Low-vibration type boiler feed pump stable in flow diversion

Abstract

The invention discloses a low-vibration type boiler feed pump stable in flow diversion. The low-vibration type boiler feed pump stable in flow diversion comprises a water inlet section (14), a middlesection (16), a water outlet section (17) and the like. A forward guide blade (5) and a back guide blade (6) are mounted on a guide vane of the boiler feed pump, and a dividing groove (8) is formed inthe back guide blade. The lower portion of the back guide blade is connected with a lengthened guide blade (9) and sleeved with an inlet of a secondary impeller (23). A fastening hole (7) is furtherformed in the back guide blade, and a locating groove (4) is formed in the guide vane. According to the low-vibration type boiler feed pump stable in flow diversion, the flow guide path is prolonged,the distance between the back guide blade and the blade inlet edge of the secondary impeller is shortened, liquid stably flows into the secondary impeller, and the interaction between vortexes and collisions on a pump shaft are reduced effectively. The low-vibration type boiler feed pump is fastened in the horizontal direction and the rotary direction through fastening holes, pin columns, locatinggrooves, groove screws and the middle section, additional vibration is prevented from being caused, the operation stability of a pump unit is improved, vibration parameter indexes of the boiler feedpump reach the standard, and high safety is achieved.

Description

technical field [0001] The invention relates to a multistage centrifugal pump, in particular to a boiler feed water pump used in power plants, industries and cities for water supply occasions. Background technique [0002] Boiler feed water pumps are generally segmental or double-cylinder multi-stage centrifugal pumps, mainly used for medium pressure, sub-high pressure expansion and high pressure boiler feed water, the conveying medium is water, the temperature range is usually between 104-160 °C, and the flow rate is between 104-160 °C. 28-500m 3 / h, the outlet pressure is 10-15MPa. It is a key centrifugal pump in the boiler water supply system. It is often equipped with "one for one use and one for standby". The unit price of the pump is generally 300,000 to 800,000 yuan. When the flow rate in its working condition is 300-500m 3 / h, the operating conditions are changeable, so that the vibration value of the bearing parts of the pump is ≥4.5mm / s (exceeding the relevant st...

AI Technical Summary

Problems solved by technology

When the flow rate in its working condition is 300-500m 3 / h, the operating conditions are changeable, so that the vibration value of the bearing parts of the pump is ≥4.5mm / s (exceeding the relevant standards), which is a substandard product and has certain hidden dangers

If both feedwater pumps fail to stop, the entire water supply system will stop, which will bring considerable economic losses to users and manufacturers

The main reason for the excessive vibration of the bearing parts is the leakage between the guide vane stages, the liquid will generate a vortex, and the distance between the back guide vane on the guide vane and the blade on the inlet edge of the secondary impeller is large, resulting in unstable diversion, which will leave the vortex to the pump Sufficient space for the shaft to collide, causing vibration of the bearing components of the boiler feed water pump to exceed the standard

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