Design and Manufacture of Kiln Car | Brick and Tile Technology

The tunnel kiln car is the most expensive component of the tunnel kiln system, and has an important impact on the safe operation and energy consumption of the tunnel kiln, tunnel kiln car often has some technical problems, they are the main factors affecting the quality of tunnel kiln firing, operational reliability, economic benefits.

Kiln car surface is the most problematic component of tunnel kiln construction. The two side walls of the kiln, the roof of the kiln and the kiln car surface form the four faces of the kiln. The kiln car surface should consume the least heat, because the temperature of the other three faces remains constant after the kiln is heated, and their heat consumption is limited to The heat loss conducted outward.

Sintered brick tunnel kiln in normal ignition production, generally will not stop the kiln. But sometimes because of the kiln car quality problems forced furnace cease-fire, resulting in the kiln can not be normal production. Therefore, the quality of kiln car manufacturing will directly affect the normal operation of the kiln.

Kiln car in the manufacturing process, in addition to reasonable design, the material selection of kiln car is a crucial part. Now on the market supply of steel channels from different sources, different manufacturers, good material off is the key to manufacturers. How to control the material requirements? Now in terms of steel kiln car:

The 1. should be based on the physical and chemical indicators and physical performance indicators of the selected material to meet the production needs of the kiln in the hot state.

According to this problem, the author has sampled some index data of some manufacturers, especially the negative deviation of geometric dimensions in the design, but it is also within some required deviation. However, in the actual use process, there are more or less different degrees of force and deformation of kiln car during operation. It will directly affect the change of the overall structure size of the kiln car, resulting in the connection operation of the kiln car colliding with the kiln wall.

Welding parts of 2. kiln car 

The technical requirements for the stress points of the main beam, secondary beam and jacking machine must be clearly stipulated, but there is no clear stipulation in the design process of many kiln cars, and the manufacturer also ignores the special treatment of key parts. In particular, the welding between the main beam, that is, the stress beam and the stress beam, should be groove welded and fillet welded according to the regular, and certain data should be given in the specific weld design. However, some manufacturers ignore the special treatment of key parts in order to save labor, resulting in the collapse of kiln cars during production and operation.

3. kiln car bottom plate in material selection 

It must not be considered because of material saving, especially for kiln cars with large cross-sectional area, there should be reinforcing rib plates in the design, and the connection between plates should be fully welded by groove welding, and indirect welding must not occur. Some manufacturers use indirect welding in order to reduce labor and save materials. During operation, the bottom of the kiln car is hot, and some materials are dropped, which leads to blockage of debris on the track in the kiln and makes the kiln car unable to run normally and smoothly. Some designs of sand sealing plate of kiln car are welded to the main beam of kiln car as a whole. When affected by high temperature, this structure is subjected to uneven heat stress, which is easy to deform the sand sealing plate, resulting in collision between the sand sealing plate and the sand sealing groove and unsmooth operation. According to the experience of some manufacturers, the sand sealing plate should be replaced by elliptical hole bolts to connect with the main beam, so that the direct stress imbalance of the sand sealing plate can be adjusted freely.

Selection of Wheels and Bearings for 4. Kiln Cars 

The kiln wheel is the supporting point of the kiln car during operation, and the assembly and selection of the kiln wheel bearing is the key to the smooth operation of the wheel. If the kiln wheel has no strength, the surface hardness is shallow or there is no quenching at all, causing the wheel to wear faster and affecting the wheel operation. Similarly, improper selection of bearings leads to increased wear resistance, resulting in increased load and poor operation of the jacking machine, which causes excessive wear of the rail surface in the kiln and affects the change of geometric dimensions in the kiln. When selecting a bearing, the clearance between the ball and the collar should be reasonable, and a bearing with a small clearance cannot be selected. The surface quenching hardness deep layer of the wheel is preferably 3-5mm.

5.Wheel and body geometry 

It is the basic guarantee during assembly. It is necessary to fine-tune the tunnel kiln car with large cross-section. When assembling the kiln car, the geometric dimensions of each part should be accurately controlled on the tooling platform. Never assemble at will on the outer track of the kiln. For multi-wheel kiln car, its stability and connection axis should be arranged and assembled, not assembled alone. After the assembly is completed, the size between each wheel and the rail contact or joint surface should be fully checked, the concentricity should be engaged with the body axis, the error number should not exceed the design requirements, and the kiln car should be operated continuously for more than two times in the whole kiln, and the corresponding size inspection should be carried out to find other problems.

To ensure the overall quality of the kiln car, the kiln car masonry must not be ignored. Many brick factories, in the process of using the kiln car, do not check the kiln car, do not pay attention to maintenance, and do not find and deal with the hidden quality problems of the kiln car in time, resulting in unnecessary accidents when the kiln car enters the kiln.

Attention should be paid to the masonry quality of the kiln car: the kiln car should also be similar to the masonry quality requirements of the kiln body, the mortar joint should not be too large, the masonry method should be reasonable, and some geometric dimensions must master the key points of negative and positive and negative. When building the kiln car, the flatness of the masonry on the car platform cannot be ignored, and the shrinkage joints should be kept well.

After the production of kiln unloading bricks, the residual brick dust on the car surface should be cleaned up anytime and anywhere. For inexperienced manufacturers, a safety inspection door should be set up on the carriage return line outside the kiln and at the carriage end of the kiln head. Kiln cars filled with brick billets should pass through the safety inspection door before entering the drying room and baking kiln. This is conducive to ensuring that the brick billets are not too wide or too high after stacking, and can ensure that the billet car will not collide with the kiln wall and kiln roof in the kiln, making it run smoothly in the kiln.

Compared with masonry kiln car, the overall cast-in-place kiln car is difficult to repair after damage, but the cast-in-place kiln car has better heat insulation and sealing performance. When the kiln car is running in the kiln, attention must be paid to the damaged block falling into the kiln passage at any time. The emergence of this problem is most likely to cause damage to the kiln body, such as damage to the curved seal brick structure, resulting in derailment of the kiln car when jacking, reversing in the kiln and so on. Therefore, in order to reduce production costs, reduce maintenance costs and sintering energy consumption, improve the service life of the kiln and kiln car, we must pay attention to the quality of the kiln car.