• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.10 s.253
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• pp.950-956
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• 2006

A mathematical heat transfer model for the prediction of heat flux on the slab surface and temperature distribution in the slab has been developed by considering the thermal radiation in the furnace and transient conduction governing equations in the slab, respectively. The furnace is modeled as radiating medium with spatially varying temperature and constant absorption coefficient. The slab is moved with constant speed through non-firing, charging, preheating, heating, and soaking zones in the furnace. Radiative heat flux which is calculated from the radiative heat exchange within the furnace modeled using the FVM by considering the effect of furnace wall, slab, and combustion gases is applied as the boundary condition of the transient conduction equation of the slab. Heat transfer characteristics and temperature behavior of the slab is investigated by changing such parameters as absorption coefficient and emissivity of the slab. Comparison with the experimental work shows that the present heat transfer model works well for the prediction of thermal behavior of the slab in the reheating furnace.

• Journal of Korea Foresty Energy
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• v.22 no.1
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• pp.37-43
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• 2003

The influence factors for char yield in the carbonization process of natural cellulose are the carbonization temperature, the heating rate and the atmosphere in the furnace. In general, it is well known that the improvement of char yield is expected under the conditions of the lower carbonization temperature, the slower heating rate and the presence of inert gas in the furnace. In this study, it has been investigated the effect of the heating rate control with sulfuric acid as a dehydrating agent for the improvement of char yield in the carbonization process of natural cellulose. The cellulose treated with sulfuric acid has shown the weak dependency of heating rate in char yield, whereas the untreated cellulose has shown the strong dependency. These findings clearly suggest that it can be useful to control heating rate with appropriate dehydrating agent in the carbonization process to improve the char yield and shortening the carbonization time.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.3
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• pp.98-102
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• 2024

In this study, the crystal characteristics of commercial AlN powders with sizes of "㎛" and "nm" were selected through XRD analysis and then sintered at different temperatures through an induction heating furnace to investigate the optimized sintering temperature and physical properties. The sintering temperature was 1,500, 1,700, and 1,900℃ in the N₂ atmosphere, and the optimized sintering temperature conditions were established for the sintered AlN pellets using SEM, XRD, and Raman analysis. Additionally, impedance analysis was performed to confirm the electrical properties of the optimized AlN pellet without sintering additives.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2285-2290
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• 2007

The main objective of this study is to analyze the heat transfer characteristics in the electric melting furnace. Local temperatures are measured at various location in the furnace using the B-type thermocouples. In this paper, the numerical simulation was performed using the ANSYS software, and compared with experimental data. Mathematical heat transfer model for the prediction of temperature distribution has been developed by considering the thermal radiation among heating element, crucible and insulating materials. The results show that the temperature distributions predicted by the numerical simulation agree with experimental results comparatively.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.4 s.33
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• pp.37-41
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• 2004

As mobile communication devices use wide bands for large data transmission, Low Temperature Co-fired Ceramic(LTCC) has been a candidate for module substrate, for it provides better electrical properties and enables various embedded passive devices compared to conventional PCB. The LTCC, however, has applied in limited area because of non-uniform shrinkage. Hybrid heating was developed to raise sample temperature uniformly in a short period of time This leads to unidirectional sintering which enables sample to be sintered layer by layer from the bottom, resulting in more stable shape of interconnection at the top surface of the sample than conventional electric furnace heating. When sintering properties of substrate and electrical/mechanical properties of interconnection were compared, hybrid heating showed possibility to be applicable to substrate miniaturization and interconnection densification superior to electric furnace heating.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.233-234
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• 2009

This study investigates the possibility of development of composite fireproof board type that is to improve the resistance of fireproof material and the problem of a conventional fire proof covering methods to prevent spalling failure of high strength concrete members.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1412-1416
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• 2003

Induction Heaters are commonly used in heating steel strip product, because it can rapidly and efficiently heat steel strip/bar. In this study, a inductive heating model is developed and the predictions are compared with measured temperatures. The temperatures are measured from POSCO thin-slab rolling facility (so called Minimill). Induction heater is installed between reduction unit and holding furnace This induction heater raise the temperature of steel bars from $930^{\circ}C$ to about $1100^{\circ}C$ which gives the required temperature for finishing mill process after holding period at holding furnace. Unlike other simple equation models, this model allows us to predict temperature profiles of sections of steel bars.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.156-165
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• 1994

Unsteady heat conduction in stacked disks in a furnace has been numerically solved The effects of relevant parameters such as disk spacing, aspect ratio, environmental temperature, Biot nember, etc. have been investigated. The highest temperature appears at the disk edge and the lowest at the center. Penetration of heat form the surface to the center requires some time. Heating should be slow for uniform temperature rise. Geometric parameters complicates the radiative and conductive heat transfer. Though the resulting dependence of temperature nonuniformity on various parameters is complicated, high uniformity of temperature is in general available by low Biot number and/or low environmental temperature.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.3
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• pp.162-168
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• 2009

A horizontal tube furnace with a wide uniform-temperature zone was developed using isothermal characteristics of a heat pipe. The heat pipe heating system consists of a concentric annular shaped stainless-steel container, sodium as a working fluid and a screen mesh wick structure. The performance test of the heat pipe revealed that temperature changes along seven consecutive positions of the heat pipe outer wall were less than${\pm}0.1^{\circ}C$, thereby ensuring the high isothermal property. The isothermal property of the heat pipe-adapted tube fumace was investigated and compared to a conventional non-heat pipe type tube furnace. The temperature distribution measurement showed that the uniform temperature zone, in which temperature change is less than${\pm}$1$^{\circ}$C, of the heat pipe employed tube furnace system was about three times longer compared to the conventional tube furnace system.

• Journal of the Korean Ceramic Society
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• v.40 no.3
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• pp.309-316
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• 2003

EAF(Electric Arc Furnace) Dust classified as special wastes containing heavy metal contaminants may cause to damage an environment such as underground water contamination if they were not treated properly. The possibility of producing the porous sintered body made from EAF Dust/clay composition system was studied. Mixing of EAF Dust and clay was carried out using wet-mixing process and two different sintering methods such as rapid and normal heat treatment were tried. By observing density, porosity and microstructure of sintered bodies, it was found that the bloating phenomenon depend on the contents of C, where the liquid phase occur or not during the sintering process. To obtain a light-aggregate of porous body due to bloating, the rapid heating was better than the normal heating at sintering process.