Effect of the outlet angle β2 on the characteristics of low specific-speed centrifugal pumps

Conclusions An experimental check of various low specific-speed pumps showed that on changing the geometry of the vaning of the impeller, in conformity with the recommendations [1], the main feature of which is an increase of the outlet angles of the vanes to values 90°₂130° and installation of short intermediate vanes in the passages between the main vanes, the head increases considerably without a decrease of pump efficiency.For centrifugal pumps with a volute and diffuser whose impellers have a different number of main vanes, the most rational is the installation of three intermediate vanes in each vane passage with a change in the direction of the flow by the main vane toward an increase of the outlet angle on diameter D₂=0.5–0.65D₃ for fecal pumps and pumps with short vanes.The use of the new impeller design is especially effective for high rotative-speed pumps. For multistage submersible pumps with a guide-vane apparatus at the inlet and axial outlet, the optimal variant is the installation of one intermediate vane with a start of the change in the flow direction D₃=0.63D₂.In conclusion, it is necessary to note that all tests were conducted without modifying the casing and branch pipes, which leaves room for a further increase of the head developed by pumps with the new type of impeller.Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 5, pp. 21–25, May, 1982.     

Basic principles and proposals for rehabilitation of radioactively contaminated objects and grounds of the kirovo-chepetsk chemical works

The results of an examination of objects and grounds of the Kirovo-Chepetsk Chemical Works are presented. The methods used to perform a radiation survey are described briefly. The data obtained are used as a basis for a concept of rehabilitation of radioactively contaminated objects and grounds of the works. The radwaste volumes are determined for each object and possible ways to handle them are proposed. The technologies for handling radwastes are examined. The primary problems that must be solved without delay are determined.     

Indirect measurement of state variables for the diagnostics of electromechanical systems

A method of estimating the actual state of electromechanical systems based on the use of a model, connected in parallel with the diagnosed equipment, and an indirect measurement of the state variables is considered. A diagnostic system structure is proposed and also versions of models which take the operating features into account. __________ Translated from Izmeritel’naya Tekhnika, No. 7, pp. 43–46, July, 2007.     

Steam generators – horizontal or vertical (which type should be used in nuclear power plants with VVER?)

The steam generator is a very important component of a nuclear power plant. Historically, vertical steam generators came to be used abroad and horizontal steam generators in our country. Both types of steam generators operate successfully in nuclear power plants and satisfactorily fulfill their functions, enabling the production of electricity. Repeated attempts to re-examine the existing concepts in one or another country have been unsuccessful because there are no convincing arguments for this. Nonetheless, the question of using a different type of steam generator is raised periodically in our country and abroad. This article briefly reviews different concepts of steam generators. Their parameters, characteristics, and thermal efficiency are compared and ways to increase the latter are analyzed. It is shown that it is impossible to choose one or the other type of steam generator without making an exhaustive study and analysis of the layout of the reactor facility and its scheme, servicing, and operation as part of a nuclear power plant. A comparative analysis of layouts of reactor facilities with different types of steam generators is made. Translated from Atomnaya énergiya, Vol. 105, No. 3, pp. 127–135, September, 2008.     

Zinc oxide molecules and clusters formed in a quasiclosed volume of reactive gas-discharge plasma

Plasma-deposited zinc oxide films were studied and it was established that oxide molecules may form and their clusters nucleate within a recombination burning zone in the volume of plasma, provided that the ion range does not exceed the size of a discharge chamber. The nucleation zone is rather narrow and its position depends on the gas pressure in the chamber. The zinc oxide films grown in this zone possess a texture with small misorientation angle and are characterized by small thickness of the nucleation texture and high piezoelectric activity.