COMPLETION OF THE SINTERING PROCESS

Abstract

The process of sintering is completed only on sinter machines with a cooling zone. The degree of completion of the process, characterized by the relative height of the melt zone during unloading of the sinter from other types of machines, which make up the absolute majority, is at the level of 60%. In practice, the “completion of the sintering process” is taken to mean the exit of the fuel combustion zone from the sintering bed. The heat exchange in the sintering bed is considered complete during process, because the temperatures of the exhaust gases and the material at the exit from the bed are close, and at 60% of the bed length they are represented by the dew point temperature. Due to this, the supply of heat from the cooled agglomeration sinter with air and the oxidation reaction of FeO to the fuel combustion zone, the high bed of the mix, the increased basicity of the sinter and the introduction of lime into the mix, the consumption of solid fuel is 40–45 kg/t of sinter with the amount of melt at the level of 60%. The expert system “Sinter’s Advisor” is simple and effective for control the sintering process. The most efficient and reliable for the necessary adjustment of the mix moisture content and solid fuel consumption are the current “advice” from the process itself. The technologist receives the first of them from the suction trends in the first vacuum chambers and in the ignition hearth, the bed surface temperature. For him to make a decision, the primary trends must be confirmed by the locations of the start of the exhaust gas temperature rise, then the maximum temperature. Fuel consumption control is effectively carried out according to the return fines balance. The process of sintering independently compensates for up to 40% of the negative impact of factors on the sintering rate, “regulating” the suction in the gas exhaust tract of the sinter machine. The use of a discrete version of “extreme control” is effective for the “Sinter's Advisor” system, in which the operating parameters of the sinter machine are processed, adjusted and set again for periods equal to the duration of the movement of the fuel combustion zone along the bed height. Installation of a thermal imager at the end of the sinter machine allows for continuous visual monitoring of the thermal level of the process, its uniformity across the bed width and not sintering mix, and to solve the control problem as a whole.