engleski

Influence of the spraying pressure and nozzle design on spray disintegration

The design of a sprayer nozzle used for chemical plant protection should fulfill technical, efficiency, and environmental demands. The level of meeting these demands as well as their optimizing can be best evaluated by gathering information during the machine operation. This paper analyses functional accuracy concerning spray coverage of upper and lower leaf surfaces in case of use of different nozzle designs operating at varied working pressures. The research was conducted at the following spraying pressures: 0.1, 0.2, 0.3, 0.4, and 0.5 MPa for three TeeJet nozzle designs, which are TeeJet 11002, 11004, and 11006. The average coverage in percentage terms and the average droplet density of the droplet impact on upper and lower sides of wheat leaves are determined. The quality of the disintegrated spray deposition is established by assessing droplet impacts on water sensitive paper. The best average upper leaf side coverage is achieved by a TeeJet 11006 nozzle (27.247%) and somewhat weaker results are achieved by a TeeJet 11004 nozzle (24.755%) and a TeeJet nozzle 11002 (22.355%). The average coverage of upper leaf sides is insufficient since the spray is present only in traces. In case when spray is applied by TeeJet 11006 nozzles the achieved coverage of upper leaf sides is 6.392%. A TeeJet 11004 nozzle achieved the coverage of 3.629%, and the weakest result by far is achieved by TeeJet 11002 nozzle (0.27%). Higher spraying pressures usually result in a better upper and lower wheat leaf sides coverage, and at the same time it produces a higher level of droplet disintegration, which is not the case for TeeJet 11002 and 11004 but for upper leaf sides. The results of a derived regression analysis show the presence of a square dependence between the spraying pressure and area impact density on a leaf as well as a dependence of pressure and leaf coverage for all the aforementioned nozzle types.

spraying pressure ; nozzle ; spray ; disintegration ; droplet ; coverage ; surface density ; sprayer

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