• Journal of the Korean Society of Combustion
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• v.7 no.1
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• pp.58-64
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• 2002

The bed combustion in an incinerator interacts with the gas flow region through heat and mass transfer. Combined bed combustion and gas flow simulations are performed to investigate this coupled interaction for various operating conditions and furnace configurations. Radiation onto the bed from the furnace is interrelated with the combustion characteristics in the bed, and is also affected by the flow pattern in the gas flow region. Since the contribution of gaseous emission to the total radiation is significant, an adequate flow pattern in a well-designed furnace shape would lead to an increased heat influx on the bed, especially in the early stage of the waste combustion. Advancing the initiation point of the waste combustion can also reduce the size of the lower gas temperature region above the bed, which can be achieved by controlling operating conditions such as the waste feeding rate, the bed height and the primary air flow distribution.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2001.05b
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• pp.19-22
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• 2001

In recent years, the creation of waste recycling society has been required to cope with the traditional ways of waste treatments. In accordance with the package recycling law in force, calls for the developments of new waste treatment techniques suitable for 21st century are growing higher. A new ash melting furnace system named Eco Burner Ash Melting Furnace System has been developed. It is a burner type ash melting system in which the fluffs made of the plastics segregated from municipal solid wastes are directly fired at high temperature in the furnace. This system provides an economical ash melting system because plastic wastes or paper scraps that have heretofore been considered hard to recycle are used in compensation for fossil fuel. In this paper, we describe the ash melting test results obtained from a substantiative facility.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.88-91
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• 2011

Glass fiber drawing from a silica preform is one of the most important processes in optical fiber manufacturing. High purify silica preform of cylindrical shape is fed into the graphite furnace, and then a very thin glass fiber of 125 micron diameter is drawn from the softened and heated preform. A computational analysis is performed to investigate the heat transfer characteristics of preform heating and the glass fiber drawing in the furnace. In addition to the dominant radiative heating of preform by the heating element in the furnace, present analysis also includes the convective heat transport by the gas flowing around the preform that experiences neck-dawn profile and the freshly drawn glass fiber at high fiber drawing speed. The computational results present the effects of gas flow on the temperature of preform and glass fiber as well as the neck-down profile of preform.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.690-696
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• 2009

This paper introduces the automatic fine Bituminous Coal injection lance position control method using flame image process. The fine Coal injection lance is used to supply additional heat into the furnace in Mill plant. It injects fine coal into high pressured air flow and produces very heated and high pressured flame. For the such high temperature and pressure, the fine coal injection lance effects not only efficiency of burner but also furnace abrasion. To keep efficient combustion status and to avoid the abrasion, in this paper, the flame is monitored by computer image process. This paper proposes the flame image process method and lance position control according to calculated result for flame image process.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.12
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• pp.1262-1268
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• 1991

The electric furnace which has time delay and time varying characteristics cannot be controlled easily. In this paper, a fuzzy controller for a electric furnace is implemented using one chip processor 8751 and IBM PC. The fuzzy controller is implemented in the PC. The One chip processor 8751 can sense the furnace internal temperature and pass it to IBM PC and generate the driving signal for SSR. The membership function of the fuzzy controller is determined by Least Square method. from the experiments, we can show that the fuzzy controller can improve robustness to the load variation. And the settling time is reduce 4500 (sec) to 2500 (sec).

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.4
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• pp.568-573
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• 1996

The amorphous silicon films deposited by low pressure chemical vapor deposition are crystallized by the various annealing techniques including low-temperature furnace annealing and two-step annealing. Two-step annealing is the combination of furnace annealing at 600 [.deg. C] for 24 h and the sequential furnace annealing at 950 [.deg. C] 1h or the excimer laser annealing. It s found that two-step annealings reduce the in-grain defects significantly without changing the grain boundary structure. The performance of the poly-Si thin film transistors (TFTs) produced by employing the tow-step annealing has been improved significantly compared with those of one-step annealing. (author). 13 refs., 6 figs., 1 tab.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.36-37
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• 2021

When the final finish of a building is designed with base concrete, complex deterioration occurs due to the harsh environment such as shrinkage and expansion due to external temperature changes, freezing and thawing, and the use of calcium chloride due to snow accumulation. Therefore, the pozzolanic reaction mechanism of blast furnace slag is clearly identified, and the causal relationship between the material properties and performance of the blast furnace slag is identified to present guidelines for mixing high-durability concrete.

• Journal of the Korean Ceramic Society
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• v.49 no.2
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• pp.161-166
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• 2012

The temperature-rasing sintering method was used in this study to fabricate the aggregates of uniform pore size and distribution containing reject ash occurred in the thermal power plant. The spheric green aggregates made of reject ash were put into the box furnace of 800~$1000^{\circ}C$, heated with a heating rate of 5~$15^{\circ}C$/min to 1200~$1275^{\circ}C$, sintered for 10 min and then discharged out of the furnace to the room temperature. The input temperature, heating rate and sintering temperature increased the bloating phenomenon of the specimen, and the sintering temperature among them was the most effective factor. The aggregate manufactured at $1275^{\circ}C$ had the specific gravity of about 1.0 and water absorption of 1~2%, and the pores of 500~1,000 ${\mu}m$ were uniformly distributed across the whole specimen. Especially, the aggregates fabricated using the temperature-rasing sintering method in this study showed an excellent bloating properties and uniform microstructure without black core phenomenon which is typical for the bloated ceramics synthesized by direct sintering method.

• Advances in materials Research
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• v.9 no.3
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• pp.203-218
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• 2020

This research paper presents the outcomes in terms of mechanical and microstructural characteristics of binary and ternary concrete when exposed to elevated temperature. Three parameter were taken into account, (a) elevated temperature (i.e., 200, 400, 600 and 800℃) (b) binary concrete with cementitious material sugarcane bagasse ash (SCBA) and ground granulated blast furnace slag (GGBFS) replacement percentage (i.e., 0, 15, 20, 25 and 30%) and (c) ternary concrete with cementitious material SCBA and GGBFS replacement percentage (i.e., 0, 15, 20, 25 and 30%). A total of 285 standard cube specimens (150 mm × 150 mm × 150 mm) containing Ordinary Portland Cement (OPC), SCBA, and GGBFS were made. These specimens then exposed to several elevated temperatures for 2 h, afterword is allowed to cool at room temperature. The following basic physical, mechanical, and microstructural characteristics were then determined and discussed. (a) mass loss ratio, (b) ultrasonic pulse velocity (UPV) (c) physical behavior, (d) compressive strength, and (e) field emission scanning electron microscope (FESEM). It was found that compressive strength increases up to 400℃; beyond this temperature, it decreases. UPV value and massloss decrease with increase in temperature as well as the change in color and crack were observed at a higher temperature.

• Journal of the Korean Society of Safety
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• v.19 no.1
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• pp.137-140
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• 2004

The minimum ignition temperature at which the dust cloud can spontaneously ignite is considered to be very important in industries to prevent explosion occurring in hot surfaces. This paper has dealt with the experimental study of the determination of minimum ignition temperature of Hydroxy Propyl Methyl Cellulose (HPMC) dust cloud. We have used the Godbert-Greenwald Furnace Apparatus to determine the ignition temperature and limiting oxyten concentration for dust could. The experimental determinations on the minimum ignition temperature were carried out with various particle size with nominal diameters 45, 75 and 106${\mu}m$. The limiting oxygen concentration of dust cloud was determinated for the smaller size(45${\mu}m$) HPMC. Minimum ignition temperature of dust cloud was at 364$^{\circ}C$ for the concentration of 2.5g/L in the air and became higher with the increasing of nitrogen concentration. It was also found that the ignition didn't occur when the oxygen concentration was below 10%, and limiting oxygen concentration is at 11%.