By utilizing optical Schlieren method, the Rayleigh Bénard Marangoni convection in mass transfer process was observed. A recorder and a camera separately recorded dynamic and static convective flow patterns during experiments . Different organic solvents were selected to investigate the RBM effects induced by different driving mechanisms including density gradient, surface tension gradient and their combination. Thermal effects produced by solvents evaporation and solute absorption/desorption are thought as an important factor in the creation of RBM convection during the mass transfer process. Qualitative analysis of experimental results is presented on the basis of photos and videotapes that were taken as direct visual evidences. Experimental results show that the thermal effect accompanying the mass transfer can be a cause at the onset of RBM convection and can′t be neglected simply in study of RBM effect driven by mass transfer.
