AFTERRBURNER COMBUSTION CONTROL METHOD OF ROTARY KILN FOR PRODUCING SPONGE IRON PELLET

摘要

PURPOSE:To perform hardening treatment in an optimum state and achieve the stabilization of characteristic through kiln treatment by detecting the temperature and O2 amount of kiln exhaust gas and combustion gas and controlling these to the specified at the time of hardening sponge- form pellets by after-burner combustion gas. CONSTITUTION:At the time of hardening the pellets for sponge-form iron making raw materials having been dry-preheated by the combustion gas of the exhaust gas after-burner 2 of a rotary kiln 1 in a treating chamber 4 during conveying with a traveling conveyor 3 and charging the same into the kiln 1, the flow rate, temperature and O2 amount of the kiln exhaust gas are measured with a flow measuring device 8, thermometer 6 and analyzer 7 and the flow rate, temperature and O2 amount of the combustion gas are measured with a flowmeter 13, thermometer 11 and analyzer 12 and the abovementioned respective measured values are sent to a control unit 4, whereby the flow rate of an outside exhaust pipe 15 and the openings of the respective valves for water supply source 9 for combustion portion, air lead-in pipe 9, etc. are controlled. In this way, the hardening of the pellets is accomplished in an optimum state and even if they are charged into the kiln, they do not become powder.