外熱式キルン炉におけるごみ熱分解の促進 : 第1報,炉壁からごみへの総括伝熱係数の測定(熱工学,内燃機関,動力など)

概要

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For pyrolysis reactor of solid wastes, the externally heated rotary kiln is the most appropriate furnace. The goal of this study is to improve the heat transfer in the externally heated rotary kiln for the waste pyrolysis. As an important property of heat transfer, we performed experimental evaluation of the overall heat transfer coefficient (k_<m-w>). The simulant waste was pyrolyzed using externally heated batch type rotary kiln pyrolyzer. In order to measure the radial heat flux through the dram wall, six pairs of thermo-couple were attached to the inside and outside surface of the drum wall. Heat flux (q_m) was calculated using the radial temperature gradient in the wall. k_<m-w> was calculated using the formula, k_<m-w>=q_m/AdT; A is internal surface area of the wall, dT is temperature difference between inside surface of the wall and the waste. q_m and dT showed the highest value at the beginning of the pyrolysis. On the other hand, k_<m-w> showed the lowest value at the beginning and increased with increase in waste temperature. In the case of the mean temperature of the kiln inner wall was 555 centigrade, k_<m-w> changed from 22 W/m^2 K to 55 W/m^2 K. Consequently, in the continuous type kiln, at the closer distance to the end of the drum, the higher k_<m-w> appears.
2008-07-25