1. Modern high pressure boiler feed pump high internal pressure and water flow rate, so that the neutral water supply has great erosion and corrosion. The high-speed flow of the impeller blades and guide vanes and the pump body material protective film or film wash, erosion in the local very quickly. In addition, in the chemical demineralized water pH value beyond bad regulations and deaerating, also will make the corrosion. Therefore, the use of ordinary phosphor bronze or ordinary steel impeller, guide vane and so on, can not be applied, and the use of high chromium stainless steel materials. This material has the advantages of erosion resistance, corrosion resistance, low thermal expansion coefficient, good mechanical properties and easy repair welding.
2. The modern high pressure boiler feed water pump uses the balance drum or the balance disc and the external thrust bearing to balance the axial force, but does not use a single balance disc. This is because the steam feed pump steam turbine speed to barring, hand due to the possible presence of a foreign body, the pump case; on the other hand in the starting stage, pressure balance disc has not been established and easy to balance seat friction. The solution is to clean the pipeline, should not remove the inlet filter and regular cleaning. Steam pump turbine engine warm stage, should pay special attention to monitoring the external check temperature and oil bearing pad flow, to prevent burning thrust bearing. Once the small steam turbine to reach the rated speed, the thrust bearing pad temperature gradually decreased to room temperature.
3. Modern high pressure boiler feed pump adopts double shell cylindrical structure.
4. Modern high pressure boiler feed water pump shaft seal, most of the labyrinth shaft end seal structure, there are a small number of mechanical shaft seal. The former is characteristic, can expand to the radial arrangement, short axial length, in addition, can adapt to the vaporization in a short period of time or cavitation operation, the external sealing water supply interruption or short time running under anhydrous conditions, to ensure the reliability of the pump.
In addition to grasp its structural characteristics, but also to ensure the stability of the water quality and pressure of external seal water. The general use of pump outlet after low-speed tube entering the water storage tank through the cooler; and the use of condensate pump external water, demineralized water for standby.
