Development of mass transfer coefficient correlation for a ceramic foam packing humidifier at elevated pressure

The cooling tower model is simple but has necessary precision for the packing design and outlet conditions forecast of the humidifier, especially under the pressure and temperature level of micro humid air turbine. This research focuses on developing a mass transfer correlation of the novel ceramic foam packing, which has the potential to be used in humidification. The heat and mass transfer properties of the packing are investigated with the mass transfer coefficients calculated from 105 groups of experimental data, and the effects of pressure, water/air mass flow ratio, inlet water temperature and inlet air enthalpy are analyzed. It is shown that the mass transfer coefficient increases with the increase of water/air mass flow ratio, but decreases with the increase of inlet water temperature and inlet air enthalpy. The effect of pressure on heat and mass transfer is related with air mass flow. A dimensionless group correlation of mass transfer coefficient is developed and evaluated. It is shown that the deviations between the predicted and experimental values are estimated within ±12% for 75% experimental conditions. The developed correlation can be used to predict the packing height and the water/air outlet conditions of the ceramic foam packing humidifier.