期刊文献+
共找到1,438篇文章
< 1 2 72 >
每页显示 20 50 100
Clogging caused by coupled grain migration and compaction effect during groundwater recharge for unconsolidated sandstone reservoir in groundwater-source heat pump
1
作者 Fujian Yang Jing Luo +3 位作者 Guiling Wang Hejuan Liu Dawei Hu Hui Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期2947-2959,共13页
In unconsolidated sandstone reservoirs,presence of numerous movable grains and a complex grain size composition necessitates a clear understanding of the physical clogging process for effective groundwater recharge in... In unconsolidated sandstone reservoirs,presence of numerous movable grains and a complex grain size composition necessitates a clear understanding of the physical clogging process for effective groundwater recharge in groundwater-source heat pump systems.To investigate this,a series of seepage experiments was conducted under in situ stress conditions using unconsolidated sandstone samples with varying grain compositions.The clogging phenomenon arises from the combined effects of grain migration and compaction,wherein the migration of both original and secondary crushed fine-grain particles blocks the seepage channels.Notably,grain composition influences the migration and transport properties of the grains.For samples composed of smaller grains,the apparent permeability demonstrates a transition from stability to decrease.In contrast,samples with larger grains experience a skip at the stability stage and directly enter the decrease stage,with a minor exception of a slight increase observed.Furthermore,a unique failure mode characterized by diameter shrinkage in the upper part of the sample is observed due to the combined effects of grain migration and in situ stress-induced compaction.These testing results contribute to a better understanding of the clogging mechanism caused by the coupled effects of grain migration and compaction during groundwater recharge in unconsolidated sandstone reservoirs used in groundwater-source heat pump systems. 展开更多
关键词 Groundwater-source heat pump clogGING Grain migration Compaction effect Groundwater recharge Unconsolidated sandstone
下载PDF
Consolidation of high replacement ratio stone column-reinforced ground:Analytical solutions incorporating clogging effect
2
作者 Jinxin Sun Mengmeng Lu +1 位作者 Baolong Xu Jie Shan 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期3311-3326,共16页
The utilization of stone columns has emerged as a popular ground improvement strategy,whereas the drainage performance can be adversely hampered by clogging effect.Despite the ample progress of calculation methods for... The utilization of stone columns has emerged as a popular ground improvement strategy,whereas the drainage performance can be adversely hampered by clogging effect.Despite the ample progress of calculation methods for the consolidation of stone column-improved ground,theoretical investigations into the clogging effect have not been thoroughly explored.Furthermore,it is imperative to involve the column consolidation deformation to mitigate computational error on the consolidation of composite ground with high replacement ratios.In this context,an analytical model accounting for the initial clogging and coupled time and depth-dependent clogging of stone columns is established.Then,the resulting governing equations and analytical solutions are obtained under a new flow continuity relationship to incorporate column consolidation deformation.The accuracy and reliability of the proposed model are illustrated by degradation analysis and case studies with good agreements.Subsequently,the computed results of the current study are juxtaposed against the existing models,and an in-depth assessment of the impacts of several crucial parameters on the consolidation behavior is conducted.The results reveal that ignoring column consolidation deformation leads to an overestimate of the consolidation rate,with maximum error reaching up to 16%as the replacement ratio increases.Furthermore,the initial clogging also has a significant influence on the consolidation performance.Additionally,the increment of depth and time-clogging factors a and b will induce a noticeable retardation of the consolidation process,particularly in the later stage. 展开更多
关键词 CONSOLIDATION Composite ground Stone column clogging effect Ground improvement Analytical model
下载PDF
Experimental Study on Clogging Characteristics of Silt Soft Soil in Nansha District of Guangzhou
3
作者 Dengheng Zheng Yueqin Wu +1 位作者 Huibing Cheng Jijie Du 《Open Journal of Applied Sciences》 2024年第10期2835-2849,共15页
The silt soft soil in Nansha District of Guangzhou was the softest soft soil in China. It had the characteristics of high natural water content, high compressibility, long consolidation time, and complex layered distr... The silt soft soil in Nansha District of Guangzhou was the softest soft soil in China. It had the characteristics of high natural water content, high compressibility, long consolidation time, and complex layered distribution of soil layers. These characteristics formed the clogging characteristics of silt soft soil, which greatly increased the construction difficulty and hindered the construction progress. Therefore, based on the basic physical and mechanical properties of silt soft soil in Nansha District of Guangzhou, this paper evaluated the clogging characteristics of three silt soft soil areas in Nansha District of Guangzhou through long-term permeability test, and carried out scanning electron microscope test to explore the influence of different parameters and microstructure on the clogging difficulty of silt soft soil. The results showed that the silt soft soil Zone I and Zone II (shallow layer) in Nansha District of Guangzhou were divided into slight siltation levels, and the silt soft soil Zone III (deep layer) was mild siltation level. Large pores were widely distributed in shallow silt soft soil, while the continuity of large pores in deep silt soft soil was poor. The migration of fine particles that failed to establish contact with surrounding particles in the soil blocks the small pores of seepage and thus produces siltation. 展开更多
关键词 Silt Soft Soil clogging Characteristics Permeability Coefficient MICROSTRUCTURE
下载PDF
Flow-Induced Clogging in Microfiltration Membranes: Numerical Modeling and Parametric Study
4
作者 Abdullah Rajah Al Qahtani 《Journal of Water Resource and Protection》 2023年第12期692-705,共14页
Microfiltration membrane technology has been widely used in various industries for solid-liquid separation. However, pore clogging remains a persistent challenge. This study employs (CFD) and discrete element method (... Microfiltration membrane technology has been widely used in various industries for solid-liquid separation. However, pore clogging remains a persistent challenge. This study employs (CFD) and discrete element method (DEM) models to enhance our understanding of microfiltration membrane clogging. The models were validated by comparing them to experimental data, demonstrating reasonable consistency. Subsequently, a parametric study was conducted on a cross-flow model, exploring the influence of key parameters on clogging. Findings show that clogging is a complex phenomenon affected by various factors. The mean inlet velocity and transmembrane flux were found to directly impact clogging, while the confinement ratio and cosine of the membrane pore entrance angle had an inverse relationship with it. Two clog types were identified: internal (inside the pore) and external (arching at the pore entrance), with the confinement ratio determining the type. This study introduced a dimensionless number as a quantitative clogging indicator based on transmembrane flux, Reynolds number, filtration time, entrance angle cosine, and confinement ratio. While this hypothesis held true in simulations, future studies should explore variations in clogging indicators, and improved modeling of clogging characteristics. Calibration between numerical and physical times and consideration of particle volume fraction will enhance understanding. 展开更多
关键词 Microfiltration Membrane Parametric Study Computational Fluid Dynamic (CFD) Discrete Element Method (DEM) CFD-DEM Modeling Membrane clogging Pore Geometry Numerical Modeling Cake Layer clogging Indicator
下载PDF
On the critical particle size of soil with clogging potential in shield tunneling 被引量:5
5
作者 Shuying Wang Zihao Zhou +3 位作者 Pengfei Liu Zhao Yang Qiujing Pan Weizhong Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第2期477-485,共9页
Shield tunneling is easily obstructed by clogging in clayey strata with small soil particles.However,soil clogging rarely occurs in strata with coarse-grained soils.Theoretically,a critical particle size of soils shou... Shield tunneling is easily obstructed by clogging in clayey strata with small soil particles.However,soil clogging rarely occurs in strata with coarse-grained soils.Theoretically,a critical particle size of soils should exist,below which there is a high risk of soil clogging in shield tunneling.To determine the critical particle size,a series of laboratory tests was carried out with a large-scale rotary shear apparatus to measure the tangential adhesion strength of soils with different particle sizes and water contents.It was found that the tangential adhesion strength at the soilesteel interface gradually increased linearly with applied normal pressure.When the particle size of the soil specimen was less than 0.15 mm,the interfacial adhesion force first increased and then decreased as the water content gradually increased;otherwise,the soil specimens did not manifest any interfacial adhesion force.The amount of soil mass adhering to the steel disc was positively correlated with the interfacial adhesion force,thus the interfacial adhesion force was adopted to characterize the soil clogging risk in shield tunneling.The critical particle size of soils causing clogging was determined to be 0.15 mm.Finally,the generation mechanism of interfacial adhesion force was explored for soils with different particle sizes to explain the critical particle size of soil with clogging risk in shield tunneling. 展开更多
关键词 Shield tunneling Soil clogging ADHESION Critical particle size
下载PDF
Scaling and clogging treatment of aging tunnel drainage pipes in karst areas using eco-friendly acid agent 被引量:1
6
作者 Zhipeng Xu Xuemei Wang +2 位作者 Chunfang Zhang Dejian Zeng Changwu Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第4期896-910,共15页
In karst areas,the drainage pipes of aging tunnels are prone to be clogged by precipitated carbonates,resulting in lining cracking and tunnel leaking.As a result,not only the driving safety will be deteriorated,but al... In karst areas,the drainage pipes of aging tunnels are prone to be clogged by precipitated carbonates,resulting in lining cracking and tunnel leaking.As a result,not only the driving safety will be deteriorated,but also the water pressure on the lining might also be elevated significantly.For the structural stability and service lifespan of old tunnels,it is of great importance to remove these precipitated carbonates in time.Traditional treatment methods are often destructive to some extent or not efficient enough.This study aims to experimentally develop an eco-friendly acid-based chemical cleaning method to remove carbonate precipitations efficiently.The proposed chemical cleaning agent is an aqueous solution with strong acidity,consisting of sulfamic acid,water,and additives.The factors affecting the cleaning efficiency include the acid solubility,temperature and flow rate of the cleaning agent,as well as additives.Elevating the solution temperature to 50C or a flow rate of no less than 0.2 m/s can improve cleaning efficiency.Although the salt effect cannot work,1 wt%of polymaleic acid as a surfactant could further promote the cleaning rate.The cleaning efficiency will increase with the flow rate in a power function.The relatively low flow rate that improves the cleaning rate considerably can avoid highpressure-induced mechanical damage to tunnel drainpipes.The waste could be easily treated to acceptable levels using commercial sewage treatment products and can also be recycled in agriculture.With the chemical cleaning,the water pressure at the arch springing of the lining will reduce with the increased radius of transverse drainpipes in a power function.The proposed acid-based cleaning method,which is highly efficient,non-or low-destructive to aging tunnels,sufficiently safe for humans,and friendly enough to the environment,will offer a promising alternative to remove the precipitated carbonates in tunnel drainpipes efficiently. 展开更多
关键词 clogGING SCALING Carbonate precipitation Acid treatment Water pressure on the lining Aging tunnel KARST
下载PDF
Flow and clogging in a horizontal silo with a rotary obstacle
7
作者 徐聪聪 史庆藩 +1 位作者 刘伟 郑宁 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期467-472,共6页
The external perturbation applied to a silo and the placement of an immobile obstacle before an exit are two common and effective ways to diminish clogging in the hopper/silo flow.Here,we incorporate the local perturb... The external perturbation applied to a silo and the placement of an immobile obstacle before an exit are two common and effective ways to diminish clogging in the hopper/silo flow.Here,we incorporate the local perturbation into a fixed obstacle,and experimentally explore the effects of a rotary obstacle on clogging and the flowing characteristics in the horizontal silo flow driven by a conveyor belt.Even with a low spin rate,the total blocking probability that a particle constructs a stable blocking arch with its neighbors significantly drops.Correspondingly,the average flow rate of the particles through the exit abruptly rises,at least 1 order of magnitude better than that with an immobile obstacle and approaching the flow rate of continuous flow.The rotation enhances the breakage of clogging arches,which is responsible for improving the flowability in the horizontal silo.In addition,there always exists an optimal obstacle position at which the total blocking probability is minimal and the average flow rate peaks,regardless of the spin rate.Finally,clogging is relieved with the increase of the driving velocity of the conveyor belt,showing a“fast is fast”effect that is opposite to the“fast is slow”effect in other systems such as crowd evacuation and gravity-driven hoppers. 展开更多
关键词 granular flow clogGING OBSTACLE ROTATION
下载PDF
Column test-based features analysis of clogging in artificial recharge of groundwater in Beijing 被引量:1
8
作者 NAN Tian SHAO Jing-li CUI Ya-li 《Journal of Groundwater Science and Engineering》 2016年第2期88-95,共8页
With the completion of South-North Water Transfer Project in China, plenty of high quality water will be transported to Beijing. To restore the groundwater level in Beijing, part of transferred water is planned to be ... With the completion of South-North Water Transfer Project in China, plenty of high quality water will be transported to Beijing. To restore the groundwater level in Beijing, part of transferred water is planned to be used for artificial recharge. Clogging is an unavoidable challenge in the artificial recharge process. Therefore, a test is designed to analyse clogging duration and scope of influence and to test the reinjection properties of different recharge media. The test employs the self-designed sand column system with variable spacing and section monitoring, composed of four parts: Sand column, water-supply system, pressure-test system and flow-test system, to simulate the clogging of artificial recharge of sand and gravel pits. The hydraulic conductivity levels of all sand column sections are obtained to analyse the clogging of the injection of different concentrations in media of different particle sizes. In this experiment, two kinds of media are used–round gravel from sand and gravel pit in Xihuang village and the sand from sand and gravel pit by the Yongding River. The concentrations of recharge fluid are respectively 0.5 g/L and 1 g/L. The results show that clogging usually lasts for 20 hrs., and the hydraulic conductivity drops to the original 10%. Clogging usually occurs at 0–12 cm section of the sand column. The scope of influence is 0–60 cm. In column 3 and 4, whose average particle sizes are larger, section 20–50 cm also suffers from clogging, apart from section 0–12 cm. The effective recharge times are respectively 33 hrs. in column 1, 14 hrs. in column 2, 12 hrs. in column 3 and 12 hrs. in column 4. The larger the average particle size is, the quicker the clogging occurs. In media of larger particles, the change in suspension concentration does not have significant influence on the development of clogging. In conclusion, it is suggested that during artificial recharge, the conditions of reinjection medium should be fully considered and effective method of recharge be employed in order to improve effective recharge time. 展开更多
关键词 Recharge clogging test Recharge conditions Hydraulic conductivity clogging scope of influence clogging rate
下载PDF
Effects of Hydraulic Loading of Vertical Flow Constructed Wetland Clogging 被引量:1
9
作者 王小毛 许巧玲 +1 位作者 崔理华 李国婉 《Agricultural Science & Technology》 CAS 2014年第11期2030-2034,共5页
[Objective] The aim was to al eviate the constructed wetland clogging problems and to explore to the effects of hydraulic loading on wetland clogging. [Method] The experiment, through artificial soil columns, simulate... [Objective] The aim was to al eviate the constructed wetland clogging problems and to explore to the effects of hydraulic loading on wetland clogging. [Method] The experiment, through artificial soil columns, simulated vertical flow arti-ficial wetland, set four hydraulic load level at 50, 100, 150 and 200 cm/d, to identify the impact of hydraulic loading on wetland clogging and to explore the factors run-ning threshold. [Result] The results show that the different levels of hydraulic loading have greater impact; in the constructed wetland clogging process under high hy-draulic loading of 200 cm/d, the effective life was only six months, and the single factor can be speculated that the threshold of the hydraulic load should be at 100-150 cm/d; system can last for six months at low hydraulic loading and last for three months at medium hydraulic load. [Conclusion] The research provides references for wetland clogging experiments in future. 展开更多
关键词 Vertical flow constructed wetlands clogging Hydraulic loading Threshold
下载PDF
Research on effect of clogging process on permeability of loose dam foundation of plateau reservoir
10
作者 XU Wenming ZHAO Shuyun WANG Gangcheng 《Global Geology》 2012年第4期291-296,共6页
Taking Zhuoyu reservoir in Shannan of Tibet as the test site,the authors collected soil samples for laboratory analysis,and devised infiltration-clogging equipment for laboratory test to research the effect of cloggin... Taking Zhuoyu reservoir in Shannan of Tibet as the test site,the authors collected soil samples for laboratory analysis,and devised infiltration-clogging equipment for laboratory test to research the effect of clogging process on permeability of loose dam foundation of plateau reservoir.Through laboratory test,the soil can cause clogging effect by itself,and the effect of clogging is relative to the water pressure.The clogging effect can be caused obviously by adding fine particles,and the clogging effect of the particles with 0.063-0.25 mm diameter is best,which verifies the rationality of the optimal diameter interval.It provides the realistic significance for the anti-seepage of the plateau reservoir dam foundation. 展开更多
关键词 clogging test clogging effect PERMEABILITY diameter interval
下载PDF
Clogging processes caused by biofilm growth and organic particle accumulation in lab-scale vertical flow constructed wetlands 被引量:34
11
作者 ZHAO Lianfang ZHU Wei TONG Wei 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第6期750-757,共8页
The accumulation of organic matter in substratum pores is regarded as an important factor causing clogging separately in the subsurface flow constructed wetlands.In this study,the developing process of clogging caused... The accumulation of organic matter in substratum pores is regarded as an important factor causing clogging separately in the subsurface flow constructed wetlands.In this study,the developing process of clogging caused by biofilm growth or organic particle accumulation instead of total organic matter accumulation was investigated in two groups of lab-scale vertical flow constructed wetlands(VFCWs),which were fed with glucose(dissolved organic matter) and starch(particulate organic matter) influent.Results showed that the growth of biofilms within the substratum pores certainly caused remarkable reduction of effective porosity,especially for the strong organic wastewater,whereas its influence on infiltration rate was negligible.It was implied that the most important contribution of biofilm growth to clogging was accelerating the occurrence of clogging.In comparison with biofilm growth,particles accumulation within pores could rapidly reduce infiltration rate besides effective porosity and the clogging occurred in the upper 0-15 cm layer.With approximately equal amount of accumulated organic matter,the effective porosity of the clogged layer in starch-fed systems was far less than that of glucose-fed systems,which indicated that composition and accumulation mode in addition to the amount of the accumulated organic matter played an important role in causing clogging. 展开更多
关键词 clogGING constructed wetland organic matter particle accumulation biofilms
下载PDF
Clogging behavior of submerged entry nozzles for Ti-bearing IF steel 被引量:20
12
作者 Heng Cui Yan-ping Bao Min Wang Wei-shuang Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第2期154-158,共5页
The nozzle clogging behavior of Ti-bearing IF steel was studied by metallographic analysis,scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).According to the exper... The nozzle clogging behavior of Ti-bearing IF steel was studied by metallographic analysis,scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).According to the experimental results,nozzle clogging primarily appears three layers.There are a lot of large-sized iron particles in the inner layer and mainly slag phase in the middle and outer layers.The principal clog constituents of the inner layer are loose alumina cluster inclusions and granular shaped alumina inclusions,containing iron particles. The clog constituents of the middle layer are mainly dendrite alumina inclusions.The primary phases existing in nozzle clogging are FeO·TiO2 and FeO·Al2O3 besidesα-Al2O3 and a-Fe.The FeO·TiO2 phases among the deposits adhere the deposits together firmly enough to lead to the inferior castability of Ti-bearing ultra low carbon steel compared with that of Ti-free low carbon Al-killed steel. 展开更多
关键词 submerged entry nozzle nozzle clogging IF steel INCLUSION
下载PDF
Tomato Yield and Quality and Emitter Clogging as Affected by Chlorination Schemes of Drip Irrigation Systems Applying Sewage Effluent 被引量:13
13
作者 LI Jiu-sheng LI Yan-feng ZHANG Hang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第10期1744-1754,共11页
Chlorination has been recognized as an efficient and economically favorable method for treating clogging in drip emitters caused by biological growth during sewage application. Further important criteria for determini... Chlorination has been recognized as an efficient and economically favorable method for treating clogging in drip emitters caused by biological growth during sewage application. Further important criteria for determining an optimal chlorination scheme are the different responses of crops to the chloride added into the soil through chlorination. During two seasons in 2008 and 2009, field experiments were conducted in a solar-heated greenhouse with drip irrigation systems applying secondary sewage effluent to tomato plants to investigate the influences of chlorine injection intervals and levels on plant growth, yield, fruit quality, and emitter clogging. Injection intervals ranging from 2 to 8 wk and injection concentrations ranging 2-50 mg L-1 of free chlorine residual at the end of the laterals were used. For the 2008 experiments, the yield from the treatments of sewage application with chlorination was 7.5% lower than the yield from the treatment of sewage application without chlorination, while the yields for the treatments with and without chlorination were similar for the 2009 experiments. The statistical tests indicated that neither the chlorine injection intervals and concentrations nor the interactions between the two significantly influenced plant height, leaf area, or tomato yield for both years. The qualities of the fruit in response to chlorination were parameter-dependent. Chlorination did not significantly influence the quality of ascorbic acid, soluble sugar, or soluble acids, but the interaction between the chlorine injection interval and the chlorine concentration significantly influenced the levels of soluble solids. It was also confirmed that chlorination was an effective method for reducing biological clogging. These results suggested that chlorination is safe for a crop that has a moderate sensitivity to chlorine, like tomato, and can maintain a high level of performance in drip irrigation systems applying sewage effluent. 展开更多
关键词 CHLORINATION drip irrigation emitter clogging fruit quality TOMATO sewage effluent YIELD
下载PDF
Biofilm structure and its influence on clogging in drip irrigation emitters distributing reclaimed wastewater 被引量:4
14
作者 YAN Dazhuang BAI Zhihui +3 位作者 Mike Rowan GU Likun Ren Shumei YANG Peiling 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第6期834-841,共8页
Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter ... Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter clogging in drip irrigation systems distributing reclaimed wastewater.Little is known about the biofilm structure and its influence on clogging in the drip emitter flow path.This study was first to investigate the microbial characteristics of mature biofilms present in the emitters and the effect of flow path structures on the biofilm microbial communities.The analysis of biofilm matrix structure using a scanning electron microscopy(SEM) revealed that particles in the matrix of the biofilm coupled extracellular polysaccharides(EPS) and formed sediment in the emitter flow path.Analysis of biofilm mass including protein,polysaccharide,and phospholipid fatty acids(PLFAs) showed that emitter flow path style influenced biofilm community structure and diversity.The correlations of biofilm biomass and discharge reduction after 360 h irrigation were computed and suggest that PFLAs provide the best correlation coeffcient.Comparatively,the emitter with the unsymmetrical dentate structure and shorter flow path(Emitter C) had the best anti-clogging capability.By optimizing the dentate structure,the internal flow pattern within the flow path could be enhanced as an important method to control the biofilm within emitter flow path.This study established electron microscope techniques and biochemical microbial analysis methods that may provide a framework for future emitter biofilm studies. 展开更多
关键词 emitter clogging drip irrigation BIOFILM microbial community phospholipid fatty acid reclaimed wastewater scanningelectron microscopy
下载PDF
Online forecasting model of tundish nozzle clogging 被引量:3
15
作者 Fangming Yuan Xinghua Wang +1 位作者 Jiongming Zhang Li Zhang 《Journal of University of Science and Technology Beijing》 CSCD 2006年第1期21-24,共4页
A nozzle clogging online forecasting model based on hydrodynamics engineering was developed, in which the actual flow rate was calculated from the mold width, thickness, and casting speed. There is a linear relationsh... A nozzle clogging online forecasting model based on hydrodynamics engineering was developed, in which the actual flow rate was calculated from the mold width, thickness, and casting speed. There is a linear relationship between the theoretical flow rate and the slide gate opening ratio as the molten steel level, argon flow rate, and the top slag weight are kept constant, and the relationship can be obtained by regression of the data collected at the beginning of the first heat in each casting sequence when the nozzle clogging does not occur. Then, during the casting, the theoretical flow rate can be calculated at intervals of one second. Comparing the theoretical flow rate with the actual flow rate, the online nozzle clogging ratio can be obtained at intervals of one second. The computer model based on the conception of the nozzle clogging ratio can display the degree of the nozzle clogging intuitively. 展开更多
关键词 continuous casting tundish nozzle clogGING online forecasting model
下载PDF
Influence of submerged entry nozzle clogging on the behavior of molten steel in continuously cast slab molds 被引量:4
16
作者 Huixiang Yu Guosen Zhu Xinhua Wang Jiongming Zhang Wanjun Wang 《Journal of University of Science and Technology Beijing》 CSCD 2005年第4期303-307,共5页
The influence of submerged entry nozzle clogging on the behavior of molten steel in continuously cast slab molds was studied using commercial code CFX4.3. The results indicate that clogging at the top part of the nozz... The influence of submerged entry nozzle clogging on the behavior of molten steel in continuously cast slab molds was studied using commercial code CFX4.3. The results indicate that clogging at the top part of the nozzle port not only increases the velocity of molten steel, but also enhances the wall shear stress, F number and heat flux. This clogging has the greatest effect on the behavior of molten steel. However, clogging at the top 1/3 of the nozzle only increases the velocity of molten steel and has little influence. Clogging at the bottom of the nozzle almost has no influence. 展开更多
关键词 clogGING submerged entry nozzle MOLD continuously cast slab numerical simulation
下载PDF
NUMERICAL SIMULATION OF 3-D DENSE SOLID-LIQUID TWO-PHASE TURBULENT FLOW IN A NON-CLOGGING MUD PUMP 被引量:10
17
作者 YuanShouqi ZhangPei~ng ZhangJinfeng XuWeixinq 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第4期623-627,共5页
A mathematical model is set to evaluate the 3-D dense solid-liquid two-phaseturbulent flow in a non-clogging mud pump, the flow feature in the impeller channel is simulatedwith the tool of IPSA. Meanwhile, resort to T... A mathematical model is set to evaluate the 3-D dense solid-liquid two-phaseturbulent flow in a non-clogging mud pump, the flow feature in the impeller channel is simulatedwith the tool of IPSA. Meanwhile, resort to TECPLOT as the post-processor, the simulation results isvisualized. The results show the main flow characteristics: There exists backflow and aberrantvelocities at inlet area and a relative velocity slip between two phases; A jet-wake flow pattern isdiscerned around the shroud-suction side area; The relative velocity vector of solid phase iscloser to the pressure surface than that of liquid phase and the trend is more obvious with theincrease of diameter; The kinetic energy of turbulence k and the dissipation rate e reach theirpeaks at the corner of pressure and suction surface. The simulation results show a good agreementwith the experimental flow features in the impeller channel, which prove the turbulent model used isvalid and provide a theoretical design basis to non-clogging pumps. 展开更多
关键词 Non-clogging pump Two-phase flow Turbulent flow Numerical simulation
下载PDF
Effect of drip irrigation method, nitrogen source, and flushing schedule on emitter clogging 被引量:3
18
作者 Mohamed Yousif Tayel Sabreen Khalil Pibars Hani Abdel-Ghani Mansour 《Agricultural Sciences》 2013年第3期131-137,共7页
Field experiments were carried out at the National Research Center farm, Nubaria area, Behura Governorate, Egypt, to study the effect of nitrogen source, flushing schedule and irrigation method on emitter clogging. Pe... Field experiments were carried out at the National Research Center farm, Nubaria area, Behura Governorate, Egypt, to study the effect of nitrogen source, flushing schedule and irrigation method on emitter clogging. Peanut Giza 5 variety (Arachishy pogaea L.) was planted in sandy soil during two successive growing seasons (2010-2011) in the 1st week of May and harvested after 130 days. Treatments used are: 1) two irrigation methods: surface drip irrigation and sub-surface drip irrigation (SDI;SSDI), 2) nitrogen source (NS):NH4NO3, (NH4)2SO4 and Ca(NO3)2 (NS1, NS2 and NS3) and 3) flushing number (FL) 0, 1 and 4 (FL1, FL2;FL3). The experiments design was split-split plot and three replicates were used. Data obtained were subjected to statistical analysis. The main effects of treatments used on clogging per cent could be written the following ascending orders: SDI 3 2 1, NS1 2 3. Concerning the 1st interaction the following ascending orders denote their effects on clogging percent: SDI × FL3 2 1, SDI × NS1 2 3, SSDI × FL3 2 1, SSDI × NS1 2 3, FL1 × NS1 1 × NS2 1 × NS3, FL2 × NS1 2 × NS2 2 × NS3 and FL3 × NS1 3 × NS2 3 × NS3. The differences between any two treatments and/or any two interactions in clogging percent were significant at the 5% level. The effect of the 2nd interaction on clogging percent was significant at the 5% level. The maximum value of clogging (20.18%) and the lowest one (3.9%) were archived in the interactions: SSDI × FL1 × NS3 and SDI × FL3 × NS1, respectively. 展开更多
关键词 IRRIGATION METHOD Nitrogen Source FLUSHING Number Water and Soil Analysis EMITTER clogGING
下载PDF
Clogging mechanism in the process of reinjection of used geothermal water: A simulation research on Xianyang No.2 reinjection well in a super-deep and porous geothermal reservoir 被引量:1
19
作者 MA Zhi-yuan XU Yong +1 位作者 ZHAI Mei-jing WU Min 《Journal of Groundwater Science and Engineering》 2017年第4期311-325,共15页
In the process of geothermal exploitation and utilization, the reinjection amount of used geothermal water in super-deep and porous reservoir is small and significantly decreases over time. This has been a worldwide p... In the process of geothermal exploitation and utilization, the reinjection amount of used geothermal water in super-deep and porous reservoir is small and significantly decreases over time. This has been a worldwide problem, which greatly restricts the exploitation and utilization of geothermal resources. Based on a large amount of experiments and researches, the reinjection research on the tail water of Xianyang No.2 well, which is carried out by combining the application of hydrogeochemical simulation, clogging mechanism research and the reinjection experiment, has achieved breakthrough results. The clogging mechanism and indoor simulation experiment results show: Factors affecting the tail water reinjection of Xianyang No.2 well mainly include chemical clogging, suspended solids clogging, gas clogging, microbial clogging and composite clogging, yet the effect of particle migration on clogging has not been found; in the process of reinjection, chemical clogging was mainly caused by carbonates(mainly calcite), silicates(mainly chalcedony), and a small amount of iron minerals, and the clogging aggravated when the temperature rose; suspended solids clogging also aggravated when the temperature rose, which showed that particles formed by chemical reaction had a certain proportion in suspended solids. 展开更多
关键词 Xianyang Super-deep and POROUS GEOTHERMAL reservoir REINJECTION clogGING MECHANISM
下载PDF
Evaluating the Clogging Behavior of Pervious Concrete(PC)Using the Machine Learning Techniques 被引量:1
20
作者 Jiandong Huang Jia Zhang Yuan Gao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第2期805-821,共17页
Pervious concrete(PC)is at risk of clogging due to the continuous blockage of sand into it during its service time.This study aims to evaluate and predict such clogging behavior of PC using hybrid machine learning tec... Pervious concrete(PC)is at risk of clogging due to the continuous blockage of sand into it during its service time.This study aims to evaluate and predict such clogging behavior of PC using hybrid machine learning techniques.Based on the 84 groups of the dataset developed in the earlier study,the clogging behavior of the PC was determined by the algorithm combing the SVM(support vector machines)and particle swarm optimization(PSO)methods.The PSO algorithm was employed to adjust the hyperparameters of the SVM and verify the performance using 10-fold cross-validation.The predicting results of the developed model were assessed by the coefficient of determination(R)and root mean square error(RMSE).The importance of the influential variables on the clogging behavior of PC was evaluated as well.The results showed that the PSO algorithm can effectively adjust the hyperparameters of the SVM model and can be used to construct the predictive model for the clogging behavior of the PC.The combined algorithm has the advantage of higher reliability and validity than the random hyperparameters selection.For the verification process,the developed model was able to obtain values of 0.9469 and 1.8148 for the R and RMSE,showing that the developed machine learning model can accurately be used to evaluate and predict the clogging behavior of the PC,guiding the mix-design of PC from the perspective of durability.The size of the clogging sand is the most important parameter and the thickness of the sample is the least significant factor affecting the clogging behavior.The proportions of the smallest aggregate size and largest aggregate size are the two most important design parameters of concrete with the consideration of the relatively higher importance scores,showing these two aggregates should be given special attention in future PC design for anti-clogging purposes. 展开更多
关键词 clogging behavior pervious concrete SVM PSO
下载PDF
上一页 1 2 72 下一页 到第
使用帮助 返回顶部