TY - JOUR

T1 - Nonisothermal Evaporation of Layers of Aqueous Salt Solutions

AU - Misyura, S. Y.

AU - Morozov, V. S.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Evaporation of layers of aqueous solutions of salts (LiBr, CaCl2, NaCl, MgCl2, BaCl2, and CsCl) is studied experimentally. Experimental data are compared with evaporation of the water layer. The solution is placed on a horizontal surface of a cylindrical heating section. Experiments on surface crystallization of salts are carried out. For aqueous solutions of salts LiBr, LiCl, and CaCl2, there is an extremum for the heat transfer coefficient αl. For water and for solutions of salts NaCl and CsCl, the extremum is absent. The first factor is a decreasing function of time, and the second factor is an increasing function of time. For the water layer, both factors continuously increase with time, and the maximum evaporation rate corresponds to the final stage of evaporation. The heat balance for interface layer is made up. The role of the free gas convection in the heat balance strongly depends on the salt concentration and varies with the rise of evaporation time. For low salt concentrations the influence of free convection in the gas phase on heat transfer in the liquid phase can be neglected; however, for high concentrations this effect is comparable with other factors. The curves for the rate of crystallization have been built. More than two time differences between the experiment and the calculation are associated with the kinetics of dendritic structures.

AB - Evaporation of layers of aqueous solutions of salts (LiBr, CaCl2, NaCl, MgCl2, BaCl2, and CsCl) is studied experimentally. Experimental data are compared with evaporation of the water layer. The solution is placed on a horizontal surface of a cylindrical heating section. Experiments on surface crystallization of salts are carried out. For aqueous solutions of salts LiBr, LiCl, and CaCl2, there is an extremum for the heat transfer coefficient αl. For water and for solutions of salts NaCl and CsCl, the extremum is absent. The first factor is a decreasing function of time, and the second factor is an increasing function of time. For the water layer, both factors continuously increase with time, and the maximum evaporation rate corresponds to the final stage of evaporation. The heat balance for interface layer is made up. The role of the free gas convection in the heat balance strongly depends on the salt concentration and varies with the rise of evaporation time. For low salt concentrations the influence of free convection in the gas phase on heat transfer in the liquid phase can be neglected; however, for high concentrations this effect is comparable with other factors. The curves for the rate of crystallization have been built. More than two time differences between the experiment and the calculation are associated with the kinetics of dendritic structures.

KW - aqueous salt solution

KW - layer evaporation

KW - evaporation rate

KW - crystallization

KW - HEAT-TRANSFER

KW - MASS-TRANSFER

KW - FILM ABSORPTION

KW - CRYSTALLIZATION

KW - LITHIUM

KW - TUBE

UR - http://www.scopus.com/inward/record.url?scp=85056146746&partnerID=8YFLogxK

U2 - 10.1115/1.4041323

DO - 10.1115/1.4041323

M3 - Article

AN - SCOPUS:85056146746

VL - 141

JO - Journal of Heat Transfer

JF - Journal of Heat Transfer

SN - 0022-1481

IS - 1

M1 - 011501

ER -