Shutdown plan for sulfur recovery unit
Thread Content
Sulfur recovery unit shutdown plan and management plan after shutdown Prepared by: Reviewed by: Approved by: II. Steps for implementing the shutdown 1. Vent acidic gas to a low-pressure flare； Close the acid gas inlet boundary valve to the sulfur recovery unit, and close the ESDV isolation valve ； 2. Extract sulfur from the sulfur solution until, as analyzed by sampling the sulfur solution with a sulfur slurry pump, the proportion of sulfur particles is less than 1% ； 3. The solution parameters are within the acceptable range (ORP: -250 to -280, pH: 7.9 to 9.3) ； 4. Start the sulfur solution pump to transfer the solution into the solution maintenance tank (the solution can remain valid in this tank for approximately 1-2 years) ； 5. Thoroughly replace the lines such as those from the sulfur slurry pump to the absorption oxidation tower, from the slurry pump to the vacuum belt filter, from the filtrate return pump to the regeneration tower, as well as those for flushing the mechanical seals of the slurry pumps and jet pumps, with deionized water ； 6. Purge and displace the acid gas pipeline in the system leading to the oxidation tower using nitrogen; stop the displacement once the hydrogen sulfide level is below 1 ppm, and then isolate the system ； 7. Close the heat transfer oil inlet valve, stop the temperature control water pump, and drain the water from the temperature control water heater and related pipelines. III. Requirements for shutdown management 1. The sections where the sulfur recovery unit is connected to other systems shall have their shut-off valves closed and locked. 2. During the shutdown period, the operation team, electrical department, and automatic control team must conduct regular inspections, with the frequency set at once a week. 3. The equipment and facilities in the sulfur recovery unit are well maintained, and the instruments are in good working condition, ensuring they are ready for operation at any time. IV. Process Management1. Pump the sulfur solution into the solution maintenance tank (the solution remains valid in this tank for approximately 1–2 years).
2. Pump the sulfur slurry to the absorption oxidation tower; return the filtrate to the tank. Pump the pulp to the vacuum belt filter; use pumps to return the filtrate to other locations. Also, use pumps for flushing equipment such as jet pumps, and replace all relevant pipelines with deionized water.
3. Isolate the sulfur unit from the process:
(1) Switch it to manual mode.
(2) Close and lock the ball valve at the boundary between the acid gas supply and the sulfur unit.
(3) Close and lock the ball valve for acid gas venting.
(4) Close and lock the inlet and outlet hand valves of the air condensate pump, and place tags on them.
(5) Close and lock the inlet and outlet hand valves of the heat transfer oil used for temperature regulation; open the bypass hand valve.
(6) Close and lock the hand valve that supplies deionized water to the sulfur unit, and place a tag on it.
4. The operating crew shall conduct regular on-site inspections of the sulfur recovery unit every shift.
V. Equipment Management
1. During periods of downtime, the operating crew shall conduct inspections once a week, the electrical department shall conduct inspections once a week, and the automation department shall also conduct inspections once a week ； 2. During the shutdown period, comprehensive maintenance of all pumps is carried out; monthly inspections and maintenance of all pumps are performed on the 25th of each month. Strictly implement the \"Ten-Point Maintenance\" policy (cleaning, lubrication, adjustment, tightening, corrosion prevention) to eliminate leaks and spills ； On the 25th of each month, all pumps in the machine set should be rotated to prevent deformation of the rotors or shafts, and records should be kept ； 3. The air cooler shall be tested for 5 minutes on the 25th to 30th of each month with no abnormalities occurring ； 4. Conduct regular weekly inspections of the vacuum filter to ensure proper cleaning, maintenance, and upkeep ； 5. All static equipment shall be regularly inspected once a week to strictly prevent leaks ； 6. All safety valves and pressure gauges shall be calibrated on schedule ； 7. Replace the lubricating oil for all pumps one week in advance of commissioning. VI. Electrical Management 1. Install visual warning signs stating “Do Not Close” at all the power disconnection points for equipment, along with an indication of the reason ； Note for on-site operations: Lock out and tag out the power supply to the distribution boxes. 2. Conduct a monthly inspection of the system’s power distribution equipment, keep records of such inspections, and address any issues found promptly to ensure that power supply to the system can be restored at any time. 3. System electric heat tracing management; the on-site control cabinet for electric heat tracing should be checked regularly to ensure it can be used properly at any time. VII. Self-control management: 1. Automated maintenance and comprehensive maintenance are used to calibrate the remote instruments, on-site instruments in the sulfur recovery unit, as well as the combustible gas detectors and fixed hydrogen sulfide detectors, to ensure that these instruments are in good working condition ； 2. The operation staff tests the control valves and on/off valves of the sulfur recovery unit on a monthly basis. Contact for automated handling as soon as a problem is detected ； 3. The pipelines of the instrument air system should be drained regularly to prevent freezing and condensation ； 4. The valves at the connection point between the instrument air pipeline and the instrument air system are closed. VIII. Warehouse Management 1. Management of the pharmaceutical warehouse; classification, arrangement, and organization of medications in the warehouse ； 2. Maintain proper inventory registration records ； 3. The pharmacy storage area is locked, with regular inspections conducted ； 4. Regularly clean the warehouse to keep it tidy ； 5. The sulfur ointment storage area should be neatly stacked in accordance with regulations, and regular inspections should be carried out. Safety facilities such as eye wash stations in the storage area must be maintained to ensure they remain in good condition ； 6. Ensure an adequate supply of production reagents and testing reagents. 9. The fire protection facility maintenance team inspects and maintains the fire protection equipment in the sulfur unit every two weeks, to ensure that such equipment is in good condition and can be used effectively
This plan outlines the detailed steps and management requirements for shutting down the sulfur recovery unit, including the procedures for shutdown, management requirements during shutdown, process management, equipment management, electrical management, automation management, warehouse management, as well as requirements for fire protection facilities. During the shutdown period, it is necessary to conduct regular inspections and maintenance of equipment and instruments, and to ensure that fire protection facilities are in good working condition. At the same time, an adequate supply of reagents for production and testing is also necessary. Overall, this plan specifies in detail the various management aspects during the shutdown period, providing effective guidance to ensure the integrity and safety of equipment and facilities. .