渣浆泵与离心泵的工作原理

为了说明离心泵的工作原理，先来看日常生活中的一个现象。 在雨天打伞，如果用手转动伞柄，伞上的水就会被甩出去，转得越快，雨点甩得越远，这是因为雨水在旋转的伞上受到离心力的作用之故。再看另一个日常生活的现象:水总往低处流，但在医院大夫打针时，抽动针筒芯往上提时能把低处药液抽入针筒内。这是因为当针筒芯上抽时，原来针筒芯占的地方被抽上去后，这块地方没有空气便形成了真空，而药面上有大气压力的作用，将药液压入针筒内。在泵中(见图2-24)，同上面情况一样,当泵的叶轮旋转时，叶轮叶片将液体

从叶轮甩出去，飞向四周泵体中并引向泵的出口，在此同时，叶轮中液体甩出去后形成真空，而液面在大气压力的作用下，将液体顺着吸水管压入叶轮中，然后又被甩出去。这样周而复始，甩出去吸上来又甩出去，这就是离心泵的工作原理。

再来讨论一下离心泵把低处的水吸上来时能吸多高呢?是不是并无限制呢?如果无限制，不管井有多深只要加长吸水管的长度就能把井中的水吸上来。但是这是不可能的。我们做一个实验，如果将一根长的玻璃管插入水中，从上部将空气抽去，如图2 -25所示。随着空气的抽出，水在大气压力的作用下沿玻璃管慢慢上升，如果将玻璃管内的空气完全抽出，也就是绝对真空时，水上升到10. 33m就不再上升了，这是因为: 1个标准大气压=760mmHg= 10.33mH20。这时玻璃管内水柱的压力与大气压力相等了，保持了平衡。同理，如果离心泵叶轮进口处也能达到绝对真空的话，水沿进水管最多也只能上升到10.33m,而不能够无限地想吸多高就多高。但是，离心泵进口处不可能达到绝对真空。这是因为水在叶轮中流动有流速，进水管有水力损失，当压力低到一定程度时液体会汽化，泵内会发生汽蚀等原因。离心泵吸水高度不可能达到10.33m更不可能超过10.33m，一般也就4-8m。 各种不同泵而不同，具体能吸多高，需要在泵的样本中汽蚀余量或允许吸上真空高度来决定。渣浆泵厂家

Working principle of slurry pump and centrifugal pump

In order to explain the working principle of centrifugal pump, first look at a phenomenon in daily life In rainy days, if you turn the handle of the umbrella by hand, the water on the umbrella will be thrown out. The faster it turns, the farther the raindrop will be thrown out. This is because the rain is affected by centrifugal force on the rotating umbrella. Look at another phenomenon in daily life: water always flows to the lower part, but when the doctor in the hospital injects the needle, he can pump the medicine liquid from the lower part into the needle cylinder when the core of the needle cylinder is pulled up. This is because when the needle cylinder core is drawn up, the original place occupied by the needle cylinder core is drawn up, and there is no air in this place, then a vacuum is formed, and the effect of atmospheric pressure on the drug surface is to hydraulic the drug into the needle cylinder. In the pump (see Figure 2-24), as above, when the impeller of the pump rotates, the impeller blade will turn the liquid

From the impeller, it flies to the surrounding pump body and leads to the outlet of the pump. At the same time, the liquid in the impeller is thrown out and forms a vacuum. Under the action of atmospheric pressure, the liquid surface presses the liquid into the impeller along the suction pipe, and then it is thrown out. This is the working principle of centrifugal pump.

Let's talk about how high the centrifugal pump can suck up the water in the lower part? Is there no limit? If there is no limit, no matter how deep the well is, as long as the length of the suction pipe is lengthened, the water in the well can be sucked up. But it's impossible. In an experiment, if a long glass tube is inserted into the water, the air is extracted from the upper part, as shown in Figure 2-25. With the extraction of air, water rises slowly along the glass tube under the action of atmospheric pressure. If the air in the glass tube is completely extracted, that is, when the absolute vacuum is reached, the water will not rise again when it rises to 10.33m, because: 1 standard atmospheric pressure = 760mmhg = 10.33mh20. At this time, the pressure of the water column in the glass tube is equal to the atmospheric pressure, maintaining a balance. In the same way, if absolute vacuum can be achieved at the impeller inlet of centrifugal pump, the water can only rise to 10.33m along the water inlet pipe at most, instead of infinite suction height. However, it is impossible to reach absolute vacuum at the inlet of centrifugal pump. This is because of the flow velocity of water in the impeller and the hydraulic loss of the water inlet pipe. When the pressure is low to a certain extent, the liquid will vaporize and cavitation will occur in the pump. The suction height of centrifugal pump can not reach 10.33m or more than 10.33m, generally 4-8M The specific suction height of different pumps depends on the NPSH in the pump sample or the allowable suction height. Slurry pump manufacturer