• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.2
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• pp.159-165
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• 1999

Experimental studies have been performed to observe the basic phenomena of waste bed combustion in MSW incinerator. A reduced scale apparatus was utilized to simulate the combustion behavior in real plant with 1-dimensional transient behavior at the experimental setup, which uses wet cubic wood with ash content as simulated waste. LHV (lower heating value) of solid fuel, fuel particle size and flow rate of combustion air were taken as important parameters of the bed combustion. For the quantitative analysis, FPR (flame propagation rate), TBT (total burn-out time) and PBT (particle burn-out time) was defined. LHV represent the capability of heat release of the fuel, so that a higher LHV results in faster reaction rate of the fuel bed, which is shown by higher FPR. Fuel particle size is related with surface area per unit mass as well as heat and mass transfer coefficient. As the particle size increases the FPR decreases owing to decreasing specific surface area. Air injection supplies oxygen to the reaction zone. However oversupply of combustion air increases convection cooling of the bed and possibly extinguishes the flame.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.115-116
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• 2023

In this study, it was confirmed whether kaolin can play a role as a bed materials and a role in reducing clinkers by using kaolin with a bed materials for the purpose of removing clinkers such as slagging and fouling generated in circulating fluidized bed combustion furnaces using solid fuel.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.71-77
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• 2005

Combustion of RDF and wastewater sludge was performed in a 0.1MWth bench scale circulating fluidized bed combustor(CFBC), Combustion characteristics of the RDF and sludge mixture demonstrated stable combustion conditions. Component analysis, Combustion characteristics was measured before and after the test, and applications for commercial 1MWe CFBC boiler were prepared. The release of hazardous components such as $SO_2$ and HCl was relatively low values of 50 and 150ppm, respectively.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.119-127
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• 2003

In this study we propose an unsteady I-dimensional model of bed combustion with multiple solid phases, which confers a phase on each solid material. This model can be applied to a variety of bed combustion cases of various configurations and ignition methods. It contains fuel combustion, gaseous reaction, heat transfers between each phase, and geometric changes of the solid particles. An iron ore sintering pot is selected for verifying the model validity and simulation results are compared with the limited experimental data set of various coke contents and air supply rates. They predict the experimental results well and show applicabilities to the various system of the fuel bed with various solid materials.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.111-117
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• 2003

The present study discusses about the combustion and thermal flow characteristics of a G+R type incinerator, which is under construction for MAPO Incineration system, to evaluate the effects of various operating and design parameters. A bed combustion model is developed to simulate the waste bed combustion on the stoker. The effects of waste composition and primary air distribution are estimated. The results of the waste bed combustion model is applied to CFD(computational fluid dynamics) simulation, which simulates the detail of the thermal flow in the combustion chamber. The effects of bypass damper opening ratio, primary air distribution, and secondary air jet configuration are discussed.

• 한국연소학회:학술대회논문집
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• 2000.12a
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• pp.236-245
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• 2000

A laboratory scale fluidized bed reactor was developed to treat the combustion characteristics of some fuels (wood, paper sludge, refuse derived fuel). The aims were to introduce the means of experiment and interpretation of the results and finally determine the particle characteristics on the pyrolysis and combustion process of the fuel. A single particle combustion process in the fluidized bed was closely observed. Understanding experimental facility characteristics and determining parameters were also carried out. The fuel combustion processes were observed by carbon conversion rate, recovery and mean carbon conversion time. They were estimated with the CO, $CO_2$ gas concentration monitored at the exit of the combustor. Fuel drying and pyrolysis process were governed by temperature distribution in the fuel particle. There was a significant overlap of the drying and devolatilization. However, transition process from devolatilization to char combustion seemed to be determined by mechanical solidity of the fuel particle after devolatilization process.

• 한국연소학회:학술대회논문집
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• 2001.11a
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• pp.161-168
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• 2001

Sintering bed of iron ore in the steel making process is one of typical applications of solid fuel bed, which has relatively uniform progress of fuel and simple processes of combustion. The sintering bed was modelled as an unsteady one-dimensional progress of fuel layer containing the two phases of solid and gas. Cokes added to the raw mix of which the amount is about 3.5% of the total weight was assumed to form a single particle with other components. In the early predition results presented in this paper, the flame propagation within the bed was not sustained after the top surface of the bed was ignited with hot gas. It suggests that the model should be extended to consider the multiple solid phase, which can treat the ore particles and the coke particles separately.

• 한국연소학회:학술대회논문집
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• 1998.10a
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• pp.59-67
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• 1998

The aim of this study is to investigate advantages that the catalytically supported combustor can have. For this purpose, the catalytic combustor was prepared which consisted of the catalyst bed and the thermal combustor at the downstream of the catalyst bed. The catalyst bed consisted of two-stage. Pd catalyst was installed in the first stage of the catalyst bed, and Pt catalyst was placed in the second stage. Results showed that the catalytically supported combustion had some advantages. One was that auto-ignition occurred in the thermal combustor. This can give merit that an igniter is not necessary to start flame ignition. Other was that the catalytically supported combustion was stable for lean mixture. When combustion of lean mixture was not supported by surface reaction it became unstable so that big combustion noise was created. Therefore, it is desirable to support flame by catalytic surface reaction to obtain the stable combustion of lean mixture.

• Environmental Engineering Research
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• v.9 no.4
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• pp.143-153
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• 2004

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.5
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• pp.677-686
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• 2000

The characteristics of combustion and of emissions in pressurized fluidized bed combustor are investigated. The pressure of the combustor is fixed at 6 atm, and the combustion temperatures are set to 850, 900, and $950^{\circ}C$. The gas velocities are 0.9, 1.1, and 1.3 m/s. The excess air ratio is varied from 5 to 35%. The coal used in the experiment is Shenhwa coal in China. All experiments are executed at 2m bed height. Consequently, NOx & $N_2O$ concentration in the flue gas is increased with incresing excess air ratio but $SO_2$ concentration is decreased with incresing excess air ratio. CO concentration is maintained below 100ppm at over 15% of excess air ratio.