laser-based characterisation of agricultural sprays d. nuyttens & b. sonck ministry of the...
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Laser-based Characterisation of Agricultural SpraysLaser-based Characterisation of Agricultural SpraysD. NUYTTENS & B. SONCK
Ministry of the Flemish Community - Agricultural Research Centre (CLO-DVL), Merelbeke (Belgium)
Contact: [email protected]
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)
ObjectiveObjectiveMeasuring the characteristics (droplets: diameter & velocity) of spray nozzles with a PDPA laser based set-up
Materials and methodsMaterials and methods
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.
Some resultsSome results Volumetric droplet size distribution for different Albuz nozzles Droplet size characteristics Dv0.1, Dv0.25, VMD, Dv0.75 and Dv0.9
for different Hardi nozzles and the 5 BCPC reference nozzlesCumulative volumetric droplet velocity distribution for different Hardi nozzles and the 5 BCPC reference nozzles
The measuring set-up inside the acclimatization room
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.
RSA
OSCILLOSCOPE
FIBRE DRIVE LASER
TRANSMITTER
RECEIVER
3 bar
Liquid temperature
controller
Fluid level
controller
Power supply
Temp. display
Measuring signals
Control signals
3 phase power supply
Pressure regulator
PLC
SPRAYUNIT
Y- direction
X-direction
Y
X
Z
Z-direction
The spray unit
PDPA laser
3-D positioning system
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)
Droplet characteristics (average ± standard deviation) of 32 nozzle-pressure combinations