The rotary cement kiln is the most vital device in a cement plant, it is the place where the raw meal is burnt and calcined into clinker. Cement rotary kiln plays a variety of roles in the cement production line at the same time. It is not only a combustion device, but also a heat exchange device, a chemical reactor, and a conveying device.
The rotary cement kiln we supply is the most ideal cement kiln for the new dry process of cement manufacturing. It has perfect performance on clinker production of ordinary Portland cement, white cement, Portland pozzolana and so on.
AGICO Rotary Cement Kiln Advantages
Over decades, our company has been summarizing experience, improving production technology and updating production equipment in the process of designing and building rotary kiln for customers. Until now, we have successfully added following advantages to our rotary cement kilns:
1. Our rotary cement kilns are all made of thermal insulation material, which reduces the radiation heat loss and energy consumption during the burning process;
2. We use compound fish scale to soft seal the front end and the back end of the rotary cement kiln. The air leakage coefficient can be thus controlled less than 10. It also helps to meet the environmental protection requirements.
Rotary Kiln Structure
The structure of a rotary cement kiln mainly includes:
Cylinder: The cylinder is the body of the rotary kiln. It is covered by the kiln shell, which is made of welded steels. Inside the shell, there is firebrick lining to prevent the shell from melting down.
Tyre: The tyre is also called riding ring, it is a steel ring mounted on the kiln shell to support the kiln. The thickness of the kiln shell increases around the tyre to prevent deformation caused by the pressure of the tyre.
Roller: The rollers are mounted on a massive cast iron or steel base plate which provides the inward horizontal forces on the rollers and distributes the weight of the kiln over the pier. The spacing between the rollers has to be small enough to prevent large horizontal forces, but large enough to keep the kiln laterally stable.
Drive Gear: The function of the drive gear is to ensure the rotation of the rotary kiln and regulate the rotation speed of the kiln.
Kiln Seal: Because the rotary kiln operates under the condition of negative pressure, and there are gaps in the places where the cylinder is connected with the kiln hood and the smoke chamber, the sealing device must be installed on both the front end and the back end to prevent air leakage and material leakage.
Kiln Hood: The function of the kiln hood is to gather the clinker temperature during the operation, prevent the clinker from overflowing, and with the help of the exhaust fan, send the hot air from the cooling machine into the kiln through the kiln hood, so as to make full use of the heat and reduce the fuel consumption.
Rotary Kiln Working Principle
Because the cylinder has a certain slope and rotates at a certain speed, the raw meal will move from the back end to the front end when it is fed into the rotary kiln.
The space inside the cylinder can be divided into the drying & preheating zone, the calcining zone, the transition zone, and the sintering zone.
The raw meal fed into the cylinder body, affected by the rotation of the cylinder, continuously rolls and moves along the axial direction, passing through the three above zones in turn. The calciner installed at the front end of the kiln injects fuel into the cylinder and heats the raw meal. The flue gas generated in the process is discharged from the back end of the kiln. Raw meal is heated in the process of moving. And after a series of physical and chemical reactions, it becomes a qualified clinker and is discharged from the front end of the kiln.
Rotary Kiln Specifications
Cement Rotary Kiln Maintenance Notifications
The operation efficiency of the rotary cement kiln will be affected if its parts are worn. At this time, the maintenance must be carried out to repair or replace the worn parts. Large scale maintenance takes a long time, usually 10-20 days. During the overhaul, it is necessary to replace all the worn parts, inspect and adjust all the units (such as replacing the important parts such as cylinder section, ring gear, wheel belt, idler, etc., and aligning the kiln center line, etc.).
Replacing Standards for Main Parts in Cement Rotary Kiln
Rotary kiln parts who match following standards must be replaced or repaired immediately.
1. The tooth thickness of transmission gear is worn more than 30%, or the tooth edge is damaged irreparably;
2. There are cracks and local deformation in the cylinder section of the kiln;
3. The section of the wheel belt is worn by 20%, or its surface is worn into a cone or a polygon, or there is a local through crack;
4. The diameter of the supporting wheel and the retaining wheel is worn by 20%, or the thickness of the supporting wheel rim is worn by 25%; the rim is grinded into a cone or other special shape, or the rim has through cracks. When replacing the supporting wheel and retaining wheel, the corresponding liner must be scratched or replaced again.