A concrete mixer is a machine with blades that rotates in a cylinder or tank to stir and mix a variety of raw materials to make it a mixture of suitable consistency. Today we introduce the working principle of the concrete mixer truck:
The concrete mixer truck is determined by multiple parameters. It is impossible to describe a concrete mixer truck with any single parameter. Shaft power (P), blade discharge (Q), pressure head (H), blade diameter (D), and mixing speed (N) are the five basic parameters that describe a concrete mixer truck. The displacement of the blade is proportional to the flow rate of the blade itself, the first power of the blade speed, and the third power of the blade diameter. The shaft power consumed by stirring is proportional to the specific gravity of the fluid, the power standard of the blade itself, the third power of the speed, and the fifth power of the blade diameter. 
In the case of a certain power and blade form, the blade displacement (Q) and pressure head (H) can be adjusted by changing the matching of the diameter (D) and speed (N) of the blade, that is, the large diameter blade is equipped with A concrete mixer with a low speed (to ensure that the shaft power remains unchanged) produces a higher flow effect and a lower pressure head, while a small diameter blade with a high speed produces a higher pressure head and a lower flow effect. In the stirred tank, to make the micelles collide with each other, the way is to provide a sufficient shear rate.
From the perspective of the concrete mixer truck, it is precise because of the difference in fluid velocity that the fluid layers are mixed. Therefore, the fluid shear rate is always involved in the mixing process. Shear stress is a force that is responsible for bubble dispersion and droplet breaking in stirring applications. It should be pointed out that the shear rate of fluid at each point in the entire stirred tank is not the same. The study on the shear rate distribution shows that there are at least four shear rate values in a stirred tank. They are regarding the blade area, no matter what type of slurry when the blade diameter is constant, the shear rate, And the average shear rate both increase with the increase of speed.
But when the rotating speed is constant, the relationship between the shear rate and the average shear rate and the diameter of the blade is related to the slurry type. When the rotation speed is constant, the shear rate of the radial blade increases with the increase of the blade diameter, and the average shear rate has nothing to do with the diameter of the blade. These concepts about the shear rate in the blade area require special care in the design of the reduction and enlargement of the concrete mixer. Compared with large tanks, small tank concrete mixer trucks often have the characteristics of high speed (N), small blade diameter (D), and low tip speed (ND), while large tank concrete mixer trucks often have The characteristics of large blade diameter (D), low speed (N) and high tip speed (ND).
