Production process flow of mechanical vertical lime kiln
Mechanical vertical lime kiln realizes efficient production through automation and thermal optimization, and its core process covers four links: raw material treatment, calcination control, waste heat utilization and environmental protection treatment.
Raw material treatment: limestone is crushed to 15-50mm grain size by crusher and graded by double-layer vibrating screen to ensure grain size uniformity. The raw materials and fuels (such as lump coal, coke or low heating value gas) are mixed in proportion, and then sent to the kiln top bin by the single bucket elevator. Circular distribution is realized by the hydraulic push rod distributor to ensure the flatness of the material surface.
Calcination control: from top to bottom, the kiln is divided into preheating zone, calcination zone and cooling zone. The pre-heating zone preheat the materials to 850-1050 ℃ with the waste heat from the kiln top, and the pre-decomposition rate reaches 30%; The calcining zone temperature shall be controlled at 1150-1250 ℃, and the decomposition rate of calcium carbonate shall be ≥ 98% by adjusting the gas/air ratio; Forced air cooling is adopted for the cooling belt, and the temperature of outgoing lime is ≤ 100 ℃. The kiln body is vertically constructed with four layers of refractory materials, the heat loss is reduced by the insulation layer, and the kiln skin temperature is controlled at about 60 ℃ higher than the ambient temperature.
Utilization of waste heat: the cooling air enters the calcining zone for combustion support after heat exchange. The waste heat of flue gas is recovered by the waste heat boiler to generate steam for power generation, and the thermal efficiency is significantly improved.
Environmental protection treatment: calcined flue gas is subject to secondary purification by cyclone dust collector+bag dust collector, with dust emission concentration ≤ 10mg/m ³, meeting environmental protection standards. CaO content of dedusting ash ≥ 60%, which can be returned to the raw material system for recycling.
