Overview of Cement Kiln System in Cement Production
Cement Kiln System in Cement Production
The cement kiln is main equipment for cement production. The whole burning process of raw materials is completed in cement rotary kiln. The simple rotary kiln is a dry hollow kiln. Raw meal powder is added from kiln tail. Pulverized coal is sprayed from kiln head with a primary air and burned inside of kiln. The flame temperature here reaches 1800-2000 °C. Raw material is continuously flowing to kiln head, and humidity is gradually increased.
After drying, dehydration, preheating and decomposition, the liquid phase appears at about 1300 °C, and rises to 1450 ° C under flame. The material is then cooled to 1300-1100 °C and left rotary kiln to fall into single cylinder cooler. It is cooled to about 100-150 °C and discharged to clinker conveyor and transported to clinker crusher. After crushing and grinding, it is stored in warehouse.
What does cement kiln system includes: rotary kiln, preheater, dryer, cooler and rotary kiln control system
What is Rotary Kiln and Cement Kiln
Cement kiln is a type of rotary kiln, so what is rotary kiln made of? As a matter of fact, rotary kiln is a cylinder rolled from a steel plate, which is internally reinforced with refractory bricks, supported by a wheel belt on loading body and a lower idler wheel, and is driven by a large ring gear mounted on kiln body. The rotary kiln is usually placed at a slope of 3.5%, revolutions number is generally within 1 rev / min, and new dry kiln is up to 3 rev / min.
Single cylinder cooler is similar to kiln, except that a lifting plate is installed in cylinder to accelerate clinker cooling. The simplified temperature of high temperature zone of kiln head was too high. It was previously cooled by water and has been changed to air cooling.
Raw Material Drying Process Before Cement Kiln
If Raw Material Moisture is high, it has to be dried before entering cement kiln system, raw material consisting of limestone, gangue and other components with approximately 7% to 8% moisture is dried in a dryer that uses heat from boiler exhaust gases to reduce the raw meal moisture content to about 0.25%. The dry raw meal is preheated in 5 stage preheaters before being loaded into a precalciner. Preheating is done by using hot gases from precalciner and rotary kiln as well as hot air from the clinker cooler.
The precalciner uses combustion of coal and gases from kiln to supply the necessary heat to material before it is discharged in rotary kiln for completing calcining and subsequent clinker burning process. The rotary kiln uses a coal burner and preheated air obtained from clinker cooler. Clinker formed in the kiln is discharged in a grate type cooler where ambient air is used in several stages to cool the clinker and recover its heat for use in several areas of the process and elsewhere in the plant.