| 摘要 |
PURPOSE:To prevent the reduction of efficiency of heat transfer due to the ash in a furnace, the corrosion of heat transfer pipes, and dirtiness in the furnace by a method wherein coal is converted into combustible gas in a fixed bed gasification furnace and the gas is supplied to the furnace to be burnt. CONSTITUTION:Introduction of combustible air into a gasification furnace 12 from under a rotating fire grating 23 causes coal to be gasified in partial combustion. The air quantity at that time is 0.3-0.7 times the theoretical air quantity necessary to burn coal in the furnace 12 and further, the temp. of a combustible gas at a gas outlet hole 27 is forced to be above 800-900 deg.C. Thus, the coal generates gas while it moves from top to bottom in the furnace 12 and becomes ash finally and falls down from the periphery of the grating 23 to be discharged from an ash discharge port 24. The combustible gas generated in the furnace 12 is supplied to burners installed at the four corners of a furnace 11 and mixed with air supplied similarly to the four corners by a forced draft fan 14 to be burnt. A minute quantity of ash contained in the combustible gas can be easily removed by a buffle plate installed at the outlet hole part 27 of the furnace 12 or the connecting part between the furnaces 12 and 11. |
