• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.19-25
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• 2006

Energy efficient and low pollution combustion systems the use gaseous fuels have been in great demand in recent year. Radiant burner in many different forms are emerging as very desirable combustion systems for same reason. Porous radiant burners are used in drying, preheating and curing, and in other type of materials processing and manufacturing processes. However, little knowledge is available about the operating characteristics and the structure of flames in porous ceramic fiber radiant burners. The objective of the present work is to investigate the global performance characteristics of the ceramic fiber burner. A detailed study which includes the spectral intensity, gas temperature, radiation efficiency and global pollutant emissions. Another objective is to study the flame structure of the ceramic fiber burner by measuring the local gas temperature. The results indicate that ceramic fiber burner do offer a 19-44% gain in radiant efficiency. The ceramic fiber burner exhibit significant spectral intensity peaks in the band at $2.0-2.5{\mu}m$. The local temperature distribution inside the mat and near the mat surface as a function of the equivalence ratio can be reasonably interpreted by the relation of the heat balance in the mat and movement of the reaction zone. Nox emission from ceramic fiber burner is less than 25ppm throughout the operating range.

• 대한기계학회논문집B
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• 제32권2호
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• pp.100-106
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• 2008

An experimental study was carried out in a small-scale test furnace to investigate the performance, such as $NO_X$ emission, enhancement of heat transfer, uniformity of temperature, and etc, of oscillating combustion applied in radiant tube burner system. A premixed type burner and a cyclic oscillating control valve were designed and used. The fuel, used commercial LPG in this study, was only oscillated using the cyclic oscillating control valve. As oscillating combustion was applied in radiant tube burner system, it is found that $NO_X$ emission, compared to no oscillation, could be reduced by 38% at $90{\sim}120rpm\;(1.5{\sim}2.0Hz)$. However, as oscillating frequency was increased, effect of abatement of $NO_X$ emission is gradually reduced. From the measurement of furnace heating time from $100^{\circ}C$ to $720^{\circ}C$, heat transfer is increased by 11.5% at the oscillation of 120rpm. Temperature distribution of radiant tube surface is more uniform at oscillation of 120rpm with decrease of the peak temperature and increase of low temperature. From these results, it is confirmed that oscillating combustion is useful in radiant tube burner system.

• 에너지공학
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• 제14권2호
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• pp.73-81
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• 2005

강판의 냉간압연 후 소둔을 하기 위한 열처리 공정에서 사용되고 있는 Radiant Tube Burner(이하 RT버너) 연비를 개선하기 위한 효율적인 방법을 실험적으로 조사하였다. 재열기가 설치된 모델 RT버너를 실험에 맞도록 개조하여, 배기 중 산소 농도 조건을 변화시키면서 연료 소모에 대한 흡입공기의 온도와 산소분율의 영향도를 파악하였다. 본 연구의 결과, 흡기 온도를 상승시키면 RT버너의 chamber온도가 상승하나 그 상승폭은 흡기 온도 상승폭의 $10\%$에 지나지 많아, 흡입 공기 온도의 상승만으로는 연료 소모 개선을 기대할 수 없다는 것을 알 수 있었다 그러나, 흡입 공기 중 산소분율 변경 실험 결과, 흡입 공기 중의 산소분율을 $1.5\%$증가시키면 NOx의 배출이 약 $40\%$정도 증가하지만 약 $20\%$의 연비 개선 효과를 보였다. 따라서, NOx 배출 증가를 억제하는 산소 고부하 전용 RT버너는 RT버너 시스템의 연료 소모를 개선하는 효과적인 방법의 하나로 기대된다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제32회 KOSCO SYMPOSIUM 논문집
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• pp.13-18
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• 2006

Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. High radiation efficiency is one of the most important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.

• 한국연소학회지
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• 제11권1호
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• pp.27-33
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• 2006

Radiant burners are applicable to drying, preheating and curing in materials manufacturing processes. Radiation efficiency is one of the important performance criteria for these burners. The wide variation in reported radiation efficiencies are partly due to the differences in the measurement techniques. In the present work, water cooled radiant heat flux meter was used to measure radiant heat flux from a metal fiber mat burner. Non-contact type thermometer was also utilized to measure the surface temperature of the burner. Combustion gas was measured by gas analyzers. According to the thermal loads and stoichiometric ratios, radiant heat transfer ratio and combustion performance were discussed here in.

• 한국안전학회지
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• 제13권1호
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• pp.47-53
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• 1998

Radiant heater tubes with an inside burner are designed to transfer the heat generated from the burner to the outside of the tube by radiation. Hence, tube metal must suffer high temperature of approximately 900-$1000^{\circ}C$. The radiant tube is usually manufactured by centrifugal casting with high Ni-Cr alloys. In this study, failure analysis results of the radiant tube are reported. Failure mechanism of the tube was investigated by visual observation of the foiled tube, metallographic study of the cracked region and chemical analysis of tube metal and oxide scales. It was argued that the main cause of the cracking is repeated oxidation of the tube metal located beneath the thick oxide scale. Oxidation was caused by abnormally high operating temperature which can be verified by aged microstructure and internal void formation.

• 한국연소학회지
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• 제6권1호
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• pp.29-35
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• 2001

The surface flames in porous ceramic burner are experimentally characterized to investigate the effects of equivalence ratio and firing rates. The results show that the surface flames are classified into green, red radiant and blue surface flame as decrease of equivalence ratio. And each flame is maintained very stably and shows the same flame characteristics at any orientation of ceramic burner. Particularly the blue surface flame was found to be very stable at very lean equivalence ratio at 200 to $800\;kw/m^2$ firing rates. And the exhausted NOx was analysed to find out which flame has lower NOx emission. The blue surface flame showed the lowest NOx emission regardless of the location of burner since it sustained very stable at lean mixture ratio.

• 대한기계학회논문집B
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• 제31권6호
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• pp.539-546
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• 2007

An experimental study was performed to investigate the characteristics of chemiluminescence in a radiant burner, varying the excess air ratio from 0.91 to 1.67 at firing rate 80.5 to 134.2 kW/m2 on $OH^*,\;CH^*,\;{C_2}^*$ in LNG-Air premixed flames. The signals from electronically excited states of $OH^*,\;CH^*,\;{C_2}^*$ were detected using a Intensified Couple Charged Detector (ICCD) camera. The measurements of exhausted emission were made to investigate the correlation between chemiluminescence and emissions. The chemiluminescence intensity was increased with increase of firing rate like characteristics of $NO_x$ emission. $NO_x$ also increased with increase of firing rate and excess air ratio. It is found that offset of firing rate is more dominant excess air ratio $NO_x$ emission. The maximum chemiluminescence intensity occurs near the stoichiometric excess air ratio or lean conditions in case of high firing rate and the maximum intensity occurs rather than rich conditions in case of relatively low firing rate. Amount of $NO_x$ emission is maximum at near stoichiometric excess air ratio, which is chemiluminescence intensity is maximum.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.49-53
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• 2001

A conventional flame type gas combustion major portion of heat is transferred to the body by convection due to small radiant ability of the gas flame. Increasing the radiation component of heat flux in the combustion zone allows to augment the efficiency of gas utilization. Such effect can be reached by using radiative gas burner applied to metal mesh combustion. Basically the gas radiant burner consists of metallic mesh of high heat resisting steels. In terms of this regards, we have made the burner consisted of metal mesh and measured the radiative flame stability of natural gas/air mixture on the metal mesh burner. The pressure loss through the metal mesh is defined by pressure-velocity slope. The more increased the pressure-velocity slope of the metal mesh is, the wider the stable zone of radiave flame on the metal mesh burner is. And the augmentation of mixture flowrate through the metal mesh make narrow the permissible range of equivalence ratio.

• 대한기계학회논문집B
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• 제35권5호
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• pp.539-545
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• 2011

맥동연소기술을 적용한 산업용 복사관버너의 연소특성을 살펴보기 위해 실규모 (120,000 kcal/h) 산업용 복사관버너 설비를 사용하여 실험실 및 현장 테스트를 수행하였다. 제철부생가스를 사용하는 산업용 복사관버너의 3 가지 종류를 하나의 W 형 복사관이 장착된 실험설비에서 실험하였다. W 형 복사관이 다수 사용되는 대형 설비를 이용하여 장기운영 실험을 실시하였다. 맥동연소기술을 적용한 기실험설비들을 대상으로 성능향상 및 배가스조절 측면에서 다양한 실험조건으로 테스트를 진행 하였다. 맥동연소기술의 적용가능성 평가를 위해 NOx 저감 및 효율향상을 분석하였다. 맥동연소기술의 적용결과 에너지 절감, 복사관 수명 향상 및 생산성 향상 등이 얻어짐을 확인할 수 있었다. 최고의 성능 및 배가스 조절을 얻기 위한 최적의 운전조건이 각 버너별로 결정되었다.