Selection of pumps for methanol-to-hydrogen production
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For the methanol-to-hydrogen production process in our company, multi-stage centrifugal pumps are used. The fluid at the bottom of the water washing tower is returned to the water injection tank. After using the water injection pump for a while, it was observed that the outlet pressure decreased and the flow rate was insufficient. Upon disassembling the pump, it was found that the impeller and other internal components were severely affected by cavitation or corrosion. When the outlet drain valve of the pump was opened, bubbles were clearly visible, indicating that gas was indeed being generated. Where does this gas come from? Is it the hydrogen brought by the water scrubber tower? Can it carry so much hydrogen? Furthermore, in our water tanks, due to the prolonged circulation at the bottom of the water washing tower, the methanol content is around 4%. Will this methanol content cause corrosion to the carbon steel pump components? How to fix the issue of air in this pump?
The methanol-to-hydrogen production units I’ve seen don’t seem to use multi-stage centrifugal pumps; instead, metering pumps and plunger pumps are used.
If cavitation occurs, use C-6 material
If cavitation occurs, use C-6 material
Ask more questions, and I’ll answer them in segments~~~ “After the water pump has been in use for some time, it was found that the outlet pressure decreased and the flow rate was insufficient. When the pump was disassembled, it was discovered that the impeller and other internal components were severely affected by cavitation or corrosion.” ~~~ This is cavitation of the impeller caused by the presence of gas and liquid mixed together~~~ “When the drain valve at the pump’s outlet was opened, bubbles were visible, which indicates that gas is indeed being produced. Where does this gas come from?” Is it the hydrogen brought by the water scrubber tower? Can it carry so much hydrogen? " To be honest: just take a sample for testing, and all doubts will be resolved~~ “Also, in our water tanks, due to the continuous circulation at the bottom of the water washing tower, the methanol content is around 4%. Will this methanol content cause corrosion to the carbon steel pump components? ” The methanol tanks and pipelines used in your factory are made of carbon steel, right? 4% methanol itself is not corrosive, but as for the 96% “water” component, that’s another matter. How can this issue of air in the pump be resolved? Add a separation tank in front, and everything becomes quiet~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Guys upstairs, can 4140 be used to resist cavitation? Then isn’t 20CrMo invincible in the face of cavitation?
The impact force of cavitation is enormous, as if countless small projectiles were continuously striking the metal surface. There is probably no metal that can resist cavitation damage
What he meant is probably the gas-liquid separation tank