scholarly journals On the Relation between Cavitation Aspect in a Centrifugal Pump and Fall of Pump Head or Shaft Power Due to Cavitation : Studies of Cavitation Aspect and Suction Performance of Centrifugal Pumps, 3rd Report

1963 ◽  
Vol 29 (204) ◽  
pp. 1294-1299
Author(s):  
Taijiro KASAI ◽  
Yasuo TAKAMATU
Keyword(s):  
Centrifugal Pump ◽  
Centrifugal Pumps ◽  
Pump Head ◽  
Shaft Power ◽  
Suction Performance

Effect of semi-open impeller side clearance on centrifugal pump cavitation inception

2018 ◽  
Vol 1 (2) ◽  
pp. 24-39
Author(s):  
A. Farid ◽  
A. Abou El-Azm Aly ◽  
H. Abdallah
Keyword(s):  
Centrifugal Pump ◽  
Static Pressure ◽  
Rotation Speed ◽  
Centrifugal Pumps ◽  
Severe Condition ◽  
Cavitation Inception ◽  
Total Input ◽  
Input Pressure ◽  
Pump Head ◽  
Pump Pressure

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.

Design Optimization of Splitter Blade Impeller in a Centrifugal Pump

2020 ◽  
Author(s):  
Shunya Takao ◽  
Kentarou Hayashi ◽  
Masahiro Miyabe
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Design Method ◽  
General Purpose ◽  
Stable Operation ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Rate Range ◽  
Flow Rate Range ◽  
Suction Performance

Abstract In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.

A Survey of Modern Centrifugal Pump Practice for Oilfield and Oil Refinery Services

1943 ◽  
Vol 150 (1) ◽  
pp. 121-134 ◽  
Author(s):  
N. Tetlow
Keyword(s):  
Centrifugal Pump ◽  
Chemical Engineering ◽  
Saturation Pressure ◽  
Difficult Problem ◽  
Future Trend ◽  
Oil Refinery ◽  
Engineering Practice ◽  
Centrifugal Pumps ◽  
Oil Companies ◽  
Suction Performance

During the last thirty years there has been a manifold increase in the demand for centrifugal pumps for oilfield and oil refinery service, an increase in which British engineers have played a worthy part. With traditional British reticence little has been said of the achievements of British oil companies and British pump manufacturers in this field of activity, and the author has written this paper with the object of correcting the omission. In the field of oil transportation over long distances, for instance, the influence of British practice is to be seen in many oilfields throughout the world. Within the refinery considerable strides have been made, particularly in solving the difficult problem of handling unstable hydrocarbon liquids under high suction pressures. Hot oil pump practice is now more or less established, and in this development the greater share of credit is due to American pump manufacturers. These developments are dealt with at some length in the appropriate section of the paper. Another point which calls for comment here is the introduction of a new term, for the characteristic of flow into the impeller eye, which is used in section 3 of the paper. When dealing with hydrocarbon liquids under saturation pressure and temperature conditions, the so-called “suction performance” of a centrifugal pump becomes extremely important. As a description of this most important characteristic of a pump the use of the phrase “suction performance” is misleading, and it has led to much confusion of thought. An attempt has been made to reduce the possibility of further confusion by coining a new phrase based on the analogy of similar characteristics encountered in electrical engineering. Throughout the paper, therefore, the pump characteristic relating to flow into the impeller eye has been described as the characteristic of “flow inductance”. The paper would not be complete without an attempt to assess the future trend. There will probably be a much greater tendency towards electrification of main-line pumping plant. A further increase in operating temperatures and pressures will, no doubt, lead to many fundamental changes in the design of pumping plant for use inside the refinery. As an example, it is suggested that for some difficult duties it may be necessary to adopt pump designs in which stuffing boxes are avoided altogether. Finally, it is probable that refinery technologists will tend more and more to adopt chemical processes and chemical engineering practice, so introducing new problems for the pump designer.

The Rotating Cavitation Performance of a Centrifugal Pump with a Splitter-Bladed Inducer under Different Rotational Speed

2015 ◽  
Vol 32 (3) ◽  
Author(s):  
XiaoMei Guo ◽  
ZuChao Zhu ◽  
BaoLing Cui ◽  
Yi Li
Keyword(s):  
Centrifugal Pump ◽  
Rotational Speed ◽  
High Speed ◽  
Internal Flow ◽  
Centrifugal Pumps ◽  
Cavitation Flow ◽  
Operation Condition ◽  
Cavitation Performance ◽  
Cavitation Behavior ◽  
Suction Performance

AbstractDesigning inducer is one of the effective ways to improve the suction performance of high-speed centrifugal pumps. The operation condition including rotational speeds can affect the internal flow and external performance of high-speed centrifugal pumps with an inducer. In order to clarify the rotating cavitation performance of a centrifugal pump with a splitter-bladed inducer under different rotational speed, a centrifugal pump with a splitter-bladed inducer is investigated in the work. By using Rayleigh–Plesset equations and Mixture model, the cavitation flow of centrifugal pump is numerically simulated, as well as the external performance experimental test is carried out. It is found that the cavitation area increases with the rotational speeds. The location of the passage where cavitation is easy to appear is explored. Asymmetric cavitation behavior is observed. That, the trail of the inducer is easy to take cavitation when the rotational speed is increased to a degree, is also observed. The trend of

Effect of Surfactant Additives on Centrifugal Pump Performance

2003 ◽  
Author(s):  
Satoshi Ogata ◽  
Keizo Watanabe ◽  
Asano Kimura
Keyword(s):  
Centrifugal Pump ◽  
Surfactant Concentration ◽  
Tap Water ◽  
Maximum Flow ◽  
Pump Efficiency ◽  
Optimal Temperature ◽  
Pump Performance ◽  
Surfactant Solutions ◽  
Pump Head ◽  
Shaft Power

Performance of a centrifugal pump when handling surfactant solutions was measured experimentally. The effects of the concentration and temperature of surfactant solutions on pump performance were investigated. It was clarified that the pump efficiency with surfactant solutions was higher than that with tap water, and increased with an increase of surfactant concentration. The value of maximum flow rate of the pump also increased. The total pump head increased with an increase in the surfactant concentration, however, the shaft power decreased with a decrease in the rotational speed of the impeller. The pump efficiency is dependent on the surfactant temperature, and there is an optimal temperature which maximizes the efficiency.

Flow loss analysis of a two-stage axially split centrifugal pump with double inlet under different channel designs

2019 ◽  
Vol 233 (15) ◽  
pp. 5316-5328 ◽  
Author(s):  
Majeed Koranteng Osman ◽  
Wenjie Wang ◽  
Jianping Yuan ◽  
Jiantao Zhao ◽  
Yiyun Wang ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Flow Characteristics ◽  
Water Diversion ◽  
Centrifugal Pumps ◽  
Loss Analysis ◽  
Flow Losses ◽  
Water Pumping ◽  
Pumping Stations ◽  
Pump Head ◽  
Flow Loss

The double-stage axially split centrifugal pump is widely used in water diversion and water pumping stations due to their ability to deliver at high heads and large flow rate for long running hours. Their flow characteristics can be greatly influenced by the geometry of the channels between the stages, which is a prominent place for irreversible loss to occur. Numerical investigations were extensively carried out and a comparison was drawn between two multistage axially split centrifugal pumps, with different channel designs between its stages. The reliability of the numerical model was confirmed after a good agreement existed between numerical results and the experiments. Subsequently, entropy generation terms were used to evaluate turbulence dissipation to characterize the flow losses. The modified channels had a great effect on reducing swirl near the impeller eye, thereby improving pump head by 12.5% and efficiency by 4.98% at the design condition. They however induced flow impact, causing an unusual separation, which generated high turbulence dissipation at the blade surfaces. The channels and second stage impeller were identified as major areas for selective optimization since their turbulence dissipation was dominant. Consequently, entropy production analysis with computational fluid dynamics could be relied upon to reveal the loss locations for selective optimization in centrifugal pumps.

scholarly journals Analysis on Centrifugal Pump Performance in Single, Serial, and Parallel

2018 ◽  
Vol 3 (2) ◽  
pp. 79
Author(s):  
Faisal Ansori ◽  
Edi Widodo
Keyword(s):  
Flow Velocity ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Mechanical Energy ◽  
Unit Weight ◽  
Centrifugal Pumps ◽  
Head Losses ◽  
Rotary Pumps ◽  
Pump Head ◽  
The Difference

The pump is a tool to provide the mechanical energy to the liquid in the pump constant fluid density and large. In terms of mechanism, the pump is divided into three types, namely, rotary pumps, pump the shaft/piston and centrifugal pumps. The use of the pump are the most widely used either in the household or in the environment industry. In the centrifugal pumps, there are losses – losses among other head losses. To find the head losses among other data needs head on the pump, the pump and the discharge flow rate of the pump. Head is defined as energy per unit weight of the fluid. The head of the unit (H) meters or feet is fluid. In the pump, the head is measured by calculating the difference between the total pressure of the suction pipe and the pipe press, when measurement is done at the same height. For single full pump openings 0,00246 m³ \ s, valve openings ¾ 0,00210 and aperture of ½ 0,00177 m³ \ s can be concluded the discharge of water at the pump the larger the opening of the valve the greater the discharge of its water. Moreover, vice versa, if the opening of the valve is getting smaller then the water debit is getting smaller. For full opening valves 3,11 m / s, for openings ¾ 2,65 m / s and ½ 2,23 m / s open valve openings. For the flow, velocity can be concluded the greater the opening of the valve the flow velocity is smaller and vice versa the smaller the opening of the valve the greater the flow rate. single centrifugal pump full valve openings 0.409 kg / cm², the opening of the valve ¾ 0,209 kg / cm² and the opening of the valve ½ 00,069 kg / cm² can be concluded the smaller the opening of the opening valve the smaller the head as well, and the greater the open valve opening, the more big head also in the can.

Effect of Surfactant Additives on Centrifugal Pump Performance

2005 ◽  
Vol 128 (4) ◽  
pp. 794-798 ◽  
Author(s):  
Satoshi Ogata ◽  
Asano Kimura ◽  
Keizo Watanabe
Keyword(s):  
Centrifugal Pump ◽  
Energy Savings ◽  
Tap Water ◽  
Maximum Flow ◽  
Pipeline System ◽  
Pump Efficiency ◽  
Rotating Speed ◽  
Surfactant Solutions ◽  
Pump Head ◽  
Shaft Power

Performance of a centrifugal pump when handling surfactant solutions was measured experimentally. It was clarified that the pump efficiency with surfactant solutions was higher than that with tap water and increased with an increase in surfactant concentration. The value of maximum flow rate also increased. The total pump head increased with an increase in concentration, and the shaft power decreased with a decrease in the impeller rotating speed. There was an optimal temperature, which maximizes the efficiency. By combining the data for the piping section and for the pump efficiency, it is possible to accurately predict the energy savings of the pumping power in the pipeline system.

An Investigation on Mechanical Energy Supply in Rotating Flow Passage of Centrifugal Pump

2003 ◽  
Author(s):  
Takaharu Tanaka
Keyword(s):  
Centrifugal Pump ◽  
High Efficiency ◽  
Mechanical Energy ◽  
Internal Flow ◽  
Centrifugal Pumps ◽  
Flow Conditions ◽  
Theoretical Design ◽  
Pump Head ◽  
Definition Of ◽  
Very High

Centrifugal pump is a typical turbomachinery, which transfers mechanical energy to hydraulic energy through the rotational motion of impeller blades. It is commonly used and generally operated at a very high efficiency. Therefore, it would seem that theoretical discussion of performance and experimental observations of internal flow conditions inside the pump should be fully understood by now. However, it appears that neither the basic expressions nor the theoretical design methods are that clear. For example, the most fundamental definition of pump head, which is the most important equation in pump textbooks, is not often well explained. The purpose of this oral presentation is to share preliminary results of on-going studies on the energy transfer in centrifugal pumps.

scholarly journals Artificial Neural Networks Approach for a Multi-Objective Cavitation Optimization Design in a Double-Suction Centrifugal Pump

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 246 ◽  
Author(s):  
Wang ◽  
Osman ◽  
Pei ◽  
Gan ◽  
Yin
Keyword(s):  
Centrifugal Pump ◽  
Optimization Design ◽  
Volume Fraction ◽  
Geometrical Parameters ◽  
Centrifugal Pumps ◽  
Original Design ◽  
Multi Objective ◽  
Fast Approach ◽  
Agricultural Applications ◽  
Suction Performance

Double-suction centrifugal pumps are widely used in industrial and agricultural applications since their flow rate is twice that of single-suction pumps with the same impeller diameter. They usually run for longer, which makes them susceptible to cavitation, putting the downstream components at risk. A fast approach to predicting the Net Positive Suction Head required was applied to perform a multi-objective optimization on the double-suction centrifugal pump. An L32 (84) orthogonal array was designed to evaluate 8 geometrical parameters at 4 levels each. A two-layer feedforward neural network and genetic algorithm was applied to solve the multi-objective problem into pareto solutions. The results were validated by numerical simulation and compared to the original design. The suction performance was improved by 7.26%, 3.9%, 4.5% and 3.8% at flow conditions 0.6Qd, 0.8Qd, 1.0Qd and 1.2Qd respectively. The efficiency increased by 1.53% 1.0Qd and 1.1% at 0.8Qd. The streamline on the blade surface was improved and the vapor volume fraction of the optimized impeller was much smaller than that of the original impeller. This study established a fast approach to cavitation optimization and a parametric database for both hub and shroud blade angles for double suction centrifugal pump optimization design.

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