The boiler feed water pump used in power plants is a high-temperature and high-pressure multi-stage pump that can transport high-temperature fluids that are non-corrosive and reach up to 210℃. It is one of the essential equipment for circulating replenishment in power plant boilers.
Working principle of boiler feed water pump
The inlet and outlet water sections are connected to the middle section of the pump through a pull rod combination. The output water pressure of the water pump can be very high and it is a type of centrifugal pump that relies on the rotation of the impeller to obtain centrifugal force. When the gas density reaches the working range of the mechanical vacuum pump and is sucked out, gradually obtaining high vacuum. The boiler feed water pump achieves suction, compression, and exhaust by changing the volume of the pump cavity, so it is a variable volume centrifugal pump.
The lower inner surface of the water ring is just tangent to the impeller hub, and the upper inner surface of the water ring just contacts the top of the blade (in fact, the blade has a certain depth of insertion in the water ring). At this time, a crescent-shaped space is formed between the impeller hub and the water ring, and this space is divided into several small chambers with the same number as the number of blades by the impeller. If the lower part of the impeller is taken as the 0° starting point, the volume of the small chamber becomes larger from small to large before the impeller rotates 180°, and it is connected to the suction port on the end face. At this time, gas is sucked in, and when the suction is completed, the small chamber is isolated from the suction port. When the impeller continues to rotate, the small chamber becomes smaller, compressing the gas. When the small chamber is connected to the exhaust port, the gas is discharged out of the pump.