Critical Rotation Speed Calculation and Application Development of Multi-Stage Centrifugal Pumps for Mining

2011 ◽  
Vol 130-134 ◽  
pp. 1119-1122
Author(s):  
Wei Li ◽  
Wei Dong Shi ◽  
Xiao Ping Jiang ◽  
Yan Xu
Keyword(s):  
Rotation Speed ◽  
Computational Method ◽  
Secondary Development ◽  
Centrifugal Pumps ◽  
Operational Environment ◽  
Application Development ◽  
Critical Rotation ◽  
Multi Stage ◽  
Pump Shaft ◽  
Critical Rotation Speed

Multi-stage centrifugal pumps for mining are widely used in mining and smelting industry. The operational environment in coal mine sewage is very harsh, so pump shaft and bearing failure happens frequently. In order to avoid disaster damage caused by failure of the pump shaft due to resonance, it is quite necessary and urgent to calculate critical rotation speed of the pump shaft. A calculation program of critical rotation speed for multi-stage centrifugal pumps for mining was developed using the secondary development tool of Object ARX, to give the computational method of the pump shaft load and static deflection and to achieve calculation of the critical speed, and which avoided the disadvantage of the traditional method. The practical application indicates that the program of critical rotation speed is convenient, intuitive and calculation accurate. It not only improves the work efficiency, but also reduces the labor intensity, so the program will have a good application prospect.

Strength Calculation Software Development and Finite Element Analysis of Pump Shaft

2011 ◽  
Author(s):  
Wei Li ◽  
Wei-dong Shi ◽  
Xiao-ping Jiang ◽  
Yi-meng Sang ◽  
Tong Li
Keyword(s):  
Strength Calculation ◽  
Secondary Development ◽  
Two Dimensional ◽  
Element Analysis ◽  
Development Tool ◽  
Ansys Apdl ◽  
Object Arx ◽  
Pump Shaft ◽  
Critical Rotation Speed ◽  
Calculation Software

With the wide applications to the fields of petrochemical, military, metallurgy and mining, pumps have to subject to more and more serious working conditions. In order to avoid disaster damage caused by failure of the shaft, it is quite necessary to calculate and examine the shaft strength. A kind of two-dimensional software was developed using the secondary development tool of Object ARX, to achieve the shaft strength calculation accurately and conveniently, and which avoided the disadvantage of the traditional method. The calculation methods of shaft critical rotation speed and the static bending displacement were proposed. Theoretical analysis and calculations on the strength, rigidity, vibration and other aspects of pump shaft were conducted under shut-off condition and best efficiency point using ANSYS APDL software of static, dynamic and transient modal analysis method. The quality of pump shaft was analyzed through the comparisons of numerical results, and further more the accuracy of two-dimensional development software was validated. The practical application indicates that the shaft parts strength calculation software can improve the quality and efficiency, reduce wastage during the pump shaft design. These research achievements will also have a great application prospect.

scholarly journals Results from a recent stellar rotation census of B stars

2010 ◽  
Vol 6 (S272) ◽  
pp. 89-90
Author(s):  
Wenjin Huang ◽  
Douglas R. Gies ◽  
M. Virginia McSwain
Keyword(s):  
Effective Temperature ◽  
Rotation Rate ◽  
Rotation Speed ◽  
Rotational Velocity ◽  
Rotation Velocity ◽  
Be Stars ◽  
Stellar Rotation ◽  
B Stars ◽  
Critical Rotation ◽  
Critical Rotation Speed

AbstractIn an analysis of the rotational properties of more than 1100 B stars (~660 cluster and ~500 field B stars), we determine the projected rotational velocity (V sin i), effective temperature, gravity, mass, and critical rotation speed for each star. The new data provide us a solid observational base to explore many hot topics in this area: Why do field B stars rotate slower than cluster B stars? How fast do B stars rotate when they are just born? How fast can B stars rotate before they become Be stars? How does the rotation rate of B stars change with time? Does the evolutionary change in rotation velocity lead to the Be phenomenon? Here we report the results of our efforts in searching for answers to these questions based on the latest B star census.

Stability Control Analysis of Rotating Plates by Finite Element: Emphasis on Slots and Holes

1972 ◽  
Vol 94 (1) ◽  
pp. 64-70 ◽  
Author(s):  
C. D. Mote
Keyword(s):  
Finite Element ◽  
Thermal Stresses ◽  
Rotation Speed ◽  
Stability Control ◽  
Control Analysis ◽  
Circular Plates ◽  
Critical Speeds ◽  
Critical Rotation ◽  
Critical Instability ◽  
Critical Rotation Speed

Accurate finite element procedures have been developed for the vibration of plates with significant membrane stresses. Thermally stressed, rotating circular plates with peripheral edge slots are examined in detail and the influence of slots upon critical rotation speed instability is clarified. In realistic environments slots can considerably increase critical speeds through the reduction of compressive thermal stresses and the introduction of geometrical assymmetry. Optimization of critical instability speeds is discussed.

scholarly journals The theoretical model for determinig critical rotation speed flexible coupling type SEGE

2018 ◽  
Vol XIX (1) ◽  
pp. 326-329
Author(s):  
Ivanova E
Keyword(s):  
Theoretical Model ◽  
Elastic Element ◽  
Radial Displacement ◽  
Rotation Speed ◽  
Impact Load ◽  
Flexible Coupling ◽  
Critical Rotation ◽  
Critical Rotation Speed ◽  
Elastic Elements ◽  
Coupling Type

It this article was studied a flexible coupling with a rubber elastic element. In exploitation period under one direction load, half of all cylinders are working. All of cylinders are made along with a carrying ring. The elastic elements are subjected to compression. On the non-loaded cylinders, a centrifugal force acts to cause their radial displacement. By the slow rubber relaxation of not loaded cylinders, in the case of reverse and impact load it is danger of can be pinched between the metal claws of semi couplings. Radial displacement and critical rotation speeds were determined, for non-loaded cylinders, in the time which is derived pinching the rubber elastic element.

Stationary Rotation of the Partially Liquid-Filled Unbalanced Rotor under External Friction Force Action

2014 ◽  
Vol 1040 ◽  
pp. 903-906 ◽  
Author(s):  
E.N. Pashkov ◽  
Nikita Martyushev ◽  
Pavel G. Yurovsky
Keyword(s):  
Rotation Speed ◽  
External Friction ◽  
Design Parameters ◽  
Mathematical Research ◽  
Rotating Shaft ◽  
Critical Rotation ◽  
Unbalanced Rotor ◽  
Liquid Type ◽  
Critical Rotation Speed ◽  
Automatic Balancing

Rotor rotation with liquid layer on the chamber wall under viscoelastic action of the shaft within a planar model is examined in the article. The solution to the problem of determining the deflection of a rotating shaft with liquid filled chamber is given, which is important when designing an automatic balancing device. The issue of the cooperative motion of a solid body and liquid is considered in mathematical research. The set task is performed by applying D'Alembert's principle. The modeling results indicate that an increase in liquid’s mass in a rotor decreases its critical rotation speed; at the same time, the external friction accelerates the system’s self-centering. The developed mathematical models enable us to select the design parameters of a liquid-type autobalancer which operates within the set range of rotor’s angular velocity.

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.

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