Features of DG series multsitage hot water boiler feed pump
1. The inlet and outlet of the multi-stage hot water pump of the DG type boiler are vertically upward, and the pump inlet, middle, outlet, bearing body and other pump casing parts are connected into one by tightening the bolts.
Select the pump stage according to the pump head.
2. The rotor part of DG boiler multi-stage hot water pump is mainly composed of shaft and impeller, shaft sleeve, balance plate and other parts installed on the shaft. The number of impellers depends on 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, while sliding bearings are lubricated with thin oil, and oil rings are used for self-lubrication and circulating water cooling.
3. The seals between the inlet section, middle section and outlet section of the DG boiler multi-stage hot water pump are all 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 of the seal ring and the guide vane sleeve has affected the performance of the pump, it should be replaced.
4. 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 correct, 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 introduced 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.
Sub-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. The remaining models use rolling bearings and dry oil lubrication. structure. The main parts of medium and low pressure pumps are generally made of high-quality cast iron, and the main parts of sub-high pressure pumps are made of cast steel or stainless steel.
5. The DG boiler feed water pump is directly driven by the original motor through the elastic coupling. From the direction of the original motor, the pump rotates clockwise.
