Fire pumps are generally used to transport clear water or liquids similar to water, mainly for pressurized water delivery in fire protection system pipelines, and sometimes for industrial and urban water supply and drainage, high-rise building pressurized water delivery, etc. From the perspective of installation, fire pumps can be divided into vertical fire pumps and horizontal fire pumps. Among them, vertical fire pumps are welcomed by many consumers for their special hydraulic design and structural design. The following is a detailed understanding of the structure of the vertical fire pump:
The vertical fire pump is composed of impeller, middle body, pump cover, pump shaft, shaft sleeve seal, bearing, bearing cover, water diversion device and check valve. The impeller is mounted on the pump shaft and pressurizes the water to the outlet.
The impeller is composed of front and rear cover plates, blades and hub. It is a closed structure. There is a liquid suction port on one side of the blade. From the liquid suction port to the outer edge of the impeller, there are six curved blades. The blades and the front and rear cover plates divide the impeller into six Curved runner. After the fire pump is running, it transfers the machinery to the transported liquid through the impeller.
2. Pump casing
The pump casing is the main fixed part, which collects the liquid from the impeller, converts part of the kinetic energy of the liquid into pressure energy, and finally guides the liquid evenly to the discharge port. Usually we call the part from the suction port to the center of the impeller in the pump body the suction chamber, and the part where the liquid is thrown out from the impeller and collected to the pump outlet is called the discharge chamber.
3. Pump shaft, bearing, shaft seal device
The role of the pump shaft is to transmit torque to make the impeller rotate;
The role of bearings in fire pumps is to support the rotating pump shaft, and rolling bearings are generally used in fire pumps;
The seal between the rotating pump shaft and the pump casing is referred to as the shaft seal device. Its main function is to prevent high-pressure liquid from leaking out of the pump and air from entering the pump. The sealing effect of the shaft seal device is closely related to whether the fire pump can work normally;
4. Water diversion device
The function of the water diversion device is to remove the air in the pump and the suction pipe to make it reach a certain degree of vacuum. Under the action of atmospheric pressure, the water pressure enters the pump body to make the fire pump enter the normal working state.
5. Check valve
The check valve is located at the water outlet of the pump and has a piston that can move up and down. It works by its own weight and the pressure of water. When exhausting water and diverting water, under the action of its own weight, the piston falls and closes with the valve seat to play a sealing role, so that the air outside the pump cannot enter. The fire pump starts to supply water, and under the pressure of the water, the valve core moves up and the check valve opens automatically. Under the action of the check valve, the water can only flow in one direction, restricting the water from the outlet pipe from entering the pump.