Simulations of water vaporization in novel internal-intensified spouted beds: Multiphase-flow, heat and mass transfer

Abstract

Novel internal-intensified spouted beds (SBs) with swirl-nozzle anticlockwise-axial-swirler (SNAAS) and swirl-nozzle clockwise-axial-swirler (SNCAS) were proposed to improve the shortcomings of conventional SBs. The water vaporization in novel internal-intensified, conventional and swirl-nozzle SBs was simulated and the multiphase flow behavior and interphase heat and mass transfer in process were analyzed. Simulation results show the co-swirling action of novel combined internal-intensified makes gas drive particles move helically upward around the axial-swirler. Therefore, compared with conventional and swirler-nozzle SBs, the radial slip velocity of gas–solid and gas–liquid in two novel SBs are larger, and the contact between gas–liquid-solid phases is more sufficient. The gas–liquid-solid three-phase temperature, water vaporization rate, and gas moisture content of two novel internal-intensified all reached the highest, indicating that novel combined internal-intensified structures are beneficial to promoting the interphase heat and mass transfer during the water vaporization process. The mass transfer enhancement factors of SNAAS and SNCAS structures are 1.91 and 1.36 times that of conventional SB, respectively.