Abstract
The raceway in front of tuyere of the blast furnace has been studied on an experimental furnace by means of raceway measurements, temperature measurements and gas composition survey. At the end of experiment, raceway is filled with light alumina particles carried by blast and is quenched with nitrogen gas. Then, profiles of the raceway, amounts and properties of coke in the raceway have been measured. The effects of coke properties on the reaction around the raceway have been studied using various kind of carbonaceous materials such as charcoal, pitch coke, carbon brick, formed coke and so on. It was shown that temperature of raceway is ruled by reactivity of coke. The temperature in the raceway is explained by assuming competitive reaction of blast against carbonaceous materials such as coke and CO gas in the furnace. As the results of observation of coke texture which is sampled from raceway, preferential reaction seems to take place between oxidizing gas and reactive component of coke texture. Fine coke powder, which is consisted mainly of inert component, is detached from coke in use of some kind of materials such as carbon brick where inert components are bound by small amount of reactive component. Accumulation of fine coke powder around the raceway prevents normal gas flow in the furnace.
