The processes of formation of droplets from a jet of liquid inside the nebulizer belong to the section of plasma physics and are currently poorly understood. There is not even constructivist dependence, with the help of which it would be possible to predict how exactly the size and mechanism of formation of drops in the case of certain modifications of the inner chamber of the nebulizer will change.
Simply put, all modern spray nozzles are created by trial and error. Engineers trite experiments, changing the structure of the inner chamber of the spray nozzles, with the subsequent evaluation of the resulting spraying.
One of the most durable - ceramic, processed in the furnace. In the process of heating they shrink, so the size of the inner chamber is set taking into account the change in the size of the entire workpiece. For high-quality processing of the territory it is necessary to purchase spray nozzles of certified manufacturers. Download the list (German language https://www.julius-kuehn.de/...). In these models, the discrepancy between the actual consumption figures and those indicated in the passport is not more than 10%. As the operation proceeds, the fluid gradually expands the channel lumen and the flow rate increases.
If we consider the average life of spray nozzles made of polymers as a unit, then brass shows 30% of this period. Spray nozzles made of stainless steel show themselves much better - 80% of service life in comparison with polymer ones. The most "long-playing" spray nozzles made of ceramics - their lifespan can be 4-10 times longer than for polymeric ones. Immediately make a reservation that the actual ceramic is not the whole spray nozzle, but only the most important parts - the nozzle and the metering element.
If during work in the field the spray nozzle is clogged, then it is permissible to either try to blow it with compressed air or rinse it. After "cleaning" with the help of wire or needle, the internal structure of the spray chamber will be so broken that it can only be thrown out. It should be remembered that the permeability of the sprayer can be completely disrupted in just one week - during this time a raid appears. Therefore, you should regularly flush the working fluid supply system of the sprayer so that the driver doesn’t even have the idea to “restore the permeability” of the nozzle with the help of available tools. By the way, UAN liquid fertilizer has a powerful cleansing effect - it dissolves very well and removes any plant protective products deposited on the pipes of the working fluid supply system. Here is another reason to regularly flush the sprayer, because an unexpected outpouring of the reagent can lead to negative consequences for the crop being processed.
Blocking the spray nozzle reduces its permeability. If the permeability of all sprayers is reduced by 30-60% at once, this will disrupt the operation of the sprayer.
In addition to clogging, sprayers are also threatened by mechanical wear due to the abrasive properties of the fluid passing through them. Gradually boring the lumen of the nozzles, the liquid changes the coefficient of variation. If the nozzles have not been changed for a long time, then maintaining a stable flow rate will be difficult even with a spray computer.
Therefore, for high-quality processing of large areas, you need to have several sets of spray nozzles.
Structurally, the working fluid supply system can have individual filter for each spray nozzle. If they were, but they were removed due to frequent blockages, then this is the worst solution possible. Now the internal chambers of the nozzles will be clogged, which will affect the quality of processing.
Solutions to this problem depend on the particular enterprise. Ideally, you need to monitor the quality of the working solution, preventing the occurrence of blockages in it and regularly flush the spray liquid supply system. But if there are few sprayers and you have to work around the clock, changing drivers in shifts, then you can buy several sets of polymer spray nozzles and simply replace them when switching to a new crop or a new section. So you will have the confidence that at least part of each section will be processed properly.
A full check of all spray nozzles is carried out on a special stand and allows you to check not only the amount of fluid passing through each spray nozzle per unit of time, but also the uniformity of each spray nozzle flow. Since such a check is impossible in the field, it is possible simply to periodically make an estimate of the fluid flow rate of each spray nozzle in one minute at a fixed pressure.
If the consumption of the two nozzles differs by more than 10%, then you need to change everything on the rod. It is not recommended to leave old spray nozzles unattended. Machine operators working on sprayers may be tempted to start collecting a collection of old spray nozzles. Further, a situation may arise with the regular replacement of spray nozzles on the boom for such spare parts from the collection. This will unexpectedly affect the flow rate and quality of the treatment. If a third of the nozzles on the boom is missing more than they are supposed to wear, the rest will pour less. As a result, there is a strip of damaged plants on the field instead of evenly growing greens.
If the number of employees allows you to regularly flush the system supply of the working fluid, we can recommend ceramic sprayers. If the season has come and the equipment is working around the clock, then it will be easier to buy several sets of spray nozzles made of polymeric materials and replace them regularly.