摘要
Solid-liquid suspension in an agitated tank with a draft tube was investigated witha newly developed infrared turbidimeter for measuring solid concentration.The diameter of theflared inlet transition tube and the distance from the inlet to the tank bottom are two importantparameters for draft tube design The NAX-4 impeller,developed in this study,is characterized byits high flow efficiency and low power consumption.Some modifications are made to the Bald′smodel by considering the effects of solid concentration and fluid viscosity on the critical speed forcomplete off-bottom suspension.The modified equation fits the experimental data satisfactority andcan be used in scale-up
Solid-liquid suspension in an agitated tank with a draft tube was investigated with a newly developed infrared turbidimeter for measuring solid concentration. The diameter of the flared inlet transition tube and the distance from the inlet to the tank bottom are two important parameters for draft tube design. The NAX-4 impeller, developed in this study, is characterized by its high flow efficiency and low power consumption. Some modifications are made to the Baldi's model by considering the effects of solid concentration and fluid viscosity on the critical speed for complete off- bottom suspension. The modified equation fits the experimental data satisfactorily and can be used in scale-up design.
