Experimental assessment of vapour adiabatic absorption into solution droplets using a full cone nozzle

Abstract

This work investigates experimentally the adiabatic absorption of ammonia vapour into ammonia–lithium nitrate solution using a full cone nozzle and an upstream single-pass subcooler. Data are representative of the working conditions of adiabatic absorbers in absorption chillers. The nozzle was located at three different heights inside the absorption chamber, separated 0.165, 0.205 and 0.225m from the bottom liquid surface. The diluted solution mass flow rate was modified between 0.04–0.08kg/s and the solution inlet temperature between 23.5 and 30.6°C. This paper analyzes the influence of these variables on the absorption ratio, mass transfer coefficient, outlet subcooling and approach to equilibrium factor. A linear relation between the inlet subcooling and the absorption ratio is observed. The approach to equilibrium factor for the conditions essayed is always between 0.64 and 0.87. Mass transfer coefficients and correlations for the approach to equilibrium factor and the Sherwood number are obtained. Results are compared with other ones reported in the literature.