Capabipty of concrete mixer is determined by several parameters, only one parameter can not be fully describe its function. Shaft power, blade discharge quantity, blade diameter, pressure head, blending speed are five basic parameter to describe a mixer.Blade discharge quantity is in proportion to its flow value, the first power of blade rotating speed is in proportion to the third power of blade diameter.
Shaft power consumed in blending is in proportion to fluid density, blade power value, third power of rotating speed and the fifth power of blade diameter. In certain power and unchanged blade form, the blade discharge quantity and pressure head can be adjusted through changing the blade diameter and rotating speed, that is, large diameter blade equipped with low speed(make sure the power is fixed) mixer can produce high flow effect and low pressure head while small diameter blade equipped with high-speed can produce high pressure head and low flow effect.In agitator tank, the only way to make the micelle colpde is to provide enough cutting speed .
In perspective of mixer principle, just as the existence of fluid speed disparity, concrete mixer can combine each layer of the fluid, therefore, agitating process always involve in fluid cutting speed. Shear stress is a kind of power, is the true reason of bubble dispersion and drop breakage in agitating apppcation. It must be point out, the cutting rate of each point of the fluid in the agitator is not consistent.
Based on the shear rate distribution in the study shows that, there at least exist four shear rate numerical. They are as follows:
The experimental study show, as far as blade concerned, whatever the syrup model, when the blade
diameter is fixed, the max cutting rate and average cutting rate are increased according to rise of rotating speed. While the rotating speed is fixed, the relation of blade diameter and the max cutting rate and average cutting rate are related to syrup style.
We should be carefully about the design of the mixer narrow and amppfication about the concept of cutting rate.Viac článkov tohto autora. >