• Title, Summary, Keyword: Explosive

Search Result 1,426, Processing Time 0.046 seconds

A Study on the Explosive Plugging of A Repair for Defective Tube/Tubeplate on the Nuclear Steam Generator (원자력 증기발생기 결함 세관 보수용 폭발 Plugging에 관한 연구)

  • 이병일;심상한;강정윤;이상래
    • Explosives and Blasting
    • /
    • v.17 no.4
    • /
    • pp.18-31
    • /
    • 1999
  • The explosive forming has been used for many year to expand tubes into tubesheets. this process has demonstrated ability to direct carefully the energy of an explosive to expand tubes into tubesheet holes without damaging the tubesheet and without causing the excessive cold work at the tube I.D. that is normally associated with mechanical expansion. The success of explosive tube expansion provided the background for the development of the explosive tube plug. The main results are as follows : (1) The optimum explosives and explosive qualities are PETN, RDX, HMS and about 18~31gr/ft of explosive plugging in nuclear steam generator. (2) Explosive plugging's thickness is 0.9~1.8mm. If groove of 0.4 mm formed in plug outside, For the hydraulic leakage is go up, explosive plugging of formed groove are applicate tube and tubrplate. (3) Sheath is designed on the polyethylene of low density, In thermal impact test of the $430^\circ{C}$, hydraulic leakage is $300kg/cm^2$. (4) About 10~60mm oxide inclusions are existed on the space of explosive plug and tube protect to the leakage.

  • PDF

Analysis for Anti-shock Characteristics of Underwater Acoustic Transducers to the Explosive Shock (수중폭발충격에 대한 수중음향 트랜스듀서의 내충격 특성 해석)

  • Goh, Byeong-Jun;Seo, Hee-Seon
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.16 no.11
    • /
    • pp.1108-1114
    • /
    • 2006
  • Underwater acoustic transducers can be exposed to a underwater explosive shock caused by various types of underwater weapon. So, a robust anti-shock design is required for transducers to endure the underwater explosive shock. To check the anti-shock characteristics of a transducer, underwater explosive shock test is needed. The conditions of underwater explosive shock test are set up referring to various oversea explosive shock test specifications, and the explosive shock pressure values are calculated according to those conditions. Transient analyses art: carried out for two kinds of underwater acoustic transducer model to verify the anti-shock characteristics. The applied model has robust anti-shock characteristics enough to endure the explosive shock up to 2300 psi. In the future, the transducer design should be certified through the fields test, and modified if needed.

A Study on the Explosion Characteristics of City Gas (도시가스의 폭발 특성에 관한 연구)

  • 최재욱;목연수;박승호
    • Journal of the Korean Society of Safety
    • /
    • v.16 no.4
    • /
    • pp.109-114
    • /
    • 2001
  • Explosive characteristics of the city gas were determined by using the gas explosion apparatues. The explosive range is determined between lower explosive limit of 5.0% and upper explosive limit of 15.3% at atmosphere and even though the oxygen concentration is decreased, lower explosive limit is not changed, but upper explosive limit is rapidly decreased. The minimum oxygen for combustion is determined 10%. The maximum explosion pressure is determined 5.72$\textrm{cm}^2$ and the maximum rate of explosion pressure rise is oxygen concentration of 12% to determined 160.12$\textrm{cm}^2{\cdot}$sec.

  • PDF

A Study on Explosive Limits of Flammable Materials - Prediction of Explosive Properties and Temperature Dependence of Explosive Limits for n-Alcohols - (가연성물질의 폭발한계에 관한 연구 -알코올화합물의 폭발특성치 및 폭발한계의 온도의존성 예측-)

  • 하동명
    • Journal of the Korean Society of Safety
    • /
    • v.14 no.1
    • /
    • pp.93-100
    • /
    • 1999
  • By using literature data, the empirical equations have been derived which describe the interrelationships of explosion and other related properties of n-alcohols. The properties which have been correlated data are : lower and upper explosive limits, heats of combustion, carbon numbers. Also, the new equation for predicting the temperature dependence of lower explosive limits(LEL) of n-alcohols on the basis of explosive limits, heats of combustion, flame propagation theory and mathematical method is proposed. The values calculated by the proposed equations were a good agreement with literature data within a few percent. From a given explosive properties. by using the proposed equations, it is possible to predict the other properties. It is hoped eventually that this method will permit the estimation of the explosive properties of alcohol with improved accuracy and the broader application for other compounds.

  • PDF

A Study on Explosive Limits of Flammable Materials - Explosive Limits of Flammable Binary liquid Mixture by Liquid Phase Compositions - (가연성물질의 폭발한계에 관한 연구 - 액상 조성에 의한 가연성 2성분 액체혼합물의 폭발한계 -)

  • 하동명
    • Journal of the Korean Society of Safety
    • /
    • v.16 no.4
    • /
    • pp.103-108
    • /
    • 2001
  • Explosive limit is one of the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limits are used to classify flammable liquids according to their relative flammability. Such a classification is important for the safe handling of flammable liquids which constitute the solvent mixtures. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this paper, Raoult,s law and van Laar equation(activity coefficient model) are shown to be applicable for the prediction of the explosive limits in the flammable ethylacetate-toluene system. The values calculated by the proposed equations were a good agreement with literature data within a given percent. From a given results, by the use of the proposed equations, it is possible to predict explosive limits of the other flammable mixtures. It is hoped eventually that this method will permit the estimation of the explosive Properties of flammable mixtures with improved accuracy and the broader application for other flammable stances.

  • PDF

An Experimental Study on the Explosive Spalling Properties of High Strength Concrete Structure Member (고강도 콘크리트 구조부재의 폭렬 특성에 관한 실험적 연구)

  • Kim, Heung-Youl;Jeon, Hyun-Kyu
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • /
    • pp.421-424
    • /
    • 2006
  • This study, in order for perceiving the mechanical attribute followed by the explosive spalling of high strength concrete material under high temperature and evaluating capacity of endurance of material, targets understanding capacity of endurance of material such as explosive spalling in high temperature, temperature by thickness of clothing, transformation extent, transformation speed and displacement, stocking the maximum load based on the Allowable Stress Design Method. As a result of experimenting the explosive spalling attribute of high strength concrete material, the one possibly causing serious damage is the 50 MPa concrete. In all aspects of 60 MPa concrete, explosive spalling happens. Especially, it is hazardous enough to reveal all the iron bar. All explosive spalling is intensively concentrated on the surface of concrete for the first $5{\sim}25$ minutes, which urges for the explosive spalling protection action. As a result of evaluating the structural safety by the transformation of high strength concrete, while beam assures the fire safety meeting regulation, 60 MPa shows the dramatic increase of transformation, which only counts 84% of safety. In a column, both the concrete exclusion and excessive explosive spalling are concentrated upper part of column, which brings about the dramatic transformation, so it only meets the 50% of safety regulation. Likewise, in 80, 100 MPa concrete which was never experimented considering the condition of domestic structural endurance stocking devices, the faster collapse is expected.

  • PDF

A Study on Explosive Limits of Flammable Materials - Explosive Limits of Ternary System by Means of Solution Thermodynamics and MRSM Model - (가연성물질의 폭발한계에 관한 연구 - 용액열역학 및 MRSM 모델에 의한 3성분계 폭발한계 -)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
    • /
    • v.20 no.3
    • /
    • pp.91-97
    • /
    • 2005
  • The research on the explosive limits is one of fundamental fields of combustion process, and information on the explosive limits of mixture of fuel and oxidant, with or without additives, is very important for the prevention in industrial fire and explosion accidents. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Batten, Le Chatelier and MRSM(modified response surface methodology) model. In this study, the reference values of lower explosive limits(LEL) of the ethanol+toluene+ethylacetate system were compared with the calculated values by using the solution thermodynamics and the MRSM model, respectively. The values calculated by the proposed equations were a good agreement with literature data within a few percent. By means of this methodology, it is possible to evaluate reliability of experimental data of the lower explosive limits of the flammable mixtures. Also, from given results, it is possible to predict explosive limits of the other flammable liquid mixtures used in the chemical process by the use of the proposed equations.

Explosive History applied to plan in Storytelling and Construction Management(Value Creative Engineering) (화약의 역사를 스토리텔링으로 한 건설사업(가치창조공학)에 적용 방안)

  • Park, Ju-Han;Ahn, Myung-Seog;Ryu, Hyun-Min
    • Explosives and Blasting
    • /
    • v.31 no.1
    • /
    • pp.87-92
    • /
    • 2013
  • Although precision blasting constructions are increased by explosive industry, the studies on the history of explosive are small in number. In this study, we tried to find the origin of explosive and make it, which we found, be storization to develop the technology of modern explosive and blasting. Also, we presented the methods that apply storytelling about the explosive technology to construction project.

A Predictive Study on Molecular and Explosive Properties of 1-Aminoimidazole Derivatives

  • Cho, Soo-Gyeong
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.7
    • /
    • pp.2319-2324
    • /
    • 2011
  • Molecular structures and chemical properties of 1-aminoimidazole derivatives have been investigated at high levels of density functional theories. Heat of formation, density, explosive performances and impact sensitivities have been estimated at the global minimum of potential energy surface. As more nitro groups are introduced, the explosive performances of 1-aminoimidazole derivatives are enhanced, while the impact sensitivity becomes more sensitive. A two-dimensional plot between explosive performance and impact sensitivity has been utilized to comprehend the technical status of new explosive candidates. Based on locations in the two-dimensional plot, 1-aminodinitroimidzole isomers appears to have a potential to be good candidates for insensitive explosives, and 1-aminotrinitroimidazole may become a powerful explosive molecule whose behavior is quite close to HMX.

A Study on the Characteristics of the interface in Tube / Tubesheet of the Nuclear Steam Generator by Explosive Bonding (폭발접합된 원자력 증기발생기 튜브/튜브시트 계면 특성에 관한 연구)

  • 이병일;공창식;심상한;강정윤;이상래
    • Explosives and Blasting
    • /
    • v.17 no.4
    • /
    • pp.32-50
    • /
    • 1999
  • This study deals with interface charactristics of tube and tubesheet of the nuclear steam generator by the explosive expansion in order to take advantage of optimum expansion ratio, pull-out strength and leakage tightness and improvement of the resisitance on the stress corrosion cracking for low residual stress. The paper also show the relationship between roll, hydraulic and explosive expansion. The results obtain are as follows (1) Because of the explosive bonding is to use the high speed pressure and energy by the explosive, workability is good, bonding region is homogenous (2) Expansion ratio is 2.7%, Pull-out strength 850kg, Leakage strength $500kg/cm^2$. Clearance gap is 10~30mm in case of explosive expansion and interface structure of the tube and tubesheet is optimum condition. (3) As the transition region of the explosive expansion is inactive, the resistance of the stress corrosion cracking is increases 30~40% compare to the roll and hydraulic expansion.

  • PDF