渣浆泵水力损失与水力效率
    水力损失发生在泵的吸水室、叶轮流道、压水室中。水力损失可分为三种情况:①液体流经泵的吸水室、叶轮流道、压水室时与壁面发生的沿程摩擦损失;②发生在上述流道的突然扩大、缩小、转弯等的局部阻力损失;③当运行工况发生改变时发生在叶片进口及出口的撞击损失。

沿程摩擦阻力损失及局部阻力损失可按水力学中的计算方法来进行计算。但是迄今为止还无法精确的计算，通过上述分析可以看出降低流道表面粗糙度，清理打磨流道，流道面积变化均匀，避免过大的扩散等，可以减小水力损失。叶片进口的冲击损失，在设计流量下，液流角与叶片安放角是一致的，撞击损失较小。但当泵不在设计流量工作时，液流角与叶片安放角不再一致，撞击损失较大，如图2-38所示。叶轮出口的水力损失，当泵在设计流量工作时，叶轮出口处的流速与压水室中液体流速基本相等，不会产生很大的损失，而当偏离设计流量工作时，两者的流速不再相等，从而产生较大的损失。所以选用泵时，应尽量在设计工况下(即高效区)工作，否则会增加泵的水力冲击损失。
水力效率:
                      ηh=H/H+△H=H/HT

式中  H----泵的有效扬程;
Ht----泵的理论扬程。

四、泵的效率η

泵的总效率η即为泵的机械效率、容积效率和水力效率的乘积。渣浆泵厂家

Hydraulic loss and efficiency of slurry pump

The hydraulic loss occurs in the suction chamber, impeller passage and pressure chamber of the pump. The hydraulic loss can be divided into three situations: ① the friction loss along the wall when the liquid flows through the suction chamber, impeller passage and pressure chamber of the pump; ② the local resistance loss when the passage expands, shrinks and turns suddenly; ③ the impact loss at the inlet and outlet of the blade when the operation conditions change.

Friction loss along the way and local resistance loss can be calculated according to the calculation method in hydraulics. However, up to now, it has not been able to calculate accurately. Through the above analysis, it can be seen that reducing the surface roughness of the runner, cleaning and polishing the runner, uniform change of the runner area, avoiding excessive diffusion, etc., can reduce the hydraulic loss. Under the design flow rate, the angle of liquid flow is the same as the angle of blade setting, and the impact loss is smaller. However, when the pump is not working at the design flow, the liquid flow angle is no longer consistent with the blade setting angle, and the impact loss is large, as shown in figure 2-38. When the pump is working at the design flow, the flow velocity at the outlet of the impeller is basically the same as that of the liquid in the water pressure chamber, which will not cause great loss. When the pump is working at the design flow, the flow velocity of the two is no longer equal, which will cause great loss. Therefore, when selecting the pump, we should try to work in the design condition (i.e. high efficiency area), otherwise, it will increase the hydraulic impact loss of the pump.

Hydraulic efficiency:

ηh=H/H+△H=H/HT

Where h is the effective head of the pump;

HT ---- theoretical head of pump.

IV. pump efficiency η

The total efficiency η of the pump is the product of the mechanical efficiency, volumetric efficiency and hydraulic efficiency of the pump. Slurry pump manufacturer