| 摘要 |
PURPOSE:To reduce consumption of heat energy and maintain coke quality, by performing first changeover to switch fuel supply from high flow in the early stage of dry distillation to low flow or stop the supply on the basis of concn. of tar contained in gas generated in a carbonization chamber. CONSTITUTION:In a coke oven, coal begins to soften and melt at around 350- 400 deg.C and its heat conductivity increases sharply in the neighborhood of 500- 600 deg.C where molten coke is resolidified and converted into semi-coke. Therefore, supply of fuel is increased until said temp. level is reached in order to expedite coking. Then feed of fuel is reduced to zero or to a very low level to maintain coke quality and reduce consumption of heat energy. Rate of change of concn. of tar contained in gas generated in a carbonization chamber is changed from near- zero to plus side when core temp. of coal reaches around 500 deg.C. Therefore, first changeover of fuel supply is performed in area C to D of the figure.
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