Erosion processes during non-stationary cavitation of irrigation pumps

The article gives the main results of the study of the dynamics of wear of the working bodies of irrigation pumps, gives the main recommendations as a result of the study of pumping units in the presence of cavitation. The authors consider the cavitation coefficient as the minimum value of this expression, at which the beginning of cavitation is detected. The process of unsteady cavitation is accompanied by many significant effects in which the water flow becomes two-phase, with a corresponding change in its properties, which affects the pump's efficiency. The effect of particle size on the erosion rate is predominant only up to a certain size limit, i.e., 600-800 microns on the blades. After that, the erosion rate increases with a comparatively slower rate. This indicates that the particle size affects the erosion rate only up to a certain particle size.

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Numerical Study on the Erosion Characteristics of U-Type Bend for Gas Solid Flow

Volume 2: I&C, Digital Controls, and Influence of Human Factors; Plant Construction Issues and Supply Chain Management; Plant Operations, Maintenance, Aging Management, Reliability and Performance; Renewable Energy Systems: Solar, Wind, Hydro and Geothermal; Risk Management, Safety and Cyber Security; Steam Turbine-Generators, Electric Generators, Transformers, Switchgear, and Electric BOP and Auxiliaries; Student Competition; Thermal Hydraulics and Computational Fluid Dynamics ◽

10.1115/power-icope2017-3412 ◽

2017 ◽

Cited By ~ 1

Author(s):

Yu Wang ◽

Qi He ◽

Ming Liu ◽

Weixiong Chen ◽

Junjie Yan

Keyword(s):

Particle Size ◽

Erosion Rate ◽

Loading Rate ◽

Pipe Wall ◽

Numerical Study ◽

Pulverized Coal ◽

Mass Loading ◽

Two Phase ◽

Inlet Velocity ◽

Pipe System

In pulverized coal-fired plant, the U-type bend is commonly used in flue gas and pulverized coal pipe system to due to the constraints of outer space. And gas-solid two-phase flow exists in these pipelines. The erosion of the pipe has significant effect on the safety and reliability of pipelines. In present paper, the erosion characteristics of U-type bend were investigated through CFD (Computational Fluid Dynamics) method. The wear distribution on the pipe wall was obtained. And the particle flow characteristics in U-type bend were analyzed. The influence of inlet velocity, mass loading rate and particle size on the erosion rate was studied as well. Result suggested that the maximum erosion rate increases exponentially with the increase of inlet velocity. And maximum erosion rate increases linearly with the increasing mass loading rate. Increasing particle size can aggravate the wear on the pipe wall.

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Experimental Investigation on the Influence of Particle Size in a Submerged Slurry Jet on Erosion Rates and Patterns

Volume 1C, Symposia: Gas-Liquid Two-Phase Flows; Gas and Liquid-Solid Two-Phase Flows; Numerical Methods for Multiphase Flow; Turbulent Flows: Issues and Perspectives; Flow Applications in Aerospace; Fluid Power; Bio-Inspired Fluid Mechanics; Flow Manipulation and Active Control; Fundamental Issues and Perspectives in Fluid Mechanics; Transport Phenomena in Energy Conversion From Clean and Sustainable Resources; Transport Phenomena in Materials Processing and Manufacturing Processes ◽

10.1115/fedsm2017-69350 ◽

2017 ◽

Cited By ~ 1

Author(s):

Soroor Karimi ◽

Amir Mansouri ◽

Siamack A. Shirazi ◽

Brenton S. McLaury

Keyword(s):

Particle Size ◽

Erosion Rate ◽

Erosive Wear ◽

Impact Angle ◽

Piping System ◽

Slurry Erosion ◽

Material Particle ◽

Impact Speed ◽

Effect Of Particle Size ◽

Sand Particles

Sand particles entrained in fluids can cause erosive wear and damage to piping materials by impacting their surfaces which could result in failure of the piping system. Several parameters have been determined to affect the erosion behavior and mechanism of solid particle erosion. Some of these parameters include surface material, particle impact speed and angle, and particle size, shape and hardness. However, the effect of particle size on the total erosion rate and local erosion pattern has not been thoroughly investigated. It has been observed that sand particles with various sizes cause different slurry erosion patterns. Changing the particle size alters the Stokes number and consequently produces different erosion patterns and magnitudes. Thus, the effects of particle size on total erosion rate and erosion pattern in a submerged slurry jet are investigated for different impingement angles. Experiments are performed on 316 stainless steel specimens for average particles sizes of 25, 75, 150, and 300 μm. The jet angle is varied to 45, 75 and 90 degrees, and the slurry jet velocity is set to 14 m/s. The erosion pattern of the specimen is examined by obtaining the 3D microscopic profile of the eroded specimen by means of an optical profiler. It is found that the erosion profile changes as the jet angle varies. It is also observed that erosion profile is significantly different for smaller particles as compared to the larger particles. Moreover, these differences become more pronounced as the jet angle decreases. The present work discusses the differences of erosion patterns produced by both large and small particles. Computational Fluid Dynamics (CFD) is also used to study the effect of particle size on particle trajectories, impact speed, and impact angle. Also, CFD results help in explaining the differences observed in the erosion profiles caused by different particle sizes.

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