What Is Rotary Kiln
Rotary kilns refer to rotary calcining kilns (sometimes called rotary furnaces). It is a pyroprocessing device used to heat materials to high temperatures in a continuous process. The kiln body is a cylinder vessel with a certain degree of tilt to horizontal level. Raw materials are feed into the vessel from the upper end and moved to the lower end, being stirred and mixed relying on the inclination and rotation of the kiln. The kiln burner generates a large amount of heat through the combustion of fuel. The heat is usually transmitted to materials by means of flame radiation, hot gas convection and kiln brick conduction so that they can react with each other chemically and finally form the clinker.
Rotary kilns can be divided into cement kiln, metallurgical and chemical rotary kiln, lime rotary kiln and so on. Cement kilns are used for calcining cement clinker in cement plant, which can be divided into dry cement kiln and wet cement kiln. Metallurgical and chemical rotary kilns are mainly applied in the metallurgical industry. As for the lime rotary kiln, it is the main equipment for calcining active lime and light-burned dolomite used in iron and steel plants, ferroalloy plants, calcium carbide plants and magnesium metal plants.
How Rotary Kilns Work
The rotary kiln is mainly composed of cylinder, supporting device, drive gear, refractory lining, catch-wheel device, kiln head sealing device, kiln tail sealing device, kiln hood and other components. There is a large gear ring fixed with a spring plate on the cylinder near the kiln tail, some pinions below are engaged with it, jointly forming the drive gear. In normal operation, the main drive motor transfers power to the gear device through the reducer to drive the rotary kiln. Raw materials usually enter the rotary kiln from the upper end and move slowly to another end along the chamber with its rotating. In this process, raw materials heated by high temperature will decompose and produce chemical reactions so that their state may finally change. Under normal conditions, the heat source of indirect fired rotary kilns is supplied from the kiln burner outside the kiln. This kind of way protects the integrity of raw materials, while the heat source of the direct fired rotary kiln is inside the kiln. In addition, the rotation speed and temperature of the cylinder are tightly controlled and changed according to different desire processes and material applications. After the calcination is completed, the clinker will be cooled in the chamber and discharged from the kiln hood into the cooler for further cooling.
Rotary Kiln Diagram
- Decades of experience with the rotary kiln production and material development
- Full automatic operation and instrument control
- Suitable for a variety of production environments
- Continuous monitoring of the equipment operation and product quality
- High production efficiency and quality