From the mechanical similarity point of view, the centrifugal effect, Ar, and the Stokes number, St, as well as the Reynolds number, Re_c for the motion of solid particles in the cyclone are the relevant parameters. I...From the mechanical similarity point of view, the centrifugal effect, Ar, and the Stokes number, St, as well as the Reynolds number, Re_c for the motion of solid particles in the cyclone are the relevant parameters. In order to apply these similarity laws for the prediction of the characteristics of the collection efficiency, ηc, geometrically similar types of uni-flow cyclones were used. The body diameters of the cyclones were D_1=30, 50, 69 and 99 mm, respectively. The feed particle concentration of the fly-ash particles was up to C_o = 60g/m^3. From the experimental results: (1) the pressure drop, △pc, in the cyclones was a function of not only the Reynods number, Re_c, but also the body diameter, D_1; (2) the collection efficiency, η_c, did not always increase with decreasing body diameter but there existed an optimal body size; (3) application of the mechanical similarity laws to the collection efficiency was not always sufficient for estimating the collection efficiency, since the feed particle concentration was an additional important factor; (4) a new parameter which was the ratio, E_(pf), of the apparent separation energy, W_p, of the solid particles to the energy loss, E_c, of the gas flow in the cyclone was introduced for discussing the collection efficiency; (5) Fuchs theory, used to estimate the collection efficiency, was examined. Fuchs theory may be applied for high feed particle concentration.展开更多
文摘From the mechanical similarity point of view, the centrifugal effect, Ar, and the Stokes number, St, as well as the Reynolds number, Re_c for the motion of solid particles in the cyclone are the relevant parameters. In order to apply these similarity laws for the prediction of the characteristics of the collection efficiency, ηc, geometrically similar types of uni-flow cyclones were used. The body diameters of the cyclones were D_1=30, 50, 69 and 99 mm, respectively. The feed particle concentration of the fly-ash particles was up to C_o = 60g/m^3. From the experimental results: (1) the pressure drop, △pc, in the cyclones was a function of not only the Reynods number, Re_c, but also the body diameter, D_1; (2) the collection efficiency, η_c, did not always increase with decreasing body diameter but there existed an optimal body size; (3) application of the mechanical similarity laws to the collection efficiency was not always sufficient for estimating the collection efficiency, since the feed particle concentration was an additional important factor; (4) a new parameter which was the ratio, E_(pf), of the apparent separation energy, W_p, of the solid particles to the energy loss, E_c, of the gas flow in the cyclone was introduced for discussing the collection efficiency; (5) Fuchs theory, used to estimate the collection efficiency, was examined. Fuchs theory may be applied for high feed particle concentration.
