scholarly journals Investigating external and internal working processes of mining machines when operating on “unclarified” water in underground conditions

2021 ◽  
Vol 6 ◽  
pp. 13-23
Author(s):  
Bulat M Gabbasov1 ◽  
Keyword(s):  
Centrifugal Pump ◽  
Mine Drainage ◽  
Underground Mining ◽  
Mechanical Efficiency ◽  
Practical Experience ◽  
Centrifugal Pumps ◽  
Mining Operations ◽  
Multistage Centrifugal Pump ◽  
Pump Head ◽  
Working Processes

Introduction. The article considers the issues of mine drainage study, including the working processes of the centrifugal pumps pumping “unclarified” water in arduous underground conditions. Such problems resolution is of high practical and scientific importance. Methods of research. Scientific and practical experience in the field of mine drainage was analyzed and generalized. The centrifugal pump modes were considered and promising research tasks in this field were outlined. Thus, the continuous income of groundwater to mine workings requires the uninterrupted operation of pumps. One of the most common types of mine-drainage plants is a multistage centrifugal pump which fulfills its functions to the full if properly operated. However, “unclarified” water pumping requires a new technique for centrifugal pump optimal modes determination in such service conditions. Result and analysis. The study of hydraulic, volumetric, and mechanical efficiency dependency on pump modes, the analysis of working processes within centrifugal pumps when operating on “unclarified” water, and the procedure and calculation of TsNS (multistage centrifugal pump) head-capacity curve were presented in the paper to justify the effectiveness of the presented solutions and conclusions. Scope of results. It is recommended that the research results are introduced in all enterprises conducting underground mining operations with the mine drainage.

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.

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.

Study on the Clearance of Impeller and Draft-Tube on Stamping and Welding Multistage Centrifugal Pump

2010 ◽  
Vol 43 ◽  
pp. 434-437
Author(s):  
Yuan Yi Liu ◽  
Rui Guang Li
Keyword(s):  
Centrifugal Pump ◽  
Design Theory ◽  
Stokes Equations ◽  
Draft Tube ◽  
Outer Edge ◽  
Navier Stokes ◽  
Centrifugal Pumps ◽  
Navier Stokes Equations ◽  
Pressure Distributions ◽  
Multistage Centrifugal Pump

Based on the Renault-averaged Navier-Stokes equations and a standard turbulence model, the different clearance of the outer edge on the impeller and the draft-tube is simulated by the commercial software CFX, in order to achieve optimal performance. The velocity distributions and pressure distributions within the stamping and welding multistage centrifugal pumps are analyzed. The reasonable clearance value which impact on its performance and properties have been discovered. This paper is helpful to improve the design theory of stamping and welding multistage 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.

Response of Blade Thickness to Hydraulic Performance of Stamping and Welding Multistage Centrifugal Pump

2012 ◽  
Vol 229-231 ◽  
pp. 351-356 ◽  
Author(s):  
Jie Gang Mu ◽  
Bo Zhu ◽  
Shui Hua Zheng ◽  
Jian Jun Gan
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Hydraulic Performance ◽  
Downward Trend ◽  
Blade Thickness ◽  
Multistage Centrifugal Pump ◽  
Pump Head ◽  
Cfd Numerical Simulation

Based on CFD numerical simulation, the effect of blade thickness on hydraulic performance was studied in DQ100-64-22 stamping and welding centrifugal pump. Six types of impellers with different blade thickness were assembled in the same pump to be investigated under design condition. The result indicates that both of head and efficiency are getting lower with the increase of blade thickness. Particularly, the downward trend is more striking when the blade thickness surpasses 2mm, but pump head decreases more gently than efficiency as the blade thickness increasing within 2mm.

scholarly journals Numerical Investigation of a First Stage of a Multistage Centrifugal Pump: Impeller, Diffuser with Return Vanes, and Casing

2013 ◽  
Vol 2013 ◽  
pp. 1-15
Author(s):  
Nicolas La Roche-Carrier ◽  
Guyh Dituba Ngoma ◽  
Walid Ghie
Keyword(s):  
Numerical Investigation ◽  
Centrifugal Pump ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Navier Stokes Equations ◽  
Wall Functions ◽  
Multistage Centrifugal Pump ◽  
Pump Head

This paper deals with the numerical investigation of a liquid flow in a first stage of a multistage centrifugal pump consisting of an impeller, diffuser with return vanes, and casing. The continuity and Navier-Stokes equations with the k-ε turbulence model and standard wall functions were used. To improve the design of the pump's first stage, the impacts of the impeller blade height and diffuser vane height, number of impeller blades, diffuser vanes and diffuser return vanes, and wall roughness height on the performances of the first stage of a multistage centrifugal pump were analyzed. The results achieved reveal that the selected parameters affect the pump head, brake horsepower, and efficiency in a strong yet different manner. To validate the model developed, the results of the numerical simulations were compared with the experimental results from the pump manufacturer.

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 Study on Fluid-Structure Interaction for the Multistage High Speed Centrifugal Pumps Rotors

2014 ◽  
Vol 8 (1) ◽  
pp. 899-903
Author(s):  
Tian Yabin ◽  
Wang Jing ◽  
Wang Liang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Centrifugal Pump ◽  
High Speed ◽  
Element Model ◽  
Rotor Dynamics ◽  
Motion Equation ◽  
Centrifugal Pumps ◽  
Multistage Centrifugal Pump ◽  
Coupling Dynamics

In the designing process of high-speed multistage centrifugal pump, in addition to the hydraulic characteristics, the calculation problem of the axis of wet critical speed is the emphasis of concern. On the base of the finite element model of the "dry" state rotor dynamics, when the flow force play a individual role in physical separate discs and cylinder, resistance formula is derived. Establish the "wet" mode of motion equation of rotor disc and shaft section, then integrate the flow force into the motion equation of the whole system unit, we can find the fluid-solid coupling finite element model of the rotor dynamics. Write the calculation procedure with ANSYS APDL language, and the analysis and testing of fluidsolid coupling dynamics program to an actual high-speed multistage centrifugal pump rotor system is done.

Effect of Axial Clearance on the Efficiency of a Shrouded Centrifugal Pump

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Cao Lei ◽  
Zhang Yiyang ◽  
Wang Zhengwei ◽  
Xiao Yexiang ◽  
Liu Ruixiang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Axial Position ◽  
Hydraulic Efficiency ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
Axial Clearance

Clearance always exists between the rotating impeller shrouds and the stationary casing covers in shrouded centrifugal pumps, which affects the pump internal flow and performance. Model tests were conducted for a shrouded centrifugal pump with back blades on the front shroud, and the performance parameters were obtained for three different impeller axial positions. Adjusting the impeller axial position can change the axial size of both the front and back clearances simultaneously. The results show that a tiny variation of the axial clearance size can substantially change the pump performance. A large front clearance reduces the pump efficiency and head with little change in the shaft power. Numerical simulations for a wide range of operating conditions for the three models with different impeller axial positions using the Reynolds-Averaged Navier–Stokes (RANS) with shear stress transport (SST) k–ω turbulence model agree well with the experimental results. The numerical results show how the clearance flow interfere with the main flow as the axial clearance is varied. The change in the pump hydraulic efficiency, volumetric efficiency, and mechanical efficiency was analyzed for various clearances. The hydraulic efficiency is the lowest one of the three kinds of efficiency and changes dramatically as the flow rate increases; thus, the hydraulic efficiency plays a decisive role in the pump performance. The volumetric efficiency is most sensitive to the axial clearance, which obviously decreases as the front clearance is increased. Therefore, the volumetric efficiency is the key factor for the change of the gross efficiency as the axial clearance changes. The mechanical loss varies little with changes in both axial clearance and flow rate so the mechanical efficiency can be regarded as a constant. The effect of axial clearances on the efficiency of shrouded centrifugal pumps should be considered to enable more efficient designs.

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