Weekly Topic 10.12.20 Issue 8: Causes and solutions for liquid slugging (vibration) in methanol distillation coolers?
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This post was last edited by fossil-zhang on 2011-1-11 at 14:01. What are the causes of liquid slugging (vibration) in methanol distillation coolers, and what are the solutions?
The cause of vibration and water hammer is that the opening degree of the outlet valve is too large, which leads to a decrease in pressure after the medium cools down; the resulting low pressure, combined with a large pressure difference, causes the medium to continuously vaporize and then liquefy. Therefore, the outlet valve should not be opened too wide, and the temperature of the cooling water should not be too low – it only needs to be at the required level. If it’s too low, it not only results in waste but also poses a risk of vibration
Generally, the reason for large vibrations in steam pipes is water hammer, which is caused by excessive water in the steam, poor drainage from the reboiler, and vaporization that occurs after the pressure of the steam condensate is reduced. If vibration of gas occurs in other pipes, it is caused by pulses; as for resonance due to the material, no research has been done on that. Generally, I opt for pipeline reinforcement, as this helps reduce the carryover of steam when getting up at night.
It is possible that pressure fluctuations in the methanol distillation tower cause pressure variations in the cooler, which in turn leads to liquid phase impacting the equipment; therefore, it is necessary to maintain stable tower pressure
Drain the reboiler before starting the machine, and control the opening degree of the outlet valve during operation! Keep the temperature under control so that steam doesn’t escape; this is how we usually handle it
Wasn’t the original poster talking about water hammer in the methanol cooler? It’s likely due to incomplete cooling – liquid vaporizes inside the heat exchanger, while gas liquefies, which causes fluid flow. All that’s needed is to open the exhaust valve along the path taken by the medium affected by water hammer (usually in the shell side), and venting the gas for a while will resolve the issue.
1. Exhaust. 2. It is recommended not to close the outlet valve, as this will increase pipeline resistance. 3. Reduce the outlet temperature of the cooler. 4. Ensure cooler pressure