关键词:

气固流化床, 射流穿透深度, 环隙气速, 静床高度

Abstract:

A simple hydrodynamic model, including additional terms in both the gas and solidphase momentum equations based on the twofluid theory by considering particlefluid interactions under a quasiequilibrium state, was used to investigate numerically the effects of jet gas velocity, slit size, annular gas velocity and static bed height on the jet penetration depth in gassolid fluidized bedsCFD simulations were conducted for a 2.00 m (high) × 0.30 m (wide) twodimensional bed with a central jet and the corresponding experiments were carried out in the rectangle fluidized bed with a thickness of 0025 m under the same operating conditionsResin particle with a diameter of 670 μm and a density of 1474 kg·m^-3 was used as solid materialComputational procedures were performed in the platform of CFX4.4, a commercial CFD software package, by integrating the userdefined Fortran subroutinesThe numerical results showed that the voidage contour of 0.8 was suitable to determine the jet boundary, and the jet penetration depth increased with increasing jet gas velocity or slit sizeThe effect of annular gas velocity (u_c) on jet penetration depth was divided [JP+3]into three stages: (1) Jet [JP+3]penetration depth increased when u_c [JP] increased from zero to the minimum fluidization velocity (u_mf); (2) At u_c=u_mf, jet penetration depth reached its maximum;(3) Jet penetration depth then decreased with increasing u_c although this tendency became weak when u_c was greater than 2.5u_mfJet penetration depth decreased with increasing static bed height and this influence was more obvious when jet gas velocity was high.

Key words:

气固流化床, 射流穿透深度, 环隙气速, 静床高度