1. Factors of axial force:
1). The front and rear sides of the impeller due to fluid pressure is not the same as the pressure (wheel side pressure is low, high disc pressure) led to the axial force A1, which is the direction of the impeller back to the impeller inlet.
2). Fluid inflow and outflow of the impeller direction and speed is not the same as the dynamic reaction force A2, its direction and A1 in contrast, so the total axial force A=A1-A2, the direction is usually the same as A1 (usually A2 smaller).
2. Axial force balance:
1). Selection of double suction impeller: the impeller suction fluid from the two symmetrical sides, axial force, active to offset balance.
2). Open the balance hole or the balance tube:
A: on the impeller wheel disc on the suction inlet opening several balance holes.
B: to avoid balance hole. Due to the mainstream of disturbed and add hydraulic loss, can set up a balance pipe to replace the balance hole, that is, the selection of a tubular directs the back side of the inlet pressure to the roulette wheel.
C: selection of balance blades: in the impeller wheel disc casting a few radial ribs, the flow of the impeller in the negative clearance of the impeller to speed up the rotation, increase the centrifugal force, so that the negative pressure on the impeller significantly decreased.
D: using thrust bearing to accept axial force. Usually small single suction pump intermittent thrust bearing can accept all the axial force, avoid pump shaft movement.
3. The balance of axial force of multistage centrifugal pump:
1). The same as a single-stage centrifugal pump
2). Symmetrical arrangement of the impeller
3. Select the balance drum, some balance axial force
4. Choose the active balance plate, all the active balance of the axial force.
