期刊文献+
共找到15篇文章
< 1 >
每页显示 20 50 100
Evaluation of the Air Leakage Flowrate in Sintering Processes
1
作者 Jin Cai Xiangwei Kong Mingzhu Yu 《Fluid Dynamics & Materials Processing》 EI 2023年第11期2791-2812,共22页
Iron ore sintering is a pre-treatment technology by which orefines are converted into porous and permeable sin-ters,which are the used in blast furnaces.This process can be adversely affected by air leakage phenomena ... Iron ore sintering is a pre-treatment technology by which orefines are converted into porous and permeable sin-ters,which are the used in blast furnaces.This process can be adversely affected by air leakage phenomena of various types.As experimental measurements are relatively difficult and often scarcely reliable,here a theoretical model based on typicalfluid-dynamic concepts and relationships is elaborated.Through the analysis of two extreme cases,namely,those in which leakage is due to a small hole or a full rupture,a generalized hole-bed mod-el is introduced,which for thefirst time also includes a complete bed permeability equation and can deal with different leakage position conditions.The results show that the model can evaluate the influence of leakage on the system at one time and be used to calculate theflowrate and pressure drop.Notably,the obtained results are within a 15%deviation with respect to available experiment values,used for comparison. 展开更多
关键词 Sintering air leakage flowrate bed permeability different leakage positions
下载PDF
A novel coating technology for fast sealing of air leakage in underground coal mines 被引量:7
2
作者 Sihua Shao Chunlei Wu +5 位作者 Min Hao Xiaolin Song Xueyou Su Weihan Wang Guosheng Li Bobo Shi 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第2期313-320,共8页
Air leakage in underground coal mines presents a serious hazard for coal production and the safety of miners.Coating technology is commonly used as an efficient means for preventing air leakage.To address existing pro... Air leakage in underground coal mines presents a serious hazard for coal production and the safety of miners.Coating technology is commonly used as an efficient means for preventing air leakage.To address existing problems with high dust concentrations in large operations involving complex processes and the high cost of traditional coating technology,a novel coating technology that ensures intrinsic safety by utilizing water pressure and wind pressure was developed.This new coating technology was designed to suction and spray,and the technical parameters of its spray performance was also studied.The experimental tests and evaluation indicated the optimum working range is 0.3–0.7 MPa of wind pressure,1.2–10.2 L/min of water quantity,and 1.0–3.5 m of spraying distance.Moreover,this novel coating technology was tested in the Dashuitou Coal Mine in Gansu Province of China.Compared with conventional counterparts,the proposed new technology is safe,efficient,and convenient to operate.During spraying,dust concentrations were kept at less than 10 mg/m3,and the average rebound ratio resilient rate of solid materials was below 13%.After spraying,the average leakage every 100 m was 4 m3/min,and the oxygen volume fraction in the adjacent goaf was approximately 4%,demonstrating excellent air leakage prevention. 展开更多
关键词 Spontaneous combustion air leakage prevention Roadway spraying Novel coating technology
下载PDF
Numerical simulation study of gob air leakage field and gas migration regularity in downlink ventilation 被引量:4
3
作者 ZHANG Jian-rang WANG Chun-qiao DONG Ding-wen 《Journal of Coal Science & Engineering(China)》 2011年第3期316-320,共5页
Aiming at the issue that mass of gas emission from mining gob and the gas exceeded in working face, gob air leakage field and gas migration regularity in downlink ventilation was studied. In consideration of the influ... Aiming at the issue that mass of gas emission from mining gob and the gas exceeded in working face, gob air leakage field and gas migration regularity in downlink ventilation was studied. In consideration of the influence of natural wind pressure to analyze the stope face differential pressure, gob air leakage field distribution and gas migration regularity theoretically. Established a two-dimensional physical model with one source and one doab, and applied computational fluid dynamics analysis software Fluent to do numerical simulation, analyzed and contrasted to the areas of gob air leakage on size and gas emission from gob to working face on strength when using the downlink ventilation and uplink ventilation. When applied downward ventilation in stope face, the air leakage field of gob nearly working face, and the air leakage intensity were smaller than uplink, this can effectively reduce the gas emission from gob to working face; when used downlink ventilation, the air leakage airflow carry the lower amount of gas to doab than uplink ventilation, and more easily to mix the gas, reduced the possibility of gas accumulation in upper comer and the stratified flows, it can provide protection to mine with safe and effective production. 展开更多
关键词 downlink ventilation natural wind pressure air leakage field gas migration numerical simulation
下载PDF
An improved lumped parameter model predicting attenuation of earmuff with air leakage
4
作者 Xu Zhong Zhe Chen Dong Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第11期364-370,共7页
Since air leakage is inevitable when earmuffs are worn improperly or together with safety glasses in factory or military,it is required to be considered to accurately predict earmuff attenuation.Besides unwanted air l... Since air leakage is inevitable when earmuffs are worn improperly or together with safety glasses in factory or military,it is required to be considered to accurately predict earmuff attenuation.Besides unwanted air leakage,under controlled air leakage is introduced to earmuff to achieve adjustable attenuations in different signal-to-noise ratios(SNRs)and balance between attenuation and speech intelligibility.This work is to develop an improved lumped parameter model(LPM)to predict earmuff attenuation with consideration of air leakage.Air leakage paths are introduced into conventional LPM without air leakage,and air leakage path impedance is analytically described by Maa’s microperforated tube impedance.Earmuff passive attenuation behavior can be analytically described and analyzed with the improved LPM.Finally,the validity of improved LPM is verified experimentally.The results indicate that the improved LPM can predict earmuff attenuation with air leakage,and air leakage deteriorates earmuff attenuation and turns resonance frequency higher. 展开更多
关键词 earmuff lumped parameter model air leakage ATTENUATION
下载PDF
Analysis of mine's air leakage based on pressure gradient matrix between nodes
5
作者 张俭让 王红刚 +1 位作者 吴奉亮 常心坦 《Journal of Coal Science & Engineering(China)》 2008年第3期443-446,共4页
Air leakage may significantly affect the effectiveness of mine ventilation by in- creasing the cost of ventilation and arousing problems for ventilation management.Fur- thermore,air leakage may accelerate the process ... Air leakage may significantly affect the effectiveness of mine ventilation by in- creasing the cost of ventilation and arousing problems for ventilation management.Fur- thermore,air leakage may accelerate the process of coal spontaneous combustion and cause gas explosion,thus greatly threatens the safety of coal production.The estimation of air leakage,therefore,have great practical significance.For any ventilation system of coal mines,there is a defined pattern of pressure gradient which drived the mine air to flow in the network,drives possible air leakage to go shortcut as well.Air leakage may occur through ventilation structures such as ventilation doors and fractures of the surroun- dig coal and rock of airways.A concept and the relevent calculation method of the pres- sure gradient matrix was put forward to assist the analysis of potential air leakage routes. A simplified example was used to introduce the application principle of'pressure gradient matrix in identifying all the potential air leaking routes,which offers a deeper understand- ing over the ventilation system and the prevention of coal spontaneous combustion. 展开更多
关键词 air leakage pressure gradient porous media air permeability
下载PDF
Application of Roadway Spray Material to Fire Prevention in Goaf Excavation
6
作者 Hao Rong 《World Journal of Engineering and Technology》 2024年第2期389-400,共12页
In order to reduce the risk of spontaneous combustion in goaf during goaf excavation process, polymer modified cement mortar spraying material was used to spray and seal the roadway surface. The experimental applicati... In order to reduce the risk of spontaneous combustion in goaf during goaf excavation process, polymer modified cement mortar spraying material was used to spray and seal the roadway surface. The experimental application was carried out in the upper channel 2304 of a mine in Henan Province. The test results showed that polymer modified cement mortar spraying material could effectively support the roadway and greatly reduce the deformation rate of the roadway. The best spraying thickness is 5 mm. Through the monitoring of tunnel air leakage, it is concluded that the polymer modified cement mortar spraying material can reduce the tunnel air leakage and play a better sealing effect. 展开更多
关键词 Goaf Excavation Thin Layer Spraying Construction Technology Shotcrete Plugging air leakage Plugging
下载PDF
Pre-placement of adhesive tape around wound sites can prevent air leakage in negative pressure wound therapy procedures
7
作者 Ran Tao Yukun Yang +1 位作者 Chunyu Xue Chuan Lv 《Chinese Journal of Plastic and Reconstructive Surgery》 2022年第2期97-99,共3页
The introduction of negative pressure wound therapy has revolutionized the management of complicated wounds.However,the maintenance of an effective negative pressure environment is difficult in some instances,such as ... The introduction of negative pressure wound therapy has revolutionized the management of complicated wounds.However,the maintenance of an effective negative pressure environment is difficult in some instances,such as wounds in close proximity to an intestinal stoma or wounds surrounded by external fixations.We found that adhesive tape adheres more easily to itself than to wet skin or uneven surfaces.Therefore,we placed adhesive tape around surgical wounds prior to covering them with foam and sealing them with more tape.As a result of the strong adhesive force between pieces of tape,this method could provide a better environmental seal,even in situations where space is limited.Pre-placed adhesive tape around the wound site prior to foam placement could provide sufficient adhesion to maintain a continuous negative pressure environment during treatment. 展开更多
关键词 Negative pressure wound therapy air leakage Adhesive tape
下载PDF
Experimental research on inorganic solidified foam for sealing air leakage in coal mines 被引量:9
8
作者 Bo tao Qin Yi Lu 《International Journal of Mining Science and Technology》 SCIE EI 2013年第1期151-155,共5页
In order to efficiently seal air leakages and control spontaneous combustion of coal, solidified foam was developed by adding a certain compound additive to fly coal ash and cement as the main materials. It was prepar... In order to efficiently seal air leakages and control spontaneous combustion of coal, solidified foam was developed by adding a certain compound additive to fly coal ash and cement as the main materials. It was prepared basing on the foaming characteristic through physical and mechanical system. We studied the effects of the different types of foaming agents, the mass ratio of cement to fly ash, and the mass ratio of solid to water and content of cellulose on the performance of solidified foam. The results show that when adding the composite protein, surfactant and cellulose foaming agents. The cement-fly ash ratio of 0.75:1, the water solid ratio as large as 2:1, and the solidified foam with high properties and density of only 516 kg/m 3 and compressive strength of up to 12.68 MPa were prepared. But the initial setting time, identity and compressive strength may be changed by varying the water solid ratio and/or the additives. We theoretically analyzed the influence mechanism of foam density, compressive strength and water solid ratio. The solidified foam is especially suitable for sealing surface leakage channels and filling the goaf with a wide application prospects. 展开更多
关键词 Spontaneous combustion of coal air leakage Inorganic solidified foam Cellulose
下载PDF
The Study of the Auto Disk Brake Air Test 被引量:1
9
作者 LI Lei Lü Hai-yuan +7 位作者 WANG Xiao-dong LI Sheng-liang YANG Shi-jun SUN Ai-qin ZHANG Peng YANG Zhi-cheng CHEN Long HU Ai-ying 《International Journal of Plant Engineering and Management》 2012年第3期169-172,共4页
In the paper weakness of air leakage system in our company is discussed firstly. Secondly the improved scheme of air leakage system including auto-control is designed. Then, the tooling with role of location and recov... In the paper weakness of air leakage system in our company is discussed firstly. Secondly the improved scheme of air leakage system including auto-control is designed. Then, the tooling with role of location and recovery is developed. At last the application of design optimization is processed. The result reveals that the system of air leakage detection is very valuable and important to manufacture. 展开更多
关键词 AUTO disk brake air leakage test PISTON
下载PDF
Design and error estimates of cut tobacco feeding by wind system
10
作者 Zhou xiao zhong 《International Journal of Technology Management》 2013年第3期94-97,共4页
The cut tobacco transporting is the absolutely necessarily important tache, Whether the transportation process stability is a direct impact on production quality and manufacturing standards. The wind system is adopted... The cut tobacco transporting is the absolutely necessarily important tache, Whether the transportation process stability is a direct impact on production quality and manufacturing standards. The wind system is adopted by most tobacco companies because of it caused least disruptive of the cut tobacco structure and the pipe network layout of system is flexible, but the wind system is greater influence by itself, different control methods are caused greater difference of process indicators, for example essence and spice ingredients, moisture proportion and smoke flavor. Based on the above reasons, so we need to design the control method of wind system necessarily, in addition we must checkout the control accuracy opportunely, so that it is satisfied by the actual working conditions. 展开更多
关键词 cut tobacco amount of supply and demand matching air leakage compensation prevent clogging of cut tobacco error estimates
下载PDF
Cause Analysis and Treatment Measures for Leakage of Top Cover of 330kV GIS Equipment
11
作者 MIN Haibin CHENG Hao +2 位作者 ZHANG Hao ZENG Qingfeng LUO Xiangyang 《International Journal of Plant Engineering and Management》 2019年第4期231-242,共12页
Based on the experience of GIS equipment maintenance, the causes of air leakage defects of GIS equipment running in a 330 substation were analyzed. After the equipment was disassembled, the main causes of air leakage ... Based on the experience of GIS equipment maintenance, the causes of air leakage defects of GIS equipment running in a 330 substation were analyzed. After the equipment was disassembled, the main causes of air leakage were found, and a series of improvement measures were taken to eliminate the GIS equipment leakage defect. And the effective and feasible advice was put forward for this type of air leakage problem. The results lay a foundation for the safe and stable operation of GIS equipment. 展开更多
关键词 GIS equipment air leakage top cover injection and sealing TREATMENT
下载PDF
Study on HAM coupling migration of complex air-tightness defect structure caused by air leakage
12
作者 Shui Yu Jiashuai Wei Xiaoting Zhou 《Energy and Built Environment》 2023年第2期244-257,共14页
The airtightness defects in building components are mainly composed of thin air gaps caused by porous materials and assembly tolerances.Indoor and outdoor air leakage,as well as risks such as condensation and mold gro... The airtightness defects in building components are mainly composed of thin air gaps caused by porous materials and assembly tolerances.Indoor and outdoor air leakage,as well as risks such as condensation and mold growth in the structure,will result in significant heat loss.In this paper,a numerical model of heat,air and moisture transfer(commonly called HAM transfer)between the air channel and the porous material is proposed.The model adopts a single-domain modeling strategy without considering the migration coefficient of the interface.A benchmark experiment of the dilution buffer model is used to further validate the model,and the results indicate good consistency.The condensation risk of a two-dimensional complex building structural component in air infiltration and seepage scene was tested,and it was shown that the existence of air passage would prolong the time for the periodic equilibrium of water in the building structure and significantly change the temperature as well as the humidity distribution in the structure.In addition,the impact of an airtightness defect on the heat flux of the structure’s internal boundary was analyzed qualitatively,and it was found that the infiltration scene has a larger effect on heat loss than the seepage scene. 展开更多
关键词 Unsaturated porous media HAM transfer air leakage air channel
原文传递
RESEARCH ON RISK OF SPONTANEOUS COMBUSTION IN MINING AREA OF FULLY-MECHANIZED WORKING FACE WITH TOP-COAL DRAWING
13
作者 罗新荣 李增华 《Journal of Coal Science & Engineering(China)》 1998年第2期48-52,共5页
Air leakage velocity in intake goaf and distribution of air leakage in mining area are determined by Instantaneous and steady liberation of tracer gas SF6. Gas concentration and temperature in gob are measured and thr... Air leakage velocity in intake goaf and distribution of air leakage in mining area are determined by Instantaneous and steady liberation of tracer gas SF6. Gas concentration and temperature in gob are measured and three oxidation areas in goaf are determined. According to oxidation experiment of coal and in-site measurements, the gases of carbon monoxide and dioxide can be produced laraely by coal and oxygen combination at ambient temperature and the temperature of coai and rock In goaf con rise 10℃ due to heat produced by coai and oxygen combination.There is a great risk of spontaneous combustion in neighboring oId gob because of air leakage for pillar mining. 展开更多
关键词 mining area air leakage spontaneous combustion fire prevention
下载PDF
Gas control technology for coal and gas outburst mines based on new sealing materials
14
作者 Hongwei Zhang Hongbao Zhao +2 位作者 Dongliang Ji Shijie Jing Yuxuan Guo 《Geohazard Mechanics》 2024年第3期181-188,共8页
In order to solve the problem of gas overlimit in corner corners of coal and gas prominent mines, through thecombination of air leakage mechanism in the goaf, near-field fissure expansion and rich area division, blockin... In order to solve the problem of gas overlimit in corner corners of coal and gas prominent mines, through thecombination of air leakage mechanism in the goaf, near-field fissure expansion and rich area division, blockingmaterial development and optimization, performance measurement of blocking materials and on-site test, westarted to study the causes of gas concentration in corner corners, analysis of roof collapse and transparency incorners and performance test of blocking materials, and optimized the blocking materials by combining laboratory test and engineering test. Considering the thickness of the sealing film, the attenuation ratio of the sealingfilm thickness, the gelation time, and the gelation viscosity under different ratios, we designed a multi factororthogonal experiment to optimize the optimal ratio suitable for the engineering site. Factors affecting blockingeffectiveness, such as gel water retention and gel flame resistance, were also tested. The sealing scheme wasimplemented in the 2109 working face of a coal and gas outburst mine in Gansu, China. Through on-sitemonitoring of the changes in temperature, gas concentration, and air leakage at each monitoring point beforeand after the use of sealing materials, the analysis of the detection results shows that the temperature changes ateach monitoring point after the use of sealing materials do not exceed 0.2C;The change in oxygen concentrationis less than 0.27 %;The gas concentration has decreased by more than 60 %, with a decrease of 71.32 % in the gasconcentration in the upper corner. The air leakage has decreased by more than 53 %, and the proportion ofdecrease in air leakage at the upper corner is as high as 56.83 %. This air leakage control technology hasremarkable blocking effect, meets the requirements of corner near-field fissure blocking material, and is easy toprepare, inexpensive, non-toxic, tasteless and green, providing a successful experience for the treatment of similarcoal and gas outburst mines that can be referenced. 展开更多
关键词 Coal and gas outburst air leakage in goaf Near-fieldfissure Gas concentration air leakage
原文传递
Pressure Drop in Cyclone Separator at High Pressure 被引量:7
15
作者 Zhu Zhiping Na Yongjie Lu Qinggang 《Journal of Thermal Science》 SCIE EI CAS CSCD 2008年第3期275-280,共6页
For the design of pressurized circulating fluidized beds, experiments were conducted in a small cyclone with 120 mm in diameter and 300 mm in height at high pressures and at atmospheric temperatures. Influence of air ... For the design of pressurized circulating fluidized beds, experiments were conducted in a small cyclone with 120 mm in diameter and 300 mm in height at high pressures and at atmospheric temperatures. Influence of air leakage from the stand pipe into the cyclone was specially focused. A semi-empirical model was developed for the prediction of the pressure drop of the cyclone separator at different operate pressures with the effect of air leakage and inlet solid loading. The operate pressure, air leakage and inlet solid loading act as significant roles in cyclone pressure drop. The pressure drop increases with the increasing of pressure and decreases with the increasing of the flow rate of air leakage from the standpipe and with the increasing of the inlet solid loading. 展开更多
关键词 cyclone separator pressure drop air leakage
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部