• Resources Recycling
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• v.4 no.2
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• pp.15-21
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• 1995

• Cement
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• s.40
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• pp.32-38
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• 1971

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.575-579
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• 2007

Sludge disposal technology has been studied with many researchers since disposal of sewage sludge has been a social problem. The current technologies include incineration, carbonization, pyrolysis, landfilling and fertilization. However, all of these processes require a dry process, because sewage sludge with more than 80% high water content is difficult to be used as a raw material. This study has the purpose to establish the optimal operation conditions and the technology as changing the variables: kiln residence time, sludge load, dryer temperature, by using the previous study that is rotary kiln type dryer designed as a numerical simulation study. As the results, optimum conditions are determined as follows: kiln residence time, sludge load, dryer temperature are $62.5kg/m^3{\cdot}hr$, 26.2 min, $330^{\circ}C$, respectively. Content of water, drying efficiency, weight loss, volume loss show that the results are $10{\pm}2$, 88, 80, 60%, and the dried sludge is released by a dryer below 10 mm.

• 한국연소학회:학술대회논문집
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• 2001.11a
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• pp.142-152
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• 2001

Three Lab-scale combustors of different types were made to observe some basic phenomena of fuel combustion in the combustors ; grate type combustor, rotary kiln and FBC. The aims were to introduce how to simulate the combustion behaviors in the real plants by utilizing the reduced apparatuses and characterize the combustors relating to some important parameters such as fuel size, water contents, bed temperature, rotating speed of kiln, flow rate. The mean carbon conversion time and the flame propagation rate were adopted for the quantitative analysis.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.492-497
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• 2014

Artificial fine aggregates (denoted AFA) were fabricated using spent bleaching clay (denoted SBC) generated from processed vegetable oil and stone sludge (denoted SS) produced from crushed aggregate manufacturing materials for use as functional construction materials. Each raw material was crushed to particle size finer than $150{\mu}m$, and fine spherical pellets of approximately 1 ~ 4 mm in diameter were prepared by a pelletizing process. The physical properties of the AFA were measured with different types of sintering equipment. A new type of vertical furnace that sinters fine aggregates in a fluidized bed at high temperatures was designed and tested. AFA sintered in a rotary kiln at $1125^{\circ}C$ showed a bulk density of $1.5g/cm^3$ and a water absorption of 16%. AFA sintered in the vertical furnace at $1125^{\circ}C$ showed a bulk density of $1.9g/cm^3$ and water absorption of 8.5%. The bulk density of the AFA sintered in the vertical furnace showed a bulk density 27% higher and water absorption 47% lower than those of AFA sintered in the rotary kiln.

• Journal of the Korean Society of Combustion
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• v.22 no.4
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• pp.9-18
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• 2017

This paper is to suggest a simple flame model for the analysis of an internal flame of rotary kilns and to present the application cases. Reaction rates in the multi combustion stages of the selected solid fuel were calculated considering the reaction rates with the Arrhenius type equations. In addition, primary and secondary air flow arrangement were considered. As a simple application case, the combustion trends according to the different solid fuels were described. Improved operating conditions as related with the fuel characteristics were shown to be important for the stable combustion characteristics and the performance of the reactors as defined by the exit temperature of the solid materials.

• Journal of Korea Foresty Energy
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• v.21 no.2
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• pp.17-24
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• 2002

Activated carbons were prepared from pine bark by steam activation, and pore structures and specific surface areas were then investigated. Three different types of kilns were used for the activation. When the stationary-vertical-or stationary-horizontal-type kiln was used for the steam activation to prepare an activated carbon from the bark, it was not possible to produce activated carbon having high specific surface areas exceeding 1,000 $m^2／g$. Using bark powder improved the specific surface area, but it was still not high enough. When the rotary-horizontal-type kiln was used for the activation, the activated carbons prepared had high specific surface areas of more than 1,000$m^2／g$, which was similar to a commercial first-grade activated carbon. The activated carbon prepared by the rotary kiln had a wide distribution of pore size ranging from microporous to mesoporous.

• Cement Symposium
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• no.17
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• pp.70-76
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• 1989

• Cement Symposium
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• s.34
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• pp.176-184
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• 2007

• Cement Symposium
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• no.16
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• pp.77-80
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• 1988