantially less than 1% 1% ? <0.1% AE <0.1% (100s) (droplet #/cm 2 ) (1000s) (10s) 25

200µm Dr Steve Parkin

BCPC ‘medium’ spray (ie. VMD 200µm) ~ has 10% ‘driftables’ (ie. vol < 100µm) the aim with sharp pins is reduce this to zero Droplet size distribution (triangles) from a spinning disc with sharp teeth, recorded using a PMS OAP-260 probe. For comparison, computer generated spectra with VMD 200µm have been added. The solid line represents a 200µm VMD spray with log span 0.1, typical for spinning discs. The dashed line represents a 200 µm VMD spray with log span 0.25, typical for hydraulic nozzles, and rotary cage atomisers such as the Micronair AU5000.

Best Management Practice (BMP) for the Australian Cotton Industry • getting pilots to understand the effect of the Australian summer Dusk Surface Temperature Inversion (DUSTI), so they that they avoid spraying at dusk ! Craig, I.P. 2004 The GDS model – a rapid computational technique for the calculation of aircraft HIGH TURBULENCE HIGH TURBULENCE HIGH TURBULENCE u u u spray drift buffer distances. Computers and Electronics in v s /u v s /u v s /u u*/u u*/u u*/u Agriculture 43 3 235-250 thin tail thin tail thin tail h h h x peak x peak x peak h = release height h = release height h = release height downwind u = mean windspeed u = mean windspeed u = mean windspeed deposition can be u* = RMS vertical air motion u* = RMS vertical air motion u* = RMS vertical air motion plume centreline plume centreline plume centreline v s = sedimentation velocity v s = sedimentation velocity v s = sedimentation velocity up to 20 times u*/u = turbulence intensity, i u*/u = turbulence intensity, i u*/u = turbulence intensity, i greater in highly stable conditions LOW TURBULENCE LOW TURBULENCE LOW TURBULENCE u u u thick tail thick tail thick tail h h h x peak x peak x peak http://www.depi.vic.gov.au/agriculture-and-food/farm-management/chemical-use/agricultural-chemical- use/spraying-spray-drift-and-off-target-damage/surface-temperature-inversions