Suggestions for restarting operations after a temporary shutdown of petrochemical plants

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After the unit comes to a temporary stop due to interlock activation, emergency shutdown, etc., restarting it is of crucial importance. This step is directly related to the stable operation of the equipment, the safety of personnel during operations, and the restoration of production order. Improper handling may easily lead to secondary accidents, resulting in safety risks and economic losses. Therefore, great importance must be attached to the management of restarting operations. It is essential to strictly adhere to scientifically sound and standardized procedures, and to avoid any blind or reckless actions. This will ensure that the startup process remains safe and under control, effectively preventing all kinds of safety hazards and enabling the facility to quickly and smoothly resume normal production. Thoroughly investigate the cause of the shutdown. After an interlock shutdown occurs, it is necessary to conduct a comprehensive review of the sources that triggered the interlock, the operating status of related equipment, the trends in process parameters, as well as historical operation records and SIS system logs. Special attention should be paid to identifying any direct causes such as excessive process parameters, equipment failures, incorrect instrument readings, or fluctuations in utility supplies. If the cause cannot be identified, it is necessary to organize technical personnel from fields such as process engineering, equipment, and instrumentation to conduct a joint analysis. Driving must not be resumed until the cause is identified. Driving must not be resumed until the cause is identified. Driving must not be resumed until the cause is identified. Science-based confirmation of conditions for resuming driving: 1. The cause of the stoppage has been thoroughly identified and corrected, measures to prevent such stoppages from occurring again have been put in place, and the operators are fully aware of the cause of the stoppage, the procedures taken to address it, and the precautions required to resume driving. 2. The mechanical equipment requiring restart has undergone comprehensive inspection and necessary commissioning. Units such as large-scale pumps and compressors are ready for startup, and the lubricating oil pressure meets the standard requirements ； The interlocking associated equipment itself and its auxiliary systems pose no safety hazards. 3. The process flow is correctly set, with all valves in the proper positions. 4. The process operation conditions meet the requirements for resuming operation. For example: (1) The reactor temperature and pressure are within safe limits for resumption, thereby preventing abnormalities such as overheating, coking, and blockages that could occur due to an attempt to resume operation too quickly ； (2) Before igniting the heating furnace, an explosive gas analysis of the furnace chamber must be conducted in accordance with the management guidelines for process heating furnaces; ignition is permitted only after the results are confirmed to be satisfactory ； (3) After the inert gas displacement is completed, the oxygen content or combustible gas concentration must meet the specified standards. 5. The supply capacity of the utility systems (such as water, electricity, steam, instrument air, etc.) meets the requirements for resuming operation. 6. The interlock protection system has been reset, and its relevant functions have been confirmed to be operating normally.