S Type Single-Stage Double Suction Centrifugal Pump in Vibration and Shaft Broken Analysis

2014 ◽  
Vol 685 ◽  
pp. 228-231
Author(s):  
Wei Liu ◽  
Feng Lan Wang

This article describes the reasons for vibration and off-axis S-type single-stage double-suction centrifugal pumps,due to the design of the pump itself and the reasons for which the work environment and the work of the pump caused by the vibration,thereby causing the shaft fracture, and other reasons, resulting in breakage of the pump shaft from a comprehensive analysis of the reason for the above problems.

2019 ◽  
Vol 287 ◽  
pp. 01025
Author(s):  
Madina Isametova ◽  
Rollan Nussipali ◽  
Aysen Isametov

The article describes an automated calculation of such an essential part of a centrifugal pumps the rotor shaft, so the highest level CAD NASTRAN system PATRAN module was used for the analysis. The computational mechanical scheme was drawn up, the axial and radial force acting on the impeller and the pump shaft were determined. The stress for the maximum feed case are determined. The results of the automated strength calculation were used for further analysis of the service life of the rotor shaft of a centrifugal pump. A computer technique for determining the service life of the shaft is given, taking into account the technological, mechanical conditions of operation and taking into account the projected service life equal to the lifetime of the uranium well. Using the automated MSC FATIGUE module, the number of loading cycles was determined, the service life safety factor was determined, which showed the efficiency of the pump throughout the entire operating time of the uranium well.


CORROSION ◽  
1959 ◽  
Vol 15 (9) ◽  
pp. 41-44
Author(s):  
JACK E. PICCARDO

Abstract Of the pumps used in the chemical and allied industries, about 90 percent are of the centrifugal and diaphragm types. These pumps are required to handle corrosive liquids under conditions of high pressure and high temperature, expensive or hazardous liquids where leakage to atmosphere cannot be tolerated, liquids with solids in suspension, often of an abrasive nature, creating both a corrosion and abrasion problems and extremely corrosive liquids which may be radioactive. Diaphragm type pumps have certain advantages over centrifugal pumps for severe chemical applications because there is no shaft sealing problem, solids in suspension can be handled at relatively low velocities and a high degree of corrosion resistance can be obtained by the use of high alloy steels for the pump body and synthetic materials for diaphragms. Packingless pumps include the so-called canned-motor centrifugal pump in which the pump impeller is mounted on the same shaft as the rotor. Both the rotor and the stator are sealed from the fluid by corrosion resistant cans or shields and the rotor moves in the liquid being pumped. The rotor-impeller shaft is supported on sleeve type bearings submerged in the liquid pumped. Canned-motor pumps usually cannot be applied where the liquid contains solids because of close clearances and possibility of damage to bearings by abrasion. Designs giving longer service life in the conventional centrifugal pump usually include the following: Improved sealing devices where the pump shaft passes through the casing, new alloys or metals for the wetted end to provide a better corrosion resistance, improved elastomers, plastics and ceramics which permit lining entire pumps for a high degree of corrosion resistance. Improved shaft seals are discussed along with a study of new materials available for pump parts, and linings for pumps commonly used in chemical pumping service. 7.3


2018 ◽  
Vol 16 (1) ◽  
pp. 25
Author(s):  
Ibnu Hajar

Pompa sentrifugal merupakan salah satu pompa yang sangat banyak digunakan pada industri pengolahan, seperti industri pengolahan air minum, industri pengolahan minyak, dan pabrik kelapa sawit. Bentuknya sederhana dan biaya perawatan lebih murah. Permasalahan yang sering terjadi pada pompa sentrifugal adalah kerusakan pada bantalan poros yang diakibatkan oleh getaran, keausan, dan misalignment. Pada makalah ini membahas pengaruh tipe bantalan bola terhadap sinyal getaran poros pompa sentrifugal satu tingkat. Tujuan penelitian ini adalah mengetahui dan mendapatkan pengaruh tipe bantalan bola pada poros pompa sentrifugal dengan mengukur sinyal getaran. Pompa yang digunakan dalam penelitian ini adalah pompa sentrifugal yang mempunyai head tekanan  9 meter, debit aliran 3 liter/detik dan daya output 746 watt. Metode penelitian dengan mengamati dan analisis perilaku sinyal getaran yang terdiri dari simpangan (displacement), kecepatan( velocity) dan percepatan (acceleration) pada bantalan bola pompa sentrifugal pada titik P-01 dan P-02 dari arah aksial, vertikal dan horizontal. Pengukuran sinyal getaran dilakukan dengan menggunakan alat ukur Vibrometer Analog VM-3314A. Bantalan (bearing) yang gunakan dalam penelitian ini adalah tipe cylindrical roller bearing dan  roller ball bearing yang dipasang pada poros pompa sentrifugal untuk diamati dan ukur sinyal getarannya. Hasil pengujian menunjukkan bahwa harga simpangan tertinggi 37,125 µm terjadi bantalan tipe ball bearing arah horizontal pada titik pengukuran P-02 tinggi tekan 3 meter dengan debit aliran 2,8 liter/detik. Sedangkan harga simpangan terendah  27,1 µm terjadi pada cylindrical roller bearing dengan tinggi tekan 3 meter dan debit aliran 2,8 liter/detik. Dengan naiknya tinggi tekan pada pompa sentrifugal menyebabkan turunnya getaran pompa sesuai penurunan beban pada pompa, sehingga untuk pompa sentrifugal satu tingkat lebih aman menggunakan tipe cylindrical roller bearing.Kata kunci: Tipe bantalan, pompa sentrifugal, sinyal getaranAbstractCentrifugal pumps are one of the most widely used pumps in the processing industry, such as the drinking water treatment industry, the oil processing industry and the palm oil mill, in addition to the simpler and cheaper maintenance costs. The most common problem with centrifugal pumps is damage to the shaft bearings caused by vibration, wear and misalignment. This paper discusses the effect of ball bearing type on the single-stage centrifugal pump vibration signal. The purpose of this research is to know and get the influence of ball bearing type on centrifugal pump shaft by measuring vibration signal. The pumps used in this study are centrifugal pumps that have a 9-meter pressure head, a flow rate of 3 liters / second and a power output of 746 watts. Research method by observing and analyzing vibration signal behavior consist of displacement, velocity and acceleration on centrifugal pump ball bearing at point P-01 and P-02 from axial, vertical and horizontal direction. Measurement of vibration signal is done by using Analog Vibrometer VM-3314A. Bearings used in this study are cylindrical roller bearing and roller ball bearings mounted on the centrifugal pump shaft to be observed and measure the vibration signal. Test results showed that the highest deviation 37,125 μm occurred bearing type ball bearing horizontal direction at the point of measurement P-02 high press 3 meter with flow debit 2,8 liter / second. While the lowest 27.1 μm deviation occurred in cylindrical roller bearing with 3 meter press and 2.8 liter / second flow rate. With the increase in the height of the tap on the centrifugal pump causes the decrease of pump vibration according to the load decrease at the pump, so for the centrifugal pump one level safer using cylindrical roller bearing type


2018 ◽  
Vol 1 (2) ◽  
pp. 24-39
Author(s):  
A. Farid ◽  
A. Abou El-Azm Aly ◽  
H. Abdallah

Cavitation in pumps is the most severe condition that centrifugal pumps can work in and is leading to a loss in their performance.  Herein, the effect of semi-open centrifugal pump side clearance on the inception of pump cavitation has been investigated.  The input pump pressure has been changed from 80 to 16 kPa and the pump side clearance has been changed from 1 mm to 3 mm at a rotation speed of 1500 rpm. It has been shown that as the total input pressure decreased; the static pressure inside the impeller is reduced while the total pressure in streamwise direction has been reduced, also the pump head is constant with the reduction of the total input pressure until the cavitation is reached. Head is reduced due to cavitation inception; the head is reduced in the case of a closed impeller with a percent of 1.5% while it is reduced with a percent of 0.5% for pump side clearance of 1mm, both are at a pressure of 20 kPa.   Results also showed that the cavitation inception in the pump had been affected and delayed with the increase of the pump side clearance; the cavitation has been noticed to occur at approximate pressures of 20 kPa for side clearance of 1mm, 18 kPa for side clearances of 2mm and 16 kPa for 3mm.


Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.


Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 60
Author(s):  
Khaled Alawadhi ◽  
Bashar Alzuwayer ◽  
Tareq Ali Mohammad ◽  
Mohammad H. Buhemdi

Since centrifugal pumps consume a mammoth amount of energy in various industrial applications, their design and optimization are highly relevant to saving maximum energy and increasing the system’s efficiency. In the current investigation, a centrifugal pump has been designed and optimized. The study has been carried out for the specific application of transportation of slurry at a flow rate of 120 m3/hr to a head of 20 m. For the optimization process, a multi-objective genetic algorithm (MOGA) and response surface methodology (RSM) have been employed. The process is based on the mean line design of the pump. It utilizes six geometric parameters as design variables, i.e., number of vanes, inlet beta shroud, exit beta shroud, hub inlet blade draft, Rake angle, and the impeller’s rotational speed. The objective functions employed are pump power, hydraulic efficiency, volumetric efficiency, and pump efficiency. In this reference, five different software packages, i.e., ANSYS Vista, ANSYS DesignModeler, response surface optimization software, and ANSYS CFX, were coupled to achieve the optimized design of the pump geometry. Characteristic maps were generated using simulations conducted for 45 points. Additionally, erosion rate was predicted using 3-D numerical simulations under various conditions. Finally, the transient behavior of the pump, being the highlight of the study, was evaluated. Results suggest that the maximum fluctuation in the local pressure and stresses on the cases correspond to a phase angle of 0°–30° of the casing that in turn corresponds to the maximum erosion rates in the region.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 886
Author(s):  
Cui Dai ◽  
Chao Guo ◽  
Yiping Chen ◽  
Liang Dong ◽  
Houlin Liu

The strong noise generated during the operation of the centrifugal pump harms the pump group and people. In order to decrease the noise of the centrifugal pump, a specific speed of 117.3 of the centrifugal pump is chosen as a research object. The bionic modification of centrifugal pump blades is carried out to explore the influence of different bionic structures on the noise reduction performance of centrifugal pumps. The internal flow field and internal sound field of bionic blades are studied by numerical calculation and test methods. The test is carried out on a closed pump test platform which includes external characteristics and a flow noise test system. The effects of two different bionic structures on the external characteristics, acoustic amplitude–frequency characteristics and flow field structure of a centrifugal pump, are analyzed. The results show that the pit structure has little influence on the external characteristic parameters, while the sawtooth structure has a relatively great influence. The noise reduction effect of the pit structure is aimed at the wide-band noise, while the sawtooth structure is aimed at the discrete noise of the blade-passing frequency (BPF) and its frequency doubling. The noise reduction ability of the sawtooth structure is not suitable for high-frequency bands.


2021 ◽  
Vol 9 (2) ◽  
pp. 121
Author(s):  
Yang Yang ◽  
Ling Zhou ◽  
Hongtao Zhou ◽  
Wanning Lv ◽  
Jian Wang ◽  
...  

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.


1978 ◽  
Vol 100 (4) ◽  
pp. 395-409 ◽  
Author(s):  
Jaroslaw Mikielewicz ◽  
David Gordon Wilson ◽  
Tak-Chee Chan ◽  
Albert L. Goldfinch

The semiempirical method described combines the ideal performance of a centrifugal pump with experimental data for single and two-phase flow to produce a so-called “head-loss ratio,” which is the apparent loss of head in two-phase flow divided by the loss of head in single-phase flow. This head-loss ratio is shown to be primarily a function of void fraction. It is demonstrated that the measured characteristics of a centrifugal pump operating in two-phase flow in normal rotation and normal and reversed flow directions (first and second -quadrant operation) and in reversed rotation and reversed flow direction (third-quadrant operation) can be reproduced with acceptable accuracy.


2019 ◽  
Vol 36 (4) ◽  
pp. 401-410 ◽  
Author(s):  
Xiao-Qi Jia ◽  
Bao-Ling Cui ◽  
Zu-Chao Zhu ◽  
Yu-Liang Zhang

Abstract Affected by rotor–stator interaction and unstable inner flow, asymmetric pressure distributions and pressure fluctuations cannot be avoided in centrifugal pumps. To study the pressure distributions on volute and front casing walls, dynamic pressure tests are carried out on a centrifugal pump. Frequency spectrum analysis of pressure fluctuation is presented based on Fast Fourier transform and steady pressure distribution is obtained based on time-average method. The results show that amplitudes of pressure fluctuation and blade-passing frequency are sensitive to the flow rate. At low flow rates, high-pressure region and large pressure gradients near the volute tongue are observed, and the main factors contributing to the pressure fluctuation are fluctuations in blade-passing frequency and high-frequency fluctuations. By contrast, at high flow rates, fluctuations of rotating-frequency and low frequencies are the main contributors to pressure fluctuation. Moreover, at low flow rates, pressure near volute tongue increases rapidly at first and thereafter increases slowly, whereas at high flow rates, pressure decreases sharply. Asymmetries are observed in the pressure distributions on both volute and front casing walls. With increasing of flow rate, both asymmetries in the pressure distributions and magnitude of the pressure decrease.


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