In the event of an emergency such as facility shutdown during process operation, the by-product gas must be urgently discharged to the vent stack to prevent leakage, fire, and explosion. At this time, the explosion drop value of the released by-product gas is calculated using ISO 10156 formula, which is 27.7 vol%. Therefore, it does not correspond to flammable gas because it is less than 13% of the explosion drop value, which is the standard for flammable gas defined by the Occupational Safety and Health Act, and since the explosion drop value is high, it can be seen that the risk of fire explosion is low even if it is discharged urgently with the vent stock. As a result of calculating the range of explosion hazard sites for hydrogen gas discharged to the Bent Stack according to KS C IEC 60079-10-1, 23 meters were calculated. Since hydrogen is lighter than air, electromechanical devices should not be installed within 23 meters of the upper portion of the Bent Stack, and if it is not possible, an explosion-proof electromechanical device suitable for type 1 of dangerous place should be installed. In addition, the height of the stack should be at least 5 meters so that the diffusion of by-product gas is facilitated in case of emergency discharge, and it should be installed so that there are no obstacles around it.
A new type of capacitor named "Super Capacitor" has been developed, in which the properties of electric double layer formed at the interface of activated carbon electrode- liquid organic electrolyte is applied. This capacitor is small In size, light in weight, wide In temperature range(-25~70℃), large in charge-discharge capability and good in voltage preservation. And this super capacitor is applied as a power back-up for electricity failure in volatile memory devices etc., a power source for a short time and a power source for operating actuators. At present the development of high power back-up types of the capacitor system and improvement of their characteristics are being actively conducted in order to find wider applications.lications.
경주, 포항 지진이후 구조물의 내진성능평가에 대한 구조기술자의 관심이 증가하고 있으며, 내진성능평가를 위해 필요한 관련 소프트웨어에 대한 관심 역시 지속적으로 증가하고 있다. 국내의 경우 30년간 가장 널리 사용되어온 대표적인 소프트 웨어는 CSI(Computers&Structures)에서 개발된 SAP2000, PERFORM-3D 및 ETABS와 마이다스아이티에서 개발된 midas Gen이다. 위 소프트웨어들은 내진성능평가에 필수적으로 필요한 비선형정적, 동적해석 기능을 포함하고 있으며 제품에 따라 해석기능 이외에도 각종 기준이나 지침에 부합하는 다양한 응용기능들을 탑재하고 있다. 하지만 MIDAS GEN을 제외하고는 소프트웨어 해석기능의 제공범위나 장,단점에 대한 자료가 부족하여 기술자들이 해석목적에 따라 프로그램을 적절히 선택하고 사용하는데 어려움이 있다. 본 자료에서는 국내에서 내진성능평가 중 비선형동적 해석분야에서 많이 적용되고 있는 PERFORM-3D와 최근 기술자들이 관심을 가지고 있는 ETABS에 대한 기능상 장단점을 간단하게 소개하고자 한다.