Chemical processing tower equipment: [Weekly Topic] Precautions or steps for cold-starting of towers (2011.07.04-07.16)
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This post was last edited by wu_pb on 2011-7-6 20:53. Please share any precautions or startup procedures regarding the tower unit when operating it in cold conditions (during the first start-up or after it has been shut down for some time before being restarted)
The main steps for cold startup of tower equipment. 1. Process inspection: mainly checks whether the relevant pipelines are unobstructed, whether the blind flanges have been removed, and whether the equipment inside the tower is complete and properly installed ； 2. Seal the manhole. 3. Purge the relevant process pipelines by using air or steam; for larger pipelines, explosive purging is required. 4. Wash or soak with water: Fresh water is introduced into the tower and used for washing from the top of the tower; meanwhile, the relevant process pipelines are connected. In cases where there are no pipelines at the top of the tower, water can be used for soaking before releasing it. 5. During the initial calibration of the instruments, and while they are in operation, test the condition of the instruments and control valves, and make timely corrections. 6. Purge the tower by using air or nitrogen to push air into it, flushing the relevant pipelines and removing water from the system. 7. Conduct pressure testing and leak checks, carry out stamping of the tower structure, perform pressure tests on the system, and address any leakage issues promptly. 8. For oil-based transportation, heavy oil systems should be switched to a circulating process using diesel, while light oil systems should use gasoline for transportation; there is no need for oil-based transportation in water systems. During the transportation process, it is necessary to check the instrument readings, ensure that the valve controls are functioning properly, and verify that the safety systems are operational. 9. Establish normal liquid level, temperature, and pressure, then wait for feeding. Personal summary, for reference only
Precautions: 1. During the inspection process, carefully check whether the valve flange gaskets are compliant; some of them are asbestos gaskets, and if such gaskets are found after operation begins, the plant must be shut down. 2. Carefully inspect the pipeline blind flanges to ensure that all of them have been removed. 3. During combined transportation, try to use all pipelines, with the main focus being to check whether they are functional. 4. Carefully check the attachments on the tower, such as whether the pressure gauges and temperature gauges are installed correctly. 5. Check that the venting and drainage systems are functional.
The key is to first develop a driving plan, listing all the possible problems. And proceed in the order of starting.