The pure oxygen catalytic partial oxidation unit shut down due to problems with the compressor itself
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In the pure oxygen catalytic partial oxidation unit, if the compressor fails due to its own issues, should the oxygen supply be cut off first, or should the conversion gas outlet be opened for venting first? Thank you all!
For the compression trip in the post-conversion section, I think one should first vent the system and then immediately switch to oxygen supply. In this way, other issues can be dealt with after ensuring proper control of system pressure. If oxygen is switched on first, there’s a risk of the oxygen pipes exploding due to pressure buildup in the system; it would be safer to carry out these actions simultaneously. Should there be enough personnel available?
There’s no issue with the staff; it’s just that I’ve just started working here and don’t have much experience.
Should the stop valves before and after the converter gas outlet vent be open during normal production? The control valve is a air-actuated valve; if there is leakage when it is closed, then the upstream and downstream shut-off valves cannot be opened, right?
Is the control valve on the gas outlet for conversion equipped as an air-operated valve? It should be an air-actuated shut-off valve. In case of leaks, the upstream and downstream shut-off valves cannot be closed for safety reasons; however, they can be adjusted to be opened to a smaller degree
First, shut off the oxygen control valve, and then quickly close the isolation valves located before and after the oxygen control valve to prevent leakage from within the valve.
May I ask whether the owner is converting the compressor at the front or the syngas compressor at the back?
It is the syngas compressor behind the conversion unit
Is it extremely dangerous for the operator if the oxygen pipeline explodes during the process of shutting off the valves before and after the oxygen control valve?
Cut oxygen – cut gas – cut steam. Make sure to set the sequence control to automatic first, and then to manual.
I don’t have much experience. Could you please be more detailed? Thank you very much!
Oxygen should be cut off first, and then the vent valve should be adjusted immediately to stabilize the system pressure. Because after oxygen cutting, the total amount of conversion gas decreases, which facilitates regulation. Also, two people can operate the center control simultaneously without any conflicts. Another issue is that if you choose a pressure relief valve that operates on an air-open principle, it represents a safety hazard; therefore, an air-close valve must be used. Moreover, in normal production, the stop valves before and after the air conditioning control valve must be opened.
What the people upstairs said is all very good. In production, if the syngas compressor shuts down, the system should first be vented to reduce the load to the lowest level possible, and the synthesis system should be treated as if it were shut down. Check the cause of the syngas compressor trip; after troubleshooting, start the compressor to generate synthesis gas. If the syngas compressor cannot be started for a short period of time, the methanol system is shut down depending on the actual situation.
After a syngas compression trip, control room personnel need not panic. Automatically open the pressure relief valve based on the conversion system pressure! (100,000 tons/year) Treatment steps: ① The control personnel in charge of the conversion process should immediately open the system vents (including the automatic control valves at the conversion site and those in the compressor building for the synthesizer), to prevent overpressure in the conversion system. ②Notify to reduce the compression volume of coke oven gas and accordingly decrease the oxygen supply, so that the system operates at a low load with the flow rate controlled between 15,000 Nm3/h and 18,000 Nm3/h. ③Adjust the pressure and temperature of the conversion system. ④Decide whether it is necessary to remove oxygen based on the situation.
First, release the pressure of the air stabilization system, and then cut off the oxygen.
As long as the system pressure can be stabilized, it is also possible to avoid oxygen cutting.
Personally, I think the approach used on floor 14 is the most suitable for dealing with compressor tripping. If the synthetic compressor can handle it within 24 hours, it will be used; if not, further consideration of conversion will be halted. The venting of the transformation system is crucial
After the syngas compressor trips, the conversion control system first activates the system venting function for automatic adjustment in order to regulate the system pressure. We can’t allow the current situation of pressure buildup to continue. Reduce the oxygen pressure in a timely manner, and lower the load on the feed gas to maintain it at 10,000–14,000 Nm3/h. During this period, pay close attention to the conversion temperature and the steam generation rate of the drum. :victory:
After the syngas compressor trips, the control room first activates the automatic venting of the downstream system, then reduces the oxygen valve opening gradually until the gas supply is cut off and the machine stops.
The principle for handling matters is to prioritize safety first, and then consider technical aspects.