summary

The boiler feedwater multi-stage pump system is a horizontal single suction multi-stage segmented centrifugal pump, which adopts the hydraulic model of high-efficiency and energy-saving products recommended by the country. It has the advantages of high efficiency, wide performance range, safe and stable operation, low noise, long service life, and convenient installation and maintenance. It can be used to transport clean water or liquids with physical and chemical properties similar to clean water, suitable for medium and low pressure boilers or sub high pressure boiler water supply, as well as for high-pressure water supply and drainage in factories or cities. The temperature of the conveying medium is -20 ℃ to 150 ℃, and the allowable inlet pressure is less than 0.6MPa. Suitable for industrial and urban water supply and drainage, pressurized water supply for high-rise buildings, garden sprinkler irrigation, fire pressurization, long-distance water supply, heating, bathroom and other cold and warm water circulation pressurization and equipment matching, especially suitable for small boiler water supply.

structure

The inlet and outlet of the boiler feedwater multi-stage pump are all vertically upward, and the pump casing parts such as the inlet section, middle section, outlet section, and bearing body are connected into a body by tightening bolts. Select the number of stages of the pump based on its head.

The rotor part of this series of pumps mainly consists of a shaft and components such as impellers, shaft sleeves, and balance plates installed on the shaft. The number of impellers is determined by the number of stages of the pump. The parts on the shaft are fastened with flat keys and shaft nuts to form a solid connection with the shaft. The entire rotor is supported by rolling bearings or sliding bearings at both ends. The bearings are determined according to different models and do not bear axial force, which is balanced by a balance plate. The pump allows the rotor to move axially in the pump casing during operation, and radial ball bearings cannot be used. Rolling bearings are lubricated with grease, sliding bearings are lubricated with thin oil, and self-lubricating with oil rings and cooled by circulating water.

The seals between the inlet, middle, and outlet sections of the pump are all sealed with molybdenum disulfide grease. The sealing ring and guide vane sleeve are installed between the rotor and fixed parts for sealing. When the wear of the sealing ring and guide vane sleeve affects the working performance of the pump, they should be replaced.

There are two types of shaft seals: mechanical seal and packing seal. When the pump adopts a packing seal, the position of the packing ring should be placed correctly, and the tightness of the packing must be appropriate, so that the liquid can drip out. The various sealing components of the pump are installed in a sealing box, and the box should be filled with water at a certain pressure to serve as a water seal, water cooling, or water lubrication. A replaceable shaft sleeve is installed at the shaft seal to protect the pump shaft.

Secondary high-pressure pumps generally use sliding bearings and thin oil lubrication structures. DG85-67 and DG155-67 pumps can use sliding bearings and thin oil lubrication, as well as rolling bearings and dry oil lubrication structures. Other models use rolling bearings and dry oil lubrication structures. The main components of medium and low pressure pumps are generally made of high-quality cast iron, while the main components of secondary high pressure pumps are made of cast steel or stainless steel. This series of pumps is directly driven by the original motor through an elastic coupling. From the direction of the original motor, the pump rotates clockwise.