Empirical Mass and Kinetic Models for the Flash Evaporation of NaCl–Water Solution

• Published in: Industrial & engineering chemistry research Vol. 57; no. 18; pp. 6115 - 6122
• Main Authors: Liu, Yong, Luo, Qiong, Wang, Guodong, Zhao, Siyuan, Li, Xianlong, Na, Ping
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.05.2018
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.8b00402

This paper attempts to provide empirical mass and kinetic models for the flash evaporation of sodium chloride (NaCl) aqueous solution based on experimental phenomena. The models have nine parameters and six affecting factors including initial temperature, operation pressure, NaCl mass fraction, solution depth, evaporator diameter and time. On the basis of a large number of flash evaporation experimental data from various literatures, the mass model parameters were optimized and validated. After optimization of the model parameters with 283 sets of literature experimental data, the average relative error between the model values and the experimental data is about 5.7%. And a statistical method proved the mass model is well posed. The verification with other 215 sets of literature experimental data showed the mass model is in good agreement with flash evaporation phenomena, and the average relative error between the model values and the experimental data is about 8.3%. Then, the kinetic model of flash evaporation was obtained according to the empirical mass model. Finally, the analysis of these models indicated that the increase of initial temperature or evaporator diameter and the decrease of operating pressure are in favor of evaporation. Although the increase of solution depth can improve the evaporated mass, the corresponding evaporation efficiency will be slightly reduced. And the increase of salt content is having a detrimental effect on the evaporation of NaCl–water solution. In addition, the influence of salt content on evaporation at higher operating pressure is more obvious than that at lower operating pressure. The above results show that these models proposed in our work have high accuracy, wide practicability, and good rationality.