Mass transfer in inverse fluidized beds

Abstract

In this work, the coefficient of fluid-wall mass transfer in an inverse fluidized bed was determined using the adsorption method. The experiments were carried out in a column with a diameter of 45 mm with spherical and non-spherical particles of polypropylene and polyethylene with a diameter of 3.3-4.9 mm and a density of about 930 kg m-3. A diluted solution of methylene blue was used as a fluidization medium, which was adsorbed on part of the surface of the column on silica gel. The obtained results showed that the presence of particles during inverse fluidization does not contribute significantly to mass transfer compared to the influence of particles on transfer in conventional fluidized beds. Therefore, the pseudofluid concept was introduced into the analysis and an empirical correlation was performed to determine the mass transfer coefficient. The obtained results were compared with literature correlations for inverse and conventional fluidized beds.

U ovom radu je određivan koeficijent prenosa mase fluid-zid u inverznofluidizovanom sloju primenom adsorpcione metode. Eksperimenti su vršeni u koloni prečnika 45 mm sa sferičnim i nesferičnim česticama polipropilena i polietilena prečnika 3.3-4.9 mm i gustine oko 930 kg m-3. Kao fluidizacioni medijum korišćen je razblaženi rastvor metilenski plavog koji je adsorbovan na delu površine kolone na silikagelu. Dobijeni rezultati pokazali su da prisustvo čestica pri inverznoj fluidizaciji ne doprinosi značajno prenosu mase u poređenju sa uticajem čestica na prenos mase u konvencionalno fluidizovanim slojevima. Zbog toga je u analizu uveden koncept pseudofluida i izvedena je empirijska korelacija za određivanje koeficijenta prenosa mase. Izvršeno je poređenje dobijenih rezultata sa literaturnim korelacijama za inverznu i konvencionalnu fluidizacije.