The agitator is a device that forces the liquid and gaseous medium to convect and evenly mix. The type, size and speed of the agitator have an effect on the distribution of the agitation power between the overall flow and the turbulent pulsation. In general, the power distribution of the turbine agitator is advantageous for turbulent pulsation, while the propeller agitator is advantageous for overall flow. For the same type of agitator, under the same power consumption conditions, the large-diameter, low-speed agitator, the power is mainly consumed by the overall flow, which is conducive to macroscopic mixing. Small-diameter, high-speed agitator, power is mainly consumed by turbulent pulsation, which is conducive to micro-mixing.
The enlargement of the agitator is a complicated problem related to the process. It can only be amplified by step-by-step experience and extrapolated to the industrial scale according to the obtained amplification criterion. The agitation viscosity of different medium viscosity refers to the resistance of the fluid to the flow. It is defined as the amount of shear stress required per 1 cm2 plane when the liquid flows at a speed of 1 cm/s, called the dynamic viscosity, in Pa?s. For the unit. Viscosity is an attribute of fluids.
When the fluid flows in the pipeline, there are three states of laminar flow, transitional flow, and turbulent flow. These three flow states are also present in the stirring equipment, and one of the main parameters determining these states is the viscosity of the fluid. During the mixing process, it is generally considered that the viscosity is less than 5 Pa?s for the viscosity fluid, such as: water, castor oil, sugar, jam, honey, lubricating oil, low viscosity emulsion, etc.; 5-50 Pa?s for medium viscosity fluid, For example: ink, toothpaste, etc.; 50-500Pa?s for high viscosity fluids, such as chewing gum, plastisol, solid fuel, etc.; more than 500Pa?s for extra high viscosity fluids such as: rubber mixture, plastic melt, silicone Wait. For fluids with low viscosity media, it is not required to be driven directly by a stirrer. Impellers for low viscosity and medium viscosity fluids are paddle, open turbine, propulsion, long thin blade propeller, disc turbine, Bruma gold, plate-frame paddle, three-leaf back-bend, MIG-style, etc. The impellers suitable for high viscosity and extra high viscosity fluids are spiral impeller, screw type, anchor type, frame type, propeller type and the like. Some fluid viscosity changes with the reaction, and it is necessary to use an impeller suitable for a wide viscosity field, such as a general-purpose impeller.