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The TwinFluid crop sprayer is equipped with an automatic application rate and droplet size control system as standard. The section entitled "Operation of GreenStar sprayer control system" describes the settings of the nozzle output.
For manual spraying, the spraying pressure must be adjusted as follows in order to spray a specific quantity in liters/hectare:
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Select the required application rate in liters/hectare (e.g. 100 l/ha)
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Select the required driving speed (e.g. 8 km/h) using an ideal combination of engine speed and transmission ratio. Make allowances for the fact that an increase in driving speed may negatively affect penetration, transverse distribution and increase spray drift.
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Always check the driving speed! This may be done as follows:
1.
Mark out a distance of 100 m in the field
2.
With the tank half full of water, drive to the field
3.
Measure the time required for driving 100 m.
4.
Determine the driving speed on the basis of the table below:
Time required to drive 100 m in relation to the driving speed
| Time (s) |
120 |
90 |
72 |
60 |
51 |
45 |
40 |
36 |
| km/h |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
The speed can also be calculated as follows:
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Driving speed (km/h) = 360 ÷ time (sec)
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Next read the output per nozzle from the spray volume table (in this example 0.67 l/min). If a value different to those in the table is required, calculate this value as follows:
Nozzle output (l/min) = (l/ha x km/h x nozzle spacing):600
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Now read in the Twin Fluid nozzle output table which combination of liquid and air pressure must be set in order to achieve the required spray quality ("e.g. "Fine") and application rate (100 l/ha). For the AirJet 035/TKVS10 this could be a liquid pressure of 3.0 bar and an air pressure of 1.0 bar.
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Always calibrate the machine to allow for loss of pressure and nozzle wear!
The pressure indicated by pressure gauge or pressure sensor is higher than the spraying pressure on the nozzles because of pressure loss in the spray line and the presence of diaphragm valves in the nozzle holders.
Check the nozzle output with clean water. Set the liquid and air pressure found (e.g. 3 bar liquid and 1.0 bar air pressure) and collect the nozzle output in a measuring jug during 1 minute. Measure several nozzles and calculate the average. If the output is different from the table value (0.67 l/min), adjust the liquid pressure until the correct output per nozzle is achieved.
In this way, determine the pressure loss on the machine for various outputs and nozzles.
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When using conventional nozzles, proceed in the same way to set the application rate. To determine the spraying pressure, refer to the table of the corresponding nozzle in this section.
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