Dispersion-concentric model for mass transfer in a packed bed with a countercurrent flow of gas and liquid

A model for the concentration of the solute in the gas in a packed column w ith a countercurrent flow of gas and liquid was developed. The mass-transfe r coefficient was needed for the model solution. A 0.61 m diameter column f illed with 38-mm ceramic Intalox saddles was used to measure mass-transfer coefficients of air-water and air-carboxymethylcellulose (CMC) solution sys tems. A 1.2 m diameter column filled with 50-mm ceramic Intalox saddles was also used with an air and calcium chloride solution. For varied flow rates of air from 1422 to 8017 kg m(-2) h(-1) and water (or the CMC solution) fr om 3888 to 15 516 kg m(-2) h(-1), the measured concentrations of water vapo r in air at the bed exit were within 2% with the model prediction. For the air-calcium chloride solution with air flow rates of 1872-7740 kg m(-2) h(- 1) and liquid rates of 12 276-45 980 kg m(-2) h(-1), the average deviation between the measured concentrations and the predicted values was about 9%.