Transcript PowerPoint-presentatie

Laser-based Characterisation of Agricultural Sprays
D. 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)
Objective
Measuring the characteristics (droplets: diameter & velocity) of spray nozzles with a PDPA laser based set-up
Materials and methods
Liquid
temperature
controller
Fluid
level
Temp.
display
OSCILLOSCOPE
The measuring set-up inside the
acclimatization room
Power
supply
controller
R
E
C
E
I
V
E
R
RSA
T
R
A
N
S
M
I
T
T
E
R
Pressure
regulator
FIBRE DRIVE
LASER
PDPA laser
3 bar
Measuring signals
PLC
Control signals
3 phase power supply
Z-direction
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 finemedium (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.
Y- direction
X-direction
Y
SPRAY
UNIT
Z
X
3-D positioning system
Some results
Volumetric droplet size distribution for different Albuz nozzles Droplet size characteristics Dv0.1, Dv0.25, VMD, Dv0.75 and Dv0.9 Cumulative volumetric droplet velocity distribution for different
for different Hardi nozzles and the 5 BCPC reference nozzles Hardi nozzles and the 5 BCPC reference nozzles
Droplet characteristics (average ± standard deviation) of 32 nozzlepressure combinations
BCPC:
-
Dv0.1:
VMD:
-
Dv0.9:
-
V100:
BCPC spray quality class based on droplet size
10 percent of the total volume is made up of drops with diameters smaller than this value (μm)
Volume Median Diameter, 50 percent of the total volume is made up of drops with diameters
smaller than this value (μm)
90 percent of the total volume is made up of drops with diameters smaller than this value (μm)
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)
the
D30, D32:
Sauter mean diameter, the diameter of a drop having the same volume to surface area ratio as
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:
(m.s-1)
50 percent of the total spray volume is made of drops with velocities smaller than this value
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.