Evaluation of Aeolian Sprayer System

• The project designed and manufactured a 2-part air knife that was attached to a 150mm rigid air pipe that also acted as a plenum chamber. This allowed 6 nozzles to be installed onto one side of an existing 2 row trailed sprayer. The Aeolian system produced finer droplets than the SFM system.
  • Aeolian system delivered smaller droplets homogenized throughout the airflow from ejector and high airspeed drag aided their transport into the bush whereas the SFM system that injected into low speed ducted airflow that moves the leaves more vigorously, exposing both sides of the leaf to be exposed to the spray.
  • Both systems provided excellent penetration at the higher application rate of 650 litres/Ha, which mimicked the typical ‘overdosing’ application of sulphur,, but penetration at the lower rate of 260litres/Ha, more commonplace with insecticide and pesticide applications, was more thorough with the SFM system.
  • Spray drift was more noticeable from the Aeolian system
  • A single nozzle was used at each air knife, not a pair as normal set up, but it was agreed that 2 liquid nozzles per air knife would not compromise matched momentum.
  • The practicality of incorporating Aeolian technology for bush spraying would provide a lighter assembly than the existing SFM system, use less energy and would facilitate the construction of multi-row sprayers.
  • However, the Aeolian system developed for these trials would need to be modified for 2 main reasons. Firstly, the blower (Roots M407) was far too noisy and a quieter model needs to be found. Secondly, although not insurmountable, the Aeolian nozzle assembly would need to incorporate physical adjustability to provide flexibility of positioning nozzles to allow growers to adapt the sprayer to suit all situations throughout the season and life of the blackcurrant bush.

Evaluate the use of existing Aeolian spray technology that had already been seen in arable crop research that Neale Thomas has developed and that has received awards, both environmental, (GB Inventions fair 1995) and commercial (DTi smart 92-94). The Aeolian system basically involves matching momentum at liquid fragmentation locus requiring velocity ratio at 30 or so. For example, liquid at 4 m/s  at fragmentation point requires air at 120 m/s. This system has not been evaluated in bush crops so it was SFM’s task to manufacture an air knife to the Aeolian specification and match this to an air delivery system.