The article presents the developed mathematical models that describe the process of spraying the working body of a low-volume sprayer. Theoretical studies show that with an increase in the supply of working fluid to the atomizing disc, the rotational speed of the pneumatic disc atomizer decreases, and in order to ensure the effect of the air flow on the droplet formation process, the radius of the disc should be larger than the radius of the base of the cone-shaped fairing, but less than its maximum critical value and for obtaining a monodisperse spray with the main droplet diameter d = 80 … 120 μm, at an axial air flow velocity of the fan installation U = 40 … 60 m/s, the parameters of the disk the sprayer and the propeller are linked together when the following values: disk radius r = 65 … 85 mm, the number of radial channels on the disk nр = 2 … 6 pcs, the width of the radial channel bр = 3 … 4 mm, and to obtain a high-quality air-droplet flow, the initial velocity of the main drops discharged from the periphery of the spraying disc must be less than the speed of the air flow and, at the same time, the rotational speed of the pneumatic disc sprayer is recommended to be used in the range of ω = 60… 200 s-1.

Ташкентский институт инженеров ирригации и механизации сельского хозяйства (ТИИИМСХ); 100000, г. Ташкент, ул. Кори Ниязи, 39, Республика Узбекистан

The reliability and efficiency of irrigation pumping stations operation primarily depends on the well-coordinated operation of all systems. Drainage system should ensure that the building and territory of the pumping station are not flooded by drainage (filtration) water. At many pumping stations (especially those with long pressure lines), water jet pumps are installed as pumps for pumping out drainage water. The experience of operating such plants has revealed their undeniable advantages in comparison with conventional vane centrifugal pumps (type K and D) – sufficient reliability in operation due to the simplicity of the design, the absence of rubbing parts in the installation, the possibility of pumping contaminated liquids and the possibility of their use in the absence of power supply. But with all this, water jet pumps are extremely low-efficiency. To justify the use of jet pumps, a methodology is needed that would allow for a comprehensive consideration of all the main factors that affect their reliability, ease of operation and energy efficiency in the drainage system. On the example of the pumping station “Kiziltepa-2”, these factors were identified and the energy efficiency of water jet pumps was calculated. Various applications of jet pumps are considered, and their efficiency is evaluated.