Comparison between spray towers with and without fin coils for air dehumidification using triethylene glycol solutions and development of the mass-transfer correlations

Spray towers with and without fin coils were compared for their efficiency in air dehumidification using triethylene glycol (TEG) solutions. Experiments were conducted using different air flow rates, liquid flow rates, temperature and air humidities, and aqueous TEG solution concentrations. Theoretically, an absorber with fin coils reduces the temperature of the desiccant solution, which leads to a greater amount of water vapor removal from the air. It was evident that the performance of the spray tower with fin coils was better than that of the spray tower without fin coils under similar operating conditions. Mass-transfer correlations were developed for both systems, which considered the changes in gas-liquid flow ratio, temperature, TEG concentration, and some physical properties. A dimensional analysis of the process variables was carried out using the Buckingham Pi method to obtain the dimensionless groups of the correlations. Most of the values predicted by the correlations were within +/-10% of the experimental data.