Mixer is determined by many parameters. It is impossible to describe a mixer with any single parameter. Shaft power (P), blade discharge (q), head (H), blade diameter (d) and mixing speed (n) are the five basic parameters to describe a mixer. The discharge volume of the blade is directly proportional to the flow standard of the blade itself, the first power of the blade speed and the third power of the blade diameter.

而攪拌消耗的軸功率則與流體比重，槳葉本身的功率準(zhǔn)數(shù)，轉(zhuǎn)速的三次方及槳葉直徑的五次方成正比。在一定功率及槳葉形式情況下，槳葉排液量（Q）以及壓頭（H）可以通過改變槳葉的直徑（D）和轉(zhuǎn)速（N）的匹配來調(diào)節(jié)，即大直徑槳葉配以低轉(zhuǎn)速（保證軸功率不變）的攪拌機產(chǎn)生較高的流動作用和較低的壓頭，而小直徑槳葉配以高轉(zhuǎn)速則產(chǎn)生較高的壓頭和較低的流動作用。在攪拌槽中，要使微團相互碰撞，的辦法是提供足夠的剪切速率。

The shaft power consumed by stirring is directly proportional 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. Under certain power and blade form, the discharge capacity (q) and head (H) can be adjusted by changing the matching of diameter (d) and rotating speed (n), that is, the mixer with large diameter blades and low speed (ensuring the same shaft power) produces higher flow effect and lower head, while small diameter blades with high speed produce higher head and lower head Mobility. In a stirred tank, the only way to make the pellets collide with each other is to provide sufficient shear rate.

從攪拌機理看，正是由于流體速度差的存在，才使流體各層之間相互混合，因此，凡攪拌過程總是涉及到流體剪切速率。剪切應(yīng)力是一種力，是攪拌應(yīng)用中氣泡分散和液滴破碎等的真正原因。必須指出的是，整個攪拌槽中流體各點剪切速率的大小并不是一致的。

From the view of stirring mechanism, it is because of the existence of fluid velocity difference that the fluid layers are mixed with each other. Therefore, the shear rate of fluid is always involved in the mixing process. Shear stress is a kind of force, which is the real cause of bubble dispersion and droplet breakup in stirring applications. It must be pointed out that the shear rate of fluid in the whole stirred tank is not the same.

通過對剪切速率分布的研究表明，在一個攪拌槽中少存在四種剪切速率數(shù)值，它們是：實驗研究表明，就槳葉區(qū)而言，無論何種漿型，當(dāng)槳葉直徑一定時，剪切速率和平均剪切速率都隨轉(zhuǎn)速的提高而增加。但當(dāng)轉(zhuǎn)速一定時，剪切速率和平均剪切速率與槳葉直徑的關(guān)系與漿型有關(guān)。

The results show that there are at least four kinds of shear rate values in a stirred tank. They are: the experimental results show that the maximum shear rate and the average shear rate increase with the increase of the rotating speed, regardless of the size of the impeller. However, when the rotating speed is constant, the relationship between the maximum shear rate and the average shear rate and the blade diameter is related to the pulp shape.

當(dāng)轉(zhuǎn)速一定時，徑向型槳葉剪切速率隨槳葉直徑的增加而增加，而平均剪切速率與槳葉直徑大小無關(guān)。這些有關(guān)槳葉區(qū)剪切速率的概念，在攪拌機縮小及放大設(shè)計中需要特別當(dāng)心。因小槽與大槽相比，小槽攪拌機往往具有高轉(zhuǎn)速（N）、小槳葉直徑（D）及低葉尖速度（ND）等特性，而大槽攪拌機往往具有低轉(zhuǎn)速（N)大槳葉直徑（D）及高葉尖速度（ND）等特性。

When the rotating speed is constant, the maximum shear rate of radial blade increases with the increase of blade diameter, but the average shear rate has nothing to do with the blade diameter. These concepts about the shear rate in the blade zone need to be taken care of in the design of the mixer to reduce and enlarge. Compared with the large tank, the small tank mixer often has the characteristics of high speed (n), small blade diameter (d) and low blade tip speed (nd), while the large tank mixer often has the characteristics of low speed (n), large blade diameter (d) and high blade tip speed (nd).