Experimental analysis of ammonia–water rectification in absorption systems with the 10 mm metal Pall ring packing

In this paper, the mass transfer performance of the 10 mm metal Pall ring packing for ammonia rectification in ammonia–water absorption refrigeration systems (AARS) is investigated. The experimental setup is described and the experimental procedure and data reduction method are explained. Experimental results of the top vapour temperature, concentration and mass flow rate are presented for different operating conditions, including reflux ratio values from 0.4 to 1 (total reflux conditions). Vapour phase mass transfer coefficients are calculated from the measured data and the results are compared with different mass transfer correlations found in the open literature. In this paper, a correlation is proposed for the packing analysed which was fitted from the experimental data. Finally, a comparison is made between the actual packing height used in the experimental setup and the height required to obtain the same ammonia rectification in AARS with the first generation packings: ½″ ceramic Berl saddles, 15 mm glass Raschig rings and ½″ ceramic Novalox saddles. It was found that a packing height reduction between a factor of 2.5 and 3 is attained with 10 mm metal Pall rings.