侧伸式搅拌槽固液悬浮性能

Suspension of Solid Particles by Side-entering Agitators

采用φ2m×4.2m侧伸式搅拌槽,研究了搅拌桨安装位置、通气速率、固体颗粒浓度和液位高度对侧伸式搅拌槽颗粒悬浮性能的影响.结果表明,搅拌轴水平偏转角对功率准数的影响很小,均布式为侧伸式搅拌槽搅拌桨的最佳排布方式,最佳偏转角βopt=10o;临界转速NJS最小值出现在搅拌桨伸入长度/搅拌桨直径比L/d=1.44处;降低搅拌桨安装高度h为0.75d左右,相比于传统的h=1.5d可减少约30%能耗;液位高度/搅拌槽直径比H/T<0.5时,NJS随H的升高而迅速增大.得到了通气量QV与NJS的关系式NJSG-NJS=1.46QV1.15和固相浓度ω对NJS影响的关系式NJS∝ω0.27.

The influences of location of agitators, gas flow rate, solid particles content and liquid level on solid suspension of particles were studied in a tank of φ2m×4.2m with side-entering agitators. The results show that the angle of agitator axis deviation from radial direction has little influence on power number. The optimum arrangement of agitators is symmetrical and the optimum angle 10°. The minimum just-suspension speed appears at L/d （entering length of agitator to diameter of impeller）=1.44. Compared with the conventional h （installing height of agitator）=1.5d, 30% energy consumption can be saved when the agitator is installed at a height of h=0.75d. When the ratio of liquid level to diameter of vessel （H/T） is less than 0.5, NJS increases rapidly with incresing of H. The relationship between NJS and gas flow rate （QV） and the influence of solid content co on NJS have been obtained respectively, NJSG-NJS=1.46QV^1.15 and NJS∝ω^0.27.