Thermal decomposition of calcium carbonate
Thermal decomposition of calcium carbonate
复制标题
碳酸钙的热分解
DOI：
10.1016/0009-2509(61)87002-4
复制
发表时间：
1961
影响因子：
4.7
通讯作者：
G. Narsimhan
中科院分区：
文献类型：
--
作者：
G. Narsimhan
碳酸钙的热分解过程被视为在准稳态条件下向分解界面同时传热传质的过程。据信，表面化学反应非常快，因此不会干扰总分解速率的测定。严格的表达式，传热速率的基础上，已经推导出，根据系统的属性，用于预测的分解时间，如球体和圆柱体的确定的几何形状。观察到的实际值和预测值之间的良好的一致性证明了该过程假设的分解方案的合理性。导出的表达式为：本文在分析传热传质速率的基础上，得出了如下关联式：该方程与小球在静止空气中蒸发的理论表达式十分相似。这一方程可以重新排列得到：，它是基于Chilton-Colburn类比的通常传热传质关联式的修正形式，并将数学处理推广到具有有限但不同平衡分解温度的两相固体体系（MgCO_3-CaCO_3）。数学分析涉及联立微分方程的解。这是用改进的龙格-库塔法在微机上进行数值计算的。所提出的方程的确认必须等待未来的实验数据的两相系统。
The process of thermal decomposition of calcium carbonate has been treated as one governed by simultaneous heat and mass transfer, under quasi steady state conditions, to the decomposition interface. It is believed that the surface chemical reaction is very fast and as such does not interfere in the determination of the overall decomposition rate. Rigorous expressions, based on heat transfer rate, have been derived, based on the system properties, for the prediction of decomposition times for definite geometric shapes such as spheres and cylinders. The good agreement observed between the actual and predicted values bears out the soundness of the decomposition scheme assumed for the process. The expression derived are: Based on an analysis of simultaneous heat and mass transfer rates the following correlation is obtaiend: This equation bears very close resemblance to the theoretical expression for the evaporation of small spheres into quiet air. This equation may be rearranged to provide: which is a modified form of the usual correlation for simultaneous heat and mass transfer based on Chilton-Colburn analogy.The mathematical treatment has been extended to a two-phase solid system (Mg CO3-Ca CO3) characterized by finite but different equilibrium decomposition temperatures. The mathematical analysis involves the solution of simultaneous differential equations. This has been done numerically by the modified Runge-Kutta method with the help of an IRM computer. The confirmation of the proposed equation must await future experimental data for the two-phase system.