According to the international standard EN-907-1997 and the national DSTU EN 907-2002, the working fluid supply system for sprayers should be equipped with a safety valve for safe operation. It should trigger when the permissible pressure is exceeded by more than 20%.
The design of the valve should prevent its reconfiguration by third parties. If unacceptable pressure figures are reached, the liquid should be redirected back into the tank, and the application process stops. The material for such a valve is usually glass-reinforced nylon or polypropylene.
In order to avoid funnels appearing in the tank anti-vortex devices of various designs are used (as example - fitting). Usually placed at the bottom of the tank and can constructively include a coarse filter. In this case, after each shift, it must be cleaned, but the load on the remaining filter elements of the working fluid supply system is reduced.
Usually, after the completion of the work shift, the sprayer should be washed, it is written in more detail in this article. For what on sprayers install tanks for clean water. Usually, there is a wash water tank, which is structurally connected to the system and a hand washing tank. There are different options for the placement of the flushing tanks, because none of them gives a definitive solution to the problem of water hammering when the sprayer moves.
According to international and national standards, handwash tanks should have a minimum volume of 15 liters and be completely isolated from the rest of the sprayer systems.
The internal structure of the sprayer tanks implies simplification of their cleaning - there are no sharp corners, the inner sides are rounded as possible. Some plant protection products may have a detrimental effect on crops for which they are not intended. Therefore, it is important to completely clean the tank and fluid supply system from previous preparations. For this are used the various technological solutions. For example, the RoGator Chellenger sprayers, are equipped with a flushing pipe with holes passes along the bottom of the tank, which ensures constant mixing of the working fluid during machine operation and cleaning of the tank upon completion.
Dammann sprayers tanks are equipped with a stainless steel pipe with rotating nozzles mounted on it. This mechanism mixes the working fluid during operation and helps to clean the tank at the end of work.
The Amazon company offers for sale the Comfort-package plus, which is an option for the new trailed sprayer UX 01 Super. Its advantage is the ability to choose one of the pre-installed mixing programs for the working fluid in the tank.
The mixer is used for high-quality mixing of all fractions of active ingredients, their supply to the tank and cleaning of the supplying container. Today mixers are divided into two groups.
The first only delivers the working substance into the tank and mixes it.
The second group of mixers, in addition to filling the tank, additionally flushes the feed tank. Thus, it turns out more economical use of drugs.
A good indicator of the work is the almost complete emptying of the mixer tank, it should remain no more than 2% of filled powder or microgranules. After cleaning the cans, the residue should be no more than 0.01% of the nominal volume of the canister.
An alternative to parallel driving is the use of foam markers. In order to maximize the use of each milliliter of fertilizer, it is necessary to precisely maintain the rate of outflow along the entire length of the driveway across the field and avoid gaps with repetitions on the sides of the processing strip.
The first part of the task is solved by a spraying computer that maintains the rate of outflow even with fluctuations in speed of movement. It compares the current speed of movement, the rate of outflow and adjusts the latter, based on the required rate of fertilizer. But in the case of lateral movement deviations, such a computer will not report the problem. At the joints of the processing bands may occur gaps or re-insertion.
To avoid unnecessary fertilizer waste, the sprayer must either follow perfectly flat lines throughout the field, or very accurately repeat a certain curve that arose at the very beginning when driving along one of the field borders.
To solve this problem, are used such the markers:
A number of farms solve this problem radically - by creating a technological track along which the sprayer moves year after year. Of course, a sprayer with a constant boom width will have to move along this track. If this approach is not applicable, equipment for marking the field with foam or a parallel driving device can be installed on the sprayer. Both have pros and cons.
The dotted line of foam that is applied from the end point of the sprayer boom helps the driver navigate the terrain. The system includes a reagent tank, a pump, tubes that must be carried along the length of the rod. Foam is chemically safe for plants and disappears completely after a certain time.
The disadvantages of such a system include the difficulty of orientation, since the tractor driver must keep the equipment in such a way that the edge of the rod follows the trail of a foam marker. This requires some skills and constant tension of the organs of vision. With a long rut, the foam can dry up by the time the driver has finished one row. In this case, the driver is already working blindly. The accuracy of the work is difficult to measure. But an error when processing more than 50 cm (the standard distance between the nozzles on the sprayer boom) means a possible overlap of the treatment areas and a two-fold excess of the plant protection product dose. In some cases, this is fraught with burns and always an overrun of the active substance.
The device of parallel driving works in other way. While moving across the field, it receives the coordinates of the vehicle and draws a movement trajectory on the screen. For better orienteering, an additional satellite image of the terrain is displayed on the screen, which can be obtained from services (more often Google Maps) or preloaded onto the device by the manufacturer. The driver sees the lines along which he has already traveled and the upcoming trajectories of movement. Standard GPS technology has an error of about 50 cm. The proximity of power lines, trees, electromagnetic interference can disrupt the operation of the system. To improve the accuracy of determining the coordinates, GPS technology is now complemented by RTK stations.
When using the device of parallel driving «Vodoley 2 + RTK» the error in determining the coordinates does not exceed 2 cm.
When processing the territory without side raids and gaps, it remains only to hold the point, which denotes the technique, as close as possible to the line that is displayed on the screen. There is a supplement in the form of an automatic rudder mounted on the steering wheel, which facilitates the work on long span.
To maintain a constant concentration before and during application operations, tank mixers are used. Their use is especially important when using tank mixes and difficultly soluble pesticides. Mixers are divided into mechanical and hydraulic. Mechanical can be found in small mounted sprayers.
Recently, it is increasingly possible to meet hydraulic mixers of various designs. Their main task is to create liquid jet that permeate the entire thickness of the tank mix, constantly setting it in motion. The design of the mixer should include work with the lowest possible foaming, to create the suspensions, emulsions and solutions directly in the sprayer tank.
Structurally, these are most often injectors with nozzle, that create solid stream of fluid. When a jet of fluid moves rapidly in one direction, the surrounding fluid is injected and begins to follow this stream. Turbulent flows occur inside the tank, which contribute to the mixing of the entire mass of working fluid. The use of hydraulic agitators is justified because they have no moving parts and are therefore simple and reliable.
The presence of hydraulic agitators in the sprayer tank means an additional load on the pump and its hydraulic actuator, which, in addition to pumping fluid into the main system, must also mix it in the tank.
