Nozzle classification system in Japan based on the relative spray ...

<strong>Nozzle</strong> <strong>classification</strong> <strong>system</strong> <strong>in</strong> <strong>Japan</strong> <strong>based</strong> on the relative spray
drift potential
Geng Bai 1 , Kazuhiro Nakano 1 *, Tomomichi Mizukami 2 , Sumihiko Miyahara 2 ,
Sh<strong>in</strong>taroh Ohashi 1 , Ken-ichi Takizawa 1 , Haijun Yan 3
1 Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050 Nishi-ku,
Niigata 950-2181, <strong>Japan</strong>
2 Institute of Agricultural Mach<strong>in</strong>ery, 1-40-2 Nissh<strong>in</strong>, Kita-ku, Saitama 331-8537, <strong>Japan</strong>
3
College of Water Resources and Civil Eng<strong>in</strong>eer<strong>in</strong>g, Ch<strong>in</strong>a Agricultural University, No. 17
Ts<strong>in</strong>ghua East Road, Beij<strong>in</strong>g 100083, Ch<strong>in</strong>a
*Correspond<strong>in</strong>g author. Email: knakano@agr.niigata-u.ac.jp
Abstract
European spray nozzle drift <strong>classification</strong>s have made the objective evaluations of the drift
reduction performance with different nozzle and operat<strong>in</strong>g parameters available <strong>in</strong> certa<strong>in</strong>
areas. Drift Potential Index Reduction Percentage (DIXRP) of one series of drift reduction
nozzles us<strong>in</strong>g <strong>in</strong> <strong>Japan</strong> were <strong>in</strong>vestigated by the w<strong>in</strong>d tunnel test. Based on the reference
spray, most of the YAMAHO KIRINASHI ES nozzles had good DIXRP values above 50%
under <strong>in</strong>vestigated conditions. Additionally, DIXRP values were above 80% when the nozzle
height was 0.3m except ES05. The large droplet diameter, the high droplet velocity and the
low recommended nozzle height could be considered as important factors that can achieve
the good performance of drift reduction ability. Besides, the DIXRP value was proportional to
the nozzle size and <strong>in</strong>versely proportional to the nozzle height. The relationship between
DIXRP value and the nozzle pressure was not obvious.
Key words: drift, <strong>classification</strong>, nozzle, w<strong>in</strong>d tunnel
1. Introduction
The spray drift of the agricultural sprayers has been attracted much attention <strong>in</strong> <strong>Japan</strong>
because of the <strong>in</strong>fluence on neighbor<strong>in</strong>g residents, pollution of the nearby crops and
contam<strong>in</strong>ation of the adjacent water (<strong>Japan</strong> Plant Protection Association, 2009).
The measurement of the relative drift potential by the w<strong>in</strong>d tunnel test was proved to be a
valuable alternative to the field measurement of the drift potential for evaluat<strong>in</strong>g the drift
reduc<strong>in</strong>g performance of the spray nozzles (Nuyttens et al., 2010). Compar<strong>in</strong>g to the field drift
experiment which could evaluate the drift reduction performance of the whole spray <strong>system</strong>,
the w<strong>in</strong>d tunnel test provides a repeatable and economical way to measure the relative drift
reduction capacities of the nozzles under different nozzle types, sizes, pressures, heights and
w<strong>in</strong>d speeds. However, from the literature cited (<strong>Japan</strong> Plant Protection Association, 2009),
the w<strong>in</strong>d tunnel test mentioned above has not been carried out <strong>in</strong> <strong>Japan</strong> where the operat<strong>in</strong>g

parameters of the nozzles are different from the European nozzles.
In this study, one series of the drift reduction nozzles under different nozzle-pressure
comb<strong>in</strong>ations were tested <strong>in</strong> the w<strong>in</strong>d tunnel <strong>in</strong> order to estimate the drift reduction
performance <strong>based</strong> on one reference spray. Additionally, the <strong>in</strong>fluences of the nozzle size,
pressure and height on the DPRP values were also <strong>in</strong>vestigated.
2. Materials and methods
2.1 W<strong>in</strong>d tunnel parameters and measur<strong>in</strong>g protocol
The w<strong>in</strong>d tunnel experiment was carried out <strong>in</strong> the Bio-oriented Technology Research
Advancement Institution (BRAIN), Saitama city, <strong>Japan</strong>. The dimensions of the w<strong>in</strong>d tunnel
were illustrated <strong>in</strong> Fig. 1. To obta<strong>in</strong> the vertical deposits of each nozzle-pressure comb<strong>in</strong>ation
under different nozzle heights at the same time, the nozzle was <strong>in</strong>stalled at 1.2m above the
floor and 6 polyethylene l<strong>in</strong>es (V 1 ~V 6 ) were placed horizontally across the w<strong>in</strong>d tunnel 2m
downw<strong>in</strong>d with the heights from 0.7m to 1.2m at an <strong>in</strong>terval of 0.1m, respectively. A tracer
(Solium fluoresce<strong>in</strong>, 200ppm) and a non-ionic surfactant (Tween 20, 0.1%) were used <strong>in</strong> this
study. After spray<strong>in</strong>g, the collector l<strong>in</strong>es were washed <strong>in</strong> 100ml de-ionized water and the liquid
was taken to measure the tracer concentration value. The volume of the spray liquid
deposited on each collector l<strong>in</strong>e was obta<strong>in</strong>ed by calculation.
FIGURE 1: The dimensions of the w<strong>in</strong>d tunnel and the sketch of drift potential
measurement <strong>in</strong> the w<strong>in</strong>d tunnel by us<strong>in</strong>g polyethylene l<strong>in</strong>es
Table 1 showed the nozzle <strong>in</strong>formation and environmental parameters of the nozzles
<strong>in</strong>vestigated <strong>in</strong> this study. The Hypro ISO F 110 03 standard flat fan nozzle with a nozzle
pressure of 0.3MPa and a nozzle height of 0.5m was used as the reference spray. The
YAMAHO KIRINASHI ES nozzles were recommended to use with a nozzle height between
0.3~0.4m. The spray time of the nozzle-pressure comb<strong>in</strong>ations was 10s when the flow rate
was above 0.8L m<strong>in</strong> -1 and 20s for the other comb<strong>in</strong>ations.

TABLE 1: Overview of the <strong>in</strong>vestigated nozzle-pressure comb<strong>in</strong>ation and the environment
parameters <strong>in</strong> the drift experiment
<strong>Nozzle</strong> <strong>in</strong>formation Environment parameters [3]
Notation [1] Flow rate [2] ,
L m<strong>in</strong> -1
Pressure,
MPa
Air
temperature,
℃
Water
temperature,
℃
Relative
humidity,
%
HS03-0.30 1.20 0.30 22.4 20.6 57.3
ES05-1.00 0.35 1.00 23.7 21.6 50.7
ES05-1.50 0.43 1.50 27.0 22.8 46.7
ES06-1.00 0.51 1.00 25.4 22.0 53.3
ES06-1.50 0.62 1.50 25.6 22.2 43.7
ES07-1.00 0.68 1.00 27.0 22.8 37.7
ES07-1.50 0.83 1.50 21.8 20.7 78.0
ES08-1.00 0.90 1.00 22.2 20.7 71.7
ES08-1.50 1.10 1.50 26.5 22.0 42.7
ES09-1.00 1.13 1.00 25.8 21.2 45.3
ES09-1.50 1.39 1.50 23.1 31.7 42.5
ES10-1.00 1.41 1.00 24.3 21.0 49.0
ES10-1.50 1.73 1.50 17.5 17.6 66.7
ES11-1.00 1.69 1.00 17.4 17.5 70.3
ES11-1.50 2.07 1.50 22.0 19.3 60.0
[1]
HS03, Hypro ISO F 110 03 standard flat fan nozzle; ES, YAMAHO KIRINASHI ES nozzle; [2] The flow
rate data were cited from manufacturer data; [3] The values of the environment parameters were
obta<strong>in</strong>ed by averag<strong>in</strong>g the value of three repetitions.
2.2 Index calculation and nozzle drift <strong>classification</strong>
In this study, the DIXRP value was calculated to estimate the drift reduction performance of
the <strong>in</strong>vestigated nozzle-pressure comb<strong>in</strong>ations (Herbst, 2001). In the calculation process, the
nozzle heights were 0.5m for the reference spray while the nozzle heights were 0.4m and
0.3m for the ES series nozzles <strong>based</strong> on the manufacturer recommendation. The details of
the calculation equations could be found <strong>in</strong> the above reference. The virtual floors (h=0m) <strong>in</strong>
the <strong>in</strong>dex calculation were assumed to be 0.6m, 0.7m and 0.8m above the floor of the w<strong>in</strong>d
tunnel correspond<strong>in</strong>g to the three nozzle heights, respectively. Thus, the nozzle heights which
equal the vertical distance between the nozzle and the lowest collector l<strong>in</strong>e were 0.5m, 0.4m
and 0.3m. The nozzle drift <strong>classification</strong> for the nozzle-pressure comb<strong>in</strong>ations <strong>in</strong>vestigated
was carried out follow<strong>in</strong>g the methods adopted by German Federal Biological Research
Centre for Agriculture and Forestry Braunschweig (BBA) (Herbst, 2001).

Drift Potential Index
Reduction Percentage, %
Drift Potential Index
Reduction Percentage, %
3. Results and discussion
The DIXRP values of ES nozzle and the correspond<strong>in</strong>g standard errors with different nozzle
sizes were shown <strong>in</strong> Fig. 2.and 3. Except ES05 nozzles, the DIXRP values of different
nozzle-pressure comb<strong>in</strong>ations experienced a gentle <strong>in</strong>crease as the nozzle sizes <strong>in</strong>creased.
The reason why the <strong>in</strong>crease was not obvious could be that compar<strong>in</strong>g with other type of
nozzles, this type of nozzle had a relatively steady volume median diameter with different
nozzle sizes. Based on the manufacturer data, the average value of the volume median
diameter of the ES nozzle was 300 μm. The <strong>in</strong>crease of the flow rate might also lead an
<strong>in</strong>crease of the drift reduction performance due to the normalization by divid<strong>in</strong>g the spray
output and the stronger resistance force to w<strong>in</strong>d produced by more dense spray. The
difference of the droplet sizes and the small flow rate might have contributed to the rapid
<strong>in</strong>crease of the DIXRP values from ES05 to ES06.
120.00
100.00
80.00
60.00
40.00
20.00
0.00
-20.00
1.0MPa
1.5MPa
ES05-1.00
ES07-1.00
ES09-1.00
ES11-1.00
ES06-1.50
ES08-1.50
ES10-1.50
ES06-1.00
ES08-1.00
ES10-1.00
ES05-1.50
ES07-1.50
ES09-1.50
ES11-1.50
FIGURE 2: DIXRP values obta<strong>in</strong>ed under different nozzle-pressure comb<strong>in</strong>ations of ES series
nozzle with the nozzle height of 0.3m
150.00
100.00
50.00
0.00
-50.00
-100.00
1.0MPa
1.5MPa
ES05-1.00
ES07-1.00
ES09-1.00
ES11-1.00
ES06-1.50
ES08-1.50
ES10-1.50
ES06-1.00
ES08-1.00
ES10-1.00
ES05-1.50
ES07-1.50
ES09-1.50
ES11-1.50
FIGURE 3: DIXRP values obta<strong>in</strong>ed under different nozzle-pressure comb<strong>in</strong>ations of ES series
nozzle with the nozzle height of 0.4m
Fig. 4 and 5 shows the <strong>in</strong>fluence of the nozzle pressure on the DIXRP values. Expect ES05,
the DIXRP values obta<strong>in</strong>ed under two nozzle pressures had just a little fluctuation to each
nozzle size and no trend was found. The ma<strong>in</strong> reasons might be that the <strong>in</strong>fluence of the
decrease of the droplet size on the DIXRP values was offset by the <strong>in</strong>crease of the flow rate
and the droplet velocity when the nozzle pressure <strong>in</strong>creased.

Drift Potential Index
Reduction Percentage, %
Drift Potential Index
Reduction Percentage, %
Drift Potential Index
Reduction Percentage, %
120.00
ES05-1.00 ES05-1.50
100.00
ES06-1.00 ES06-1.50
80.00
ES07-1.00 ES07-1.50
60.00
ES08-1.00 ES08-1.50
40.00
ES09-1.00 ES09-1.50
20.00
ES10-1.00 ES10-1.50
0.00
ES11-1.00 ES11-1.50
-20.00
05 06 07 08 09 10 11
FIGURE 4: DIXRP values obta<strong>in</strong>ed under different nozzle-pressure comb<strong>in</strong>ations of ES series
nozzle with the nozzle height of 0.3m
150.00
100.00
ES05-1.00
ES06-1.00
ES05-1.50
ES06-1.50
50.00
ES07-1.00
ES07-1.50
0.00
ES08-1.00
ES09-1.00
ES08-1.50
ES09-1.50
-50.00
ES10-1.00
ES10-1.50
-100.00
05 06 07 08 09 10 11
ES11-1.00
ES11-1.50
FIGURE 5: DIXRP values obta<strong>in</strong>ed under different nozzle-pressure comb<strong>in</strong>ations of ES series
nozzle with the nozzle height of 0.4m
The <strong>in</strong>fluence of the nozzle height on the DIXRP values under different nozzle heights were
illustrated <strong>in</strong> Fig. 6 and 7. The nozzle height was <strong>in</strong>versely proportional to the DIXRP although
the change of the nozzle height was just 0.1m. Compar<strong>in</strong>g with the <strong>in</strong>fluence of the nozzle
size and pressure on the DIXRP values, the nozzle height might be the most important factor
that <strong>in</strong>fluences the drift reduction ability.
120.00
100.00
80.00
60.00
40.00
20.00
ES05-0.3
ES06-0.3
ES07-0.3
ES08-0.3
ES09-0.3
ES10-0.3
ES11-0.3
ES05-0.4
ES06-0.4
ES07-0.4
ES08-0.4
ES09-0.4
ES10-0.4
ES11-0.4
0.00
05 06 07 08 09 10 11
FIGURE 6: DIXRP values obta<strong>in</strong>ed under different nozzle-pressure comb<strong>in</strong>ations of ES series
nozzle with the nozzle pressure of 1.0MPa

Drift Potential Index
Reduction Percentage, %
150.00
100.00
50.00
0.00
-50.00
ES05-0.3
ES06-0.3
ES07-0.3
ES08-0.3
ES09-0.3
ES10-0.3
ES11-0.3
ES05-0.4
ES06-0.4
ES07-0.4
ES08-0.4
ES09-0.4
ES10-0.4
ES11-0.4
-100.00
05 06 07 08 09 10 11
FIGURE 7: DIXRP values obta<strong>in</strong>ed under different nozzle-pressure comb<strong>in</strong>ations of ES series
nozzle with the nozzle pressure of 1.5MPa
Based on the <strong>classification</strong> method of the spray nozzle drift adopted by BBA, the ES series
nozzles (except ES05) with a nozzle height of 0.3m and 0.4m have drift reduction ability over
50%. Moreover, the drift reduction abilities of some ES nozzles could be over 90% with the
nozzle height of 0.3m.
4. Conclusions
The w<strong>in</strong>d tunnel tests for the relative drift spray of the nozzle used <strong>in</strong> <strong>Japan</strong> were carried out.
The results showed that the nozzle size and height had relatively obvious <strong>in</strong>fluence on the
DIXRP values while the relationship between the DIXRP value and the nozzle pressure was
not obta<strong>in</strong>ed. The ma<strong>in</strong> reason could be the relatively steady droplet size of the ES nozzles.
Based on the <strong>classification</strong> method adopted by BBA (Herbst, 2001), the ES nozzles (except
ES05) could be considered as the drift reduction nozzle with a drift reduction ability over 50%.
Additionally, some of the ES nozzles operated under a nozzle height of 0.3m could be
classified as the 90% reduction group <strong>in</strong> this study.
5. References
Herbst A. (2001). A method to determ<strong>in</strong>e spray drift potential from nozzles and its l<strong>in</strong>k to buffer
zone restrictions. ASAE International Meet<strong>in</strong>g Paper No. 01-1047, Sacramento, California.
<strong>Japan</strong> Plant Protection Association (2009). Menu of technical countermeasures for spray drift.
Nuyttens, D., De Schampheleire, M., Baetens, K., Brusselman, E., Dekeyser, D., Verboven, P.
(2010). Drift from field crop sprayers us<strong>in</strong>g an <strong>in</strong>tegrated approach: results of a 5 year study.
ASABE International Meet<strong>in</strong>g Paper No. 1009017, Pittsburgh, Pennsylvania.