• Journal of the Korean GEO-environmental Society
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• v.11 no.6
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• pp.31-37
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• 2010

In this study, optimization of MEK and Toluene removal was conducted by HTO(Hybrid Thermal Oxidation) system. HTO system has a multi-bed reaction plate and the plate consisted of wasted heat regeneration part and catalysis part. VOCs removal by HTO system was estimated by changing inlet flow rates with different valve changing times. Under $350^{\circ}C$ of combustion temperature, VOCs was fully converted and the equivalent conversion was 100%. The thermal oxidation efficiency, related to the amount of injected fuel into HTO system and the valve change time, was revealed at the level of 93.0~96.3%. In case of MEK removal by HTO system, the efficiency was ranged from 91.1 to 97.1%. Also, Toluene removal efficiency(93.2~97.4%) was good and stable with respect to the operating conditions. Considering above results, it was proved that HTO system could be a stable and compact system for VOCs, especially MEK and Toluene with high removal efficiency.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.173-181
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• 2014

The propagation behavior and structural variation of a premixed propane/air flame with frequency change in an ultrasonic standing wave at various equivalence ratios were experimentally investigated using Schlieren photography and pressure measurement. The propagating flame was observed in high-speed Schlieren images, allowing local flame velocities of the moving front to be analyzed in detail. The study reveals that the distorted flame front and horizontal splitting in the burnt zone are due to the ultrasonic standing wave. Vertical locations of the distortion and horizontal stripes are intimately dependent on the frequency of the ultrasonic standing wave. In addition, the propagation velocity of the flame front bounded by the standing wave is greater than that of the flame front without acoustic excitation. As expected, the influence of the ultrasonic standing wave on premixed-flame propagation becomes more prominent as the frequency increases.

• Fire Science and Engineering
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• v.24 no.3
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• pp.131-138
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• 2010

Experimental and numerical studies were conducted to investigate the thermal and chemical characteristics of heptane fires in a full-scale ISO 9705 room. Representative fire conditions were considered for over-ventilated fire (OVF) and under-ventilated fire (UVF). Fuel flow rate and doorway width were changed to create OVF and UVF conditions. Detailed comparisons of temperature and species concentrations between experimental and numerical data were presented in order to validate the predictive performance of FDS (Fire Dynamic Simulator). The OVF and UVF were explicitly characterized with distributions of temperature and product formation measured in the upper layer, as well as combustion efficiency and global equivalence ratio. It was shown that the numerical results provided a quantitatively realistic prediction of the experimental results observed in the OVF conditions. For the UVF, the numerically predicted temperature showed reasonable agreement with the measured temperature. The predicted steady-state volume fractions of $O_2$, $CO_2$, CO and THC also agreed quantitatively with the experimental data. Although there were some limitations to predict accurately the transient behavior in terms of CO production/consumption in the UVF condition, it was concluded that the current FDS was very useful tool to predict the fire characteristics inside the compartment for the OVF and UVF.