• Fire Science and Engineering
• /
• v.16 no.3
• /
• pp.32-38
• /
• 2002

The synthesis of $CF_3$I and $C_2F_5I from $CF_3Br$ was studied for the reuse of $CF_3Br$ which is abolished to save the ozone layer of the earth. Reaction experiments were carried out in experimental scale synthesis equipment with catalysts, such as CuI, Kl, $K_2$$CO_3$, KF metal salt/active carbon and alumina support at $400~600^{\circ}C$. Main products of reaction were $CF_3i$ and $C_2F_5I$ with small amounts of $C_2F_5I$, $CF_4$, $CF_2Br_2$ by-products. 7.5wt% KI and $K_2CO_3$over activated carbon catalysts show the highest yield of $CF_3$I and 7.5wt% CuI over alumina catalysts show the highest yield of $C_2F_5i$. And optimal reaction temperature was about $500^{\circ}C$.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2009.04a
• /
• pp.180-187
• /
• 2009

한국형 헬기 개발사업 (KHP)에서 개발 중인 한국형 기동 헬기(KUH)의 엔진실에 적용되는 소화시스템의 성능평가를 수행하였다. 사용된 소화약제는 할론 1301 이며, 국방규격에 맞게 설계 되었다. 실물모형의 엔진 목업을 제작하여 소화시스템을 배치하고, 화재 소화실험과 할론 농도 측정 실험을 수행하였다. 실험 결과 설계된 소화시스템은 엔진실 내부의 화재를 효과적으로 소화시켰으며, 국방 규격에서 요구하는 분사 시간 조건 및 농도조건을 만족함을 확인 하였다.

• Journal of the Korean Institute of Gas
• /
• v.11 no.3
• /
• pp.7-12
• /
• 2007

The search for a new fire-extinguishing agent with all the desirable properties of halon 1301 has not been successful. To study binary gaseous extinguishing agents instead, one has to determine the extinguishing concentrations for several compositions of a given chemical in an inert gas. This process is expensive and time consuming. The fire suppression efficiencies of gas mixtures of HFC 125 and HFC 227ea with nitrogen as total flooding agents were studied by cup burner method. It was shown that addition of small amounts of those extinguishants to nitrogen can enhance the suppression effectiveness of the inert gas. As expected, the degree of synergism was highest at low concentrations of the chemical. For each binary system, extinguishing concentrations of the pure compounds and one binary data were used to predict the extinguishing concentrations for the entire range of binary composition. The predicted values were very close to experimental data.

• Journal of Korean Society for Atmospheric Environment
• /
• v.30 no.4
• /
• pp.387-397
• /
• 2014

This work aims at estimating global warming potentials (GWP) of $CF_3Br$ and HFC-134a among green house gases. It has been reported that they have much higher GWP than $CO_2$ in the atmosphere. $CF_3Br$, halon 1301 which is well known to be a fire extinguisher, as one of the bromine-containing halons has been banned since 2003 due to destruction of ozone. HFCs, a kind of chiller which replaced chlorofluorocarbons (CFCs) are one of greenhouse gases regulated by the Kyoto Protocol. In this study, we produced GWPs of $CF_3Br$ and HFC-134a by calculating a life time and measuring an absorption cross section to obtain a radiative forcing (RF). Their absorption cross sections were measured by using Fourier-transformed infrared spectroscopy (FTS) with a gas cell filled with their certified reference materials at room temperature. As a result, the RFs of $CF_3Br$ and HFC-134a were 0.32 and $0.168Wm^{-2}ppb^{-1}$, respectively and the GWPs were calculated as 7989, 6076, 3903 for $CF_3Br$ and 3855, 1300, 656 for HFC-134a for the time horizon of 20, 100, 500 years, respectively. Overall, uncertainty of the estimated GWPs can be estimated to be about 2.6%. Our results were compared with those proposed by the previous studies (IPCC, 2007; WMO, 1999).