Issues regarding system purging and cleaning after a long-term shutdown of coal-to-methanol plants
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Dear colleagues, our company produces 500,000 tons of methanol from coal; the plant has been shut down for over 8 months now and needs to be restarted. Is it still necessary to perform pipeline purging and cleaning at this stage? Most of the gas piping has been sealed with nitrogen. The focus now is on how to blow the steam pipeline Are there any standards? There are 98-kilogram steam pipelines, 25-kilogram steam pipelines, as well as 11- and 3.5-kilogram pipelines; the 25-kilogram pipelines are used for the turbines.
If you’re worried, remove the valve first to check the inner wall of the steam pipeline. Personally, I don’t think it’s necessary to perform purging; after our air compressor has been shut down for more than four months, we can simply warm up the pipes and start it up.
I think it’s better to do a purge – safety first; taking a little shortcut isn’t worth the risks!
It needs to be purged; over time, the pipes rust, which can lead to blockages in instruments and valves. And practice operating the valves more, remember that!
Steam purging is a type of purging that uses steam with different parameters as the medium, with a steam generator providing the steam source. Steam purging has a very high purging speed, and therefore possesses a great deal of energy (or momentum). The intermittent steam purging method causes the pipeline to contract and expand due to temperature changes, which facilitates the removal of deposits adhering to the inner wall of the pipeline; thus, it achieves the best purging results. Steam pipelines should be purged with steam, and this is especially necessary for power steam pipelines. Under normal circumstances, only steam and thermal pipelines are purged with steam; chemical medium pipelines generally only require water flushing and air purging. However, there are exceptions – in cases where air purging is not sufficient for non-steam pipelines, steam purging can also be used. It is necessary to consider whether the pipeline’s structure can withstand high temperatures and thermal expansion/contraction, and appropriate measures must be taken to ensure the safety of personnel and equipment during the purging process. The specific definition shall be determined by the owner based on process requirements.
It is still recommended to perform a purge before driving