To obtain clinker prevented from deterioration and having stable quality by blowing a solid synthetic resin having equal to or below a specific particle diameter as an auxiliary fuel at a jetting rate equal to or below that of a main fuel and equal to or below a specific turning angle from an exclusive nozzle in the front of a rotary kiln oven to fire a cement raw material compound.
The particle diameter of the solid synthetic resin is ≤6 mm and the turning angle is ≤20°. When the distance between the center of the exclusive nozzle and the center of a main burner is expressed by L and the inside diameter of the rotary kiln is expressed by D, the exclusive nozzle is mounted at a position to be L/D ≤0.25 from the main burner and at the upper side of a main fuel blowing nozzle so that the tip of the exclusive nozzle preferably faces downward or is in parallel to the main burner. The jetting rate of the auxiliary fuel does not exceed that of the main fuel and is ≤25 m/sec, further preferably the solid synthetic resin is jetted at a ratio by weight of ≤1 to the jetted air. Waste plastics or the like, which is rapidly increased, enable to be used in place of the fuel for the clinker.
YAMAMOTO YASUSHI
AOYAMA HISANORI
TAMAE TAKAMIKI
NARISHIMA RYOSUKE