• Proceedings of the KSME Conference
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• 2000.04b
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• pp.175-179
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• 2000

A combustion project was completed regarding the development of a high-flow-rate purge burner in cooperation with three city gas companies(Pusan, Taegu, Samchulli). The project, started in May 1991, aimed at purging the line-packed-gas safely and quickly before getting into gas pipe working or relocation. According to the results, the purging noise is less than 80dB due to silencer screen. multi-nozzle and outlet inserted tube employed. In addition, the developed burner shows an increased work efficiency of 40-50% more as compared to the performance of conventional purge equipments. The project result is regarded as the first high-flow-rate purge burner developed within Korea. contributing to shortening purge hours, safe field work and easiness of purge site selection.

• Journal of the Korean Applied Science and Technology
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• v.19 no.2
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• pp.108-116
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• 2002

Experimental Study was carried out for benzene desorption by purge gas or evacuation in an activated carbon bed. As purge gas flow rate increased, desorption rate increased due to the higher interstitial linear gas velocity. For various purge gas flow rates, desoption curves almost got together if they were plotted against dimensionless time. At a higher flow rate, mass transfer zone became narrower. Temperature drop in the bed was more fast and severe at higher flow rates and higher outer temperature. It was found out that desorption was almost completed when the temperature in the drop of the bed returned to the initial temperature before temperature drop. Desorption by vacuum purge was completed in shorter time than desorption by purge gas. Countercurrent purge was more effective than cocurrent purge.

• The Korean Journal of Food And Nutrition
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• v.12 no.2
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• pp.191-191
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• 1999

A Purge & Trap Concentrator was used to analyze various volatile organic compounds(VOCs) in wat-er. The object of this study was to observe the purge efficiency of 40 VOCs in water according to the change of parameters (purge time drypurge time sample temperature) and to determine the optimum condition for VOCs using the purge & Trap concentrator interfaced with a narrow capillary connected to a gas chromatography/mass spectrometry. The optimum condition of purge and trap is as follows: purge time at 11min drypurge time at 5min sample temperature at 6$0^{\circ}C$ at constant purge flow (40mol/min) constant desorption flow(20ml/min) desorption temperature(2$25^{\circ}C$) and desorption time (1min) At this analytical condition the detection limits of VOCs was in the range of 0.1~0.5$\mu$g/ml and the purge efficiency of each compound was over 70%.

• Journal of the Korean Society of Safety
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• v.39 no.3
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• pp.14-19
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• 2024

Hydrogen is one of the most popular eco-friendly energy sources for reducing global warming. To use hydrogen as a conventional fuel, liquid hydrogen plants should introduce waste hydrogen treatment processes. A major safety issue of liquid hydrogen plants is choosing the most suitable purge gas to use in case of an accident. A purge gas prevents the formation of explosive mixed gases in the vent header. In general, nitrogen is the main purge gas used in chemical plants. Nitrogen has a freezing point of -210℃, which is higher than the boiling point of hydrogen. Helium, with a freezing point lower than hydrogen, is instead recommended as a purge gas of the vent header during hydrogen liquefaction. However, helium is roughly 100 times more expensive than nitrogen. To address this issue, this study uses simulations to investigate safe conditions for introducing nitrogen as the purge gas during hydrogen liquefaction. The temperature change from the safety valve to the vent header is evaluated when the external temperature of the safety valve discharge pipe is at 5℃, 10℃, and 20℃. Additionally, the most optimal length for a discharge pipe according to pipe diameter is investigated.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.157-160
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• 2021

As an insulator for a thin film transistor(TFT) and an encapsulation material of organic light emitting diode(OLED), aluminum oxide (Al₂O₃) has been widely studied using several technologies. Especially, in spite of low deposition rate, atomic layer deposition (ALD) has been used as a process method of Al₂O₃ because of its low process temperature and self-limiting reaction. In the Al₂O₃ deposition by ALD method, Ar Purge had some crucial effects on the film properties. After reaction gas is injected as a formation of pulse, an inert argon(Ar) purge gas is injected for gas desorption. Therefore, the process parameter of Ar purge gas has an influence on the ALD deposited film quality. In this study, Al₂O₃ was deposited on glass substrate at a different Ar purge time and its structural characteristics were investigated and analyzed. From the results, the growth rate of Al₂O₃ was decreased as the Ar purge time increases. The surface roughness was also reduced with increasing Ar purge time. In order to obtain the high quality Al₂O₃ film, it was known that Ar purge times longer than 15 sec was necessary resulting in the self-limiting reaction.

• Journal of the Semiconductor & Display Technology
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• v.5 no.4 s.17
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• pp.23-27
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• 2006

Semiconductor industry has been dramatically developed with the information era of 21C, and the trend now is to consider that the technology of management system of the computer utility that has a high efficiency is important. This study investigated the intelligent decision system for residual gas purge process to effectively remove the residual gas in the tube after replacing the cylinder that is used for the gas cabinet or BSGS(Bulk Specialty Gas Supply System) of the semiconductor process. It was suggest from this study that it is possible to decide the type, frequency and volume of purge gas using various toxic gases which is necessary for each process. Also, this result will be utilized for operating the system, increasing the efficiency of management and saving energy.

• Membrane Journal
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• v.6 no.3
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• pp.117-126
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• 1996

Membrane-based gas separation systems are now widely accepted and employed as unit operation in industrial gas, chemical, and allied industries. Following their successful commercialization in the late seventies to recover hydrogen from ammonia purge gas streams, membrane-based systems have gained acceptance in a wide variety of applications. Numerous systems are in operation today to: recover hydrogen from other purge gas and hydrocarbon streams; adjust the $H_{2}/CO$ ratio in syngas; remove $CO_{2}$ from natural gas; recover helium; dry gas streams; and separate air. Lower cost, ease of operation, operational flexibility and portability are a few of the reasons membrane-based systems are chosen over absorption and cryogenic-based separations in certain applications.

• Journal of the Korean Chemical Society
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• v.39 no.8
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• pp.635-642
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• 1995

Improved sample introduction system has been investigated for the determination of volatile organic compounds in water using a purge & trap preconcentration apparatus and a capillary gas chromatography/mass spectrometry. The present limitations associated with the moisture control module and cryorefocusing system suggested by EPA were discussed. To solve the problems such as improper separation of peaks due to the adsorption of water and contamination of purge & trap system, a more efficient connection system between the purge & trap apparatus and the gas chromatograph was introduced and the optimum operational conditions were suggested. A carbopack B/carboxen 1000 and 1001 trap was used for the purge & trap procedure and a custom made crosslinked dimethyldiphenylpolysiloxane capillary column was used for the separation of compounds. Accuracy and precision of the method suggested in this report were examined and the method detection limit of each compound was proposed for the simultaneous determination of 54 volatile organic compounds in water.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.171-178
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• 2001

A Purge and Trap Concentrator has been used to analyze various volatile organic compounds in water, operating several parameters affecting the extraction efficiencies of these compounds. The object of the present study was to observe the purge efficiencies of 40 volatile organic compounds (VOCs) in water, according to the change of parameters (purge time, dry purge time, sample temperature), and to determine the optimum condition of analysis of VOCs. The Purge and Trap Concentrator was interfaced with a narrow capillary connected to a gas chromatography mass spectrometer. At this condition, the detection limits of VOCs were in the range of 0.1-0.5 ㎍/L.

• Archives of Pharmacal Research
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• v.15 no.2
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• pp.109-114
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• 1992

For the risk assessment of human exposure to volatile halogenated hydrocarbons, a dynamic purge trap/on-column cryofocusing method using capillary gas chromatograph-$^{63}Ni$ electron capture detector and thermal desorption unit was applied to analyze the free forms, metabolites of 1, 1, 2-trichloroethylene and 1, 1, 2, 2-tetrachloroethylene. The urine sample was diluted with distilled water, hydrolyzed and sealed. Then the inert gas was infused to purge out free 1, 1, 2-trichloroethylene, free 1, 1, 2, 2-tetrachloroethylene and urichloroethanol. These compounds were trapped to $Tenax^R$ / GC-gas trap device throughout clean up tube. Being undertectable to gas chromatograph directly, trichloroacetic acid was methyl esterificated and trapped in the manner above mentioned. The optimal incubation time to get best recovery of methyl ester was 4 hours at $60^circ$C. The concentrations of free volatile halogenated hydrocarbons and their metabolites in urine were obtained of free volatile halogenated hydrocarbons and their metabolites in urine were obtained from 5 healthy volunteers. This analytical method is expected to make the biological monitoring more precise and convenient.