DG boiler feed water multi-stage pump is a horizontal single-suction multi-stage centrifugal pump, which can be used to transport clean water or liquid with physical and chemical properties similar to clean water. . The temperature of the conveying medium is -20℃～150℃, and the inlet allowable pressure is less than 0.6MPa.
This series of horizontal multi-stage centrifugal pumps adopts the hydraulic model of energy-efficient products recommended by the state. It has the advantages of high efficiency, wide performance range, safe and stable operation, low noise, long life and easy installation and maintenance.
Such as: DG46-50×4
DG- means multi-stage boiler feed water centrifugal pump
46-Indicated that the design point flow is 46m3/h
50-Indicates that the single-stage head of the design point is 50m
4- means the level is 4
Pump suction and discharge diameter: 40 ~ 150mm
Temperature range: ≤105℃
Working pressure: ≤3.0MPa
The inlet and outlet of this type of pump are vertically upward, and the pump inlet, middle, outlet, bearing body and other pump housing parts are connected into one by tightening the bolts. Select the pump stage according to the pump head.
The rotor part of this type of pump is mainly composed of the shaft and the impeller, shaft sleeve, balance plate and other parts installed on the shaft, where the number of impellers is determined according to the number of pump stages. The parts on the shaft are fastened with flat keys and shaft nuts to make them integrated with the shaft. The entire rotor is supported by rolling bearings or sliding bearings at both ends. The bearings are different according to the model and do not bear the axial force. The axial force is balanced by the balance plate. During operation of the pump, the rotor is allowed to move axially in the pump casing, and radial ball bearings cannot be used. Rolling bearings are lubricated with grease, sliding bearings are lubricated with thin oil, and self-lubricated with oil rings, and cooled with circulating water.
The sealing surfaces between the inlet section, middle section and outlet section of the pump are sealed with molybdenum disulfide grease. There is a sealing ring and guide vane sleeve between the rotor part and the fixed part for sealing. If the degree of wear has affected the performance of the pump, it should be replaced.
There are two types of shaft seals: mechanical seal and packing seal. When the pump is sealed with packing, the position of the packing ring should be set correctly, the degree of tightness of the packing must be appropriate, and the liquid can seep drop by drop. Various sealing elements of the pump are installed in a sealed box. Water of a certain pressure must be passed into the box to play the role of water seal, water cooling or water lubrication. A replaceable shaft sleeve is installed at the shaft seal to protect the pump shaft.
This type of pump generally adopts rolling bearing and dry oil lubrication structure. DG85-67 and DG155-67 pumps can adopt sliding bearing and thin oil lubrication structure, and can also use rolling bearing and dry oil lubrication structure. The material of the main parts of the pump is generally high-quality cast iron, but also cast steel or stainless steel.
This series of pumps is directly driven by the prime mover through an elastic coupling. From the direction of the prime mover, the pump rotates clockwise.