✍ Scribed by V. Linek; V. Machoń
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The influence of cellular convection, mduced by oxygen absorption m sochum sulplute solution, upon the mass transfer coefficient was studled expenmentally both m a mechamcally agitated non-aerated vessel (MANV), where absorption proceeds through the hqmd surface, and m a mechamtally agitated gas-hqmd dispersion (MAD) It was found that the relation denved for correlation of the enhancement factor of the mass transfer coefficient for physical absorption as suggested m [ 1,4] 1s not suitable for correlating the results obtained m the MANV The probable mechanism of cellular convectlon occurmg m this system IS density dnven, induced by concentration gradients An empmcal formula was obtained for the crmcal value of Raylelgh number It was deduced from the formula that the onset of cellular convection does not depend on hydrodynannc conditions prevailing m the hqmd phase within the whole range of Reynolds number used (3 4 X lo3 to 5 3 X 103 The enhancement factor R of the physical mass transfer coefficient caused by cellular convection 1s suitably described by the relation R = (RalRa,JU The value of the exponent y IS not constant
We present the correlation of expenmentally determmed values of y For values of Reynolds number not higher than 3 X lo4 the value of y IS constant and equal to 0 73 For higher values of Re the value of y 1s lower (y = 5 33 X lo*" Ree4 "") It IS shown that it would be more suitable to correlate the exponent y by the ratio of the time scale of mltlatlon of cellular convection and thatof surface renewal It was proved expenmentally, that the absorption of oxygen mto sodium sulplute solution m the MAD does not induce cellular convection m the studied range of oxygen absorption rated
📜 SIMILAR VOLUMES
A model was derived describing cellular convection during absorption accompanied by a firstorder chemical reaction. The model assumes that the concentration profiles of components A and R extend only through part of the liquid layer of finite depth; in the remaining part the unperturbed concentratio