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Description of Lime Production Line:
This active lime production line is a complete line that includes vertical preheater, rotary kiln, grate cooler, air treatment system, raw material conveyor system, finished product conveyor system, raw coal grinding system, and so on. DCS central control system is employed to make concentrated operation management.
Process Flow of Lime Production Line:
1. Raw Material Conveying:
The 20-40mm limestone on the stock ground is sent to storage silo by the B1000 belt conveyor with large inclination. In the storage silo, qualified limestone with granularity more than 10mm will be sent to the gravel silo, while limestone with particle size less than 10mm will be conveyed to the powder silo.
2. Limestone Calcining:
The limestone calcining system is mainly made up of 10.5×8.5m vertical preheater, 4.0×60m rotary kiln and vertical coolder whose output is 600t/d and heat consumption of 5.75GJ/t. Limestone inside the preheater is heated by high-temperature gases from rotary kiln to 600-800°C, at which temperature limestone can be partly decomposed. Then the limestone will be sent by 12 hydraulic push rods to the kiln end, where it will undergo high-temperature calcination before sent to the vertical cooler. The processed limestone will be cooled down by cold air to 65°C. Air from the vertical cooler enters into the rotary kiln as the second air to take part in calcining process.
3. Finished Product Conveying:
The final lime will be sent to the storage bin for final products by NE500 bucket elevator. After screening, qualified lime whose particle size is more than 5mm will be sent to storage for active lime, while powder lime whose size is less than 5mm will be sent to storage bin for powder.
4. Gas Treating:
High-temperature gases from rotary kiln will do heat exchange with limestone inside the preheater, and after that, the temperature of these gases will reduce to lower 280°C. Then these gases will be cooled down by multi-tube cooler to 200°C lower. Finally, they enter into the bag filer before discharged into the atmosphere.
