加热体积膨胀剂对壁流式蜂窝陶瓷堵孔材料膨胀性能的影响

研究了壁流式蜂窝陶瓷堵孔材料的制备工艺,探讨了加热体积膨胀剂的加入量、烧成温度以及各烧成温度下堵孔材料的膨胀与收缩情况对壁流式蜂窝陶瓷堵孔材料膨胀性能的影响。研究结果表明,当配方中加入25 wt%的加热体积膨胀剂,在1160℃下烧成,可以制备出与壁流式蜂窝陶瓷载体结合牢固,抗折强度为3.72 MPa且干燥收缩率和烧成收缩率符合壁流式蜂窝陶瓷性能要求的堵孔材料。

Study of the Liquid Phase Volume Expansion for CO_2/Organic Solvent Systems

The supercritical antisolvent （SAS） process has been developed in recent years for the tormation of nanoand micro-particles. It is necessary to study the liquid phase volume expansion （LPVE） and find the relationships between the operating conditions and the LPVE in order to develop a practical method for determining the operation conditions and selecting an organic solvent for SAS process. The PR equation of state with vdW-1 mixing rule is used to calculate the LPVE for CO2/toluene, CO2/acetone and CO2/ethyl acetate systems, and the results show that the LPVE for each CO2/organic solvent system decreases as the temperature increases. The relationship between the LPVE and the solubility of CO2 in the liquid phase for CO2/organic solvent systems is investigated, and the results show that the LPVE is determined directly by the solubility of CO2 in the liquid phase, xCO2, and can be related to xCO2 independently. No matter what system of CO2/organic solvent is and how different the temperature is, the LPVEs have little difference as long as the solubility of CO2 in the liquid phase, xCO2, keeps constant. The lower temperature is always favorable to the SAS process. The higher the solubility of CO2 in an organic solvent under certain operation condition, the more suitable it is to the SAS process.

卷烟燃烧锥面孔率与主流烟气CO释放量的关系

为了研究卷烟燃烧过程中形成的燃烧锥结构与主流烟气CO释放量之间的关系,采用包埋切片法考察了卷烟燃烧锥的内部结构,分析了卷烟燃烧锥面孔率变化影响烟气CO释放量的机理,并通过调节燃烧锥结构降低了主流烟气CO释放量。结果表明:①卷烟燃烧锥的面孔率与CO释放量呈显著的负相关关系,燃烧锥面孔率越大,燃烧锥结构越疏松,烟丝燃烧越充分,主流烟气CO总释放量越低;②降低烟丝的填充密度、添加低比例的膨胀烟丝均可使燃烧锥面孔率增加和烟气CO释放量降低;③在常规卷烟样品中添加1%的可膨胀石墨,可有效调节燃烧锥结构,燃烧锥面孔率从18.25%增大至35.60%,主流烟气CO释放量降低12.30%,卷烟危害性指数从7.31下降至7.01。