scholarly journals CAVITATION WEAR OF PUMP IMPELLERS

2016 ◽  
Vol 2 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Mirosław Szala ◽  
Daniel Łukasik
Keyword(s):  
Centrifugal Pump ◽  
Cavitation Erosion ◽  
Operating Parameters ◽  
Common Phenomenon ◽  
Cavitation Wear ◽  
Financial Losses ◽  
Selection Of

Cavitation is a common phenomenon in pump systems, negatively influencing their operating parameters and components such as impellers and, thus, causing considerable financial losses. This paper explains the problem of cavitation and cavitation erosion. The causes of cavitation in pump systems are analyzed. A selection of centrifugal pump impellers damaged by cavitation erosion are presented and examined. The authors also discuss ways of preventing cavitation and cavitation erosion in pump systems. Finally, relevant conclusions are drawn.

Influence of Applied CrN+WC/C and WC/C Coatings on the Cavitation Wear Processes of Constructional Elements

2019 ◽  
Vol 813 ◽  
pp. 62-67
Author(s):  
Tomasz Linek ◽  
Tomasz Tański ◽  
Wojciech Borek
Keyword(s):  
Cavitation Erosion ◽  
Vapour Deposition ◽  
Elevated Temperatures ◽  
Protective Coatings ◽  
Low Friction ◽  
Mechanical Fatigue ◽  
Cavitation Wear ◽  
The Individual ◽  
304L Steel ◽  
Selection Of

When designing the individual subassemblies of machines or entire devices one has to draw special attention to the resistance of the elements working there, to tribological damages (mechanical, fatigue, adhesion, abrasion, hydrogen and other damages) as well as to non-tribological damages (corrosion, diffusion, cavitation, erosion, ablation and others). The main purpose of this publication was to examine the influence of the applied CrN+WC/C and WC/C protective coating deposited by PVD (Physical Vapour Deposition) method on the cavitation wear processes of construction elements working in difficult cavitation environment. Two steels were selected for detailed examinations in the conditions of cavitation wear. The first one is P265GH steel commonly used for pressure devices working at elevated temperatures, with a ferritic – pearlitic structure, and the other derives from a group of stainless steels, i.e. chromium – nickel X2CrNi18-9 (304L) steel with an austenitic structure. The tests results obtained allow to conclude that the application of special low – friction protective coatings allows to reduce costs associated with selection of engineering materials for a substrate of constructional elements working in a cavitation wear environment. P265GH steel is 4.5 times cheaper than austenitic chromium – nickel X2CrNi18-9 (304L) steel, and if a CrN+WC/C and WC/C coating is deposited in this case, this considerably extends the working time of such elements in a cavitation environment.

Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials

1973 ◽  
Vol 31 ◽  
pp. 444-445
Author(s):  
P.J. Killingworth ◽  
M. Warren
Keyword(s):  
Electron Beam ◽  
Organic Materials ◽  
Operating Parameters ◽  
Low Density ◽  
Beam Diameter ◽  
Incident Electron Beam ◽  
Specimen Material ◽  
Voltage Compensation ◽  
Selection Of ◽  
Scanning Electron

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

scholarly journals To the issue of energy efficiency of using frequency-controlled centrifugal pump units

2018 ◽  
Vol 170 ◽  
pp. 03017 ◽  
Author(s):  
Alexey Dmitriev ◽  
Vyacheslav Gerasimov
Keyword(s):  
Control Systems ◽  
Centrifugal Pump ◽  
Energy Efficient ◽  
Point Of View ◽  
Operating Parameters ◽  
Variable Frequency Drive ◽  
Automatic Control Systems ◽  
Efficient Management ◽  
Pumping Stations ◽  
Pumping Units

The expediency of using a variable frequency drive for pumping units was repeatedly proved both from the point of view of the economic component and the technological one. However, the construction of automatic control systems for the operating parameters of pumping stations is mainly based on maintaining the pressure setpoint and does not include monitoring the efficiency of the aggregates working in the group and, the more so, its regulation. In this paper, an algorithm is developed for the energy efficient management of centrifugal pump units, which allows not only maintaining the pressure setpoint, but also optimizing their efficiency.

Selection of operating parameters and geometry for liquid-gas injector

1970 ◽  
Vol 6 (10) ◽  
pp. 834-838
Author(s):  
B. N. Basargin ◽  
N. I. Gel'perin ◽  
B. S. Ossovskii ◽  
G. A. Kuzyanov ◽  
A. A. Baraev
Keyword(s):  
Operating Parameters ◽  
Selection Of

scholarly journals Prediction of Cavitation Evolution and Cavitation Erosion on Centrifugal Pump Blades by the DCM-RNG Method

Scanning ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Han Zhu ◽  
Ning Qiu ◽  
Chuan Wang ◽  
Qiaorui Si ◽  
Jie Wu ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Cavitation Erosion ◽  
Flow Characteristics ◽  
Prediction Method ◽  
Pressure Change ◽  
Correction Method ◽  
Centrifugal Pumps ◽  
Suction Surface ◽  
Term Operation ◽  
Pressure Surface

Cavitation can reduce the efficiency and service life of the centrifugal pumps, and a long-term operation under cavitation conditions will cause cavitation damage on the surface of material. The external characteristic test of the IS65-50-174 single-stage centrifugal pump was carried out. Moreover, the cavitation mechanism under specific conditions was analyzed by numerical simulation. Considering the macroscopic cavitation flow structure in the centrifugal pump, three different cavitation erosion prediction methods were used to predict the erodible areas. The results show that the calculation results obtained by the density correction method (DCM) can well match the flow characteristics of the centrifugal pump under the rated conditions. When the centrifugal pump head drops by 3%, cavitation mainly occurs on the suction surface, and the cavity on the pressure surface is mainly concentrated near the front cover. The cavitation prediction method based on the time derivation of pressure change is not suitable for centrifugal pumps, while the prediction result of the erosive power method is more reasonable than the others. At time 0.493114 s, the maximum erosive power appears on the blade near the volute tongue, and its value is 1.46 e − 04  W.

Cavitation Erosion-Corrosion Resistance of Deposited Austenitic Stainless Steel/E308L-17 Electrode

2020 ◽  
Vol 299 ◽  
pp. 908-913 ◽  
Author(s):  
Hussam L. Alwan ◽  
Yury S. Korobov ◽  
N.N. Soboleva ◽  
N.V. Lezhnin ◽  
A.V. Makarov ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Cavitation Erosion ◽  
Shielded Metal Arc Welding ◽  
Protective Material ◽  
Metal Arc Welding ◽  
Erosion Corrosion ◽  
Cavitation Wear ◽  
Substrate Steel

The ultrasonic vibratory test was carried out to evaluate the cavitation erosion/corrosion resistance of welded-deposited austenitic stainless steel/E308L-17. Three layers of the E308L-17 electrode were deposited onto AISI 1040 substrate utilizing Shielded Metal Arc Welding (SMAW) process. The eroded surfaces of the E308L welded deposit/coating and AISI 1040 substrate steel have been analyzed by evaluating surface topography, as well as scanning electron microscope (SEM) micrographs. In addition, the cumulative weight loss and erosion rate curves were attained to evaluate the cavitation resistance of the tested materials. The cavitation results showed that the E308L-17 deposited stainless steel has lost about 15 mg as a cumulative weight, while the loss of AISI 1040 substrate was about 123 mg. This is equal to 0.12% and 1.0% of the original test specimen weight for the E308L-17 and AISI 1040, respectively. Consequently, E308L-17 austenitic stainless steel can be effectively used as a protective material for surfaces exposed to cavitation wear, since the AISI 1040 substrate has been enhanced by 8 times using E308L stainless steel.

scholarly journals Comparison of energy parameters of a centrifugal pump with a multi-piped impeller in cooperation either with an annular channel and a spiral channel

2018 ◽  
Vol 8 (1) ◽  
pp. 513-522 ◽  
Author(s):  
Bartłomiej Chomiuk ◽  
Janusz Skrzypacz
Keyword(s):  
Centrifugal Pump ◽  
Annular Channel ◽  
Operating Parameters ◽  
Centrifugal Pumps ◽  
Impeller Outlet ◽  
Flow Geometry ◽  
Quantitative Verification ◽  
Flow Through ◽  
Low Specific Speed ◽  
Specific Speed

Abstract The article presents results of numerical analyzes, which raise a subject of influence of the cooperation the multi-piped impeller with a rationalized flow geometry of annular casing and volute casing for liquid flow through centrifugal pump and their operating parameters in the extremely low specific speed nq<10. The multi-piped impeller (patented by authors) is a major alternative to classic vane impellers. The stator type is responsible for the conversion of the kinetic energy of the liquid by the impeller outlet into potential energy, which determines the overall efficiency of the pump. Also, the article presents qualitative and quantitative verification of results obtained by computer modeling and an attempt to estimate their accuracy. The article focuses mainly on the comparison of the performance parameters of the pump with a multi-piped impeller in cooperation with two stator types with a rationalized flow geometry. Both outlet elements were tested in various configurations of constructional features. The complexity of the construction of the stator can significantly affect the manufacturing costs of pump unit. Knowledge concerning construction of hydraulic elements of centrifugal pumps working in the range of parameters corresponding specific speed (nq<10) is insufficient. As shown in the paper, the annular type casing model pump cooperating with a multi-piped impeller, designed in accordance with literature, reached far poorer operating parameters than the rational annular construction in a configuration with the same impeller.

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