와이어 로프의 파단특성(破斷特性)에 관한 실험적 연구

이근오,태순호,김종현 한국산업안전학회 1994 한국안전학회지 Vol.9 No.4

This study examines fracture characteristics of wire rope of 6×37+FC 14㎜ B degree, Which has been widely used for the strength support for machinery, cranes and shipping. The examination is based on the following experimental conditions. Firstly, this study analyzes the effect of the strength of wire rope. When number of broken wires is occuring at the level of 5%, 10% and 15% degree respectively in the following two cases : 1) Case of broken down to each strand equally. 2) Case of broken down to one strand only. Secondly, this study analyzes the effect of corrosion on the strength of wire rope. Corrosion times are 72hours, 144hours and 216hours corrosion respectively under following conditions : 1) Case of only a corrosion without wire breaking. 2 ) Case of corrosion after 5% degree wire breaking to each strand equally. Some outcomes of these experiment are as follows. 1) From the of tension test, We can find that the ratio of strength reduction case of wire broke down to one strand concentrically is greater than that ratio case of broke down to each strand equally. 2) From the corrosion test, We can also find that the ratio of strength reduction case of corroded after 5% degree wire breaking to each strand equally is greater than that ratio case of corroded without wire breaking. 3) After comparing theoretical fracture load of wires with experimental fracture load of wires, we can find the fracture load of the case of broken down to each strand equally is most similar to theoretical fracture load. 4) It is proposed that safety rules on wire rope in the industrial safety and healthy labor of law have to change "breaking over 10% of number of wires in one strand of wire rope(excluded filler wire)" has to be replaced by "breaking over 10% of number of all wires in all strand of wire rope(excluded filler wire)"

프레스 방호장치 안전거리 산정을 위한 손속도상수

이근오,김종현 한국안전학회 2010 한국안전학회지 Vol.25 No.6

To protect press operator from the after-reach hazard, current Ministry of Labor Notification(MOLN) requires the use of a formula for calculating the safe distance away from the point of operation for locating press protective devices, Two Hand Control Devices(THCD) and Active Opto-Electronic Protective Devices(AOPD), on a power press. This formula is based on a same hand speed constant of 160cm/s. While EN standards use different hand speed constant for THCD and AOPD respectively. The objective of this study is to compare two guidelines on the hand speed constant published by MOLN and EN 692, also to propose a proper hand speed constant and validate it experimentally. As a experimental result, it could be known that hand speed constant of Ministry of Labor Notification should be improved as that of EN standards.

노통연관식 보일러의 압궤사고 방지대책

이근오 한국안전학회 2004 한국안전학회지 Vol.19 No.4

Boiler is a hazardous equipment to have potential explosion all the time. And not only it has malfunction at explosion, it lead to people death but also secondary accident such as explosion and fire. Therefore, this equipment should not be broken for keeping its own function. And also, high level of safety should be kept in the process of the use not to be malfunctioned A large scale of accident due to boiler explosion can be preventive in advance. Boiler fracture is occurred by instant expansion (approximately 1700 time) from quick evaporation of water in boiler, due to pressure decrease in boiler. Emitting energy from it is tremendous and it is so dangerous because of its high temperature. Secondary explosion such as fire is also a main hazard occurring at fuel supply place. If any devices with high pressure is broken, then not only boiler vessel but also components of it are spread with high speed, causing secondary accident. This study is to analyze integrally accident cause of fire and flue tube boiler to have occurred pressure fracture actually, to show countermeasures to prevent accident loss from the fire and flue tube boiler.

미소중력장에서의 연소특성 연구

이근오,이경욱 한국산업안전학회 2002 한국안전학회지 Vol.17 No.4

The transient soot distributions within the region bounded by the droplet surface and the flame were measured using a full-field light extinction technique and subsequent tomographic inversion using Abel transforms. The soot volume fraction results for n-heptane droplets represent the first quantitative assessment of the degree of sooting for isolated droplets burning under microgravity condition. The absence of buoyancy(which produces longer residence times) and the effects of thermophoresis produce a situation in which a significant concentration of soot is produced and accumulated into a soot-cloud. Results indicate that indeed the soot concentration within the microgravity droplet flames(with maximum soot volume fractions as high as ~60ppm) are significantly higher than corresponding values that are reports for normal-gravity flames. This increase is likely due to longer residence times and thermophoretic effects that manifested under microgravity conditions.

亂流擴散火焰의 安定性에 대한 保焰器의 影響

李謹悟 서울産業大學校 1989 논문집 Vol.29 No.1

This paper deals with the experimental study of the stability of a turbulent diffusion flames on the various types of the flame holders. Experiments were carried out to investigate the effects of flame holder and fuel flow rate on the flow characteristics and the combustion characteristics in both nonreacting and reacting flow field of the model combustor which symplifys the continous type combustor. The flame structure are observed by naked-eyes, and then the fuel-air mixing characteristics have been investgated by means of visualizing the flow field in the nonreacting flow field and the reacting flow field through the Schlieren photography. The flame configuration is observed by direct photography, flame temperature distribution which is major to character a flame property is measured by using PR thermocouple. And they make sure the effect of flame holder and fuel flow rate on the stability in the turbulent diffusion flame.

뉴스포츠 활동이 초등학생의 체육 학습에 미치는 효과

이근오,박영수 한국교원대학교 학교체육연구소 2006 학교체육연구소지 Vol.13 No.1

The purpose of this study was to apply new sporting events, which could be intriguing for school children and boost their class participation, into P.E. instruction in an effort to further their attitude, interest and basic physical fitness. The subjects

가스터어빈형 연속류연소기의 유동에 관한 연구(II) -연소기내의 유동특성-

이근오,지용욱,김형섭 한국안전학회 1989 한국안전학회지 Vol.4 No.1

This paper deals with the experimental study on the flow characteristics in straight flow can type combustor which has been used for high pressure ratio gas turbine combustor. The author has investigated the effects of swirl number and secondary air hole arrays in axial position on the flow characteristics by adopting the tuft method and 5-Hole Pilot Tube. From these experiments, as the swirl number increases, the results obtained is that the area of recirculation zone becomes wide and the position of vortex-core region approaches to the near of fuel nozzle in the model combustor. The most favourable penetration is obtained when secondary air jet is introduced through the air holes distributed in the form of paralled two rows in axial position of model combustor.

선회 동축 분류의 난류특성에 관한 연구

이근오,김종현 한국산업안전학회 1993 한국안전학회지 Vol.8 No.3

This paper deals with the experimental study of the turbulent characteristics in the swirling coaxial jets. In this research, the experimental study has been carried out to investigate the effect of swirl number and equivalence ratio on the flow characteristics in nonreacting flow field of the model combustor which symplifys the continuous type combustor for the practical use. Author particularly intends to find out the fuel-air mixing in the recirculation zone in order to make sure the effects of swirl number and equivalence ratio on the stabilization of flame.

가스터어빈형 연속유연소기의 유동에 관한 연구(Ⅰ) : 연소기의 설계 및 시작

이근오,김형섭 한국산업안전학회 1987 한국안전학회지 Vol.2 No.3

The combustion process in gas turbine combustor mainly influenced by flow pattern in combustor, and especially the flow pattern near the nozzle and the shape of recircutation zone affect strongly on the flame stabilization, temperature distribution and combustion efficiency in combustor. In this paper, the author has designed and manufactured transparent simplified model combustors on the basis of K. Suzuki's combuster design method to investigate the effects of swirl number and secondary air hold arrays in axial position on the flow characteristics by adopting the tuft method and 5 hole pitot tube.

호이스트 크레인의 권상로프 자동수직 조정장치 개발에 관한 연구

이근오,구건호,이충렬 한국산업안전학회 1995 한국안전학회지 Vol.10 No.3

We got operational safety limit angle being able to affect operators or materials surrounding the center of vertical line of the hoist on working from the theoretical review and experimental result. Then we inferred the distance to about 1.2m-1.4m from the center which materials hanged on the hook were able to effect to the surround. Therefore, we got about 7˚ to the inclined or crossed operational safety limit angle of the crane with 6m lift. Also, we developed hoisting rope automatic vertical controller which could control this kind of dangerous operation. And we did experiments again after establishing the inclined or crossed operational safety limit to 7˚. The result is satisfied.