In order to increase heat transfer area, some of the low temperature portion in the rotary kiln with heat exchange means. In long wet kilns kiln is usually suspended in the chain, the chain hanging part buried material layer, a portion exposed to the hot gas stream with the feed end of the chain, the material of the slurry flow, stop the kiln rotation, when the chain rises from the material, the slurry was sticky linked to the chain's surface. Hot air passes through the gap between the chain and heat to stick to the surface of the chain hanging slurry, which greatly increases the hot air heat exchange area and the material, to improve the heat transfer efficiency. Therefore, the size of the surface area of ​​the chain has become one of the main impact of the heat transfer efficiency, the chain belt outfeed part, due to the slurry water is evaporated, the material is dried, the material falls from the chain, then the chain do not hang on the slurry viscosity. When the chain is exposed to hot air, hot air convection heat to raise its temperature to a chain, when the chain to the lower part of the kiln with the material layer is embedded in the chain in turn transfer to the material, then the chain plays an accumulator The role or the role of the media is called heat, other forms of heat exchange device and the chain transfer process basically similar. The above article by Henan YuFeng Heavy Machinery  finishing release, reproduced, please indicate the source!