Safety procedures for operating CO2 compressors during power outages

1. First, turn off the host and close the main outlet valve； 2. Notify the relevant departments by phone ； 3. Release pressure gradually, and shut down the oil pump and fan. Precautions: 1. When one of the two machines in the system stops operating, it is necessary to closely monitor the outlet pressure of the other machine to prevent overpressure. 2. In the event of an emergency shutdown due to external factors and the spread of toxic gases, evacuate along the escape route after the shutdown.

Centrifugal carbon dioxide compressor: 1 To shut down the compressor in an emergency, first quickly close the main steam valve to break the vacuum. Close all inlet and outlet valves, and open all discharge valves for pressure relief. 2 The oil pump equipped with an emergency power supply must be started urgently; pay attention to cranking it, whether electrically or manually. 3 Close the valves connected to the system to prevent backflow. 4 The oil cooler is quickly disconnected to prevent a sudden drop in shaft temperature. 5 Units equipped with dehydrogenation, desulfurization, and demethanization systems also need to be disconnected. 6 Check whether the high-level oil tank is working properly.

I’m no expert in the operation of CO2 compressors, but I would like to point out that we have a CO2 stripping unit here that uses multi-stage piston CO2 compressors. When shutting down the equipment, especially in the event of a power outage, it is absolutely forbidden to first open the vent valves to release pressure. Otherwise, if there is a problem with the check valve in the CO2 pipeline leading to the CO2 stripping tower, a large amount of ammonium methylate liquid could flow into that pipeline. If this isn’t detected in time, it could lead to a serious overpressure accident involving the CO2 compressor, with potentially fatal consequences ! !

When there is a sudden power outage, all operating equipment comes to a stop; to some extent, this is actually a relatively safe situation, so it’s crucial not to act recklessly! The most important safety precaution is: as mentioned on floor 4, never empty it blindly! The recommended proper handling procedure is as follows: First, close the large valves at the outlet of the final stage of the CO2 compressor promptly (close as many valves as there are!) ） ； Next, close the primary inlet valve to isolate the unit from the outside world ； Finally, slowly open the relief valves for each section to release pressure to atmospheric level. Of course, to be safe, you can first call the pump room to confirm whether the large CO2 valve at the bottom of the urine tower is closed. After it is shut down, depressurizing each section of the unit further ensures safety and prevents urine in the urine tower from flowing back and blocking the pipes. If a power outage occurs at night, there is one safety precaution that requires special attention: the fact that the production area will be completely dark (it would be even better if there were emergency lighting!) ), at this time it is most important for the operator to be highly vigilant in protecting themselves to avoid getting injured. Anyway, after a power outage the unit stops, so there is no need to worry about overheating or overpressure; it’s safe to go to the site and close the aforementioned valves.

I don’t understand why the other outlet is overpressured

Thank you to all marine friends for their participation! ! Here, I would like to share my views on our plant’s full-circulation aqueous solution process: I believe that in case an emergency requires shutdown, the outlet valve of stage 5 should be closed immediately, while the vent valve of stage 5 should be opened at the same time. Then open 2-3 direct-flow valves, close the inlet and outlet valves of the desulfurization tank, and maintain the pressure inside the tank without releasing it. Immediately afterwards, the oil and water valves for each section are opened to relieve pressure. Precautions for the safe operational handling of compressors in industrial processes: (1) The suction line of the carbon dioxide compressor must not be made negative pressured. (2) The inlet temperature at the fifth stage shall not be lower than 35°C. (3) The direct-through valves in the second and third sections must be closed tightly to prevent undesulfurized gas from taking a short circuit; the desulfurization system should be disconnected from the system when the compressor stops operating. (4) The speed of draining oil and water in each section should be fast; in particular, the duration of the process in sections 4 and 5 should not be long, to prevent CO2 from turning into dry ice and blocking the pipes. (5) When the compressor supplies or stops feeding CO2 to the synthesis tower, ensure that the pressure in the main pipeline remains at least 20.0 MPa.