The Temperature Uniformity During Air Drying of a Colloidal Liquid Droplet
The Temperature Uniformity During Air Drying of a Colloidal Liquid Droplet
复制标题
胶体液滴空气干燥过程中的温度均匀性
DOI：
10.1080/07373930500340437
复制
发表时间：
2005
影响因子：
3.3
通讯作者：
Saptarshi Kar
中科院分区：
文献类型：
--
作者：
K. Patel;X. Chen;Saptarshi Kar
随着喷雾干燥操作在各种化学品、陶瓷、药品、食品和乳粉以及纳米颗粒的生产中的日益普及，对含有溶解或悬浮固体的单个液滴的干燥的数学分析已经变得非常重要。最终产品的物理和生物质量主要取决于烘干机内液滴所经历的历史。因此，准确地估计液滴的行为和各种特征，如水分含量和温度分布是可取的。在文献中，已经提出了几个模型来估计颗粒内部的水分和温度分布，考虑了各种假设。一个常见的假设是被干燥的液滴内的温度分布是均匀的。本文提出了一种评估多孔型脱脂乳滴内温度分布的估算方法，以确定均匀温度分布假设是否合理。在这里，通过考虑球形液滴的一维非稳态热传导方程来估计表面中心温差。在建模过程中考虑了液滴的收缩。本条款还采用了毕奥数这一新概念，以协助确定限速进程。
ABSTRACT The mathematical analysis for drying of individual droplets containing dissolved or suspended solids has been given significant importance due to the increasing popularity of the spray drying operation in the production of various chemicals, ceramics, drugs, food, and dairy powders as well as nanoparticles. The physical and biological qualities of the final products primarily depend on the history experienced by the droplet within the dryer. It is, therefore, desirable to ‘estimate’ the droplet's behavior and various characteristics such as moisture content and temperature profiles accurately. In the literature, several models have been presented to estimate moisture and temperature profiles inside a particle considering various assumptions. One common assumption is the uniform temperature distribution within the droplets being dried. The present article has presented an estimation procedure to evaluate the temperature distribution within a porous skim milk droplet to determine whether the uniform temperature distribution assumption is reasonable. Here, the surface-center temperature differences were estimated by considering the one-dimensional, unsteady-state heat conduction equation for a spherical droplet. Shrinkage of droplets was taken into consideration during modeling. A new concept of the Biot number has also been applied in the current article to assist in the determination of the rate-limiting process.