Investigation on coupled heat and mass transfer coefficients between compressed air and liquid desiccant in a packed dryer

This paper presents experimental tests and theoretical analysis on coupled heat and mass transfer characteristic of a compressed air drying system using liquid desiccant proposed in our previous work. The minimum possible humidity ratio of the processed compressed air can reach 0.11 g/kg under 0.80 MPa, which can satisfy demand of various industrial applications. Effects of operation parameters of the packed dryer on heat and mass transfer coefficients are obtained based on the experimental data and mathematical model. It is found that heat and mass transfer coefficients between compressed air and solution could be remarkably enhanced by increasing the air pressure, compressed air velocity and solution concentration while the influence of solution temperature is negative linearly. Reliable heat and mass transfer coefficients are provided for optimum design of pressurized air dryers, which is also meaningful to understand the heat and mass transfer behavior between compressed air and liquid desiccant. (C) 2015 Elsevier Ltd. All rights reserved.