ZLB Vertical Axial Flow Pump

Working Principle and Structure of Vertical Axial Flow Pumps
1. Working Principle of Vertical Axial Flow Pumps
Vertical axial flow pumps operate based on the airfoil lift theory in aerodynamics. When fluid flows around an airfoil profile, it splits into two streams at the leading edge of the airfoil. The two streams flow over the upper and lower surfaces of the airfoil respectively and converge simultaneously at the trailing edge.
Since the flow path along the lower airfoil surface is longer than that along the upper surface, the fluid velocity on the lower surface is higher. Correspondingly, the pressure on the lower surface is lower than that on the upper surface, generating a downward force exerted by the fluid on the airfoil. In return, the airfoil applies an equal and opposite reaction force to the fluid. Driven by this reaction force, water is lifted to a specified height.

2. Structure of Vertical Axial Flow Pumps

• Bell mouth
  The bell mouth serves as the suction chamber for small and medium-sized vertical axial flow pumps, cast from cast iron. Its function is to guide water evenly to the impeller with minimal energy loss.
• Impeller
  As the core working component of the axial flow pump, the impeller is composed of blades, hub and flow cone.
• Guide vane body
  Installed above the impeller, the guide vane body primarily eliminates the rotational flow of water to reduce head loss. Meanwhile, it converts part of the kinetic energy of the water flow into pressure energy.
• Pump shaft and bearings
  The pump shaft is manufactured from high-quality carbon steel, which transmits torque to the impeller.
• Transmission shaft
  The transmission shaft connects the vertical motor and the water pump, transferring power from the motor to the pump.
• Stuffing box
  A packing sealing device is mounted at the position where the pump shaft passes through the discharge elbow.