Discussion and analysis of the causes of corrosion in sewage pumps, pump casings, and impellers
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The two sewage pumps, which are used to transport the neutralized aluminum-containing wastewater, have recently experienced overcurrent issues – they shut down prematurely even before the outlet valves had opened after startup. The inlet and outlet pipelines were checked and showed no abnormalities. Upon starting the pump, erosion and corrosion were found on the pump casing, along with irregular holes; there were also grooves at the casing’s flange area. You can see this in the pictures ； There are also grooves in the impeller flow channel, as well as a small hole. Medium: The aluminum-containing wastewater containing pentane petroleum resin with a pH of 12 is neutralized using concentrated sulfuric acid, which reduces its pH to 7–9. After adding a flocculant, flocculates of sodium aluminate are formed; these are then pumped up from the bottom of the tank using a sewage pump and sent to a plate and frame filter press to be converted into filter cakes. Temperature: 40°C Flow rate: 16 m3/h Head: 130 m
Could it be that the larger particles formed as a result of flocculation caused wear on the pump casing and impeller, altering the flow channels of the impeller? This, in turn, led to the pump operating at an excessive flow rate, thereby causing the pump’s motor to work under overload
The material after flocculation is fluffy, like marshmallows, and water makes up the majority of it. After replacing the pump head, the current when starting the equipment was 43A. Running normally
Use that kind of slurry pump; I can recommend one for you if you need it. I’m not the manufacturer
There are obvious signs of corrosion and cavitation; surface thermal spraying treatment is required. Those interested may contact us.
Corrosion of sewage pumps is generally caused by corrosive media; in addition, cavitation can easily occur due to vacuum conditions
The medium transported by sewage pumps usually contains various substances; it is recommended to take samples of the sewage for analysis in order to determine its composition and concentration, so that appropriate measures can be taken. Judging from the image, there is scouring wear caused by solid particles, as well as a possibility of material corrosion and cavitation.
This post was last edited by Wang Genrong on 2018-6-1 07:24. There are obvious signs of corrosion and cavitation; polymer materials can be used to repair these issues, and applying them at room temperature does not cause any additional thermal stress problems