Bubble absorber, bubble formation, absorption, bubble dynamics, swirl flow.
Vapour absorption refrigeration (VAR) system is one of the better system compared to other high grade energy utilized refrigeration system from thermodynamics point of view. For the successful operation of this system, the components are required to be designed and developed effectively and efficiently. Absorber is one of the crucial component of such a refrigeration system and bubble absorber is one type of absorber among different types of absorber. Bubble characteristics are studied experimentally with tangential nozzles, which may enhance the heat and mass transfer characteristics by following a swirling motion. Based on the inference drawn from these studies, experiments are planned with R134a and DMF combination for performance improvement of the VAR system. Visualization study of bubble growth with multiple tangential nozzles is investigated in a bubble absorber. Bubble behavior is studied with different flowing condition like still, co-current and counter-current flow of water. Bubble diameter during detachment increases with increase in gas flow rate in the above flow conditions. Effect of air flow rate, water flow rate, nozzle diameters, number of nozzles and nozzle angle with reference to vertical plane on bubble diameter is also studied. Results are compared with the available correlation in the literature which is found to be in good agreement. Comparison of performance between single and double nozzle also presented in this paper. Based on this study correlations are proposed. References:  M. Suresh, A. Mani, Heat and mass transfer studies on R134a bubble absorber in 134a/DMF based on phenomenological theory, International Journal of Heat and Mass Transfer 53 (2010) 2813–2825.  S. Ramakrishnan, R. Kumar, R.Kuloor, Studies in bubble formation-I Bubble formation under constant flow conditions, Chemical Engineering Science, 24 (1969) 731-747.  M. Jamialahmadi, M. R. Zehtaban , H. Muller-Steinhagen, A. Sarrafi A, J. M. Smith, Study of bubble formation under constant flow conditions, Trans IChemE, 79 (2001) Part A 523.  E.S. Gaddis, A. Vogelpohl, Bubble formation in quiescent liquids under constant flow conditions, Chemical Engineering Science, 41 (1986) 97-105.