液液射流装置的搅拌混合效果

Mixing Effect of Jet Agitation Device

以活性污泥、消化污泥为研究对象,分析液液射流搅拌装置对这两种污泥在搅拌槽内混合效果;同时利用计算流体力学软件ANSYS Fluent 15.0模拟了在入射压力为226 043 Pa工况下,射流搅拌装置的工作性能。该入射压力下,液液喷嘴泵送活性污泥时入射流量314.57 m^3/h,入射速度为3.37 m/s,消化污泥入射流量为312.05 m^3/h,入射速度为3.20 m/s。模拟结果表明在液液喷嘴内部搅拌混合效果不受流体性质的影响,均得到很好的搅拌混合;但在搅拌槽内活性污泥的搅拌混合效果明显优于消化污泥,搅拌槽内活性污泥流速方差加权平均值f为144.24,死区的体积分数φ为13.33%,平均流速为0.108 2 m/s,消化污泥在搅拌槽内的平均流速为0.031 8 m/s。

The effects of the mixing of the two kinds of sludge in the agitated tank were analyzed with the activated sludge and digested sludge as the research objects. ANSYS Fluent 15. 0 was used to simulate the performance of the jet mixing device under the condition of the incident pressure of 226 043 Pa. The incident flow rate of the activated sludge was 314. 57 m^3/h,the incident velocity was 3. 37 m/s,the digested sludge flow rate was 312. 05 m^3/h,the incident velocity was 3. 20 m/s. The simulation results show that the mixing effect is not affected by the nature of the fluid in the liquid-liquid nozzle inside,and all of them are well stirred and mixed. But in the stirring tank activated sludge mixing and mixing effect is better than digestive sludge,the mean flow velocity of the activated sludge in the stirred tank was 144. 24,the volume fraction of the dead zone was 13. 33%,the average flow velocity was 0. 108 2 m/s,the average velocity of the digested sludge in the stirred tank was 0. 031 8 m/s