The impeller of the ammonium sulfate circulation pump in our plant’s flue gas desulfurization unit is severely corroded; we seek help
Thread Content
The impeller of the ammonium sulfate circulation pump in our plant’s flue gas desulfurization unit is severely corroded, as shown in the image. The material of the impeller is 316L, and its service life was only 13 months. Additionally, the mechanical seal of the pump is also severely damaged; the typical service life of a double-end face mechanical seal is around 3 months. The cause of these problems has not yet been identified, so we kindly ask experts for guidance on what material should be used for the impeller and how to address the issue with the mechanical seal ! ? ! ?
The impeller is severely corroded, and the mechanical seal is heavily damaged. Could it be due to operating conditions, such as not being in optimal operating conditions for an extended period of time? Excessive flow or low flow is most likely due to cavitation. The reasons for cavitation include 1: the effective net positive suction head of the centrifugal pump does not meet the requirements of the operating conditions ； 2. There is some vacuum at the pump inlet, causing cavitation. Impeller corrosion and wind-induced damage reinforce each other; when the impeller is damaged, the balance of the shaft is disrupted, which in turn leads to damage to the mechanical seal.
It is recommended to use double-sided stainless steel 2205 or apply a corrosion-resistant coating to the outer surface of the impeller! ! For ammonium sulfate circulation pumps, the one with the best cost-performance ratio in China is Xiangfan 525 Factory, an old military-industrial enterprise! !
Which manufacturer’s mechanical seal is being used? Is it a modular mechanical seal?
For ammonium sulfate circulation pumps, the one with the best cost-performance ratio in China is Xiangfan 525 Factory – an established military-industry enterprise; our company chooses products from this factory
The material is fine; it’s mainly caused by blockages in the inlet and cavitation. It is recommended to install steam purging systems on the inlet pipes and to carry out regular purging to ensure smooth flow. Additionally, there may be issues with process adjustments; crystals may not be removed in a timely manner, which leads to increased wear and erosion.
Improper material selection: 316L is not resistant to chloride ions; the chloride ion concentration in the slurry is quite high, around 20,000–40,000 PPM
Add me on QQ 46885442; I work in the ammonia-based desulfurization process
Material selection principles: The impeller is made of special duplex stainless steel, while the shaft is made of 1.4529; the parts that come into contact with the flow of fluid are made of MM-4 or 2605. Please contact me via QQ at 46885442 for technical guidance on the ammonia-based desulfurization process