Influence of characteristics of particles and fluid on gas-liquid oxygen mass transfer and bubble distribution in three-phase system

Abstract

This paper presents the study of bubble distribution and volumetric mass transfer coefficient, kLa, in a three-phase system with spherical particles of glass and ceramic and non-spherical particles of ceramic and zeolite. Experiments were carried out in a cylindrical column with 64 mm diameter and height of 2000 mm and 2D column (278x20.4x500 mm). Gas velocity varied in the range of 0.03 to 0.09 m/s and liquid velocity was 0-0.1 m/s. Tap water and ammonium chloride solution of different concentrations were used as the liquid phase. Results showed that the presence of particles in the system increases volumetric coefficient of mass transfer, but it depends on the characteristics of the particles. It was shown that the presence of dissolved ammonium chloride in water contributes significantly to the reduction of the k,a value, compared to values obtained in pure water system.

U ovom radu je proučavana distribucija mehurova i zapreminski koeficijent prenosa mase, kLa, u trofaznom sistemu, sa sferičnim česticama od stakla i keramike i nesferičnim česticama od keramike i zeolita. Eksperimenti su vršeni u cilindričnoj koloni prečnika 64 mm i visine 2000 mm i 2D koloni dimenzija 278 x 20,4 x 500 mm. Brzine gasa su se kretale u intervalu 0,03-0,09 m/s, a brzine tečnosti 0-0,1 m/s. Kao tečna faza korišćena je česmenska voda i rastvor amonijum hlorida različitih koncentracija. Rezultati su pokazali da prisustvo čestica u sistemu utiče na povećanje zapreminskog koeficijenta prenosa mase, ali koliko će biti to povećanje zavisi od karakteristika samih čestica. Takođe je pokazano da prisustvo rastvorenog amonijum hlorida u vodi znatno doprinosi smanjenju vrednosti k,a u odnosu na vrednosti koje su dobijene u sistemu sa čistom vodom.