• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.3
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• pp.330-341
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• 1999

An experimental study for the two types of burners used in the non-oxidizing direct fired furnaces of the heat treatment process for the cold rolled plate has been carried out to investigate the combustion characteristics and the oxidization of the surface of steel plate. A steep temperature gradient and entrainment of residual oxygen were found near the heating surface in the flame of the nozzle mixing burner which has strong swirl velocity component. It was concluded that the elimination of the residual oxygen and the increase of the temperature of combustion gas on the heating surface are needed to enhance the performance of the burners for application to the non-oxidizing direct fired furnaces.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.189-193
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• 2006

Experiments were performed to investigate the melting characteristics of pellet fuel made of LDPE and PP for a waste plastic firing boiler. Pellet fuel in a burner goes through conduction, convection and radiation transferred from flame in a furnace, and complex thermo/chemical processes. To figure out effects of ambient temperature and size of pellet on melting time pellets with a diameter from 5 mm to 40 mm were made to contact high temperature flue gas generated by a LNG firing pilot burner. Though melting processes of plastics include complicated heat transfer in a burner, parameters are limited to flue gas temperature and size for the simplicity in this study. From the results, melting times of LDPE and PP with a diameter of 5mm are 63 and 62 secs respectively at 600 $^{\circ}C$ while 677 and 583 sees respectively for a diameter of 40 mm. At $900^{\circ}C$, melting times of LDPE and PP with a diameter of 5mm are 21 and 24 sees respectively while 408 and 337 secs respectively for a diameter of 40 mm. It is found that melting time of LDPE is longer than that of PP, and melting times of both in general increase with diameter of pellets. It is thought melting is dependent mostly on melting temperature of plastic. It is expected melting times obtained from the study might be taken into account in designing a pellet firing burner for a boiler

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.860-865
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• 2012

Although biomass syngas is very low calorific gas, it is utilized by means of dual fuel combustion technology in the fields of industrial furnace and boiler as a substitute oil technology. The basic structure of duel fuel combustion burner is designed so that low caloric gas fuel is supplied around an oil burner in the middle. In the present study, three types of mixing burners were manufactured to conduct performance experiment. Low caloric gas was evenly distributed around the oil burner and the method of changing the angle of gas nozzle was applied. CO generation decreased according to the increase of the amount of air for combustion. In addition, the shapes and colors of flame changed according to the proportions of gas and oil used. Remained flame after combustion was from the lack of atomization at the exit of oil burner. Although it was difficult to maintain the optimum air ratio due to different required air ratio for oil and syngas, stable combustion was able to maintained within excess oxygen concentration of 4.7~8.2%. From this study, it was shown that the oil atomization at the exit of fuel oil nozzle was promoted by the increased rate of syngas combustion and the CO concentration in flue gas lower than only fuel oil combustion.

• Journal of the Korean Society of Combustion
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• v.10 no.2
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• pp.26-34
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• 2005

The performance of oxygen combustion with $CO_2$ feeding was investigated in a pyrex tube furnace. The inverse type multi-hole burner was used for improving mixing and wide operating range. It introduced oxygen, fuel, and oxygen, respectively, from center tube to outer tubes. Oxygen combustion characteristics with excess oxygen ratio, oxygen feeding ratio, and $CO_2$ feeding flow rate were studied to optimize the operating condition and to apply the oxygen combustion with recirculation of flue gas to a real furnace. This paper presents results on the effect of $CO_2$ feeding flow rate on the structure of the flames and concentrations of NO and CO emissions. The visible flame length was shortest due to well mixing between fuel and oxygen when the oxygen feeding ratio was 0.25. The NO emission was reduced drastically regardless of excess oxygen ratio when the $CO_2$ feeding flow rate was larger than 15 lpm. The CO emission is varied by changing the $CO_2$ feeding flow rate but the CO emission characteristics is highly affected by excess oxygen ratio. When the excess oxygen ratio is below $\lambda=1.1$, the CO emission increased as the $CO_2$ feeding flow rate increased.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.162-169
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• 2005

The performance of oxygen combustion with $CO_2$ feeding was investigated in a pyrex tube furnace. The inverse type multi-hole burner was used for improving mixing and wide operating range. It introduced oxygen, fuel, and oxygen, respectively, from center tube to outer tubes. Oxygen combustion characteristics with excess oxygen ratio, oxygen feeding ratio, and $CO_2$ feeding flow rate were studied to optimize the operating condition and to apply the oxygen combustion with recirculation of flue gas to a real furnace. This paper presents results on the effect of $CO_2$ feeding flow rate on the structure of the flames and concentrations of NO and CO emissions. The visible flame length was shortest due to well mixing between fuel and oxygen when the oxygen feeding ratio was 0.25. The NO emission was reduced drastically regardless of excess oxygen ratio when the $CO_2$ feeding flow rate was larger than 15 lpm. The CO emission is varied by changing the $CO_2$ feeding flow rate but the CO emission characteristics is highly affected by excess oxygen ratio. When the excess oxygen ratio is below ${\lamda}=1.1$, the CO emission increased as the $CO_2$ feeding flow rate increased.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.10
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• pp.807-815
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• 2014

This study was performed using a laminar flow reactor that could replicate the combustion environment of pulverized coal in a blast furnace. Since a pulverized coal injection system was developed for iron making, the combustion characteristics of pulverized coal have been important in the iron and steel industry. The flame structure, particle temperature, and exhaust gas were investigated for different types of coal. The results of this study demonstrated that the combustion characteristics of coal are influenced by several properties of individual coals. In particular, the CO emission and volatile matter content of individual coals were found to have a strong influence on their combustion characteristics. Thus, this study found the properties of the coals to be significant and focused on the particle temperature and CO and $CO_2$ emissions.

• Elastomers and Composites
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• v.46 no.2
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• pp.164-170
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• 2011

In this study, silicone rubber filled with environmentally-friendly perlite was prepared by mechanical mixing in order to improve thermal properties, such as heat and fire resistances. We found that the properties of silicone rubber composites depended on perlite concentration by various characterization methods. Thermogravimetric analysis(TGA) indicated that the initial degradation temperature of silicone/perlite composite was higher than that of pristine silicone rubber. The gas torch test showed that the opposite side temperature of composite materials was remarkably low as compared to that of pristine silicone rubber. In addition, the composites containing 5 wt% and 10 wt% of perlite showed remarkable thermal stability at elevated temperatures according to the results of both fireproof furnace tests under the RABT condition and carbonization furnace tests. The images from a scanning electron microscope(SEM) showed the degree of dispersion of perlite in silicone rubber. Finally, it was confirmed that limited oxygen index(LOI) was increased with perlite concentration.

• The Journal of the Petrological Society of Korea
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• v.10 no.3
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• pp.172-178
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• 2001

K-Ar dating system of Korea Basic Science Institute (KBSI) was installed in 1997 and has been used since then. The system consists of high temperature graphite furnace, gas purification system, and mass spectrometer with data acquisition system. K-Ar age is determined by the measurement of the concentrations of Ar and K through isotope dilution method using $^{38}Ar$ as spike and flame spectroscopy, respectively. The accuracy and reliability for the K-Ar age are checked using the several K-Ar standard materials. Although the exact age determination for young samples of less than 1 Ma is hampered by small fluctuations of sensitivity and mass discrimination, the present system yields the reliable K-Ar age compared to the standard materials of Tertiary and Mesozoic age. The measurements for the SORI93 biotite with the recommended K-Ar age of $92.6\pm$0.6 Ma and Bern4M muscovite of $18.5\pm$0.6 Ma yield the reliable age of $92.1\pm$1.1 Ma and $17.8\pm$0.2 Ma, respectively.

• Journal of Energy Engineering
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• v.19 no.2
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• pp.136-142
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• 2010

Combustion reactivity and thermal behavior of two imported coals used as a pulverized fuel of commercially thermal power plant were investigated by thermogravimetric analysis (TGA) and large scale test furnace of 200 kg/hr. TGA results showed that combustion efficiency of high moisture coal has lower than reference coal due to the slow combustion completion rate although it has the low ignition temperature, and activation energies of high moisture coal with 79 kJ/mol for overall combustion was higher than reference coal of 53 kJ/mol. Test furnace results ascertained that flame of black band of high moisture coal during the combustion in boiler broke out compared to reference coal and then it becomes to unburned carbon due to the less reactivity and combustion rate. But, Blending combustion of high moisture coal with design coal of high sulfur are available because sulfur content of high moisture coal was too low to generate the low SOx content in flue gas from boiler during the combustion. The ash analysis results show that it was not expected to be associated with slagging and fouling in pulverized coal fired systems due to the low alkali metal content of $Na_2O$ and $K_2O$ compared to bituminous coal.