The mixer of the self feeding mixer truck is a machine in which the shaft with blades rotates in the cylinder or tank to mix various materials into a mixture or proper consistency. The self feeding mixer will introduce the working principle of the mixer: the mixer is determined by multiple parameters, and it is impossible to describe the mixer with any one parameter. Shaft power (P), blade flow (Q), pressure head (H), blade diameter (D) and mixing speed (N) are the five basic parameters describing cement mixer trucks. The flow rate 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 the mixing truck is in direct proportion to the specific gravity of the fluid, the power criterion of the blade itself, the third power of the rotating speed, and the fifth power of the blade diameter.

某些形式的叶片,叶片排水数量(Q)和压头(H)通过改变叶片的直径(D)和速度(N)匹配调整,大直径叶片与低速(保证轴功率恒定)水泥搅拌车高流量和低压力水头的影响,和小直径叶片高速度生产低的压头和流量的影响。在搅拌槽中，使颗粒相互碰撞的方法是提供足够的剪切速率。

For some types of blades, the discharge quantity (Q) and pressure head (H) of the blade are adjusted by changing the diameter (D) and speed (N) of the blade. The influence of large diameter blades and low speed (ensuring constant shaft power) cement mixer trucks on high flow and low pressure head, and the influence of small diameter blades on high speed production of low pressure head and flow. In the stirred tank, the method to make particles collide with each other is to provide sufficient shear rate.

自上料搅拌车从搅拌机理来看，正是由于流体速度的不同，使得流体层之间相互混合。因此，混合过程总是涉及到流体剪切速率。剪切应力是搅拌过程中引起气泡分散和液滴破裂的一种力。需要指出的是，搅拌槽内流体各点的剪切速率是不均匀的。根据剪切速率分布的研究，搅拌槽中至少有4个剪切速率值。它们是：在叶片区域，无论何种纸浆类型，当叶片直径固定时，大剪切速率和平均剪切速率都随着转速的增加而增加。

From the perspective of mixing mechanism, it is precisely because of different fluid velocities that fluid layers mix with each other. Therefore, the mixing process always involves the fluid shear rate. Shear stress is a force that causes bubble dispersion and droplet breakage during stirring. It should be pointed out that the shear rate of fluid at each point in the stirred tank is uneven. According to the study of shear rate distribution, there are at least 4 shear rate values in the stirred tank. They are: in the blade area, no matter what type of pulp, when the blade diameter is fixed, the large shear rate and average shear rate increase with the increase of rotating speed.

当转速一定时，大平均剪切速率与叶片直径的关系与纸浆形状有关。当转速一定时，径向叶片的大剪切速率随叶片直径的增大而增大，而平均剪切速率与叶片直径无关。这些叶片剪切速率的概念在搅拌器的放大和缩小设计中需要特别注意。与大缸相比，小缸水泥搅拌车通常具有高速(N)、小叶径(D)和低叶尖速度(ND)的特点，而大缸自上料搅拌车通常具有低速(N)、大叶径(D)和高叶尖速度(ND)的特点。

When the rotation speed is constant, the relationship between the large average shear rate and the blade diameter is related to the pulp shape. When the rotating speed is constant, the large shear rate of the radial blade increases with the increase of the blade diameter, while the average shear rate is independent of the blade diameter. These blade shear rate concepts require special attention in the design of the scale-up and downsizing of the agitator. Compared with large cylinders, small cylinder cement mixers are generally characterized by high speed (N), small blade diameter (D) and low tip speed (ND), while large cylinder self loading mixers are generally characterized by low speed (N), large blade diameter (D) and high tip speed (ND).