Date of Graduation
Pulverized coal instead of natural gas as a fuel for slab preheating furnaces is evaluated for economic and technical feasibility. Pulverized coal firing is more complex than natural gas firing and requires higher equipment and operating costs including the cost of flue gas cleaning. However, coal is cheaper than natural gas on a unit heat energy cost basis. Savings in fuel energy cost easily compensate for higher equipment and operating costs of pulverized coal fired slab preheating systems. The effect of coal burning environment on the chemistry of slabs is also included in the evaluation. The experimental results from the operation of a small scale laboratory furnace indicate loss of carbon content in steel slabs preheated with pulverized coal. But the depth of decarburization is limited to within one half of a millimeter of the surface for 1 inch thick slabs. No change in the sulfur content of slab material is observed. The experimental results also show that the flue gas can effectively be desulfurized by mixing lime with pulverized coal prior to combustion. This process does not require a scrubbing plant and therefore, has much lower equipment cost as compared to the lime slurry process. The amount of lime required, however, is about 50% more than that for the lime slurry process.
Burhanuddin, Sheikh, "An economic and technical feasibility of pulverized coal-fired slab preheaters." (1988). Graduate Theses, Dissertations, and Problem Reports. 8551.