新型自吸式多相搅拌槽临界悬浮特性的实验研究

Experimental Investigation on Solid-Liquid Suspension in a New Self-aeration Monolayer Multiphase Stirred Tank

在不通气的情况下,对新型多相搅拌槽进行实验,得出了其固相含量ω、颗粒密度ρ、搅拌槽内径D与临界悬浮转速Nc的关系,在相同条件下,与给定结构尺寸的标准搅拌槽对比了临界悬浮转速.结果表明,Nc随固相分率增加和粒径dp增大而增大,不利于达到良好的悬浮效果;固相颗粒密度越大,临界悬浮转速随之增大;槽径增大使达到悬浮状态的临界转速降低.该新型搅拌槽临界悬浮转速的关联式是N0.21c=6.3dp(gΔρ/ρL)0.45ω0.19/D0.55;同一固相分率下,新型多相搅拌槽的临界悬浮转速比标准搅拌槽降低了30%,在较低转速下就能使颗粒悬浮.

A new self-made tornado flow stirred tank was used to carry out experiments without ventilation, the relationship of critical suspension rotational speed （No） with the solid content ca, particle density p, and inner diameter （D） of the suspension stirred tank was obtained. Under the same geometrical conditions, the new stirred tank was compared with a standard stirred tank in Nc. The results show that Nc increases with the increase of solid phase fraction φ and particle size dp, which is not conducive to good suspension. With the increase of solid particle density, Arc goes up. With the increase of the tank diameter, Nc decreases. An expression for Nc of the new stirred tank is obtained, Nc=6.3dp^0.21（g△p/PL）0.45ω^0.19/D^0.55. At the same solid phase fraction, Nc in the new stirred tank is below 30% of that in a standard suspension stirred tank, which means that the particles can be suspended at a lower stirring speed.