The technological process of rotary kiln is mainly made of limestone and clay as the main raw materials. After crushing, batching and grinding, raw materials are made into raw materials and fed into the cement rotary kiln to calcinate the mature materials. Appropriate amount of gypsum (and sometimes mixed materials or admixtures) are added into the cement rotary kiln for grinding. At the same time, with the kiln body rotating in accordance with the designed slope and speed, the raw materials also periodically roll forward in the kiln, so as to transport the raw materials from the feed end to the discharge end.
Common equipment of rotary kiln is cement rotary kiln, metallurgical chemical rotary kiln and lime rotary kiln, etc. Cement rotary kiln is mainly used for calcining cement clinker, metallurgical chemical rotary kiln is mainly used for magnetization roasting of lean iron ore in steel works in metallurgical industry, lime rotary kiln is used for roasting active lime and light fired dolomite in steel works and ferroalloy works, although its processing materials are different, But the process flow is basically the same, let's understand the process flow of rotary kiln.
Structural characteristics of rotary kiln
Rotary kiln wheel supporting device: wheel supporting device is divided into two kinds with and without retaining wheel, a set of wheel supporting device includes two wheel supporting group and a wheel supporting base, some wheel supporting device and retaining wheel group, wheel supporting group includes supporting wheel, supporting wheel shaft and supporting wheel bearing, etc. The supporting wheel is the load-bearing device of rotary kiln cylinder body, so the tug is a part that works under heavy load condition. The supporting wheel of rotary kiln is mainly composed of the tug, shaft and the retaining ring on the shaft. When the supporting wheel moves in tandem due to the axial movement of the kiln body, the supporting wheel can be supported on the top of the bronze bearing bush by the retaining ring.
Rotary kiln retaining wheel: The retaining wheel is installed on both sides of the rotary kiln rolling ring, mainly to indicate and appropriately prevent the axial movement of the cylinder. The retaining wheel is generally only a pair, which is sandwiched on both sides of the rolling ring. The distance between the two sides of the rolling ring and the rolling ring depends on the allowable axial movement distance of the cylinder body, so as to ensure the contact between the rolling ring and the supporting wheel of the rotary kiln. It can also play the role of sealing device at both ends of the rotary kiln cylinder body.
Rotary kiln rolling ring: In order to prevent the rolling ring from falling down when the cylinder is heated and axial expansion and extension, the surface width of the rotary kiln supporting wheel should be 10-80mm wider than the rolling ring.
Big gear of rotary kiln: The cylinder body of mechanically driven rotary kiln is covered with big gear, which is generally located in the middle of the rotary kiln. The big gear is driven by the small gear located on the civil foundation of the transmission device. The general structure of mechanical transmission is that the main drive motor drives the main reducer, and then drives a pair of open gears. After several changes of speed, the pinion connected with the big gear ring can be driven according to the required speed, so that the big gear ring drives the kiln body to rotate and can meet the requirements of process operation.
Rotary kiln coupling: the auxiliary drive motor is connected with the high-speed input shaft of the reducer after a set of reduction device, and the main transmission motor and the reducer are directly connected with the coupling. In addition to the low speed output shaft, the two ends of the high speed input shaft are connected with a motor, one is the main engine transmission motor, the other is the auxiliary drive motor.
Rotary kiln bearings: rotary kiln bearings are generally made of plain bearings with thin oil lubrication and water cooling tubes. Considering the possible bending of the cylinder, the sudden increase of load on the supporting wheel and the harsh working environment of the supporting wheel, the bearings of rotary kiln must have a large safety factor and good lubrication seal and water cooling. In order to adjust the axial movement of the cylinder, the bearing of the supporting wheel of the rotary kiln must be made to be adjustable and mobile, so that the supporting wheel can move in the horizontal direction.