| Fluidization denitration of uranyl nitrate preparation to get uranium trioxideis widely used in reprocessing plants. Spry atomizer is used to atomize uranylnitrate. Then the uranyl nitrate droplets can fully contact with the fluidizing gas,and enhance the heat and mass transfer, increase the uranyl nitrate temperaturerapidly for pyrolysis. Simulation method is applied to get the spraycharacteristics including velocity distribution and particle size distribution toprovide a good basis for design of the uranyl nitrate denitrification fluidized bed.According to the wide application of the two-channel airblast atomizer inuranyl nitrate denitrification fluidized, a single-phase flow model is built. Basedon the results at the nozzle outlet, an Euler-Lagrange two-phase flow modelwhich considers the breakup model is built.The pressure and velocity of gas phase increase with increasing thegas-liquid mass flow ration in the nozzle, while the gas temperature decreasesnear the outlet of the nozzle. The liquid pressure decreases gradually along theflow direction in the nozzle. Liquid pressure and velocity change greatly near thenozzle outlet.The gas velocity increases in the spray field with increasing the gas-liquidmass flow rate, and the interaction between the gas and liquid is also enhanced.Meanwhile, the droplets Sauter Mean Diameter (SMD) decreases, and the spraypenetration distance increases. When the mass flow rate is100, the maximumSMD is210.98)im, the minimum spray penetration is0.263m; when the massflow rate is500, the maximum SMD is20.43)im, the minimum spray penetrationis0.5m. While the spray cone angle changes little, it is almost45°.According to the influence of air to the spray characteristics, nine optimizedatomizers are designed with screw channel near the outlet. With the decrease ofthe screw-pitch, the SMD and the spray penetration distance decrease, while thespray cone angle increases. Screw channel is a good way to improve the spraycharacteristic of the atomizer. |
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