Context
The nozzle is one of the key elements of the application of plant protection products (PPP) by spraying. Of its performances depend the success and efficiency of the treatment.There are several tools to assess the performances of spraying nozzles : flowrate, transversal distribution and distribution of droplets’ size. These quality parameters will develop according to the nozzles’ wear and should therefore be good performance indicators.
The relevance of these parameters, their correlation / interaction, their comparison are so many fields being unexplored up to now. However, some of them are already used daily within the framework of the technical inspection and some empirical and not validated tolerance limits were fixed.
Objectives
The project aims at studying and compare the three main quality parameters of spraying nozzles : the flowrate, the distribution and droplets arrangement.The parameters are measured regularly during a forced utilization of the nozzles, in order to observe their evolution.
The measuring methods of the parameters and the accelerated wear process are in accordance with standard ISO 5682-1 : “Crop protection equipment – Spraying equipment – Part 1 : Testing methods of spraying nozzles”.
The research presently concerns flat fan nozzles since this is the most used type (used by more than 90 % of the operators). On the other hand, within the flat fan nozzles family, different models (classical, with calibration disc and with air induction) and component materials (ceramic, plastic, and stainless steel) are studied.
Description of tasks
The three main quality parameters of the nozzles are measured in the laboratory. The following information and sizes are retained.Flowrate measurement
The nozzles flowrate is measured individually in mastered conditions (pressure) by means of an electronic testing device. The main variable retained is the deviation between the measured flowrate and the nominal flowrate (= flowrate of a new nozzle at the same pressure). The more nozzles are worn, the more the deviation is important.
Measurement of the transversal distribution
The transversal distribution is measured in mastered conditions (pressure, boom height, air temperature and moisture) by means of a spray patternator. The distribution is measured either individually, or for several nozzles spraying simultaneously. The main variable retained is the Coefficient of Variation of the spread volumes (CV).
Measurement of the droplets’ size
The distribution of the droplets’ size is measured on deposit (wastes ?) in mastered conditions (pressure, boom height, real speed volume / hectare, air temperature and moisture. A measuring chain based on digital image analysis makes it possible to determine a set of variables : representative diameters of the distribution (NMD, SMD, ND10, …), the covering rate, the number of impacts, …
Results obtained
Up to now, comparative studies showed that the evolution of the different quality parameters is not correlated to the nozzles wear, that some parameters / variables are best indicators of the “nozzles wear rate” and at last, that the wear dynamics observed in the laboratory does not correspond to the one observed in the field.Partners
AR Lublin, ISO, CENCRAW off coordinator
HUYGHEBAERT Bruno (Attaché scientifique)Département Génie rural
Chaussée de Namur, 146
B-5030 Gembloux
Téléphone direct :62 71 67
Téléphone département :+ 32(81) 61 25 01
Fax département :+ 32(81) 61 58 47
E-mail :huyghebaert@cra.wallonie.be
MOSTADE Olivier (Attaché scientifique)
Département Génie rural
Chaussée de Namur, 146
B-5030 Gembloux
Téléphone direct :62 71 46
Téléphone département :+ 32(81) 61 25 01
Fax département :+ 32(81) 61 58 47
E-mail :mostade@cra.wallonie.be
Funding
- CRA-W - Walloon Agricultural Research Centre
Team
