• 대한기계학회논문집B
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• 제29권1호
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• pp.151-158
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• 2005

A characteristic of discharge for a foam spray nozzle with various parameters was investigated. The discharge patterns from a fire foam spray nozzle are important to evenly spray over a maximum possible floor area. Two parameters of a foam spray nozzle were chosen, and compared with those from the standard one. Also, in order to evaluate the performance of discharged foam agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams were experimentally investigated. A simple repeatable test for fire-protection foams subjected to fire radiation was developed. This test involves foam generation equipment, a fire source for heat generation, and data acquisition techniques. Results show that the bubble size of foam is increased by large inside diameter of orifice or closed air hole, but phenomenon of discharge angle and expansion ratio is opposite. For the case of the open air hole, liquid film of a circular cone discharges with formation, growth, split and fine grain. In case of the closed air hole, a pillar of foam solution discharges with that. Though the temperature gradient in the foam increases with increased foam expansion ratio. it is not change with increased intensity of heat flux.

• 설비공학논문집
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• 제3권2호
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• pp.142-151
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• 1991

In the present investigation, it has been proposed to utilize a direct contact heat exchanger as an evaporator to solve the difficulties such as scaling, corrosion and law thermal efficiencies, associated with the conventional evaporator. Liquified nitrozen was utilized as a working fluid to investigate basic natures of bubble dynamics in the evaporator, and spray nozzles were adopted to inject liquified nitrozen into the spray column with varying flow rates of dispersed phase fluids. Experimentations were carried out in the range of $6.54{\times}10^{-4}kg/s$ - 0.030 kg/s for dispersed phase flow rates with one, three and five nozzle holes. Observing the bubble dynamics for the evaporator the feasibility of utilizing a direct contact heat exchanger as a LNG evaporator has been evaluated. The results show that no eruption phenomena was observed in the present investigation with $LN_2$ and the interface between $N_2$ bubbles and water was fully turbulent. It is believed that the high injection velocity of $LN_2$ through the spray nozzles provide good mixing effects for both heat and mass transfers between water and $N_2$ bubbles. Ice was formed on the surface of the spray nozzle for higher $LN_2$ flow rates. However, even in this case, it is observed that the ice was detached as soon as it was formed. Under the present experimental conditions, the shapes of $LN_2$ bubbles were in the spherical-cap region according to the Clift, Grace and Weber Graphs. The height of foam region caused by the breakup of larger bubbles keeps increasing with high injection velocities until it reaches it's maximum height.

• 한국화재소방학회논문지
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• 제28권5호
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• pp.14-22
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• 2014

석유화학공장에서 화재 폭발사고는 매년 반복되고 있으나 화재 방호시스템에 관한 국내 법규는 최악의 화재 시나리오에 대응하기에는 미흡한 실정이다. 이에 본 연구에서는 석유화학공장에서 국내외 화재 방호시스템의 기준을 비교 분석하고 울산국가산업단지 석유화학공장 32개소의 소화설비 현황을 조사하였다. 결론적으로 석유화학공장에서 소화용수는 최악의 화재 시나리오를 기반으로 하여 설계하고 고정식 물분무 설비, 고가 모니터 노즐, 워터커튼 설비, 대용량 포모니터 설비와 같은 소화설비가 최악의 화재 시나리오에 대비하여 설치되어야 할 것으로 나타났다.