The article discusses the use of the design of the forebays of a polygonal cross-section to improve the hydraulic characteristics of the water intake structures of pumping stations, in which the longitudinal slope in the direction of the middle chamber is i = 0.1, the adjacent longitudinal slope is 0.15 and with the extreme chambers the longitudinal the slope is 0.2. The faces of each chamber with a forebay have a transverse slope equal to i c = 0.1 and the angle of taper of the forebays in the plan is α = 35°. In the joint operation of 5 pumps, for the forebays of a polygonal cross-section, the total resistance coefficient is ∑ξ total ext. = 0.568 and for a typical ∑ξ total ext. = 0.72. With the simultaneous operation of 5 pumps, the average supply of 3 pumps is 0.0051 m3/s, 2, and 4 pumps, respectively 0.00498 … 0.00504 m 3 /s, for 1 and 5 pumps, 0.00478, and 0.00481 m 3 /s, respectively at the extreme pumps, the flow rate increases by 4.9…6.3% relative to the standard forebays.

One of the most important objectives in the world is to improve rational water resources management methods. In this regard, the rational management of water resources and optimal water resources distribution, especially on on-farm systems, are considered very important. In this direction, given the negative consequences that have developed over the past more than 40 years in the lower reaches of the Amu Darya River, the need to improve the methods of effective management of water resources in the Aral Sea basin is urgent.

The article presents the results of studies of the degree of influence of the operating mode of the centrifugal pump on the intensity of the water jet at constant values of the sediment concentration P = 20 kg/ m3, particle diameter d = 0.25…0.5 mm, test duration T = 2 hours and shaft speed n0 = 2900 rpm. Experiments were carried out on pump feeds from 0.5 Qopt to 1.25 Qopt with various materials and polymer coatings that were applied to the surfaces of the blades made of St.3. The best adhesion of the polymer coating is obtained at a metal temperature of 21°C. Polymer materials based on epoxy resin with silicon carbide have the highest wear resistance, while silumin shows low wear resistance. When testing ground pumps, it was found that parts made of electro corundum on an epoxy-phenol-formaldehyde bond, in comparison with parts made of wear-resistant cast iron, increases the service life of pumps 3 - 8 times.

The results of experiments on studying the nature of changes in the concentration and dispersion of solid suspended particles showed that the highest average monthly sediment concentration is 2.5...3.8 kg/m3, and sometimes in rainy weather, the maximum water turbidity reaches 7kg/m3. In the composition of solid mechanical impurities, a significant amount consists of particles with a grain size of 0.1-0.05mm. Observations have established that particles larger than 0.01 mm at a low flow velocity in the supply channel and the water intake chamber of the pumping station were easily deposited in them. Siltation volumes at various stations ranged from 20 to 60%. As a result, the hydraulic resistance increased, which led to a decrease in the pump head. The wear of parts of centrifugal pumps in natural conditions was also studied, and the dependences of wear on the characteristic dimensions and duration of their operation are given. The results of micrometering of the working parts of the pumps showed that the blades of the impellers along the length and width wear out unevenly both in size and shape. This is explained by the fact that when the hydroabrasive flow moves in the interblade space, the kinetic energy of solid particles and their local concentration increase due to an increase in the values of centrifugal and Coriolis forces along the radius of the impeller.

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