Laser-based Characterisation of Agricultural Sprays

1. PLC Z-direction Temp. display Fluid level controller Power supply Liquid temperature controller Y- direction X-direction Y SPRAY UNIT Z X OSCILLOSCOPE Pt 100 L.C.D. Pt 100 pump mixing cooling heating volume control system R E C E I V E R liquid level sensor RSA T R A N S M I T T E R Pressure regulator 3 bar FIBRE DRIVE LASER Measuring signals Control signals 3 phase power supply Laser-based Characterisation of Agricultural Sprays D. NUYTTENS & B. SONCK Ministry of the Flemish Community - Agricultural Research Centre (CLO-DVL), Merelbeke (Belgium) Contact:d.nuyttens@clo.fgov.be M. DE SCHAMPHELEIRE & W. STEURBAUT Department of Crop Protection, University Ghent(Belgium) K. BAETENS, P. VERBOVEN, B. NICOLAI & H. RAMON Department of Agro-Engineering and Economics, Catholic University of Leuven (Belgium) Objective Measuring the characteristics (droplets: diameter & velocity) of spray nozzles with a PDPA laser based set-up Materials and methods The measuring set-up inside the acclimatization room PDPA laser The spray unit Three nozzles are selected for each nozzle-pressure combination to be tested. Each nozzle is tested three times. Each scan yields data for at least 10 000 droplets. The BCPC reference nozzle fine-medium (Lurmark F 110 03 @ 3 bar) is used as a reference nozzle to check for the repeatability of the measurements and the measuring equipment. Measurements are made by spraying water with a temperature of about 20 °C. Environmental conditions are kept constant at a temperature of about 20°C and a relative humidity of 60-70%. The nozzle is positioned 50 cm above the measuring point of the PDPA. A different scan trajectory is programmed depending on the type of nozzle to enable the whole of the spray fan to be sampled. 3-D positioning system Some results Volumetric droplet size distribution for different Albuz nozzles Droplet size characteristicsDv0.1, Dv0.25, VMD, Dv0.75 and Dv0.9 for different Hardi nozzles and the 5 BCPC reference nozzles Cumulative volumetric droplet velocity distribution for different Hardi nozzles and the 5 BCPC reference nozzles Droplet characteristics (average ± standard deviation) of 32 nozzle-pressure combinations BCPC: BCPC spray quality class based on droplet size -     Dv0.1: 10 percent of the total volume is made up of drops with diameters smaller than this value (μm) -     VMD: Volume Median Diameter, 50 percent of the total volume is made up of drops with diameters smaller than this value (μm) -      Dv0.9: 90 percent of the total volume is made up of drops with diameters smaller than this value (μm) -      V100: Percentage of total volume of droplets smaller than 100 μm (%) -      V200: Percentage of total volume of droplets smaller than 200 μm (%) - D10, D20: Arithmetic mean diameter, Surface mean diameter, Volume mean diameter (μm) -     D30, D32: Sauter mean diameter, the diameter of a drop having the same volume to surface area ratio as the total volume of all the drops to the total surface area of all the drops (μm) -     NMD: Number mean diameter, 50% of the number of drops is smaller than this value (μm) -     RSF: Relative Span Factor -      Vvol50: 50 percent of the total spray volume is made of drops with velocities smaller than this value (m.s-1) This research was funded by the Ministry of the Flemish Community IWT-Vlaanderen and Federal Public Service Health, Food Chain Safety and Environment, DG Plants, Animals and Food.