Analysis of the Absorption-Dehumidification Process Variables Using the Experimental Design Methodology

Abstract

A spray tower in the absorption-dehumidification process was designed to study the separation of water vapor from moist air. The performance of the absorption tower was evaluated under various operating parameters. The role of each operating parameter and the relationship between the parameters are still unknown. A second-order polynomial model with a multiple linear regression was used to estimate the model coefficients. The model coefficients of the five selected parameters, including air- and liquid-flow rates, liquid concentration and temperature, and orifice diameter of nozzles were proposed to study the influence of these factors on the response of the mass-transfer coefficient. A factorial design model of the five variables is discussed in a two-level analysis. Only 32 (or 25) experimental runs were necessary to assess these variables and the model satisfied the process very well since the coefficient of determination (R2) was very close to 1. The influence of operating parameters on mass-transfer performance is discussed by the analysis of variance (ANOVA). A statistical methodology was applied to this process to describe the relationship between factors and the response coefficient. The factorial design of experimental design methodology used in this study is able to simulate or elucidate the relationship between the process variables and the mass-transfer coefficient. In addition, the F-ratio was calculated by means of analysis of variance to discuss whether the effect of factors on the mass-transfer coefficient is significant or insignificant.