Safety measures for removing the horizontal tube primary cooler
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The horizontal tube primary cooler has been shut down for a year, with the manhole open. We are now preparing to carry out the demolition using fire; there is no steam at the site, and we plan to use axial flow fans for purging. What other safety measures should be taken? Please advise
1. Isolation of relevant pipelines； 2. Hot work analysis ； 3. Dedicated supervision ； 4. Ensure protection on all five sides ；
I’m worried that flammable substances might have accumulated inside. If conditions permit, is it possible to inject water before performing welding work, or to fill the area with an inert gas?
Effectively isolate the process system; check whether there are any deposits at the bottom and in the heat exchange pipes. Ensure proper isolation of the area where welding will take place from other areas, conduct gas analysis before starting the welding work. Fill water at the bottom of the primary cooler, and have fire-fighting water and extinguishers available at the site during welding. Assign personnel with relevant welding experience to supervise the entire process.
The gas system must be effectively isolated (by installing blind flanges)； All process pipelines and the pre-cooler are properly isolated (using blind plates); the tar and tar residues in the bottom tank are removed, and the tank is filled with water ； Open the top vent pipe; the manhole is simply sealed, and nitrogen is introduced through the manhole for purging. Once the gas levels at the top vent pipe meet the specifications (with regard to combustible gases or carbon monoxide), the manhole is opened to ensure that the oxygen level is within the required range. Prepare fire hoses and fire extinguishers.
It is also necessary to prevent ferrous sulfide from burning or catching fire on its own, and tar, naphthalene, and similar substances on the pipe walls should be removed as well.