The advantages of circular mobile tunnel kiln, compared with straight fixed tunnel kiln
1）Fixed tunnel kiln requires a large number of kiln cars and their operating equipment. Mobile tunnel kiln requires no kiln cars nor operating equipment. Compared to fixed kilns, mobile kilns save construction funds.
2）Limited by the size of the kiln cars and the operating equipment’s drive power, the width of fixed tunnel kiln could not be too large. The widest fixed kiln is 9.23m in China. Whereas, mobile kiln doesn’t need any kiln car or operating equipment, the width of kiln is more often wider than 9.23m. The widest mobile kiln in China is 24m or so.
3） As far as the kiln bottom is concerned, a fixed kiln is a movable kiln bottom composed of several kiln cars, and it is difficult to seal tightly between the kiln cars, which is prone to air leakage. The leakage of hot gas in the positive pressure site into the inspection tunnels results in deformation and cracking of the metal parts on the kiln cars, resulting in ineffective operation of the kiln car, increased push car burden, and even damage the kiln body. At the negative pressure inspection tunnel, the cold air inside the tunnel leaks into the kiln chamber, causing the lower layer product on the kiln car to be under burned and reducing the product qualification rate. The biggest drawback of a fixed kiln is the leakage of air between kiln cars. However, the mobile kiln’s green bricks are stacked on the ground of circular kiln directly and there’s no air leakage from top to bottom. Given that the kiln car’s bottom is movable, its structural sealing is much difficult than that of a mobile kiln.
4） The bricks of a fixed kiln are stacked on the kiln car and move with the kiln car, which is prone to shaking during movement. In order to prevent brick collapse, its stability is particularly important. The pallets of a moving kiln are stacked on the ground and remain stationary. In this regard, the possibility of brick collapse is much lower than that of a fixed kiln.
5）The circular mobile tunnel kiln has effectively achieved the ‘one-stop, one-time’ firing process. The so-called ‘one-stop’ refers to the connection between the output end of the drying kiln and the input end of the roasting kiln, and the gap between the two kilns at the connection is isolated by a shut-off valve. Due to improper practices by some factories, the kiln car is often deformed, causing the position of the designated billet stack to move, while the position of the cut-off valve cannot move with it. Often, the cut-off valve falls on the billet stack and is forced to not use it, making it difficult to control the thermal system. The mobile kiln has satisfactorily solved the above problems and effectively achieved the ‘one-stop, one-time’ firing process. This is because the billet stack does not move on the ground plane, and the kiln body equipped with a cut-off valve is moving during processing. Therefore, the cut-off valve can accurately fall into the gap between the two billet stacks, completely separating the drying section and the roasting section.
Production process of circular mobile tunnel kiln: