Mass Transfer through an Inside Tube Wall to a Pulsation Flow

Abstract

It was observed that mass transfer was greater in a pulsation flow than in a steady flow. As one of the simplest cases of mass transfer in a pulsation flow, we studied mass transfer through an inside tube wall to a pulsation flow, using a sample tube, whose inside wall was coated with β-naphthol. An experimental apparatus as shown in Fig. 1 was employed for the analyses of the systems. A piston type pulse generator was used for determining relationships between mass transfer and pulsation characteristics in the pulsation flow caused by superposing the "sine waveflow" on the steady flow.Experimental conditions were as follows(a) Flow condition; Apparent Re. number: 500-10, 000(b) Pulsation characteristics:Frequcncy: 100-500(cycle/min)Linear amplitude for l cycle: 0-2.0×10-1(m)(c) Dimensions of sample tubeLength: 0.3(m)Inside diameter: 1x10-2(m)The mass-transfer Coefficient kL(kg-mol/m2·hr·kg.mol/m3) and JD-factor were obtained from the experimental results, and are shown in Table l and Figs. 4 and 5.Conclusions:(1) Mass-transfer coefficient increases in direct proportion to the increase of amplitude and frequency, but in inverse proportion to that of Re. number.(2) The following equation represents the rate JD-factor increase, (Jp-J8/J8)D, as obtained by the dimensional analysis.(3) It is supposed that the charactristic increment of mass transfer in the pulsation increase in turbulency, affecting such flow conditions as frequency and amplitude.