The suspending preheaters function in preheating raw material, separating gas and solid and transmitting raw material, and can also eliminate such problems as high thermal consumption and pipeline congestion caused by short out and turbulence of raw material flow, relating to the system’s operating and energy-utilizing rates. But up to now, the nickel and chrome heat-resistant steel inner cylinders are still extensively used in cement kilns, and the poor heat-resistance, abrasion-resistance and corrosion-resistance lead to a short working life, which causes an energy consumption of hundreds of thousands of tons of standard coal per year. Moreover, nickel and chrome belong to the national strategic reserve resource, and the consumption of steel inner cylinders is over 10 thousand tons per year. Furthermore, the chrome in the steel inner cylinders will enter into cement and cause the chrome pollution.

The ceramic inner cylinders are made up of highly elastic carborundum ceramics by conditioning the material’s microcosmic structure, stress release, elastic modulus and processing technic, and take the strip-type connecting structure, which endows it with performances of heat-resistance, oxidation-resistance, high intensity in high temperature, abrasion-resistance, and acid and alkali resistance. China is the first to realize the ceramic inner cylinders for suspending preheaters in the world. Though some foreign companies began to develop the inner cylinders from 1980s, this technic hasn’t been applied in the market due to structure and material problems. Tested by extensive domestic application, the ceramic inner cylinders have many advantages over the foreign inner cylinders.

The ceramic inner cylinders have no chrome and eliminate the chrome pollution. With good sealing and separating effects, the product can increase the recycling efficiency and thermal-exchange efficiency of preheaters by a wide margin, increase the whole productivity of the production line, and decrease the thermal loss due to leakage. With good tenacity and corrosion-resistance, the product has a working life of 2—5 times the heat-resistant steel, which can decrease the maintenance rate and increase the operation rate of kilns by a large margin.