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Date submitted2022-01-20
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Date accepted2022-07-21
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Date published2023-12-25
Tribodynamic aspects of the resource of electric submersible vane pumps for oil production
The operation of electric submersible vane pumps for oil production is accompanied by the presence of solid particles, corrosive substances, asphalt-resin-paraffin deposits in the reservoir fluid, leading to changes in performance characteristics and equipment failures. The reduction of the resource as a result of this is accompanied by an increase in the costs of repair and replacement of equipment. The main processes that negatively affect the failure are the wear of the seals of the working stages, the pump plain bearings and vibration, the level of which can significantly exceed the initial level. A test bench and methodology for testing pump sections for wear in water with an abrasive and simultaneous registration of vibration characteristics have been developed. Two main forms of wear of radial seals have been identified – one-sided and equal-dimensional. The one-sided form of sleeve wear is caused by synchronous shaft precession, whereas the equal-dimensional one is an asynchronous precession, and the vibration level increases with increasing wear. The wear distribution of radial seals along the length of the pump correlates with the shape of the elastic shaft line. The wear of the axial seals does not significantly increase the vibration level. During wear the frequency spectrum of vibrations changes; there occurs a frequency that can serve as a diagnostic sign of ultimate wear of the pump. The calculated dependence of the vibration velocity on the wear of the radial seals of the working stages is obtained, which makes it possible to predict the onset of a failure of functioning.
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Date submitted2019-03-13
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Date accepted2019-09-19
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Date published2020-02-25
Specifying the technical state limit value of the pump pulp without disassembling
The northern part of the territory of the Republic of Sakha (Yakutia) is rich in vast deposits of diamonds. These deposits are developed by the mining company “Almazy Anabara”, which is engaged in the extraction of diamonds at seasonal processing plants using various technological equipment. One of the key types of equipment is the pulp pump of a foreign company “KETO”. The work of pulp pumps of this company in the enrichment of diamond-containing raw materials is accompanied by intensive hydroabrasive wear of their impellers, the service life of which usually does not exceed three months. In practice, untimely replacement of a worn impeller can lead to emergency breakdowns of sealing elements and bearings, which is explained by super-permissible deflections of the shaft of pumping equipment arising from a significant unbalance of the rotor. The main cause of breakdown of slurry pumps at “Almazy Anabara” seasonal processing plants is the inability to quickly identify their ultimate technical condition, the key sign of which is the maximum wear of the impeller. The seasonal beneficiation plants of “Almazy Anabara” currently need a simple and at the same time reliable diagnostic sign of pulp pumps reaching their ultimate technical state, the identification of which can be quickly performed without disassembling and using complex equipment, which is very important when operating pumping equipment in short wash season on the Far North.
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Date submitted2018-09-04
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Date accepted2018-11-18
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Date published2019-02-22
Operation experience of centrifugal single-stage pumps in «ALROSA» Joint Stock Company
- Authors:
- N. P. Ovchinnikov
When mining diamond-bearing raw materials and further extracting diamonds from it in the joint-stock company ALROSA, which is a city-forming enterprise in the north-east of the Russian Federation, various pumping equipment is used, in particular, centrifugal single-stage pumps. In the present work, it is noted that the least reliable in terms of absence of failures of centrifugal single-stage pumps used in the joint-stock company ALROSA are the impellers, seals and bearing assemblies. Using linear correlation and regression analysis, it was found that the durability of the seals and bearing assemblies of the investigated pumps largely depends on the durability of their impellers. In the course of research, it was found that unbalancing the pump rotor due to excessive hydroabrasive wear of the impeller also leads to deformation and fracture of the shaft. In general, residual deformations and destructions are characteristic of the shafts of domestic pulp pumps of GrAT, GrT and Gr types. The most loaded sections of shafts of centrifugal single-stage pumps are installed. The most effective from the point of view of application among the pulp (ground, slurry and sand) pumps are pulp pumps of the Finnish company «Metso». When working on highly mineralized water (brines), the «X» type pumps have proven to be the best among centrifugal single-stage pumps.