The head of the pump and the head of the pump
The lift of the pump is the energy that is transported by the liquid from the inlet of the pump to the outlet of the pump. The lift of the pump is indicated by the letter H, the unit is mH2O and the ellipsis is m.
For the horizontal centrifugal pump device shown in Fig. 2-1, if the pump axis is the datum, when the pump is running, the total energy of the unit gravity water at the pump inlet cross-section is
The total energy of the unit gravity water at the outlet section of the pump is
Defined according to the lift
In the type: the water head, the absolute pressure head, the flow head, m, corresponding to the inlet section of the pump at 1-1.
Corresponding to the water head, the absolute pressure head, the flow head, m, at the outlet section of the pump at 2-2.
The diagram of the head of the pump is as follows: (the following diagram is a drawing of a horizontal centrifugal pump).
In order to monitor the running condition of the pump, the vacuum meter and pressure gauge are installed at the inlet and outlet sections of the pump, as shown in Figure 2-1. The readings of the vacuum meter and the pressure gauge are relative pressure, and the readings of the vacuum table are V (lower than the value of a atmospheric pressure, that is, the value of the atmospheric pressure. "
) the readings of the pressure meter are M (higher than the value of a atmospheric pressure, that is), and the formula (2-1) can be written.
When the readings of the vacuum table and pressure meter are MPa (MPa), the readings of the MPa V and M are converted to the rice column (mH2O).
The lift calculated by the formula (2-3) is the head of the pump working condition. The lift marked on the pump nameplate is the design lift of this pump, that is, the lift in the design flow, also called the rated lift.
From Figure 2-1, we can clearly see that the lift H and the actual pump head H are actually two different concepts. The former is the number of unit gravity liquid increasing from the pump inlet and outlet energy, and the latter is the difference between the inlet and outlet water level. It is clear that the pump head is always larger than the actual lift.
- Close This Page
- Recommendation：
- Browse：
