Preparation And Application Of Inorganic Non-metallic Ceramic Heat Exchanger Materials

New type of inorganic non-metallic ceramic heat exchanger materials is mainly applied in heat exchange field. The inorganic non-metallic ceramic heat exchanger is installed in the industrial furnace. It is used to recover the waste gas and preheat the combustion air. Energy efficiency can be increased by 20%～30%, so as to achieve the purpose of saving energy. Because thermal stability and thermal shock resistance of some ceramic heat exchanger is poor, with low thermal conductivity and heat exchange efficiency, how to improve the thermal shock resistance and thermal conductivity of inorganic non-metallic ceramic heat exchanger material and reducing production cost in further become researching hot topic. Different new inorganic non-metallic materials are adopted to prepare ceramic heat exchanger materials in this paper. The XRD, SEM, thermal test, thermal shock resistance test, mechanical test methods are used to analysis the affection of formula composition, preparation and additives on the phase, microstructure and strength, thermal shock resistance, and thermal properties of inorganic non-metallic ceramic heat exchanger materials.The fabrication of mullite is investigated with aluminum and Suzhou, Kaolin clay to synthesis the mullite phase. The effect of vanadium pentoxide, aluminum fluoride addition on mullite properties and microstructure is studied. The results show that aluminum hydroxide and Suzhou, Kaolin clay, with addition of 0.75% aluminum fluoride and 0.75% vanadium pentoxide, sintered at 1450℃for 2h,the morphology of mullite can be homogeneous. With the different mullite content, the strength and thermal shock resistance and thermal conductivity of the mullite bonded sic composite is studied. Obviously the distribution of mullite is very uniform and forms a network structure. When the mullite content was 25%, the flexural strength of Complex phases ceramic is up to 85.4 Mpa, the largest thermal shock resistance up to 47 times and coefficient of thermal conductivity up to12.8 W/(m-k).The fabrication of the cordierite is investigated with aluminum, kaolin caly and steatite used to synthesis the cordierite phase. With the different alumina content, the phase and microstructure of alumina-cordierite complex phases ceramic material is studied in the paper, also the affection of silicon carbide, graphite, silicon micro powders additives on alumina-cordierite complex phases ceramic materials. When the ratio of cordierite and alumina is 20%,the flexural strength of complex phases ceramic is up to 54.6Mpa,the largest thermal shock resistance up to 21 times and the coefficient of thermal conductivity up to 4.69W/(m-k).In the research project of inorganic non-metallic materials in Hubei Province Tobacco Company, the casting molding is used to prepare alumina/cordierite ceramic heat exchanger in the Hubei Huiyi Ceramic Co.ltd. When alumina/cordierite ceramic composites are sintered under 1340℃for 2h, the thermal shock resistance can be up to 23 times, with the coefficient of thermal conductivity up to3.865W/(m·k).The experiments within 90 days show the heat exchange efficiency of alumina-cordierite ceramic heat exchanger is very good. The coal consumption can achieve a kilo of tobacco/kilo. The cost of coal consumption is decreased by 8%. The service life is long. The cost of manufacture is decreased by 30%. It can be used to replace metal heat exchanger. It has a broad prospect of application.