NW Series Low Pressure Heater Drain Pump
The NW series low-pressure dewatering pump is a new dewatering pump product independently developed by our company based on the actual needs of the market and using excellent hydraulic models. It is used to transport low-pressure heater dewatering in 125,000-kilowatt to 1,000,000-kilowatt thermal power plants.
NW Series Low Pressure Heater Drain Pump
The NW pump operates reliably, with low NPSH and high efficiency; the hydraulic components are optimized and designed using CFD flow field analysis technology, with excellent performance and a wide range of shapes; the balance plate structure is used to completely balance the axial force; the entire series adopts integrated cooling water Pipeline water supply is convenient for users to install and use; the impeller and guide vane are made of precision casting, with smooth flow path, high dimensional accuracy and high efficiency; there are two sealing forms of mechanical seal and packing seal for users to choose; the shaft is made of high-strength heat-resistant alloy steel , excellent comprehensive performance, precision manufacturing with multiple heat treatment processes, the main key components are manufactured in machining centers, with high precision and long life; the pump bearings use short cylindrical roller bearings, and the lubrication uses thin oil lubrication, with pressure circulating cooling water.
The bearing parts can be equipped with thermometers and oil level gauges; in order to improve the cavitation performance, in addition to the induction theory and the anti-cavitation design of the first-stage impeller, the design method of reducing the rotation speed is also used to fully guarantee the cavitation performance, which is very important. Suitable for working conditions under low NPSH conditions; unique structural design, the rotor component adopts a multi-stage impeller, and the range of water pump pressure selection is increased by adding and subtracting stages; except for the 150NW-58 type pump, the outlet water channel of the NW type pump uses a worm The shell-type pressure water chamber can improve the efficiency of the pump and greatly adjust the performance of the pump; assembly and maintenance are very convenient.
- Main Parts Material List
- Model Description
- Product Structure Diagram
- Installation Dimension Drawing
| Part name Material grade | S-5 | S-6 | C-6 |
| Water inlet section | ZG230-450 | ZG230-450 | ZG1Cr13Ni |
| Outlet section | ZG230-450 | ZG230-450 | ZG1Cr13Ni |
| Middle section | ZG230-450 | ZG230-450 | ZG1Cr13Ni |
| Shaft | 42CrMo | 42CrMo | 3Cr13 |
| Guide leaf | ZG230-450 | ZG1Cr13Ni | ZG1Cr13Ni |
| Impeller | ZG230-450 | ZG1Cr13Ni | ZG1Cr13Ni |
| Induction wheel | ZG1Cr13Ni | ZG1Cr13Ni | ZG1Cr13Ni |
| Balance disc | 1Cr13NiMo | 1Cr13NiMo | 1Cr13NiMo |
| Balance ring | 1Cr13MoS | 1Cr13MoS | 1Cr13MoS |
| Bearing bod | HT250 | HT250 | HT250 |
| Note: The standard material grade is S-5. | |||
- Anti-cavitation hydraulic design
Excellent anti-cavitation hydraulic model, combined with inducer design, the pump has excellent anti-cavitation performance. Especially suitable for 12. 5WkW -30 WkW thermal power plants to transport low-pressure heater water drainage
- Segmented multistage pump design
Segmented multi-stage pump design, with large flow, high lift and high efficiency, is a recommended high-efficiency and energy-saving product.
- Water cooling jacket structural design
Water-cooled jacket design, suitable for high temperatures; equipped with standard mechanical seal, reliable and stable in use
- Balance plate mechanism design
Precise balance plate mechanism design, small axial pulsation of the rotor, smooth water flow in the return pipe, and smooth and reliable pump operation
Medium: saturated steam water with temperature ≤135 °C
Flow: 36~450m3/h
Lift: 55~ 310 m
Pressure-bearing: The water pump inlet flange has a pressure-bearing pressure of 1.6MPa, and the outlet flange has a pressure-bearing pressure of 4.0MPa.
Steering: Counterclockwise rotation when viewed from the motor end.
Packing seal water: cooling water with a flow rate of 1~2 m3/h and a pressure slightly higher than the water pump inlet pressure.
Cooling water: industrial water with a flow rate of 2~3m3/h, a temperature of <38 °C, and a pressure of 0.2~0.3MPa. The mechanical seal cooling water is integrated into the cooling main pipe.
1) Shell part: It mainly consists of the water inlet section, the middle section, the water outlet section, the sealing chamber, the guide vane, the final guide vane, and the bearing components. Except for the 300NW-50 upper inlet and upper outlet, the inlet and outlet of other products are L-shaped. The exit is vertically upward (the top-in and top-out structure can also be adopted according to customer needs).
2) Rotor part: It consists of impeller, shaft, mechanical seal sleeve or packing sleeve, bearing sleeve, bearing bushing, sleeve and sleeve nut. The shaft adopts a ladder structure, which makes it very convenient to assemble and disassemble the water pump.
3) Shaft seal part: packing seal or mechanical seal, both with pressurized circulating cooling water. .
4) Bearing part: The bearing adopts short cylindrical roller bearing (the 150NW-27.5 non-drive end bearing adopts deep groove ball bearing to bear the remaining axial force). The bearing is lubricated with thin oil and has pressure circulating cooling water. The bearing assembly has an oil level gauge.
5) Axial force balance structure: The 150NW-27.5 pump balances the axial force through the rear sealing ring of the final impeller and the return pipe. The remaining axial force is borne by the deep groove ball bearing at the non-transmission end. The other models are all balanced by the balance plate mechanism. Balance the axial force, so the water flow in the return pipe must be smooth and unimpeded.