Raw Material Preheating and Decomposition
Now, a suspension preheater is utilized to preheat and partially decompose the raw materials, which was completed in rotary kiln
. Thus, the length of the rotary kiln
can be shortened.Consequently, the efficiency of kiln system can be increased and heat consumption of clinker sintering can be reduced.In addition, in the rotary kiln, the raw materials are stacked for heat transferring with the air while in the preheater, they are suspended for heating, which can make the raw materials be intensively mixed with the red-hot air exhausted from the kiln and enlarging contact area, thus ensuring fast heat transferring and high heat exchanging efficiency.
Raw Material Dispersion
Due to the impact of airflow rising rapidly, the raw materials fed into the suspension preheater pipe will move upward along with the airflow and be dispersed.80% heat transferring is completed in the preheater pipe.
When the material powders laden gas flows into the cyclone separator at high velocity, it will be forced to revolve rapidly in the annular space between the cyclone wall and the exhaust pipe. Simultaneously, it will move downward from the cylinder part all the way to the end of the cone part. Then, it will revolve upward in turn and be exhausted from the exhaust pipe.
It can be completed in the decomposition furnace added between the preheater and the rotary kiln. The pre-decomposition technology is a great leap in cement manufacturing process. Based on the kiln tail uptake flue, a fuel injection device is equipped to ensure that the exothermic process of fuels combusting and the endothermic process of raw materials decomposing can be rapidly competed in the decomposition furnace in suspension or flow condition, consequently increasing decomposition rate to over 90%.
The most of fuels can be added directly from inside of the decomposition furnace while small part of fuel is added from the kiln head, which can relieve the thermal load of calcining zone in the kiln and prolong service life of the refractory materials, thus being favorable for large-scale production. The pre-decomposition process moves the carbonate decomposition previously completed in the rotary kiln into the newly added decomposition furnace. Due to uniform mixing of the fuels and raw materials, the heat caused by the fuel combusting can be timely transferred to the raw materials, optimizing the combustion, heat transferring and carbonate decomposition process. To sum up, the pre-decomposition technology features superior quality, high efficiency and low energy consumption.
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