Feb04 hotspot success for SPRAY

Natural production of food crops by "universal organic farming" is nowadays probably an unattainable ideal against harsh reality of commercial pressures by supermarket-driven consumer demands for year-round provision of competitively priced quality and quantity produce. The target for attention must be reduced usage of agrochemicals - not because they pose end-point consumer hazards but to reduce farming overheads.

SPRAY = "Stimulated Precision Ranging of Applications deliverY" won DTI SMART Awards for FRED as a creative concept to reduce the ecological intrusion of intensive arable farming which is increasingly perceived to impose unacceptable burdens on hedgerow wildlife whilst at the same time being seen as "safer" than transgenic crops.

FRED = "Flow Research Evaluation Diagnostics" Ltd was founded 1988 as campus start-up SME by Neale Thomas to channel commercial consultancies, later also as platform for 4 DTI SMART Awards on WATER & SPRAY envirotech principles now as near market protoproducts in urgent need of champions for commercial carrythrough.

Neale Thomas - graduated in aeronautics, doctored in oceanography, postdoctored in nuclear / civil engineering flows, specialising in military / industrial / environmental heat, turbulence and two-phase transport dynamics. 100+ outputs plus 25+ reports, also 20 PhD and 20 MSc projects, with 10 years faculty finals core course teaching

philosophy- soundly scienced simple sufficiency surpasses superficially sophisticated simulation in significance for feasibility formulations and technical troubleshooting ... indeed individual imagination inspires ingenious innovation which by implication is inaccessible to consensus correlation capabilities of complex computational codes.

principle - biological impact scales pretty much on drop number delivered accessibly for deposition onto susceptible surfaces inside the crop canopy and strongly favours small drops under a practical constraint on minimum drop size dictated by losses as uncontrolled windrift. Larger drops are wasted in plummeting through the canopy.

position - flat fan nozzles have been unchanging sector standard for over a decade but are being displaced as leading specialist suppliers increasingly supplement their established product ranges with airmix nozzles and airbag systems - neither serving as sensibly scienced strategy for achievement of arable advantage in market margin.

premise - airmix nozzles don't supply a solution for radically reduced chemical usage ... hollow drop rupture is an uncharacterised phenomenon and reliance on internally induced bubbles by air compressor or venturi induction is energetically unappealing.

premise - airbag booms don't deliver an appropriate answer .... striving to reassert control after droplet dispersive emission from fan fragmentation necessarily incurs airflow substantially exceeding that intercepted by the spray sheet resulting in costly equipment replacements incorporating cumbersome ducted fans and boom bags.

SPRAY - emergent protoproducts spawned via DTI SMART Awards supplemented subsequently by ongoing in-house RDT upgrade extending to case study evaluations in FRED's Powergen windunnel and independent verification of physical performance as commissioned consultancy with Silsoe Research Institute - in all a 250k program of investment resulting in technoprospect revolutionising market margin for the sector


SPRAY nozzle control from FRED spawned via SMART Awards from DTI 1993-5



airjet induction- quasi-coplanar matched momentum sheet airjet impinged on breaking edge of liquid flat fanjet stretches and thins it resulting in smaller fragmentation drops. Flexural reaction of liquid momentum excites kHz galloping that sheds a train of airjet vortices transporting clustered droplets with greatly enhanced resistance to winddrift

realisation - cluster macroporosity reduces crosswind interstitial velocity - doubling spray sheet open area allows quartering of drop size for fixed fractional scavenging. Cluster jitter aids precipitation patterns augmented by airjet agitation of compliant crop canopy - actively assists penetrative droplet dispersion onto sensitive surface sites.

manifestation- 0.6 L/min per liquid nozzle on 0.5m boom spacing +4m/s tractor speed = 50 L/ha application. Liquid exit speed 10m/s down to 3+ m/s at fragmentation locus and momentum matched induction met by 100 m/s airjet or 0.2 barg (75% loss) - so 6kW Rootes blower (900m3/h at 0.2 barg) serves 20m boom at 375L/min per airjet

attraction - essential simplicity of fabrication / assembly hybridising standard flat fan liquid nozzle with fishtail airjet nozzle, either as retrofit attachment or compound unit. Also zero-maintenance rugged Rootes blowers against compressors used with airmix nozzles and compactness against bulkiness of ducted fans used with airbag booms.

financial - SPRAY's direct cost 2500 dominated by 6kW blower 1500 retail + uniset 40 airjet nozzles 1000 reducible respectively to 1000 (trade) + 250 (bulk/in-house) As (min) price guidelines airmix 5000 and airbag 10000 respectively give chemical savings up to 20% and 40% on traditional standard systems. With airjet saving 80+% (halved dropsize and windrift) SPRAY could be priced 20000 or x8 to x16 direct cost.

market - 10% UK as arable land served by 10k sprayers each for 1kha- 10 days spray at 4m/s (10m boom) and 4 sprays per crop. With 5-year unit lifetime 2000 sales pa be worth 40Mpa (20k per unit) against SPRAY's direct cost 2.5Mpa (1250/unit). UK market is 10% Euro market and 1% World market - so 10% + 1% + 0.1% be very tidy!

economics - as guideline measure consider that 50M UK consumers spend 400pa on arable-derived products - 20Bpa equivalent to 2000/ha of which farmers spend 200/ha on chemicals to get maybe 600/ha. Prospect of 80+% less chemical calls for radically rethought strategy as leasing for % savings on 2Bpa chemicals market..

SPRAY accesses generic new capability for cheaper fine sprays to 50+VMD - a paper project on cyclical flash cooling showed it beat on energy hydraulic and airmix options