Lime and cement productions have been soaring worldwide. Plants are under pressure to keep up with the demand. They can deliver on time only when their equipments are reliable. The rotary-kiln is an important piece of equipment at any such production plant site. Cement producers have to make sure this equipment is always in an excellent condition.
Why is It Important to Keep the Kiln Aligned?
A kiln is a massive piece of equipment with multiple parts. Accurate kiln alignment is necessary to maintain operational efficiency. This equipment is a large rotary machine that moves at a very slow speed. Generally, it is the fast moving and heavy machinery that requires frequent alignment to maintain precision operation. Even though the kiln moves at slow speed, it has lots of dynamic and static load. Additionally, the extreme temperature of kiln causes thermal expansion. These factors cause misalignment in a kiln. If this misalignment is not fixed in time, it can result in extensive damage including component failures, hot bearings and refractory failure.
The Process of Aligning the Kiln
Kiln alignment is needed to achieve accurate operation. State of the art computerised procedure is used to find the coordinates of kiln axis. The drive pier is inspected thoroughly. An analysis of kin shell profile is performed. All other mechanical components of the kiln are also inspected. When aligning the kiln, support rollers that handle the thrust loads are adjusted. The shell ovality of kiln is optimised. This whole procedure ensures complete and accurate alignment of kiln.
Kiln Aligning Steps
In the first step, the shell rotating centre's coordinates on all piers are located with the help of laser equipment. Perpendicular cross between the kiln axis and rotating centre of each pier is calculated to determine the misalignment of kiln axis. The ovality of shell on all piers is measured. The kiln axis is strengthened by adjusting the support rollers. The goal is to optimise shell ovality by properly adjusting pier load distribution. All bearings are adjusted if required. It helps align support rollers. The dogleg conditions adversely impact kiln stability. These conditions can be detected by measuring the movement of horizontal tyre on all piers. Unnecessary tyre clearance can cause high shell ovality. This problem can be fixed by replacing the support pads. All other components of the kiln are inspected. Any part of kiln that requires repair is reported to the kiln operating company. All these processes are carried out by professionals with expertise and experience in this field.
Why Hot Alignment Is Preferred?
Kiln alignment has been the most popular option when it comes to aligning the kiln. It is aligned while it is hot because this is the time when components expand due to high operating temperature. On the other hand, the tyres expand differently. It results in misalignment of the kiln axis in the elevational or vertical plane. Another reason alignment of kiln is done during operation is that it does not affect production. It is a convenient process for the kin operating company. It is due to these reasons that kiln alignment is the most popular aligning method used in the industry.
The purpose of this alignment is to ensure high mechanical stability of kiln during operation.