Common accidents involving molecular sieves and their handling methods
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Seeking advice from experts in air separation – common accidents involving molecular sieves and their solutions. It needs to be fairly comprehensive.
1. The gas content at the outlet exceeds the specified limits; the bed layer gets blown over. Access the manhole to inspect the bed layer and level it out. If the bed layer blows over several times, remove the molecular sieve to check whether the bottom filter is damaged and repair it if necessary. 2. Increased resistance: Check the condition of the molecular sieve at the bottom, and determine whether the molecular sieve has become ineffective based on the parameters during use; replace it if necessary. 3. The peak value decreases during cold blowing. Check whether the nitrogen gas entering the heating stage has reached the temperature required by the process, and verify that the heater is functioning properly. 4. The pressure cannot be completely released during pressure relief; check whether the molecular sieve valve is leaking. 5. The moisture content in the nitrogen waste stream exiting the heater is above the limit; check whether there is a dew point in the molecular sieve steam heater and take action to address it!
The heating temperature is not high enough. Is it good to reduce the amount of regenerative gas in the next cycle to increase the regeneration temperature? Is it better to shorten the usage time?
Reply to 2#: It’s me. By ‘excessive gas levels’, do you mean carbon dioxide? If that level is too high, those alkenes can penetrate through; just leveling things out won’t solve the problem.
Reply to 4#: It should be fine regarding ranking among the best in the world. . . . . Some time ago, here we experienced excessive carbon dioxide levels at the outlet of the air separation unit, but the total carbon analysis in the liquid oxygen was normal (mainly methane with a small amount of ethane); we use a chromatograph to determine the total carbon content here. . . The analysis value is below 100 ppm, and no other hydrocarbons such as acetylene are present. . . Olefins generally contain very little air, unless in areas with severe pollution. . . .
1. Water contamination in the molecular sieve: This leads to excessive levels of carbon dioxide and other gases in the outlet gas. Solution: Turn on the drain valve at the molecular sieve’s inlet, then shut down the system urgently so that the molecular sieve can dry itself. 2. Failure of the programmable valve to function: The main control system will pause the program, and maintenance personnel should be contacted to address the issue; if it cannot be resolved within a reasonable time, the system must be shut down first before any action can be taken. 3. If the regeneration gas uses an electric heater, remember to supply gas first before turning on the heater.
Reply to 6# yeying34: There’s a small tip – use the unit that is in use for feeding water into the molecular sieve. Don’t release pressure by removing the safety valve on the inlet main pipe; instead, manually open the inlet valve to blow out most of the water.
gader: Active participation in wealth generation + 5 points. Boss, it costs me a lot in terms of experience to say this; it’s the first time I’m mentioning it. My enthusiasm isn’t just ordinary at all.