The type, size and rotating speed of agitator in decentralized sewage treatment equipment have an influence on the distribution of stirring power between total flow and turbulent pulsation. Generally speaking, the power distribution of turbine agitator is beneficial to turbulent pulsation, while propeller agitator is beneficial to overall flow.
For the same type of agitator, under the same power consumption condition, the power of large-diameter low-speed agitator is mainly consumed by the overall flow, which is beneficial to macro-mixing. The agitator with small diameter and high speed is mainly consumed by turbulent pulsation, which is beneficial to micro-mixing. At present, the complex problems related to the technological process of agitator can only be amplified gradually through experience and according to the amplification criterion obtained.
Screw mixer is a product with simple structure and convenient manufacture. When stirring, the degree of fluid turbulence is not high, and the circulation is large. Screw agitator is suitable for reaction, high viscosity mixing, dissolution, heat transfer and other operations: it is mainly used for mixing liquid systems with uniform temperature; Prevent sludge settling in low concentration solid-liquid system. Moreover, under the condition of low viscosity and large flow rate, better mixing effect can be obtained with less stirring power. Spiral agitator is a widely used axial-flow high-performance agitator with good removal performance and low shear force. At low speed, it is in a state of convective circulation, and at high speed, it is in a state of turbulent dispersion. The larger blade inclination angle and blade twist can make the agitator reach a higher flow field even in transition flow and turbulence, and its liquid discharge capacity is obviously improved compared with the traditional propulsion type. Spiral agitator is suitable for low viscosity and mixing, dissolution, heat transfer, reaction, etc.