Axial flow pump is a kind of pump with high specific speed in vane water pump. It is characterized by large flow and low head. In water supply and drainage projects, such as large steel plants, thermal power plants, circulating pump stations in thermal power stations, urban rainwater flood pumping stations, large sewage pumping stations, and some large lift pumping stations such as those introduced into the Tianjin project, they are widely used. .
Axial flow pumps and centrifugal pumps work differently, but the main components are similar. The shape of the axial flow pump is cylindrical. The diameter of the pump casing is similar to the diameter of the suction port. It can be installed vertically (vertical) and horizontally (horizontally), or inclined (inclined). The axial flow pump is shown in the figure above:
The work of the axial flow pump is based on the theory of wing lift in aerodynamics. Its blade cross section is similar to the shape of the wing, which is called the airfoil, as shown in Figure 2-24. According to the knowledge of fluid mechanics, we know that when the fluid flows through the streamlined airfoil, it will be divided into two streams at the leading end of the airfoil. They pass through the upper surface of the airfoil (that is, the working surface of the axial flow pump blade) and the lower surface. (Backside of the axial flow pump blade), because the flow along the lower surface of the airfoil is longer than the flow on the upper surface, it will cause a large flow velocity under the airfoil, a small pressure, and a small flow velocity and a high pressure on the airfoil. From the top downward force P, likewise, the airfoil will also generate a reaction force P ′ equal to P in the direction of the fluid.
Axial flow pump is to tilt and fix the airfoil blade on the hub of the impeller. The airfoil blade rotates around the shaft in the fluid as the hub rotates. As a result, the fluid flows around the airfoil blade. The type blade will generate a downward force P1 'on the fluid. Under the action of the airfoil blade that continuously rotates at high speed, the fluid is lifted by obtaining energy.